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)
 279 {
 280         struct tc_action_ops *a;
 281
 282         /* Must supply act, dump and init */
 283         if (!act->act || !act->dump || !act->init)
 284                 return -EINVAL;
 285
 286         /* Supply defaults */
 287         if (!act->lookup)
 288                 act->lookup = tcf_hash_search;
 289         if (!act->walk)
 290                 act->walk = tcf_generic_walker;
 291
 292         write_lock(&act_mod_lock);
 293         list_for_each_entry(a, &act_base, head) {
 294                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 295                         write_unlock(&act_mod_lock);
 296                         return -EEXIST;
 297                 }
 298         }
 299         list_add_tail(&act->head, &act_base);
 300         write_unlock(&act_mod_lock);
 301         return 0;
 302 }
 303 EXPORT_SYMBOL(tcf_register_action);
 304
 305 int tcf_unregister_action(struct tc_action_ops *act)
 306 {
 307         struct tc_action_ops *a;
 308         int err = -ENOENT;
 309
 310         write_lock(&act_mod_lock);
 311         list_for_each_entry(a, &act_base, head) {
 312                 if (a == act) {
 313                         list_del(&act->head);
 314                         err = 0;
 315                         break;
 316                 }
 317         }
 318         write_unlock(&act_mod_lock);
 319         return err;
 320 }
 321 EXPORT_SYMBOL(tcf_unregister_action);
 322
 323 /* lookup by name */
 324 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 325 {
 326         struct tc_action_ops *a, *res = NULL;
 327
 328         if (kind) {
 329                 read_lock(&act_mod_lock);
 330                 list_for_each_entry(a, &act_base, head) {
 331                         if (strcmp(kind, a->kind) == 0) {
 332                                 if (try_module_get(a->owner))
 333                                         res = a;
 334                                 break;
 335                         }
 336                 }
 337                 read_unlock(&act_mod_lock);
 338         }
 339         return res;
 340 }
 341
 342 /* lookup by nlattr */
 343 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 344 {
 345         struct tc_action_ops *a, *res = NULL;
 346
 347         if (kind) {
 348                 read_lock(&act_mod_lock);
 349                 list_for_each_entry(a, &act_base, head) {
 350                         if (nla_strcmp(kind, a->kind) == 0) {
 351                                 if (try_module_get(a->owner))
 352                                         res = a;
 353                                 break;
 354                         }
 355                 }
 356                 read_unlock(&act_mod_lock);
 357         }
 358         return res;
 359 }
 360
 361 int tcf_action_exec(struct sk_buff *skb, const struct list_head *actions,
 362                     struct tcf_result *res)
 363 {
 364         const struct tc_action *a;
 365         int ret = -1;
 366
 367         if (skb->tc_verd & TC_NCLS) {
 368                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 369                 ret = TC_ACT_OK;
 370                 goto exec_done;
 371         }
 372         list_for_each_entry(a, actions, list) {
 373 repeat:
 374                 ret = a->ops->act(skb, a, res);
 375                 if (TC_MUNGED & skb->tc_verd) {
 376                         /* copied already, allow trampling */
 377                         skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
 378                         skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
 379                 }
 380                 if (ret == TC_ACT_REPEAT)
 381                         goto repeat;    /* we need a ttl - JHS */
 382                 if (ret != TC_ACT_PIPE)
 383                         goto exec_done;
 384         }
 385 exec_done:
 386         return ret;
 387 }
 388 EXPORT_SYMBOL(tcf_action_exec);
 389
 390 void tcf_action_destroy(struct list_head *actions, int bind)
 391 {
 392         struct tc_action *a, *tmp;
 393
 394         list_for_each_entry_safe(a, tmp, actions, list) {
 395                 if (tcf_hash_release(a, bind) == ACT_P_DELETED)
 396                         module_put(a->ops->owner);
 397                 list_del(&a->list);
 398                 kfree(a);
 399         }
 400 }
 401
 402 int
 403 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 404 {
 405         return a->ops->dump(skb, a, bind, ref);
 406 }
 407
 408 int
 409 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 410 {
 411         int err = -EINVAL;
 412         unsigned char *b = skb_tail_pointer(skb);
 413         struct nlattr *nest;
 414
 415         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 416                 goto nla_put_failure;
 417         if (tcf_action_copy_stats(skb, a, 0))
 418                 goto nla_put_failure;
 419         nest = nla_nest_start(skb, TCA_OPTIONS);
 420         if (nest == NULL)
 421                 goto nla_put_failure;
 422         err = tcf_action_dump_old(skb, a, bind, ref);
 423         if (err > 0) {
 424                 nla_nest_end(skb, nest);
 425                 return err;
 426         }
 427
 428 nla_put_failure:
 429         nlmsg_trim(skb, b);
 430         return -1;
 431 }
 432 EXPORT_SYMBOL(tcf_action_dump_1);
 433
 434 int
 435 tcf_action_dump(struct sk_buff *skb, struct list_head *actions, int bind, int ref)
 436 {
 437         struct tc_action *a;
 438         int err = -EINVAL;
 439         struct nlattr *nest;
 440
 441         list_for_each_entry(a, actions, list) {
 442                 nest = nla_nest_start(skb, a->order);
 443                 if (nest == NULL)
 444                         goto nla_put_failure;
 445                 err = tcf_action_dump_1(skb, a, bind, ref);
 446                 if (err < 0)
 447                         goto errout;
 448                 nla_nest_end(skb, nest);
 449         }
 450
 451         return 0;
 452
 453 nla_put_failure:
 454         err = -EINVAL;
 455 errout:
 456         nla_nest_cancel(skb, nest);
 457         return err;
 458 }
 459
 460 struct tc_action *tcf_action_init_1(struct net *net, struct nlattr *nla,
 461                                     struct nlattr *est, char *name, int ovr,
 462                                     int bind)
 463 {
 464         struct tc_action *a;
 465         struct tc_action_ops *a_o;
 466         char act_name[IFNAMSIZ];
 467         struct nlattr *tb[TCA_ACT_MAX + 1];
 468         struct nlattr *kind;
 469         int err;
 470
 471         if (name == NULL) {
 472                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 473                 if (err < 0)
 474                         goto err_out;
 475                 err = -EINVAL;
 476                 kind = tb[TCA_ACT_KIND];
 477                 if (kind == NULL)
 478                         goto err_out;
 479                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 480                         goto err_out;
 481         } else {
 482                 err = -EINVAL;
 483                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 484                         goto err_out;
 485         }
 486
 487         a_o = tc_lookup_action_n(act_name);
 488         if (a_o == NULL) {
 489 #ifdef CONFIG_MODULES
 490                 rtnl_unlock();
 491                 request_module("act_%s", act_name);
 492                 rtnl_lock();
 493
 494                 a_o = tc_lookup_action_n(act_name);
 495
 496                 /* We dropped the RTNL semaphore in order to
 497                  * perform the module load.  So, even if we
 498                  * succeeded in loading the module we have to
 499                  * tell the caller to replay the request.  We
 500                  * indicate this using -EAGAIN.
 501                  */
 502                 if (a_o != NULL) {
 503                         err = -EAGAIN;
 504                         goto err_mod;
 505                 }
 506 #endif
 507                 err = -ENOENT;
 508                 goto err_out;
 509         }
 510
 511         err = -ENOMEM;
 512         a = kzalloc(sizeof(*a), GFP_KERNEL);
 513         if (a == NULL)
 514                 goto err_mod;
 515
 516         a->ops = a_o;
 517         INIT_LIST_HEAD(&a->list);
 518         /* backward compatibility for policer */
 519         if (name == NULL)
 520                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
 521         else
 522                 err = a_o->init(net, nla, est, a, ovr, bind);
 523         if (err < 0)
 524                 goto err_free;
 525
 526         /* module count goes up only when brand new policy is created
 527          * if it exists and is only bound to in a_o->init() then
 528          * ACT_P_CREATED is not returned (a zero is).
 529          */
 530         if (err != ACT_P_CREATED)
 531                 module_put(a_o->owner);
 532
 533         return a;
 534
 535 err_free:
 536         kfree(a);
 537 err_mod:
 538         module_put(a_o->owner);
 539 err_out:
 540         return ERR_PTR(err);
 541 }
 542
 543 int tcf_action_init(struct net *net, struct nlattr *nla,
 544                                   struct nlattr *est, char *name, int ovr,
 545                                   int bind, struct list_head *actions)
 546 {
 547         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 548         struct tc_action *act;
 549         int err;
 550         int i;
 551
 552         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 553         if (err < 0)
 554                 return err;
 555
 556         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 557                 act = tcf_action_init_1(net, tb[i], est, name, ovr, bind);
 558                 if (IS_ERR(act)) {
 559                         err = PTR_ERR(act);
 560                         goto err;
 561                 }
 562                 act->order = i;
 563                 list_add_tail(&act->list, actions);
 564         }
 565         return 0;
 566
 567 err:
 568         tcf_action_destroy(actions, bind);
 569         return err;
 570 }
 571
 572 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 573                           int compat_mode)
 574 {
 575         int err = 0;
 576         struct gnet_dump d;
 577         struct tcf_common *p = a->priv;
 578
 579         if (p == NULL)
 580                 goto errout;
 581
 582         /* compat_mode being true specifies a call that is supposed
 583          * to add additional backward compatibility statistic TLVs.
 584          */
 585         if (compat_mode) {
 586                 if (a->type == TCA_OLD_COMPAT)
 587                         err = gnet_stats_start_copy_compat(skb, 0,
 588                                 TCA_STATS, TCA_XSTATS, &p->tcfc_lock, &d);
 589                 else
 590                         return 0;
 591         } else
 592                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 593                                             &p->tcfc_lock, &d);
 594
 595         if (err < 0)
 596                 goto errout;
 597
 598         if (gnet_stats_copy_basic(&d, &p->tcfc_bstats) < 0 ||
 599             gnet_stats_copy_rate_est(&d, &p->tcfc_bstats,
 600                                      &p->tcfc_rate_est) < 0 ||
 601             gnet_stats_copy_queue(&d, &p->tcfc_qstats) < 0)
 602                 goto errout;
 603
 604         if (gnet_stats_finish_copy(&d) < 0)
 605                 goto errout;
 606
 607         return 0;
 608
 609 errout:
 610         return -1;
 611 }
 612
 613 static int
 614 tca_get_fill(struct sk_buff *skb, struct list_head *actions, u32 portid, u32 seq,
 615              u16 flags, int event, int bind, int ref)
 616 {
 617         struct tcamsg *t;
 618         struct nlmsghdr *nlh;
 619         unsigned char *b = skb_tail_pointer(skb);
 620         struct nlattr *nest;
 621
 622         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
 623         if (!nlh)
 624                 goto out_nlmsg_trim;
 625         t = nlmsg_data(nlh);
 626         t->tca_family = AF_UNSPEC;
 627         t->tca__pad1 = 0;
 628         t->tca__pad2 = 0;
 629
 630         nest = nla_nest_start(skb, TCA_ACT_TAB);
 631         if (nest == NULL)
 632                 goto out_nlmsg_trim;
 633
 634         if (tcf_action_dump(skb, actions, bind, ref) < 0)
 635                 goto out_nlmsg_trim;
 636
 637         nla_nest_end(skb, nest);
 638
 639         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 640         return skb->len;
 641
 642 out_nlmsg_trim:
 643         nlmsg_trim(skb, b);
 644         return -1;
 645 }
 646
 647 static int
 648 act_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
 649                struct list_head *actions, int event)
 650 {
 651         struct sk_buff *skb;
 652
 653         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 654         if (!skb)
 655                 return -ENOBUFS;
 656         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 657                 kfree_skb(skb);
 658                 return -EINVAL;
 659         }
 660
 661         return rtnl_unicast(skb, net, portid);
 662 }
 663
 664 static struct tc_action *
 665 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 portid)
 666 {
 667         struct nlattr *tb[TCA_ACT_MAX + 1];
 668         struct tc_action *a;
 669         int index;
 670         int err;
 671
 672         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 673         if (err < 0)
 674                 goto err_out;
 675
 676         err = -EINVAL;
 677         if (tb[TCA_ACT_INDEX] == NULL ||
 678             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 679                 goto err_out;
 680         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 681
 682         err = -ENOMEM;
 683         a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
 684         if (a == NULL)
 685                 goto err_out;
 686
 687         INIT_LIST_HEAD(&a->list);
 688         err = -EINVAL;
 689         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 690         if (a->ops == NULL) /* could happen in batch of actions */
 691                 goto err_free;
 692         err = -ENOENT;
 693         if (a->ops->lookup(a, index) == 0)
 694                 goto err_mod;
 695
 696         module_put(a->ops->owner);
 697         return a;
 698
 699 err_mod:
 700         module_put(a->ops->owner);
 701 err_free:
 702         kfree(a);
 703 err_out:
 704         return ERR_PTR(err);
 705 }
 706
 707 static void cleanup_a(struct list_head *actions)
 708 {
 709         struct tc_action *a, *tmp;
 710
 711         list_for_each_entry_safe(a, tmp, actions, list) {
 712                 list_del(&a->list);
 713                 kfree(a);
 714         }
 715 }
 716
 717 static struct tc_action *create_a(int i)
 718 {
 719         struct tc_action *act;
 720
 721         act = kzalloc(sizeof(*act), GFP_KERNEL);
 722         if (act == NULL) {
 723                 pr_debug("create_a: failed to alloc!\n");
 724                 return NULL;
 725         }
 726         act->order = i;
 727         INIT_LIST_HEAD(&act->list);
 728         return act;
 729 }
 730
 731 static int tca_action_flush(struct net *net, struct nlattr *nla,
 732                             struct nlmsghdr *n, u32 portid)
 733 {
 734         struct sk_buff *skb;
 735         unsigned char *b;
 736         struct nlmsghdr *nlh;
 737         struct tcamsg *t;
 738         struct netlink_callback dcb;
 739         struct nlattr *nest;
 740         struct nlattr *tb[TCA_ACT_MAX + 1];
 741         struct nlattr *kind;
 742         struct tc_action *a = create_a(0);
 743         int err = -ENOMEM;
 744
 745         if (a == NULL) {
 746                 pr_debug("tca_action_flush: couldnt create tc_action\n");
 747                 return err;
 748         }
 749
 750         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 751         if (!skb) {
 752                 pr_debug("tca_action_flush: failed skb alloc\n");
 753                 kfree(a);
 754                 return err;
 755         }
 756
 757         b = skb_tail_pointer(skb);
 758
 759         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 760         if (err < 0)
 761                 goto err_out;
 762
 763         err = -EINVAL;
 764         kind = tb[TCA_ACT_KIND];
 765         a->ops = tc_lookup_action(kind);
 766         if (a->ops == NULL) /*some idjot trying to flush unknown action */
 767                 goto err_out;
 768
 769         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t), 0);
 770         if (!nlh)
 771                 goto out_module_put;
 772         t = nlmsg_data(nlh);
 773         t->tca_family = AF_UNSPEC;
 774         t->tca__pad1 = 0;
 775         t->tca__pad2 = 0;
 776
 777         nest = nla_nest_start(skb, TCA_ACT_TAB);
 778         if (nest == NULL)
 779                 goto out_module_put;
 780
 781         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 782         if (err < 0)
 783                 goto out_module_put;
 784         if (err == 0)
 785                 goto noflush_out;
 786
 787         nla_nest_end(skb, nest);
 788
 789         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 790         nlh->nlmsg_flags |= NLM_F_ROOT;
 791         module_put(a->ops->owner);
 792         kfree(a);
 793         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 794                              n->nlmsg_flags & NLM_F_ECHO);
 795         if (err > 0)
 796                 return 0;
 797
 798         return err;
 799
 800 out_module_put:
 801         module_put(a->ops->owner);
 802 err_out:
 803 noflush_out:
 804         kfree_skb(skb);
 805         kfree(a);
 806         return err;
 807 }
 808
 809 static int
 810 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
 811                u32 portid)
 812 {
 813         int ret;
 814         struct sk_buff *skb;
 815
 816         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 817         if (!skb)
 818                 return -ENOBUFS;
 819
 820         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
 821                          0, 1) <= 0) {
 822                 kfree_skb(skb);
 823                 return -EINVAL;
 824         }
 825
 826         /* now do the delete */
 827         tcf_action_destroy(actions, 0);
 828
 829         ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 830                              n->nlmsg_flags & NLM_F_ECHO);
 831         if (ret > 0)
 832                 return 0;
 833         return ret;
 834 }
 835
 836 static int
 837 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 838               u32 portid, int event)
 839 {
 840         int i, ret;
 841         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 842         struct tc_action *act;
 843         LIST_HEAD(actions);
 844
 845         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 846         if (ret < 0)
 847                 return ret;
 848
 849         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
 850                 if (tb[1] != NULL)
 851                         return tca_action_flush(net, tb[1], n, portid);
 852                 else
 853                         return -EINVAL;
 854         }
 855
 856         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 857                 act = tcf_action_get_1(tb[i], n, portid);
 858                 if (IS_ERR(act)) {
 859                         ret = PTR_ERR(act);
 860                         goto err;
 861                 }
 862                 act->order = i;
 863                 list_add_tail(&act->list, &actions);
 864         }
 865
 866         if (event == RTM_GETACTION)
 867                 ret = act_get_notify(net, portid, n, &actions, event);
 868         else { /* delete */
 869                 ret = tcf_del_notify(net, n, &actions, portid);
 870                 if (ret)
 871                         goto err;
 872                 return ret;
 873         }
 874 err:
 875         cleanup_a(&actions);
 876         return ret;
 877 }
 878
 879 static int
 880 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
 881                u32 portid)
 882 {
 883         struct sk_buff *skb;
 884         int err = 0;
 885
 886         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 887         if (!skb)
 888                 return -ENOBUFS;
 889
 890         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
 891                          RTM_NEWACTION, 0, 0) <= 0) {
 892                 kfree_skb(skb);
 893                 return -EINVAL;
 894         }
 895
 896         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 897                              n->nlmsg_flags & NLM_F_ECHO);
 898         if (err > 0)
 899                 err = 0;
 900         return err;
 901 }
 902
 903 static int
 904 tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 905                u32 portid, int ovr)
 906 {
 907         int ret = 0;
 908         LIST_HEAD(actions);
 909
 910         ret = tcf_action_init(net, nla, NULL, NULL, ovr, 0, &actions);
 911         if (ret)
 912                 goto done;
 913
 914         /* dump then free all the actions after update; inserted policy
 915          * stays intact
 916          */
 917         ret = tcf_add_notify(net, n, &actions, portid);
 918         cleanup_a(&actions);
 919 done:
 920         return ret;
 921 }
 922
 923 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n)
 924 {
 925         struct net *net = sock_net(skb->sk);
 926         struct nlattr *tca[TCA_ACT_MAX + 1];
 927         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
 928         int ret = 0, ovr = 0;
 929
 930         if ((n->nlmsg_type != RTM_GETACTION) && !capable(CAP_NET_ADMIN))
 931                 return -EPERM;
 932
 933         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
 934         if (ret < 0)
 935                 return ret;
 936
 937         if (tca[TCA_ACT_TAB] == NULL) {
 938                 pr_notice("tc_ctl_action: received NO action attribs\n");
 939                 return -EINVAL;
 940         }
 941
 942         /* n->nlmsg_flags & NLM_F_CREATE */
 943         switch (n->nlmsg_type) {
 944         case RTM_NEWACTION:
 945                 /* we are going to assume all other flags
 946                  * imply create only if it doesn't exist
 947                  * Note that CREATE | EXCL implies that
 948                  * but since we want avoid ambiguity (eg when flags
 949                  * is zero) then just set this
 950                  */
 951                 if (n->nlmsg_flags & NLM_F_REPLACE)
 952                         ovr = 1;
 953 replay:
 954                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr);
 955                 if (ret == -EAGAIN)
 956                         goto replay;
 957                 break;
 958         case RTM_DELACTION:
 959                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
 960                                     portid, RTM_DELACTION);
 961                 break;
 962         case RTM_GETACTION:
 963                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
 964                                     portid, RTM_GETACTION);
 965                 break;
 966         default:
 967                 BUG();
 968         }
 969
 970         return ret;
 971 }
 972
 973 static struct nlattr *
 974 find_dump_kind(const struct nlmsghdr *n)
 975 {
 976         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
 977         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 978         struct nlattr *nla[TCAA_MAX + 1];
 979         struct nlattr *kind;
 980
 981         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
 982                 return NULL;
 983         tb1 = nla[TCA_ACT_TAB];
 984         if (tb1 == NULL)
 985                 return NULL;
 986
 987         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
 988                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
 989                 return NULL;
 990
 991         if (tb[1] == NULL)
 992                 return NULL;
 993         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
 994                       nla_len(tb[1]), NULL) < 0)
 995                 return NULL;
 996         kind = tb2[TCA_ACT_KIND];
 997
 998         return kind;
 999 }
1000
1001 static int
1002 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1003 {
1004         struct nlmsghdr *nlh;
1005         unsigned char *b = skb_tail_pointer(skb);
1006         struct nlattr *nest;
1007         struct tc_action_ops *a_o;
1008         struct tc_action a;
1009         int ret = 0;
1010         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1011         struct nlattr *kind = find_dump_kind(cb->nlh);
1012
1013         if (kind == NULL) {
1014                 pr_info("tc_dump_action: action bad kind\n");
1015                 return 0;
1016         }
1017
1018         a_o = tc_lookup_action(kind);
1019         if (a_o == NULL)
1020                 return 0;
1021
1022         memset(&a, 0, sizeof(struct tc_action));
1023         a.ops = a_o;
1024
1025         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1026                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1027         if (!nlh)
1028                 goto out_module_put;
1029         t = nlmsg_data(nlh);
1030         t->tca_family = AF_UNSPEC;
1031         t->tca__pad1 = 0;
1032         t->tca__pad2 = 0;
1033
1034         nest = nla_nest_start(skb, TCA_ACT_TAB);
1035         if (nest == NULL)
1036                 goto out_module_put;
1037
1038         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1039         if (ret < 0)
1040                 goto out_module_put;
1041
1042         if (ret > 0) {
1043                 nla_nest_end(skb, nest);
1044                 ret = skb->len;
1045         } else
1046                 nla_nest_cancel(skb, nest);
1047
1048         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1049         if (NETLINK_CB(cb->skb).portid && ret)
1050                 nlh->nlmsg_flags |= NLM_F_MULTI;
1051         module_put(a_o->owner);
1052         return skb->len;
1053
1054 out_module_put:
1055         module_put(a_o->owner);
1056         nlmsg_trim(skb, b);
1057         return skb->len;
1058 }
1059
1060 static int __init tc_action_init(void)
1061 {
1062         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
1063         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
1064         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1065                       NULL);
1066
1067         return 0;
1068 }
1069
1070 subsys_initcall(tc_action_init);