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/act_api.h>
  28 #include <net/netlink.h>
  29
  30 void tcf_hash_destroy(struct tc_action *a)
  31 {
  32         struct tcf_common *p = a->priv;
  33         struct tcf_hashinfo *hinfo = a->ops->hinfo;
  34
  35         spin_lock_bh(&hinfo->lock);
  36         hlist_del(&p->tcfc_head);
  37         spin_unlock_bh(&hinfo->lock);
  38         gen_kill_estimator(&p->tcfc_bstats,
  39                            &p->tcfc_rate_est);
  40         /*
  41          * gen_estimator est_timer() might access p->tcfc_lock
  42          * or bstats, wait a RCU grace period before freeing p
  43          */
  44         kfree_rcu(p, tcfc_rcu);
  45 }
  46 EXPORT_SYMBOL(tcf_hash_destroy);
  47
  48 int tcf_hash_release(struct tc_action *a, int bind)
  49 {
  50         struct tcf_common *p = a->priv;
  51         int ret = 0;
  52
  53         if (p) {
  54                 if (bind)
  55                         p->tcfc_bindcnt--;
  56
  57                 p->tcfc_refcnt--;
  58                 if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
  59                         if (a->ops->cleanup)
  60                                 a->ops->cleanup(a, bind);
  61                         tcf_hash_destroy(a);
  62                         ret = 1;
  63                 }
  64         }
  65         return ret;
  66 }
  67 EXPORT_SYMBOL(tcf_hash_release);
  68
  69 static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
  70                            struct tc_action *a)
  71 {
  72         struct tcf_hashinfo *hinfo = a->ops->hinfo;
  73         struct hlist_head *head;
  74         struct tcf_common *p;
  75         int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
  76         struct nlattr *nest;
  77
  78         spin_lock_bh(&hinfo->lock);
  79
  80         s_i = cb->args[0];
  81
  82         for (i = 0; i < (hinfo->hmask + 1); i++) {
  83                 head = &hinfo->htab[tcf_hash(i, hinfo->hmask)];
  84
  85                 hlist_for_each_entry_rcu(p, head, tcfc_head) {
  86                         index++;
  87                         if (index < s_i)
  88                                 continue;
  89                         a->priv = p;
  90                         a->order = n_i;
  91
  92                         nest = nla_nest_start(skb, a->order);
  93                         if (nest == NULL)
  94                                 goto nla_put_failure;
  95                         err = tcf_action_dump_1(skb, a, 0, 0);
  96                         if (err < 0) {
  97                                 index--;
  98                                 nlmsg_trim(skb, nest);
  99                                 goto done;
 100                         }
 101                         nla_nest_end(skb, nest);
 102                         n_i++;
 103                         if (n_i >= TCA_ACT_MAX_PRIO)
 104                                 goto done;
 105                 }
 106         }
 107 done:
 108         spin_unlock_bh(&hinfo->lock);
 109         if (n_i)
 110                 cb->args[0] += n_i;
 111         return n_i;
 112
 113 nla_put_failure:
 114         nla_nest_cancel(skb, nest);
 115         goto done;
 116 }
 117
 118 static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a)
 119 {
 120         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 121         struct hlist_head *head;
 122         struct hlist_node *n;
 123         struct tcf_common *p;
 124         struct nlattr *nest;
 125         int i = 0, n_i = 0;
 126
 127         nest = nla_nest_start(skb, a->order);
 128         if (nest == NULL)
 129                 goto nla_put_failure;
 130         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 131                 goto nla_put_failure;
 132         for (i = 0; i < (hinfo->hmask + 1); i++) {
 133                 head = &hinfo->htab[tcf_hash(i, hinfo->hmask)];
 134                 hlist_for_each_entry_safe(p, n, head, tcfc_head) {
 135                         a->priv = p;
 136                         if (ACT_P_DELETED == tcf_hash_release(a, 0)) {
 137                                 module_put(a->ops->owner);
 138                                 n_i++;
 139                         }
 140                 }
 141         }
 142         if (nla_put_u32(skb, TCA_FCNT, n_i))
 143                 goto nla_put_failure;
 144         nla_nest_end(skb, nest);
 145
 146         return n_i;
 147 nla_put_failure:
 148         nla_nest_cancel(skb, nest);
 149         return -EINVAL;
 150 }
 151
 152 static int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
 153                               int type, struct tc_action *a)
 154 {
 155         if (type == RTM_DELACTION) {
 156                 return tcf_del_walker(skb, a);
 157         } else if (type == RTM_GETACTION) {
 158                 return tcf_dump_walker(skb, cb, a);
 159         } else {
 160                 WARN(1, "tcf_generic_walker: unknown action %d\n", type);
 161                 return -EINVAL;
 162         }
 163 }
 164
 165 static struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 166 {
 167         struct tcf_common *p = NULL;
 168         struct hlist_head *head;
 169
 170         spin_lock_bh(&hinfo->lock);
 171         head = &hinfo->htab[tcf_hash(index, hinfo->hmask)];
 172         hlist_for_each_entry_rcu(p, head, tcfc_head)
 173                 if (p->tcfc_index == index)
 174                         break;
 175         spin_unlock_bh(&hinfo->lock);
 176
 177         return p;
 178 }
 179
 180 u32 tcf_hash_new_index(struct tcf_hashinfo *hinfo)
 181 {
 182         u32 val = hinfo->index;
 183
 184         do {
 185                 if (++val == 0)
 186                         val = 1;
 187         } while (tcf_hash_lookup(val, hinfo));
 188
 189         hinfo->index = val;
 190         return val;
 191 }
 192 EXPORT_SYMBOL(tcf_hash_new_index);
 193
 194 int tcf_hash_search(struct tc_action *a, u32 index)
 195 {
 196         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 197         struct tcf_common *p = tcf_hash_lookup(index, hinfo);
 198
 199         if (p) {
 200                 a->priv = p;
 201                 return 1;
 202         }
 203         return 0;
 204 }
 205 EXPORT_SYMBOL(tcf_hash_search);
 206
 207 int tcf_hash_check(u32 index, struct tc_action *a, int bind)
 208 {
 209         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 210         struct tcf_common *p = NULL;
 211         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 212                 if (bind)
 213                         p->tcfc_bindcnt++;
 214                 p->tcfc_refcnt++;
 215                 a->priv = p;
 216                 return 1;
 217         }
 218         return 0;
 219 }
 220 EXPORT_SYMBOL(tcf_hash_check);
 221
 222 void tcf_hash_cleanup(struct tc_action *a, struct nlattr *est)
 223 {
 224         struct tcf_common *pc = a->priv;
 225         if (est)
 226                 gen_kill_estimator(&pc->tcfc_bstats,
 227                                    &pc->tcfc_rate_est);
 228         kfree_rcu(pc, tcfc_rcu);
 229 }
 230 EXPORT_SYMBOL(tcf_hash_cleanup);
 231
 232 int tcf_hash_create(u32 index, struct nlattr *est, struct tc_action *a,
 233                     int size, int bind)
 234 {
 235         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 236         struct tcf_common *p = kzalloc(size, GFP_KERNEL);
 237
 238         if (unlikely(!p))
 239                 return -ENOMEM;
 240         p->tcfc_refcnt = 1;
 241         if (bind)
 242                 p->tcfc_bindcnt = 1;
 243
 244         spin_lock_init(&p->tcfc_lock);
 245         INIT_HLIST_NODE(&p->tcfc_head);
 246         p->tcfc_index = index ? index : tcf_hash_new_index(hinfo);
 247         p->tcfc_tm.install = jiffies;
 248         p->tcfc_tm.lastuse = jiffies;
 249         if (est) {
 250                 int err = gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
 251                                             &p->tcfc_lock, est);
 252                 if (err) {
 253                         kfree(p);
 254                         return err;
 255                 }
 256         }
 257
 258         a->priv = (void *) p;
 259         return 0;
 260 }
 261 EXPORT_SYMBOL(tcf_hash_create);
 262
 263 void tcf_hash_insert(struct tc_action *a)
 264 {
 265         struct tcf_common *p = a->priv;
 266         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 267         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
 268
 269         spin_lock_bh(&hinfo->lock);
 270         hlist_add_head(&p->tcfc_head, &hinfo->htab[h]);
 271         spin_unlock_bh(&hinfo->lock);
 272 }
 273 EXPORT_SYMBOL(tcf_hash_insert);
 274
 275 static LIST_HEAD(act_base);
 276 static DEFINE_RWLOCK(act_mod_lock);
 277
 278 int tcf_register_action(struct tc_action_ops *act, unsigned int mask)
 279 {
 280         struct tc_action_ops *a;
 281         int err;
 282
 283         /* Must supply act, dump and init */
 284         if (!act->act || !act->dump || !act->init)
 285                 return -EINVAL;
 286
 287         /* Supply defaults */
 288         if (!act->lookup)
 289                 act->lookup = tcf_hash_search;
 290         if (!act->walk)
 291                 act->walk = tcf_generic_walker;
 292
 293         act->hinfo = kmalloc(sizeof(struct tcf_hashinfo), GFP_KERNEL);
 294         if (!act->hinfo)
 295                 return -ENOMEM;
 296         err = tcf_hashinfo_init(act->hinfo, mask);
 297         if (err) {
 298                 kfree(act->hinfo);
 299                 return err;
 300         }
 301
 302         write_lock(&act_mod_lock);
 303         list_for_each_entry(a, &act_base, head) {
 304                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 305                         write_unlock(&act_mod_lock);
 306                         tcf_hashinfo_destroy(act->hinfo);
 307                         kfree(act->hinfo);
 308                         return -EEXIST;
 309                 }
 310         }
 311         list_add_tail(&act->head, &act_base);
 312         write_unlock(&act_mod_lock);
 313         return 0;
 314 }
 315 EXPORT_SYMBOL(tcf_register_action);
 316
 317 int tcf_unregister_action(struct tc_action_ops *act)
 318 {
 319         struct tc_action_ops *a;
 320         int err = -ENOENT;
 321
 322         write_lock(&act_mod_lock);
 323         list_for_each_entry(a, &act_base, head) {
 324                 if (a == act) {
 325                         list_del(&act->head);
 326                         tcf_hashinfo_destroy(act->hinfo);
 327                         kfree(act->hinfo);
 328                         err = 0;
 329                         break;
 330                 }
 331         }
 332         write_unlock(&act_mod_lock);
 333         return err;
 334 }
 335 EXPORT_SYMBOL(tcf_unregister_action);
 336
 337 /* lookup by name */
 338 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 339 {
 340         struct tc_action_ops *a, *res = NULL;
 341
 342         if (kind) {
 343                 read_lock(&act_mod_lock);
 344                 list_for_each_entry(a, &act_base, head) {
 345                         if (strcmp(kind, a->kind) == 0) {
 346                                 if (try_module_get(a->owner))
 347                                         res = a;
 348                                 break;
 349                         }
 350                 }
 351                 read_unlock(&act_mod_lock);
 352         }
 353         return res;
 354 }
 355
 356 /* lookup by nlattr */
 357 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 358 {
 359         struct tc_action_ops *a, *res = NULL;
 360
 361         if (kind) {
 362                 read_lock(&act_mod_lock);
 363                 list_for_each_entry(a, &act_base, head) {
 364                         if (nla_strcmp(kind, a->kind) == 0) {
 365                                 if (try_module_get(a->owner))
 366                                         res = a;
 367                                 break;
 368                         }
 369                 }
 370                 read_unlock(&act_mod_lock);
 371         }
 372         return res;
 373 }
 374
 375 int tcf_action_exec(struct sk_buff *skb, const struct list_head *actions,
 376                     struct tcf_result *res)
 377 {
 378         const struct tc_action *a;
 379         int ret = -1;
 380
 381         if (skb->tc_verd & TC_NCLS) {
 382                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 383                 ret = TC_ACT_OK;
 384                 goto exec_done;
 385         }
 386         list_for_each_entry(a, actions, list) {
 387 repeat:
 388                 ret = a->ops->act(skb, a, res);
 389                 if (TC_MUNGED & skb->tc_verd) {
 390                         /* copied already, allow trampling */
 391                         skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
 392                         skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
 393                 }
 394                 if (ret == TC_ACT_REPEAT)
 395                         goto repeat;    /* we need a ttl - JHS */
 396                 if (ret != TC_ACT_PIPE)
 397                         goto exec_done;
 398         }
 399 exec_done:
 400         return ret;
 401 }
 402 EXPORT_SYMBOL(tcf_action_exec);
 403
 404 void tcf_action_destroy(struct list_head *actions, int bind)
 405 {
 406         struct tc_action *a, *tmp;
 407
 408         list_for_each_entry_safe(a, tmp, actions, list) {
 409                 if (tcf_hash_release(a, bind) == ACT_P_DELETED)
 410                         module_put(a->ops->owner);
 411                 list_del(&a->list);
 412                 kfree(a);
 413         }
 414 }
 415
 416 int
 417 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 418 {
 419         return a->ops->dump(skb, a, bind, ref);
 420 }
 421
 422 int
 423 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 424 {
 425         int err = -EINVAL;
 426         unsigned char *b = skb_tail_pointer(skb);
 427         struct nlattr *nest;
 428
 429         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 430                 goto nla_put_failure;
 431         if (tcf_action_copy_stats(skb, a, 0))
 432                 goto nla_put_failure;
 433         nest = nla_nest_start(skb, TCA_OPTIONS);
 434         if (nest == NULL)
 435                 goto nla_put_failure;
 436         err = tcf_action_dump_old(skb, a, bind, ref);
 437         if (err > 0) {
 438                 nla_nest_end(skb, nest);
 439                 return err;
 440         }
 441
 442 nla_put_failure:
 443         nlmsg_trim(skb, b);
 444         return -1;
 445 }
 446 EXPORT_SYMBOL(tcf_action_dump_1);
 447
 448 int
 449 tcf_action_dump(struct sk_buff *skb, struct list_head *actions, int bind, int ref)
 450 {
 451         struct tc_action *a;
 452         int err = -EINVAL;
 453         struct nlattr *nest;
 454
 455         list_for_each_entry(a, actions, list) {
 456                 nest = nla_nest_start(skb, a->order);
 457                 if (nest == NULL)
 458                         goto nla_put_failure;
 459                 err = tcf_action_dump_1(skb, a, bind, ref);
 460                 if (err < 0)
 461                         goto errout;
 462                 nla_nest_end(skb, nest);
 463         }
 464
 465         return 0;
 466
 467 nla_put_failure:
 468         err = -EINVAL;
 469 errout:
 470         nla_nest_cancel(skb, nest);
 471         return err;
 472 }
 473
 474 struct tc_action *tcf_action_init_1(struct net *net, struct nlattr *nla,
 475                                     struct nlattr *est, char *name, int ovr,
 476                                     int bind)
 477 {
 478         struct tc_action *a;
 479         struct tc_action_ops *a_o;
 480         char act_name[IFNAMSIZ];
 481         struct nlattr *tb[TCA_ACT_MAX + 1];
 482         struct nlattr *kind;
 483         int err;
 484
 485         if (name == NULL) {
 486                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 487                 if (err < 0)
 488                         goto err_out;
 489                 err = -EINVAL;
 490                 kind = tb[TCA_ACT_KIND];
 491                 if (kind == NULL)
 492                         goto err_out;
 493                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 494                         goto err_out;
 495         } else {
 496                 err = -EINVAL;
 497                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 498                         goto err_out;
 499         }
 500
 501         a_o = tc_lookup_action_n(act_name);
 502         if (a_o == NULL) {
 503 #ifdef CONFIG_MODULES
 504                 rtnl_unlock();
 505                 request_module("act_%s", act_name);
 506                 rtnl_lock();
 507
 508                 a_o = tc_lookup_action_n(act_name);
 509
 510                 /* We dropped the RTNL semaphore in order to
 511                  * perform the module load.  So, even if we
 512                  * succeeded in loading the module we have to
 513                  * tell the caller to replay the request.  We
 514                  * indicate this using -EAGAIN.
 515                  */
 516                 if (a_o != NULL) {
 517                         err = -EAGAIN;
 518                         goto err_mod;
 519                 }
 520 #endif
 521                 err = -ENOENT;
 522                 goto err_out;
 523         }
 524
 525         err = -ENOMEM;
 526         a = kzalloc(sizeof(*a), GFP_KERNEL);
 527         if (a == NULL)
 528                 goto err_mod;
 529
 530         a->ops = a_o;
 531         INIT_LIST_HEAD(&a->list);
 532         /* backward compatibility for policer */
 533         if (name == NULL)
 534                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
 535         else
 536                 err = a_o->init(net, nla, est, a, ovr, bind);
 537         if (err < 0)
 538                 goto err_free;
 539
 540         /* module count goes up only when brand new policy is created
 541          * if it exists and is only bound to in a_o->init() then
 542          * ACT_P_CREATED is not returned (a zero is).
 543          */
 544         if (err != ACT_P_CREATED)
 545                 module_put(a_o->owner);
 546
 547         return a;
 548
 549 err_free:
 550         kfree(a);
 551 err_mod:
 552         module_put(a_o->owner);
 553 err_out:
 554         return ERR_PTR(err);
 555 }
 556
 557 int tcf_action_init(struct net *net, struct nlattr *nla,
 558                                   struct nlattr *est, char *name, int ovr,
 559                                   int bind, struct list_head *actions)
 560 {
 561         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 562         struct tc_action *act;
 563         int err;
 564         int i;
 565
 566         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 567         if (err < 0)
 568                 return err;
 569
 570         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 571                 act = tcf_action_init_1(net, tb[i], est, name, ovr, bind);
 572                 if (IS_ERR(act)) {
 573                         err = PTR_ERR(act);
 574                         goto err;
 575                 }
 576                 act->order = i;
 577                 list_add_tail(&act->list, actions);
 578         }
 579         return 0;
 580
 581 err:
 582         tcf_action_destroy(actions, bind);
 583         return err;
 584 }
 585
 586 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 587                           int compat_mode)
 588 {
 589         int err = 0;
 590         struct gnet_dump d;
 591         struct tcf_common *p = a->priv;
 592
 593         if (p == NULL)
 594                 goto errout;
 595
 596         /* compat_mode being true specifies a call that is supposed
 597          * to add additional backward compatibility statistic TLVs.
 598          */
 599         if (compat_mode) {
 600                 if (a->type == TCA_OLD_COMPAT)
 601                         err = gnet_stats_start_copy_compat(skb, 0,
 602                                 TCA_STATS, TCA_XSTATS, &p->tcfc_lock, &d);
 603                 else
 604                         return 0;
 605         } else
 606                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 607                                             &p->tcfc_lock, &d);
 608
 609         if (err < 0)
 610                 goto errout;
 611
 612         if (gnet_stats_copy_basic(&d, &p->tcfc_bstats) < 0 ||
 613             gnet_stats_copy_rate_est(&d, &p->tcfc_bstats,
 614                                      &p->tcfc_rate_est) < 0 ||
 615             gnet_stats_copy_queue(&d, &p->tcfc_qstats) < 0)
 616                 goto errout;
 617
 618         if (gnet_stats_finish_copy(&d) < 0)
 619                 goto errout;
 620
 621         return 0;
 622
 623 errout:
 624         return -1;
 625 }
 626
 627 static int
 628 tca_get_fill(struct sk_buff *skb, struct list_head *actions, u32 portid, u32 seq,
 629              u16 flags, int event, int bind, int ref)
 630 {
 631         struct tcamsg *t;
 632         struct nlmsghdr *nlh;
 633         unsigned char *b = skb_tail_pointer(skb);
 634         struct nlattr *nest;
 635
 636         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
 637         if (!nlh)
 638                 goto out_nlmsg_trim;
 639         t = nlmsg_data(nlh);
 640         t->tca_family = AF_UNSPEC;
 641         t->tca__pad1 = 0;
 642         t->tca__pad2 = 0;
 643
 644         nest = nla_nest_start(skb, TCA_ACT_TAB);
 645         if (nest == NULL)
 646                 goto out_nlmsg_trim;
 647
 648         if (tcf_action_dump(skb, actions, bind, ref) < 0)
 649                 goto out_nlmsg_trim;
 650
 651         nla_nest_end(skb, nest);
 652
 653         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 654         return skb->len;
 655
 656 out_nlmsg_trim:
 657         nlmsg_trim(skb, b);
 658         return -1;
 659 }
 660
 661 static int
 662 act_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
 663                struct list_head *actions, int event)
 664 {
 665         struct sk_buff *skb;
 666
 667         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 668         if (!skb)
 669                 return -ENOBUFS;
 670         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 671                 kfree_skb(skb);
 672                 return -EINVAL;
 673         }
 674
 675         return rtnl_unicast(skb, net, portid);
 676 }
 677
 678 static struct tc_action *
 679 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 portid)
 680 {
 681         struct nlattr *tb[TCA_ACT_MAX + 1];
 682         struct tc_action *a;
 683         int index;
 684         int err;
 685
 686         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 687         if (err < 0)
 688                 goto err_out;
 689
 690         err = -EINVAL;
 691         if (tb[TCA_ACT_INDEX] == NULL ||
 692             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 693                 goto err_out;
 694         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 695
 696         err = -ENOMEM;
 697         a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
 698         if (a == NULL)
 699                 goto err_out;
 700
 701         INIT_LIST_HEAD(&a->list);
 702         err = -EINVAL;
 703         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 704         if (a->ops == NULL) /* could happen in batch of actions */
 705                 goto err_free;
 706         err = -ENOENT;
 707         if (a->ops->lookup(a, index) == 0)
 708                 goto err_mod;
 709
 710         module_put(a->ops->owner);
 711         return a;
 712
 713 err_mod:
 714         module_put(a->ops->owner);
 715 err_free:
 716         kfree(a);
 717 err_out:
 718         return ERR_PTR(err);
 719 }
 720
 721 static void cleanup_a(struct list_head *actions)
 722 {
 723         struct tc_action *a, *tmp;
 724
 725         list_for_each_entry_safe(a, tmp, actions, list) {
 726                 list_del(&a->list);
 727                 kfree(a);
 728         }
 729 }
 730
 731 static struct tc_action *create_a(int i)
 732 {
 733         struct tc_action *act;
 734
 735         act = kzalloc(sizeof(*act), GFP_KERNEL);
 736         if (act == NULL) {
 737                 pr_debug("create_a: failed to alloc!\n");
 738                 return NULL;
 739         }
 740         act->order = i;
 741         INIT_LIST_HEAD(&act->list);
 742         return act;
 743 }
 744
 745 static int tca_action_flush(struct net *net, struct nlattr *nla,
 746                             struct nlmsghdr *n, u32 portid)
 747 {
 748         struct sk_buff *skb;
 749         unsigned char *b;
 750         struct nlmsghdr *nlh;
 751         struct tcamsg *t;
 752         struct netlink_callback dcb;
 753         struct nlattr *nest;
 754         struct nlattr *tb[TCA_ACT_MAX + 1];
 755         struct nlattr *kind;
 756         struct tc_action *a = create_a(0);
 757         int err = -ENOMEM;
 758
 759         if (a == NULL) {
 760                 pr_debug("tca_action_flush: couldnt create tc_action\n");
 761                 return err;
 762         }
 763
 764         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 765         if (!skb) {
 766                 pr_debug("tca_action_flush: failed skb alloc\n");
 767                 kfree(a);
 768                 return err;
 769         }
 770
 771         b = skb_tail_pointer(skb);
 772
 773         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 774         if (err < 0)
 775                 goto err_out;
 776
 777         err = -EINVAL;
 778         kind = tb[TCA_ACT_KIND];
 779         a->ops = tc_lookup_action(kind);
 780         if (a->ops == NULL) /*some idjot trying to flush unknown action */
 781                 goto err_out;
 782
 783         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t), 0);
 784         if (!nlh)
 785                 goto out_module_put;
 786         t = nlmsg_data(nlh);
 787         t->tca_family = AF_UNSPEC;
 788         t->tca__pad1 = 0;
 789         t->tca__pad2 = 0;
 790
 791         nest = nla_nest_start(skb, TCA_ACT_TAB);
 792         if (nest == NULL)
 793                 goto out_module_put;
 794
 795         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 796         if (err < 0)
 797                 goto out_module_put;
 798         if (err == 0)
 799                 goto noflush_out;
 800
 801         nla_nest_end(skb, nest);
 802
 803         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 804         nlh->nlmsg_flags |= NLM_F_ROOT;
 805         module_put(a->ops->owner);
 806         kfree(a);
 807         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 808                              n->nlmsg_flags & NLM_F_ECHO);
 809         if (err > 0)
 810                 return 0;
 811
 812         return err;
 813
 814 out_module_put:
 815         module_put(a->ops->owner);
 816 err_out:
 817 noflush_out:
 818         kfree_skb(skb);
 819         kfree(a);
 820         return err;
 821 }
 822
 823 static int
 824 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
 825                u32 portid)
 826 {
 827         int ret;
 828         struct sk_buff *skb;
 829
 830         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 831         if (!skb)
 832                 return -ENOBUFS;
 833
 834         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
 835                          0, 1) <= 0) {
 836                 kfree_skb(skb);
 837                 return -EINVAL;
 838         }
 839
 840         /* now do the delete */
 841         tcf_action_destroy(actions, 0);
 842
 843         ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 844                              n->nlmsg_flags & NLM_F_ECHO);
 845         if (ret > 0)
 846                 return 0;
 847         return ret;
 848 }
 849
 850 static int
 851 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 852               u32 portid, int event)
 853 {
 854         int i, ret;
 855         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 856         struct tc_action *act;
 857         LIST_HEAD(actions);
 858
 859         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 860         if (ret < 0)
 861                 return ret;
 862
 863         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
 864                 if (tb[1] != NULL)
 865                         return tca_action_flush(net, tb[1], n, portid);
 866                 else
 867                         return -EINVAL;
 868         }
 869
 870         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 871                 act = tcf_action_get_1(tb[i], n, portid);
 872                 if (IS_ERR(act)) {
 873                         ret = PTR_ERR(act);
 874                         goto err;
 875                 }
 876                 act->order = i;
 877                 list_add_tail(&act->list, &actions);
 878         }
 879
 880         if (event == RTM_GETACTION)
 881                 ret = act_get_notify(net, portid, n, &actions, event);
 882         else { /* delete */
 883                 ret = tcf_del_notify(net, n, &actions, portid);
 884                 if (ret)
 885                         goto err;
 886                 return ret;
 887         }
 888 err:
 889         cleanup_a(&actions);
 890         return ret;
 891 }
 892
 893 static int
 894 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
 895                u32 portid)
 896 {
 897         struct sk_buff *skb;
 898         int err = 0;
 899
 900         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 901         if (!skb)
 902                 return -ENOBUFS;
 903
 904         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
 905                          RTM_NEWACTION, 0, 0) <= 0) {
 906                 kfree_skb(skb);
 907                 return -EINVAL;
 908         }
 909
 910         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 911                              n->nlmsg_flags & NLM_F_ECHO);
 912         if (err > 0)
 913                 err = 0;
 914         return err;
 915 }
 916
 917 static int
 918 tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 919                u32 portid, int ovr)
 920 {
 921         int ret = 0;
 922         LIST_HEAD(actions);
 923
 924         ret = tcf_action_init(net, nla, NULL, NULL, ovr, 0, &actions);
 925         if (ret)
 926                 goto done;
 927
 928         /* dump then free all the actions after update; inserted policy
 929          * stays intact
 930          */
 931         ret = tcf_add_notify(net, n, &actions, portid);
 932         cleanup_a(&actions);
 933 done:
 934         return ret;
 935 }
 936
 937 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n)
 938 {
 939         struct net *net = sock_net(skb->sk);
 940         struct nlattr *tca[TCA_ACT_MAX + 1];
 941         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
 942         int ret = 0, ovr = 0;
 943
 944         if ((n->nlmsg_type != RTM_GETACTION) && !capable(CAP_NET_ADMIN))
 945                 return -EPERM;
 946
 947         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
 948         if (ret < 0)
 949                 return ret;
 950
 951         if (tca[TCA_ACT_TAB] == NULL) {
 952                 pr_notice("tc_ctl_action: received NO action attribs\n");
 953                 return -EINVAL;
 954         }
 955
 956         /* n->nlmsg_flags & NLM_F_CREATE */
 957         switch (n->nlmsg_type) {
 958         case RTM_NEWACTION:
 959                 /* we are going to assume all other flags
 960                  * imply create only if it doesn't exist
 961                  * Note that CREATE | EXCL implies that
 962                  * but since we want avoid ambiguity (eg when flags
 963                  * is zero) then just set this
 964                  */
 965                 if (n->nlmsg_flags & NLM_F_REPLACE)
 966                         ovr = 1;
 967 replay:
 968                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr);
 969                 if (ret == -EAGAIN)
 970                         goto replay;
 971                 break;
 972         case RTM_DELACTION:
 973                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
 974                                     portid, RTM_DELACTION);
 975                 break;
 976         case RTM_GETACTION:
 977                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
 978                                     portid, RTM_GETACTION);
 979                 break;
 980         default:
 981                 BUG();
 982         }
 983
 984         return ret;
 985 }
 986
 987 static struct nlattr *
 988 find_dump_kind(const struct nlmsghdr *n)
 989 {
 990         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
 991         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 992         struct nlattr *nla[TCAA_MAX + 1];
 993         struct nlattr *kind;
 994
 995         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
 996                 return NULL;
 997         tb1 = nla[TCA_ACT_TAB];
 998         if (tb1 == NULL)
 999                 return NULL;
1000
1001         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1002                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1003                 return NULL;
1004
1005         if (tb[1] == NULL)
1006                 return NULL;
1007         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1008                       nla_len(tb[1]), NULL) < 0)
1009                 return NULL;
1010         kind = tb2[TCA_ACT_KIND];
1011
1012         return kind;
1013 }
1014
1015 static int
1016 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1017 {
1018         struct nlmsghdr *nlh;
1019         unsigned char *b = skb_tail_pointer(skb);
1020         struct nlattr *nest;
1021         struct tc_action_ops *a_o;
1022         struct tc_action a;
1023         int ret = 0;
1024         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1025         struct nlattr *kind = find_dump_kind(cb->nlh);
1026
1027         if (kind == NULL) {
1028                 pr_info("tc_dump_action: action bad kind\n");
1029                 return 0;
1030         }
1031
1032         a_o = tc_lookup_action(kind);
1033         if (a_o == NULL)
1034                 return 0;
1035
1036         memset(&a, 0, sizeof(struct tc_action));
1037         a.ops = a_o;
1038
1039         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1040                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1041         if (!nlh)
1042                 goto out_module_put;
1043         t = nlmsg_data(nlh);
1044         t->tca_family = AF_UNSPEC;
1045         t->tca__pad1 = 0;
1046         t->tca__pad2 = 0;
1047
1048         nest = nla_nest_start(skb, TCA_ACT_TAB);
1049         if (nest == NULL)
1050                 goto out_module_put;
1051
1052         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1053         if (ret < 0)
1054                 goto out_module_put;
1055
1056         if (ret > 0) {
1057                 nla_nest_end(skb, nest);
1058                 ret = skb->len;
1059         } else
1060                 nla_nest_cancel(skb, nest);
1061
1062         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1063         if (NETLINK_CB(cb->skb).portid && ret)
1064                 nlh->nlmsg_flags |= NLM_F_MULTI;
1065         module_put(a_o->owner);
1066         return skb->len;
1067
1068 out_module_put:
1069         module_put(a_o->owner);
1070         nlmsg_trim(skb, b);
1071         return skb->len;
1072 }
1073
1074 static int __init tc_action_init(void)
1075 {
1076         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
1077         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
1078         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1079                       NULL);
1080
1081         return 0;
1082 }
1083
1084 subsys_initcall(tc_action_init);