net/sched/act_api.c

   1 /*
   2  * net/sched/act_api.c  Packet action API.
   3  *
   4  *              This program is free software; you can redistribute it and/or
   5  *              modify it under the terms of the GNU General Public License
   6  *              as published by the Free Software Foundation; either version
   7  *              2 of the License, or (at your option) any later version.
   8  *
   9  * Author:      Jamal Hadi Salim
  10  *
  11  *
  12  */
  13
  14 #include <linux/types.h>
  15 #include <linux/kernel.h>
  16 #include <linux/string.h>
  17 #include <linux/errno.h>
  18 #include <linux/slab.h>
  19 #include <linux/skbuff.h>
  20 #include <linux/init.h>
  21 #include <linux/kmod.h>
  22 #include <linux/err.h>
  23 #include <linux/module.h>
  24 #include <net/net_namespace.h>
  25 #include <net/sock.h>
  26 #include <net/sch_generic.h>
  27 #include <net/pkt_cls.h>
  28 #include <net/act_api.h>
  29 #include <net/netlink.h>
  30
  31 static int tcf_action_goto_chain_init(struct tc_action *a, struct tcf_proto *tp)
  32 {
  33         u32 chain_index = a->tcfa_action & TC_ACT_EXT_VAL_MASK;
  34
  35         if (!tp)
  36                 return -EINVAL;
  37         a->goto_chain = tcf_chain_get(tp->chain->block, chain_index, true);
  38         if (!a->goto_chain)
  39                 return -ENOMEM;
  40         return 0;
  41 }
  42
  43 static void tcf_action_goto_chain_fini(struct tc_action *a)
  44 {
  45         tcf_chain_put(a->goto_chain);
  46 }
  47
  48 static void tcf_action_goto_chain_exec(const struct tc_action *a,
  49                                        struct tcf_result *res)
  50 {
  51         const struct tcf_chain *chain = a->goto_chain;
  52
  53         res->goto_tp = rcu_dereference_bh(chain->filter_chain);
  54 }
  55
  56 /* XXX: For standalone actions, we don't need a RCU grace period either, because
  57  * actions are always connected to filters and filters are already destroyed in
  58  * RCU callbacks, so after a RCU grace period actions are already disconnected
  59  * from filters. Readers later can not find us.
  60  */
  61 static void free_tcf(struct tc_action *p)
  62 {
  63         free_percpu(p->cpu_bstats);
  64         free_percpu(p->cpu_qstats);
  65
  66         if (p->act_cookie) {
  67                 kfree(p->act_cookie->data);
  68                 kfree(p->act_cookie);
  69         }
  70         if (p->goto_chain)
  71                 tcf_action_goto_chain_fini(p);
  72
  73         kfree(p);
  74 }
  75
  76 static void tcf_idr_remove(struct tcf_idrinfo *idrinfo, struct tc_action *p)
  77 {
  78         spin_lock_bh(&idrinfo->lock);
  79         idr_remove_ext(&idrinfo->action_idr, p->tcfa_index);
  80         spin_unlock_bh(&idrinfo->lock);
  81         gen_kill_estimator(&p->tcfa_rate_est);
  82         free_tcf(p);
  83 }
  84
  85 int __tcf_idr_release(struct tc_action *p, bool bind, bool strict)
  86 {
  87         int ret = 0;
  88
  89         ASSERT_RTNL();
  90
  91         if (p) {
  92                 if (bind)
  93                         p->tcfa_bindcnt--;
  94                 else if (strict && p->tcfa_bindcnt > 0)
  95                         return -EPERM;
  96
  97                 p->tcfa_refcnt--;
  98                 if (p->tcfa_bindcnt <= 0 && p->tcfa_refcnt <= 0) {
  99                         if (p->ops->cleanup)
 100                                 p->ops->cleanup(p, bind);
 101                         tcf_idr_remove(p->idrinfo, p);
 102                         ret = ACT_P_DELETED;
 103                 }
 104         }
 105
 106         return ret;
 107 }
 108 EXPORT_SYMBOL(__tcf_idr_release);
 109
 110 static int tcf_dump_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
 111                            struct netlink_callback *cb)
 112 {
 113         int err = 0, index = -1, s_i = 0, n_i = 0;
 114         u32 act_flags = cb->args[2];
 115         unsigned long jiffy_since = cb->args[3];
 116         struct nlattr *nest;
 117         struct idr *idr = &idrinfo->action_idr;
 118         struct tc_action *p;
 119         unsigned long id = 1;
 120
 121         spin_lock_bh(&idrinfo->lock);
 122
 123         s_i = cb->args[0];
 124
 125         idr_for_each_entry_ext(idr, p, id) {
 126                 index++;
 127                 if (index < s_i)
 128                         continue;
 129
 130                 if (jiffy_since &&
 131                     time_after(jiffy_since,
 132                                (unsigned long)p->tcfa_tm.lastuse))
 133                         continue;
 134
 135                 nest = nla_nest_start(skb, n_i);
 136                 if (!nest) {
 137                         index--;
 138                         goto nla_put_failure;
 139                 }
 140                 err = tcf_action_dump_1(skb, p, 0, 0);
 141                 if (err < 0) {
 142                         index--;
 143                         nlmsg_trim(skb, nest);
 144                         goto done;
 145                 }
 146                 nla_nest_end(skb, nest);
 147                 n_i++;
 148                 if (!(act_flags & TCA_FLAG_LARGE_DUMP_ON) &&
 149                     n_i >= TCA_ACT_MAX_PRIO)
 150                         goto done;
 151         }
 152 done:
 153         if (index >= 0)
 154                 cb->args[0] = index + 1;
 155
 156         spin_unlock_bh(&idrinfo->lock);
 157         if (n_i) {
 158                 if (act_flags & TCA_FLAG_LARGE_DUMP_ON)
 159                         cb->args[1] = n_i;
 160         }
 161         return n_i;
 162
 163 nla_put_failure:
 164         nla_nest_cancel(skb, nest);
 165         goto done;
 166 }
 167
 168 static int tcf_del_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
 169                           const struct tc_action_ops *ops)
 170 {
 171         struct nlattr *nest;
 172         int n_i = 0;
 173         int ret = -EINVAL;
 174         struct idr *idr = &idrinfo->action_idr;
 175         struct tc_action *p;
 176         unsigned long id = 1;
 177
 178         nest = nla_nest_start(skb, 0);
 179         if (nest == NULL)
 180                 goto nla_put_failure;
 181         if (nla_put_string(skb, TCA_KIND, ops->kind))
 182                 goto nla_put_failure;
 183
 184         idr_for_each_entry_ext(idr, p, id) {
 185                 ret = __tcf_idr_release(p, false, true);
 186                 if (ret == ACT_P_DELETED) {
 187                         module_put(ops->owner);
 188                         n_i++;
 189                 } else if (ret < 0) {
 190                         goto nla_put_failure;
 191                 }
 192         }
 193         if (nla_put_u32(skb, TCA_FCNT, n_i))
 194                 goto nla_put_failure;
 195         nla_nest_end(skb, nest);
 196
 197         return n_i;
 198 nla_put_failure:
 199         nla_nest_cancel(skb, nest);
 200         return ret;
 201 }
 202
 203 int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
 204                        struct netlink_callback *cb, int type,
 205                        const struct tc_action_ops *ops)
 206 {
 207         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 208
 209         if (type == RTM_DELACTION) {
 210                 return tcf_del_walker(idrinfo, skb, ops);
 211         } else if (type == RTM_GETACTION) {
 212                 return tcf_dump_walker(idrinfo, skb, cb);
 213         } else {
 214                 WARN(1, "tcf_generic_walker: unknown action %d\n", type);
 215                 return -EINVAL;
 216         }
 217 }
 218 EXPORT_SYMBOL(tcf_generic_walker);
 219
 220 static struct tc_action *tcf_idr_lookup(u32 index, struct tcf_idrinfo *idrinfo)
 221 {
 222         struct tc_action *p = NULL;
 223
 224         spin_lock_bh(&idrinfo->lock);
 225         p = idr_find_ext(&idrinfo->action_idr, index);
 226         spin_unlock_bh(&idrinfo->lock);
 227
 228         return p;
 229 }
 230
 231 int tcf_idr_search(struct tc_action_net *tn, struct tc_action **a, u32 index)
 232 {
 233         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 234         struct tc_action *p = tcf_idr_lookup(index, idrinfo);
 235
 236         if (p) {
 237                 *a = p;
 238                 return 1;
 239         }
 240         return 0;
 241 }
 242 EXPORT_SYMBOL(tcf_idr_search);
 243
 244 bool tcf_idr_check(struct tc_action_net *tn, u32 index, struct tc_action **a,
 245                    int bind)
 246 {
 247         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 248         struct tc_action *p = tcf_idr_lookup(index, idrinfo);
 249
 250         if (index && p) {
 251                 if (bind)
 252                         p->tcfa_bindcnt++;
 253                 p->tcfa_refcnt++;
 254                 *a = p;
 255                 return true;
 256         }
 257         return false;
 258 }
 259 EXPORT_SYMBOL(tcf_idr_check);
 260
 261 void tcf_idr_cleanup(struct tc_action *a, struct nlattr *est)
 262 {
 263         if (est)
 264                 gen_kill_estimator(&a->tcfa_rate_est);
 265         free_tcf(a);
 266 }
 267 EXPORT_SYMBOL(tcf_idr_cleanup);
 268
 269 int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
 270                    struct tc_action **a, const struct tc_action_ops *ops,
 271                    int bind, bool cpustats)
 272 {
 273         struct tc_action *p = kzalloc(ops->size, GFP_KERNEL);
 274         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 275         struct idr *idr = &idrinfo->action_idr;
 276         int err = -ENOMEM;
 277         unsigned long idr_index;
 278
 279         if (unlikely(!p))
 280                 return -ENOMEM;
 281         p->tcfa_refcnt = 1;
 282         if (bind)
 283                 p->tcfa_bindcnt = 1;
 284
 285         if (cpustats) {
 286                 p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
 287                 if (!p->cpu_bstats) {
 288 err1:
 289                         kfree(p);
 290                         return err;
 291                 }
 292                 p->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
 293                 if (!p->cpu_qstats) {
 294 err2:
 295                         free_percpu(p->cpu_bstats);
 296                         goto err1;
 297                 }
 298         }
 299         spin_lock_init(&p->tcfa_lock);
 300         /* user doesn't specify an index */
 301         if (!index) {
 302                 idr_preload(GFP_KERNEL);
 303                 spin_lock_bh(&idrinfo->lock);
 304                 err = idr_alloc_ext(idr, NULL, &idr_index, 1, 0,
 305                                     GFP_ATOMIC);
 306                 spin_unlock_bh(&idrinfo->lock);
 307                 idr_preload_end();
 308                 if (err) {
 309 err3:
 310                         free_percpu(p->cpu_qstats);
 311                         goto err2;
 312                 }
 313                 p->tcfa_index = idr_index;
 314         } else {
 315                 idr_preload(GFP_KERNEL);
 316                 spin_lock_bh(&idrinfo->lock);
 317                 err = idr_alloc_ext(idr, NULL, NULL, index, index + 1,
 318                                     GFP_ATOMIC);
 319                 spin_unlock_bh(&idrinfo->lock);
 320                 idr_preload_end();
 321                 if (err)
 322                         goto err3;
 323                 p->tcfa_index = index;
 324         }
 325
 326         p->tcfa_tm.install = jiffies;
 327         p->tcfa_tm.lastuse = jiffies;
 328         p->tcfa_tm.firstuse = 0;
 329         if (est) {
 330                 err = gen_new_estimator(&p->tcfa_bstats, p->cpu_bstats,
 331                                         &p->tcfa_rate_est,
 332                                         &p->tcfa_lock, NULL, est);
 333                 if (err) {
 334                         goto err3;
 335                 }
 336         }
 337
 338         p->idrinfo = idrinfo;
 339         p->ops = ops;
 340         INIT_LIST_HEAD(&p->list);
 341         *a = p;
 342         return 0;
 343 }
 344 EXPORT_SYMBOL(tcf_idr_create);
 345
 346 void tcf_idr_insert(struct tc_action_net *tn, struct tc_action *a)
 347 {
 348         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 349
 350         spin_lock_bh(&idrinfo->lock);
 351         idr_replace_ext(&idrinfo->action_idr, a, a->tcfa_index);
 352         spin_unlock_bh(&idrinfo->lock);
 353 }
 354 EXPORT_SYMBOL(tcf_idr_insert);
 355
 356 void tcf_idrinfo_destroy(const struct tc_action_ops *ops,
 357                          struct tcf_idrinfo *idrinfo)
 358 {
 359         struct idr *idr = &idrinfo->action_idr;
 360         struct tc_action *p;
 361         int ret;
 362         unsigned long id = 1;
 363
 364         idr_for_each_entry_ext(idr, p, id) {
 365                 ret = __tcf_idr_release(p, false, true);
 366                 if (ret == ACT_P_DELETED)
 367                         module_put(ops->owner);
 368                 else if (ret < 0)
 369                         return;
 370         }
 371         idr_destroy(&idrinfo->action_idr);
 372 }
 373 EXPORT_SYMBOL(tcf_idrinfo_destroy);
 374
 375 static LIST_HEAD(act_base);
 376 static DEFINE_RWLOCK(act_mod_lock);
 377
 378 int tcf_register_action(struct tc_action_ops *act,
 379                         struct pernet_operations *ops)
 380 {
 381         struct tc_action_ops *a;
 382         int ret;
 383
 384         if (!act->act || !act->dump || !act->init || !act->walk || !act->lookup)
 385                 return -EINVAL;
 386
 387         /* We have to register pernet ops before making the action ops visible,
 388          * otherwise tcf_action_init_1() could get a partially initialized
 389          * netns.
 390          */
 391         ret = register_pernet_subsys(ops);
 392         if (ret)
 393                 return ret;
 394
 395         write_lock(&act_mod_lock);
 396         list_for_each_entry(a, &act_base, head) {
 397                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 398                         write_unlock(&act_mod_lock);
 399                         unregister_pernet_subsys(ops);
 400                         return -EEXIST;
 401                 }
 402         }
 403         list_add_tail(&act->head, &act_base);
 404         write_unlock(&act_mod_lock);
 405
 406         return 0;
 407 }
 408 EXPORT_SYMBOL(tcf_register_action);
 409
 410 int tcf_unregister_action(struct tc_action_ops *act,
 411                           struct pernet_operations *ops)
 412 {
 413         struct tc_action_ops *a;
 414         int err = -ENOENT;
 415
 416         write_lock(&act_mod_lock);
 417         list_for_each_entry(a, &act_base, head) {
 418                 if (a == act) {
 419                         list_del(&act->head);
 420                         err = 0;
 421                         break;
 422                 }
 423         }
 424         write_unlock(&act_mod_lock);
 425         if (!err)
 426                 unregister_pernet_subsys(ops);
 427         return err;
 428 }
 429 EXPORT_SYMBOL(tcf_unregister_action);
 430
 431 /* lookup by name */
 432 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 433 {
 434         struct tc_action_ops *a, *res = NULL;
 435
 436         if (kind) {
 437                 read_lock(&act_mod_lock);
 438                 list_for_each_entry(a, &act_base, head) {
 439                         if (strcmp(kind, a->kind) == 0) {
 440                                 if (try_module_get(a->owner))
 441                                         res = a;
 442                                 break;
 443                         }
 444                 }
 445                 read_unlock(&act_mod_lock);
 446         }
 447         return res;
 448 }
 449
 450 /* lookup by nlattr */
 451 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 452 {
 453         struct tc_action_ops *a, *res = NULL;
 454
 455         if (kind) {
 456                 read_lock(&act_mod_lock);
 457                 list_for_each_entry(a, &act_base, head) {
 458                         if (nla_strcmp(kind, a->kind) == 0) {
 459                                 if (try_module_get(a->owner))
 460                                         res = a;
 461                                 break;
 462                         }
 463                 }
 464                 read_unlock(&act_mod_lock);
 465         }
 466         return res;
 467 }
 468
 469 /*TCA_ACT_MAX_PRIO is 32, there count upto 32 */
 470 #define TCA_ACT_MAX_PRIO_MASK 0x1FF
 471 int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,
 472                     int nr_actions, struct tcf_result *res)
 473 {
 474         u32 jmp_prgcnt = 0;
 475         u32 jmp_ttl = TCA_ACT_MAX_PRIO; /*matches actions per filter */
 476         int i;
 477         int ret = TC_ACT_OK;
 478
 479         if (skb_skip_tc_classify(skb))
 480                 return TC_ACT_OK;
 481
 482 restart_act_graph:
 483         for (i = 0; i < nr_actions; i++) {
 484                 const struct tc_action *a = actions[i];
 485                 int repeat_ttl;
 486
 487                 if (jmp_prgcnt > 0) {
 488                         jmp_prgcnt -= 1;
 489                         continue;
 490                 }
 491
 492                 repeat_ttl = 32;
 493 repeat:
 494                 ret = a->ops->act(skb, a, res);
 495
 496                 if (unlikely(ret == TC_ACT_REPEAT)) {
 497                         if (--repeat_ttl != 0)
 498                                 goto repeat;
 499                         /* suspicious opcode, stop pipeline */
 500                         net_warn_ratelimited("TC_ACT_REPEAT abuse ?\n");
 501                         return TC_ACT_OK;
 502                 }
 503
 504                 if (TC_ACT_EXT_CMP(ret, TC_ACT_JUMP)) {
 505                         jmp_prgcnt = ret & TCA_ACT_MAX_PRIO_MASK;
 506                         if (!jmp_prgcnt || (jmp_prgcnt > nr_actions)) {
 507                                 /* faulty opcode, stop pipeline */
 508                                 return TC_ACT_OK;
 509                         } else {
 510                                 jmp_ttl -= 1;
 511                                 if (jmp_ttl > 0)
 512                                         goto restart_act_graph;
 513                                 else /* faulty graph, stop pipeline */
 514                                         return TC_ACT_OK;
 515                         }
 516                 } else if (TC_ACT_EXT_CMP(ret, TC_ACT_GOTO_CHAIN)) {
 517                         tcf_action_goto_chain_exec(a, res);
 518                 }
 519
 520                 if (ret != TC_ACT_PIPE)
 521                         break;
 522         }
 523
 524         return ret;
 525 }
 526 EXPORT_SYMBOL(tcf_action_exec);
 527
 528 int tcf_action_destroy(struct list_head *actions, int bind)
 529 {
 530         const struct tc_action_ops *ops;
 531         struct tc_action *a, *tmp;
 532         int ret = 0;
 533
 534         list_for_each_entry_safe(a, tmp, actions, list) {
 535                 ops = a->ops;
 536                 ret = __tcf_idr_release(a, bind, true);
 537                 if (ret == ACT_P_DELETED)
 538                         module_put(ops->owner);
 539                 else if (ret < 0)
 540                         return ret;
 541         }
 542         return ret;
 543 }
 544
 545 int
 546 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 547 {
 548         return a->ops->dump(skb, a, bind, ref);
 549 }
 550
 551 int
 552 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 553 {
 554         int err = -EINVAL;
 555         unsigned char *b = skb_tail_pointer(skb);
 556         struct nlattr *nest;
 557
 558         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 559                 goto nla_put_failure;
 560         if (tcf_action_copy_stats(skb, a, 0))
 561                 goto nla_put_failure;
 562         if (a->act_cookie) {
 563                 if (nla_put(skb, TCA_ACT_COOKIE, a->act_cookie->len,
 564                             a->act_cookie->data))
 565                         goto nla_put_failure;
 566         }
 567
 568         nest = nla_nest_start(skb, TCA_OPTIONS);
 569         if (nest == NULL)
 570                 goto nla_put_failure;
 571         err = tcf_action_dump_old(skb, a, bind, ref);
 572         if (err > 0) {
 573                 nla_nest_end(skb, nest);
 574                 return err;
 575         }
 576
 577 nla_put_failure:
 578         nlmsg_trim(skb, b);
 579         return -1;
 580 }
 581 EXPORT_SYMBOL(tcf_action_dump_1);
 582
 583 int tcf_action_dump(struct sk_buff *skb, struct list_head *actions,
 584                     int bind, int ref)
 585 {
 586         struct tc_action *a;
 587         int err = -EINVAL;
 588         struct nlattr *nest;
 589
 590         list_for_each_entry(a, actions, list) {
 591                 nest = nla_nest_start(skb, a->order);
 592                 if (nest == NULL)
 593                         goto nla_put_failure;
 594                 err = tcf_action_dump_1(skb, a, bind, ref);
 595                 if (err < 0)
 596                         goto errout;
 597                 nla_nest_end(skb, nest);
 598         }
 599
 600         return 0;
 601
 602 nla_put_failure:
 603         err = -EINVAL;
 604 errout:
 605         nla_nest_cancel(skb, nest);
 606         return err;
 607 }
 608
 609 static struct tc_cookie *nla_memdup_cookie(struct nlattr **tb)
 610 {
 611         struct tc_cookie *c = kzalloc(sizeof(*c), GFP_KERNEL);
 612         if (!c)
 613                 return NULL;
 614
 615         c->data = nla_memdup(tb[TCA_ACT_COOKIE], GFP_KERNEL);
 616         if (!c->data) {
 617                 kfree(c);
 618                 return NULL;
 619         }
 620         c->len = nla_len(tb[TCA_ACT_COOKIE]);
 621
 622         return c;
 623 }
 624
 625 struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
 626                                     struct nlattr *nla, struct nlattr *est,
 627                                     char *name, int ovr, int bind)
 628 {
 629         struct tc_action *a;
 630         struct tc_action_ops *a_o;
 631         struct tc_cookie *cookie = NULL;
 632         char act_name[IFNAMSIZ];
 633         struct nlattr *tb[TCA_ACT_MAX + 1];
 634         struct nlattr *kind;
 635         int err;
 636
 637         if (name == NULL) {
 638                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL, NULL);
 639                 if (err < 0)
 640                         goto err_out;
 641                 err = -EINVAL;
 642                 kind = tb[TCA_ACT_KIND];
 643                 if (kind == NULL)
 644                         goto err_out;
 645                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 646                         goto err_out;
 647                 if (tb[TCA_ACT_COOKIE]) {
 648                         int cklen = nla_len(tb[TCA_ACT_COOKIE]);
 649
 650                         if (cklen > TC_COOKIE_MAX_SIZE)
 651                                 goto err_out;
 652
 653                         cookie = nla_memdup_cookie(tb);
 654                         if (!cookie) {
 655                                 err = -ENOMEM;
 656                                 goto err_out;
 657                         }
 658                 }
 659         } else {
 660                 err = -EINVAL;
 661                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 662                         goto err_out;
 663         }
 664
 665         a_o = tc_lookup_action_n(act_name);
 666         if (a_o == NULL) {
 667 #ifdef CONFIG_MODULES
 668                 rtnl_unlock();
 669                 request_module("act_%s", act_name);
 670                 rtnl_lock();
 671
 672                 a_o = tc_lookup_action_n(act_name);
 673
 674                 /* We dropped the RTNL semaphore in order to
 675                  * perform the module load.  So, even if we
 676                  * succeeded in loading the module we have to
 677                  * tell the caller to replay the request.  We
 678                  * indicate this using -EAGAIN.
 679                  */
 680                 if (a_o != NULL) {
 681                         err = -EAGAIN;
 682                         goto err_mod;
 683                 }
 684 #endif
 685                 err = -ENOENT;
 686                 goto err_out;
 687         }
 688
 689         /* backward compatibility for policer */
 690         if (name == NULL)
 691                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, &a, ovr, bind);
 692         else
 693                 err = a_o->init(net, nla, est, &a, ovr, bind);
 694         if (err < 0)
 695                 goto err_mod;
 696
 697         if (name == NULL && tb[TCA_ACT_COOKIE]) {
 698                 if (a->act_cookie) {
 699                         kfree(a->act_cookie->data);
 700                         kfree(a->act_cookie);
 701                 }
 702                 a->act_cookie = cookie;
 703         }
 704
 705         /* module count goes up only when brand new policy is created
 706          * if it exists and is only bound to in a_o->init() then
 707          * ACT_P_CREATED is not returned (a zero is).
 708          */
 709         if (err != ACT_P_CREATED)
 710                 module_put(a_o->owner);
 711
 712         if (TC_ACT_EXT_CMP(a->tcfa_action, TC_ACT_GOTO_CHAIN)) {
 713                 err = tcf_action_goto_chain_init(a, tp);
 714                 if (err) {
 715                         LIST_HEAD(actions);
 716
 717                         list_add_tail(&a->list, &actions);
 718                         tcf_action_destroy(&actions, bind);
 719                         return ERR_PTR(err);
 720                 }
 721         }
 722
 723         return a;
 724
 725 err_mod:
 726         module_put(a_o->owner);
 727 err_out:
 728         if (cookie) {
 729                 kfree(cookie->data);
 730                 kfree(cookie);
 731         }
 732         return ERR_PTR(err);
 733 }
 734
 735 static void cleanup_a(struct list_head *actions, int ovr)
 736 {
 737         struct tc_action *a;
 738
 739         if (!ovr)
 740                 return;
 741
 742         list_for_each_entry(a, actions, list)
 743                 a->tcfa_refcnt--;
 744 }
 745
 746 int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
 747                     struct nlattr *est, char *name, int ovr, int bind,
 748                     struct list_head *actions)
 749 {
 750         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 751         struct tc_action *act;
 752         int err;
 753         int i;
 754
 755         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL, NULL);
 756         if (err < 0)
 757                 return err;
 758
 759         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 760                 act = tcf_action_init_1(net, tp, tb[i], est, name, ovr, bind);
 761                 if (IS_ERR(act)) {
 762                         err = PTR_ERR(act);
 763                         goto err;
 764                 }
 765                 act->order = i;
 766                 if (ovr)
 767                         act->tcfa_refcnt++;
 768                 list_add_tail(&act->list, actions);
 769         }
 770
 771         /* Remove the temp refcnt which was necessary to protect against
 772          * destroying an existing action which was being replaced
 773          */
 774         cleanup_a(actions, ovr);
 775         return 0;
 776
 777 err:
 778         tcf_action_destroy(actions, bind);
 779         return err;
 780 }
 781
 782 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *p,
 783                           int compat_mode)
 784 {
 785         int err = 0;
 786         struct gnet_dump d;
 787
 788         if (p == NULL)
 789                 goto errout;
 790
 791         /* compat_mode being true specifies a call that is supposed
 792          * to add additional backward compatibility statistic TLVs.
 793          */
 794         if (compat_mode) {
 795                 if (p->type == TCA_OLD_COMPAT)
 796                         err = gnet_stats_start_copy_compat(skb, 0,
 797                                                            TCA_STATS,
 798                                                            TCA_XSTATS,
 799                                                            &p->tcfa_lock, &d,
 800                                                            TCA_PAD);
 801                 else
 802                         return 0;
 803         } else
 804                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 805                                             &p->tcfa_lock, &d, TCA_ACT_PAD);
 806
 807         if (err < 0)
 808                 goto errout;
 809
 810         if (gnet_stats_copy_basic(NULL, &d, p->cpu_bstats, &p->tcfa_bstats) < 0 ||
 811             gnet_stats_copy_rate_est(&d, &p->tcfa_rate_est) < 0 ||
 812             gnet_stats_copy_queue(&d, p->cpu_qstats,
 813                                   &p->tcfa_qstats,
 814                                   p->tcfa_qstats.qlen) < 0)
 815                 goto errout;
 816
 817         if (gnet_stats_finish_copy(&d) < 0)
 818                 goto errout;
 819
 820         return 0;
 821
 822 errout:
 823         return -1;
 824 }
 825
 826 static int tca_get_fill(struct sk_buff *skb, struct list_head *actions,
 827                         u32 portid, u32 seq, u16 flags, int event, int bind,
 828                         int ref)
 829 {
 830         struct tcamsg *t;
 831         struct nlmsghdr *nlh;
 832         unsigned char *b = skb_tail_pointer(skb);
 833         struct nlattr *nest;
 834
 835         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
 836         if (!nlh)
 837                 goto out_nlmsg_trim;
 838         t = nlmsg_data(nlh);
 839         t->tca_family = AF_UNSPEC;
 840         t->tca__pad1 = 0;
 841         t->tca__pad2 = 0;
 842
 843         nest = nla_nest_start(skb, TCA_ACT_TAB);
 844         if (nest == NULL)
 845                 goto out_nlmsg_trim;
 846
 847         if (tcf_action_dump(skb, actions, bind, ref) < 0)
 848                 goto out_nlmsg_trim;
 849
 850         nla_nest_end(skb, nest);
 851
 852         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 853         return skb->len;
 854
 855 out_nlmsg_trim:
 856         nlmsg_trim(skb, b);
 857         return -1;
 858 }
 859
 860 static int
 861 tcf_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
 862                struct list_head *actions, int event)
 863 {
 864         struct sk_buff *skb;
 865
 866         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 867         if (!skb)
 868                 return -ENOBUFS;
 869         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event,
 870                          0, 0) <= 0) {
 871                 kfree_skb(skb);
 872                 return -EINVAL;
 873         }
 874
 875         return rtnl_unicast(skb, net, portid);
 876 }
 877
 878 static struct tc_action *tcf_action_get_1(struct net *net, struct nlattr *nla,
 879                                           struct nlmsghdr *n, u32 portid)
 880 {
 881         struct nlattr *tb[TCA_ACT_MAX + 1];
 882         const struct tc_action_ops *ops;
 883         struct tc_action *a;
 884         int index;
 885         int err;
 886
 887         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL, NULL);
 888         if (err < 0)
 889                 goto err_out;
 890
 891         err = -EINVAL;
 892         if (tb[TCA_ACT_INDEX] == NULL ||
 893             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 894                 goto err_out;
 895         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 896
 897         err = -EINVAL;
 898         ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 899         if (!ops) /* could happen in batch of actions */
 900                 goto err_out;
 901         err = -ENOENT;
 902         if (ops->lookup(net, &a, index) == 0)
 903                 goto err_mod;
 904
 905         module_put(ops->owner);
 906         return a;
 907
 908 err_mod:
 909         module_put(ops->owner);
 910 err_out:
 911         return ERR_PTR(err);
 912 }
 913
 914 static int tca_action_flush(struct net *net, struct nlattr *nla,
 915                             struct nlmsghdr *n, u32 portid)
 916 {
 917         struct sk_buff *skb;
 918         unsigned char *b;
 919         struct nlmsghdr *nlh;
 920         struct tcamsg *t;
 921         struct netlink_callback dcb;
 922         struct nlattr *nest;
 923         struct nlattr *tb[TCA_ACT_MAX + 1];
 924         const struct tc_action_ops *ops;
 925         struct nlattr *kind;
 926         int err = -ENOMEM;
 927
 928         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 929         if (!skb) {
 930                 pr_debug("tca_action_flush: failed skb alloc\n");
 931                 return err;
 932         }
 933
 934         b = skb_tail_pointer(skb);
 935
 936         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL, NULL);
 937         if (err < 0)
 938                 goto err_out;
 939
 940         err = -EINVAL;
 941         kind = tb[TCA_ACT_KIND];
 942         ops = tc_lookup_action(kind);
 943         if (!ops) /*some idjot trying to flush unknown action */
 944                 goto err_out;
 945
 946         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION,
 947                         sizeof(*t), 0);
 948         if (!nlh)
 949                 goto out_module_put;
 950         t = nlmsg_data(nlh);
 951         t->tca_family = AF_UNSPEC;
 952         t->tca__pad1 = 0;
 953         t->tca__pad2 = 0;
 954
 955         nest = nla_nest_start(skb, TCA_ACT_TAB);
 956         if (nest == NULL)
 957                 goto out_module_put;
 958
 959         err = ops->walk(net, skb, &dcb, RTM_DELACTION, ops);
 960         if (err <= 0)
 961                 goto out_module_put;
 962
 963         nla_nest_end(skb, nest);
 964
 965         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 966         nlh->nlmsg_flags |= NLM_F_ROOT;
 967         module_put(ops->owner);
 968         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 969                              n->nlmsg_flags & NLM_F_ECHO);
 970         if (err > 0)
 971                 return 0;
 972
 973         return err;
 974
 975 out_module_put:
 976         module_put(ops->owner);
 977 err_out:
 978         kfree_skb(skb);
 979         return err;
 980 }
 981
 982 static int
 983 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
 984                u32 portid)
 985 {
 986         int ret;
 987         struct sk_buff *skb;
 988
 989         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 990         if (!skb)
 991                 return -ENOBUFS;
 992
 993         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
 994                          0, 1) <= 0) {
 995                 kfree_skb(skb);
 996                 return -EINVAL;
 997         }
 998
 999         /* now do the delete */
1000         ret = tcf_action_destroy(actions, 0);
1001         if (ret < 0) {
1002                 kfree_skb(skb);
1003                 return ret;
1004         }
1005
1006         ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1007                              n->nlmsg_flags & NLM_F_ECHO);
1008         if (ret > 0)
1009                 return 0;
1010         return ret;
1011 }
1012
1013 static int
1014 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
1015               u32 portid, int event)
1016 {
1017         int i, ret;
1018         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1019         struct tc_action *act;
1020         LIST_HEAD(actions);
1021
1022         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL, NULL);
1023         if (ret < 0)
1024                 return ret;
1025
1026         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
1027                 if (tb[1] != NULL)
1028                         return tca_action_flush(net, tb[1], n, portid);
1029                 else
1030                         return -EINVAL;
1031         }
1032
1033         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
1034                 act = tcf_action_get_1(net, tb[i], n, portid);
1035                 if (IS_ERR(act)) {
1036                         ret = PTR_ERR(act);
1037                         goto err;
1038                 }
1039                 act->order = i;
1040                 list_add_tail(&act->list, &actions);
1041         }
1042
1043         if (event == RTM_GETACTION)
1044                 ret = tcf_get_notify(net, portid, n, &actions, event);
1045         else { /* delete */
1046                 ret = tcf_del_notify(net, n, &actions, portid);
1047                 if (ret)
1048                         goto err;
1049                 return ret;
1050         }
1051 err:
1052         if (event != RTM_GETACTION)
1053                 tcf_action_destroy(&actions, 0);
1054         return ret;
1055 }
1056
1057 static int
1058 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
1059                u32 portid)
1060 {
1061         struct sk_buff *skb;
1062         int err = 0;
1063
1064         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1065         if (!skb)
1066                 return -ENOBUFS;
1067
1068         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
1069                          RTM_NEWACTION, 0, 0) <= 0) {
1070                 kfree_skb(skb);
1071                 return -EINVAL;
1072         }
1073
1074         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1075                              n->nlmsg_flags & NLM_F_ECHO);
1076         if (err > 0)
1077                 err = 0;
1078         return err;
1079 }
1080
1081 static int tcf_action_add(struct net *net, struct nlattr *nla,
1082                           struct nlmsghdr *n, u32 portid, int ovr)
1083 {
1084         int loop, ret;
1085         LIST_HEAD(actions);
1086
1087         for (loop = 0; loop < 10; loop++) {
1088                 ret = tcf_action_init(net, NULL, nla, NULL, NULL, ovr, 0,
1089                                       &actions);
1090                 if (ret != -EAGAIN)
1091                         break;
1092         }
1093
1094         if (ret)
1095                 return ret;
1096
1097         return tcf_add_notify(net, n, &actions, portid);
1098 }
1099
1100 static u32 tcaa_root_flags_allowed = TCA_FLAG_LARGE_DUMP_ON;
1101 static const struct nla_policy tcaa_policy[TCA_ROOT_MAX + 1] = {
1102         [TCA_ROOT_FLAGS] = { .type = NLA_BITFIELD32,
1103                              .validation_data = &tcaa_root_flags_allowed },
1104         [TCA_ROOT_TIME_DELTA]      = { .type = NLA_U32 },
1105 };
1106
1107 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n,
1108                          struct netlink_ext_ack *extack)
1109 {
1110         struct net *net = sock_net(skb->sk);
1111         struct nlattr *tca[TCA_ROOT_MAX + 1];
1112         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
1113         int ret = 0, ovr = 0;
1114
1115         if ((n->nlmsg_type != RTM_GETACTION) &&
1116             !netlink_capable(skb, CAP_NET_ADMIN))
1117                 return -EPERM;
1118
1119         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ROOT_MAX, NULL,
1120                           extack);
1121         if (ret < 0)
1122                 return ret;
1123
1124         if (tca[TCA_ACT_TAB] == NULL) {
1125                 pr_notice("tc_ctl_action: received NO action attribs\n");
1126                 return -EINVAL;
1127         }
1128
1129         /* n->nlmsg_flags & NLM_F_CREATE */
1130         switch (n->nlmsg_type) {
1131         case RTM_NEWACTION:
1132                 /* we are going to assume all other flags
1133                  * imply create only if it doesn't exist
1134                  * Note that CREATE | EXCL implies that
1135                  * but since we want avoid ambiguity (eg when flags
1136                  * is zero) then just set this
1137                  */
1138                 if (n->nlmsg_flags & NLM_F_REPLACE)
1139                         ovr = 1;
1140                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr);
1141                 break;
1142         case RTM_DELACTION:
1143                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1144                                     portid, RTM_DELACTION);
1145                 break;
1146         case RTM_GETACTION:
1147                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1148                                     portid, RTM_GETACTION);
1149                 break;
1150         default:
1151                 BUG();
1152         }
1153
1154         return ret;
1155 }
1156
1157 static struct nlattr *find_dump_kind(struct nlattr **nla)
1158 {
1159         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1160         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1161         struct nlattr *kind;
1162
1163         tb1 = nla[TCA_ACT_TAB];
1164         if (tb1 == NULL)
1165                 return NULL;
1166
1167         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1168                       NLMSG_ALIGN(nla_len(tb1)), NULL, NULL) < 0)
1169                 return NULL;
1170
1171         if (tb[1] == NULL)
1172                 return NULL;
1173         if (nla_parse_nested(tb2, TCA_ACT_MAX, tb[1], NULL, NULL) < 0)
1174                 return NULL;
1175         kind = tb2[TCA_ACT_KIND];
1176
1177         return kind;
1178 }
1179
1180 static int tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1181 {
1182         struct net *net = sock_net(skb->sk);
1183         struct nlmsghdr *nlh;
1184         unsigned char *b = skb_tail_pointer(skb);
1185         struct nlattr *nest;
1186         struct tc_action_ops *a_o;
1187         int ret = 0;
1188         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1189         struct nlattr *tb[TCA_ROOT_MAX + 1];
1190         struct nlattr *count_attr = NULL;
1191         unsigned long jiffy_since = 0;
1192         struct nlattr *kind = NULL;
1193         struct nla_bitfield32 bf;
1194         u32 msecs_since = 0;
1195         u32 act_count = 0;
1196
1197         ret = nlmsg_parse(cb->nlh, sizeof(struct tcamsg), tb, TCA_ROOT_MAX,
1198                           tcaa_policy, NULL);
1199         if (ret < 0)
1200                 return ret;
1201
1202         kind = find_dump_kind(tb);
1203         if (kind == NULL) {
1204                 pr_info("tc_dump_action: action bad kind\n");
1205                 return 0;
1206         }
1207
1208         a_o = tc_lookup_action(kind);
1209         if (a_o == NULL)
1210                 return 0;
1211
1212         cb->args[2] = 0;
1213         if (tb[TCA_ROOT_FLAGS]) {
1214                 bf = nla_get_bitfield32(tb[TCA_ROOT_FLAGS]);
1215                 cb->args[2] = bf.value;
1216         }
1217
1218         if (tb[TCA_ROOT_TIME_DELTA]) {
1219                 msecs_since = nla_get_u32(tb[TCA_ROOT_TIME_DELTA]);
1220         }
1221
1222         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1223                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1224         if (!nlh)
1225                 goto out_module_put;
1226
1227         if (msecs_since)
1228                 jiffy_since = jiffies - msecs_to_jiffies(msecs_since);
1229
1230         t = nlmsg_data(nlh);
1231         t->tca_family = AF_UNSPEC;
1232         t->tca__pad1 = 0;
1233         t->tca__pad2 = 0;
1234         cb->args[3] = jiffy_since;
1235         count_attr = nla_reserve(skb, TCA_ROOT_COUNT, sizeof(u32));
1236         if (!count_attr)
1237                 goto out_module_put;
1238
1239         nest = nla_nest_start(skb, TCA_ACT_TAB);
1240         if (nest == NULL)
1241                 goto out_module_put;
1242
1243         ret = a_o->walk(net, skb, cb, RTM_GETACTION, a_o);
1244         if (ret < 0)
1245                 goto out_module_put;
1246
1247         if (ret > 0) {
1248                 nla_nest_end(skb, nest);
1249                 ret = skb->len;
1250                 act_count = cb->args[1];
1251                 memcpy(nla_data(count_attr), &act_count, sizeof(u32));
1252                 cb->args[1] = 0;
1253         } else
1254                 nlmsg_trim(skb, b);
1255
1256         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1257         if (NETLINK_CB(cb->skb).portid && ret)
1258                 nlh->nlmsg_flags |= NLM_F_MULTI;
1259         module_put(a_o->owner);
1260         return skb->len;
1261
1262 out_module_put:
1263         module_put(a_o->owner);
1264         nlmsg_trim(skb, b);
1265         return skb->len;
1266 }
1267
1268 static int __init tc_action_init(void)
1269 {
1270         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, 0);
1271         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, 0);
1272         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1273                       0);
1274
1275         return 0;
1276 }
1277
1278 subsys_initcall(tc_action_init);