kernel/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, bool bind, bool strict)
  49 {
  50         struct tcf_common *p = a->priv;
  51         int ret = 0;
  52
  53         if (p) {
  54                 if (bind)
  55                         p->tcfc_bindcnt--;
  56                 else if (strict && p->tcfc_bindcnt > 0)
  57                         return -EPERM;
  58
  59                 p->tcfc_refcnt--;
  60                 if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
  61                         if (a->ops->cleanup)
  62                                 a->ops->cleanup(a, bind);
  63                         tcf_hash_destroy(a);
  64                         ret = 1;
  65                 }
  66         }
  67
  68         return ret;
  69 }
  70 EXPORT_SYMBOL(__tcf_hash_release);
  71
  72 static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
  73                            struct tc_action *a)
  74 {
  75         struct tcf_hashinfo *hinfo = a->ops->hinfo;
  76         struct hlist_head *head;
  77         struct tcf_common *p;
  78         int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
  79         struct nlattr *nest;
  80
  81         spin_lock_bh(&hinfo->lock);
  82
  83         s_i = cb->args[0];
  84
  85         for (i = 0; i < (hinfo->hmask + 1); i++) {
  86                 head = &hinfo->htab[tcf_hash(i, hinfo->hmask)];
  87
  88                 hlist_for_each_entry_rcu(p, head, tcfc_head) {
  89                         index++;
  90                         if (index < s_i)
  91                                 continue;
  92                         a->priv = p;
  93                         a->order = n_i;
  94
  95                         nest = nla_nest_start(skb, a->order);
  96                         if (nest == NULL)
  97                                 goto nla_put_failure;
  98                         err = tcf_action_dump_1(skb, a, 0, 0);
  99                         if (err < 0) {
 100                                 index--;
 101                                 nlmsg_trim(skb, nest);
 102                                 goto done;
 103                         }
 104                         nla_nest_end(skb, nest);
 105                         n_i++;
 106                         if (n_i >= TCA_ACT_MAX_PRIO)
 107                                 goto done;
 108                 }
 109         }
 110 done:
 111         spin_unlock_bh(&hinfo->lock);
 112         if (n_i)
 113                 cb->args[0] += n_i;
 114         return n_i;
 115
 116 nla_put_failure:
 117         nla_nest_cancel(skb, nest);
 118         goto done;
 119 }
 120
 121 static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a)
 122 {
 123         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 124         struct hlist_head *head;
 125         struct hlist_node *n;
 126         struct tcf_common *p;
 127         struct nlattr *nest;
 128         int i = 0, n_i = 0;
 129         int ret = -EINVAL;
 130
 131         nest = nla_nest_start(skb, a->order);
 132         if (nest == NULL)
 133                 goto nla_put_failure;
 134         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 135                 goto nla_put_failure;
 136         for (i = 0; i < (hinfo->hmask + 1); i++) {
 137                 head = &hinfo->htab[tcf_hash(i, hinfo->hmask)];
 138                 hlist_for_each_entry_safe(p, n, head, tcfc_head) {
 139                         a->priv = p;
 140                         ret = __tcf_hash_release(a, false, true);
 141                         if (ret == ACT_P_DELETED) {
 142                                 module_put(a->ops->owner);
 143                                 n_i++;
 144                         } else if (ret < 0)
 145                                 goto nla_put_failure;
 146                 }
 147         }
 148         if (nla_put_u32(skb, TCA_FCNT, n_i))
 149                 goto nla_put_failure;
 150         nla_nest_end(skb, nest);
 151
 152         return n_i;
 153 nla_put_failure:
 154         nla_nest_cancel(skb, nest);
 155         return ret;
 156 }
 157
 158 static int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
 159                               int type, struct tc_action *a)
 160 {
 161         if (type == RTM_DELACTION) {
 162                 return tcf_del_walker(skb, a);
 163         } else if (type == RTM_GETACTION) {
 164                 return tcf_dump_walker(skb, cb, a);
 165         } else {
 166                 WARN(1, "tcf_generic_walker: unknown action %d\n", type);
 167                 return -EINVAL;
 168         }
 169 }
 170
 171 static struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 172 {
 173         struct tcf_common *p = NULL;
 174         struct hlist_head *head;
 175
 176         spin_lock_bh(&hinfo->lock);
 177         head = &hinfo->htab[tcf_hash(index, hinfo->hmask)];
 178         hlist_for_each_entry_rcu(p, head, tcfc_head)
 179                 if (p->tcfc_index == index)
 180                         break;
 181         spin_unlock_bh(&hinfo->lock);
 182
 183         return p;
 184 }
 185
 186 u32 tcf_hash_new_index(struct tcf_hashinfo *hinfo)
 187 {
 188         u32 val = hinfo->index;
 189
 190         do {
 191                 if (++val == 0)
 192                         val = 1;
 193         } while (tcf_hash_lookup(val, hinfo));
 194
 195         hinfo->index = val;
 196         return val;
 197 }
 198 EXPORT_SYMBOL(tcf_hash_new_index);
 199
 200 int tcf_hash_search(struct tc_action *a, u32 index)
 201 {
 202         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 203         struct tcf_common *p = tcf_hash_lookup(index, hinfo);
 204
 205         if (p) {
 206                 a->priv = p;
 207                 return 1;
 208         }
 209         return 0;
 210 }
 211 EXPORT_SYMBOL(tcf_hash_search);
 212
 213 int tcf_hash_check(u32 index, struct tc_action *a, int bind)
 214 {
 215         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 216         struct tcf_common *p = NULL;
 217         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 218                 if (bind)
 219                         p->tcfc_bindcnt++;
 220                 p->tcfc_refcnt++;
 221                 a->priv = p;
 222                 return 1;
 223         }
 224         return 0;
 225 }
 226 EXPORT_SYMBOL(tcf_hash_check);
 227
 228 void tcf_hash_cleanup(struct tc_action *a, struct nlattr *est)
 229 {
 230         struct tcf_common *pc = a->priv;
 231         if (est)
 232                 gen_kill_estimator(&pc->tcfc_bstats,
 233                                    &pc->tcfc_rate_est);
 234         kfree_rcu(pc, tcfc_rcu);
 235 }
 236 EXPORT_SYMBOL(tcf_hash_cleanup);
 237
 238 int tcf_hash_create(u32 index, struct nlattr *est, struct tc_action *a,
 239                     int size, int bind)
 240 {
 241         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 242         struct tcf_common *p = kzalloc(size, GFP_KERNEL);
 243
 244         if (unlikely(!p))
 245                 return -ENOMEM;
 246         p->tcfc_refcnt = 1;
 247         if (bind)
 248                 p->tcfc_bindcnt = 1;
 249
 250         spin_lock_init(&p->tcfc_lock);
 251         INIT_HLIST_NODE(&p->tcfc_head);
 252         p->tcfc_index = index ? index : tcf_hash_new_index(hinfo);
 253         p->tcfc_tm.install = jiffies;
 254         p->tcfc_tm.lastuse = jiffies;
 255         if (est) {
 256                 int err = gen_new_estimator(&p->tcfc_bstats, NULL,
 257                                             &p->tcfc_rate_est,
 258                                             &p->tcfc_lock, est);
 259                 if (err) {
 260                         kfree(p);
 261                         return err;
 262                 }
 263         }
 264
 265         a->priv = (void *) p;
 266         return 0;
 267 }
 268 EXPORT_SYMBOL(tcf_hash_create);
 269
 270 void tcf_hash_insert(struct tc_action *a)
 271 {
 272         struct tcf_common *p = a->priv;
 273         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 274         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
 275
 276         spin_lock_bh(&hinfo->lock);
 277         hlist_add_head(&p->tcfc_head, &hinfo->htab[h]);
 278         spin_unlock_bh(&hinfo->lock);
 279 }
 280 EXPORT_SYMBOL(tcf_hash_insert);
 281
 282 static LIST_HEAD(act_base);
 283 static DEFINE_RWLOCK(act_mod_lock);
 284
 285 int tcf_register_action(struct tc_action_ops *act, unsigned int mask)
 286 {
 287         struct tc_action_ops *a;
 288         int err;
 289
 290         /* Must supply act, dump and init */
 291         if (!act->act || !act->dump || !act->init)
 292                 return -EINVAL;
 293
 294         /* Supply defaults */
 295         if (!act->lookup)
 296                 act->lookup = tcf_hash_search;
 297         if (!act->walk)
 298                 act->walk = tcf_generic_walker;
 299
 300         act->hinfo = kmalloc(sizeof(struct tcf_hashinfo), GFP_KERNEL);
 301         if (!act->hinfo)
 302                 return -ENOMEM;
 303         err = tcf_hashinfo_init(act->hinfo, mask);
 304         if (err) {
 305                 kfree(act->hinfo);
 306                 return err;
 307         }
 308
 309         write_lock(&act_mod_lock);
 310         list_for_each_entry(a, &act_base, head) {
 311                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 312                         write_unlock(&act_mod_lock);
 313                         tcf_hashinfo_destroy(act->hinfo);
 314                         kfree(act->hinfo);
 315                         return -EEXIST;
 316                 }
 317         }
 318         list_add_tail(&act->head, &act_base);
 319         write_unlock(&act_mod_lock);
 320         return 0;
 321 }
 322 EXPORT_SYMBOL(tcf_register_action);
 323
 324 int tcf_unregister_action(struct tc_action_ops *act)
 325 {
 326         struct tc_action_ops *a;
 327         int err = -ENOENT;
 328
 329         write_lock(&act_mod_lock);
 330         list_for_each_entry(a, &act_base, head) {
 331                 if (a == act) {
 332                         list_del(&act->head);
 333                         tcf_hashinfo_destroy(act->hinfo);
 334                         kfree(act->hinfo);
 335                         err = 0;
 336                         break;
 337                 }
 338         }
 339         write_unlock(&act_mod_lock);
 340         return err;
 341 }
 342 EXPORT_SYMBOL(tcf_unregister_action);
 343
 344 /* lookup by name */
 345 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 346 {
 347         struct tc_action_ops *a, *res = NULL;
 348
 349         if (kind) {
 350                 read_lock(&act_mod_lock);
 351                 list_for_each_entry(a, &act_base, head) {
 352                         if (strcmp(kind, a->kind) == 0) {
 353                                 if (try_module_get(a->owner))
 354                                         res = a;
 355                                 break;
 356                         }
 357                 }
 358                 read_unlock(&act_mod_lock);
 359         }
 360         return res;
 361 }
 362
 363 /* lookup by nlattr */
 364 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 365 {
 366         struct tc_action_ops *a, *res = NULL;
 367
 368         if (kind) {
 369                 read_lock(&act_mod_lock);
 370                 list_for_each_entry(a, &act_base, head) {
 371                         if (nla_strcmp(kind, a->kind) == 0) {
 372                                 if (try_module_get(a->owner))
 373                                         res = a;
 374                                 break;
 375                         }
 376                 }
 377                 read_unlock(&act_mod_lock);
 378         }
 379         return res;
 380 }
 381
 382 int tcf_action_exec(struct sk_buff *skb, const struct list_head *actions,
 383                     struct tcf_result *res)
 384 {
 385         const struct tc_action *a;
 386         int ret = -1;
 387
 388         if (skb->tc_verd & TC_NCLS) {
 389                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 390                 ret = TC_ACT_OK;
 391                 goto exec_done;
 392         }
 393         list_for_each_entry(a, actions, list) {
 394 repeat:
 395                 ret = a->ops->act(skb, a, res);
 396                 if (TC_MUNGED & skb->tc_verd) {
 397                         /* copied already, allow trampling */
 398                         skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
 399                         skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
 400                 }
 401                 if (ret == TC_ACT_REPEAT)
 402                         goto repeat;    /* we need a ttl - JHS */
 403                 if (ret != TC_ACT_PIPE)
 404                         goto exec_done;
 405         }
 406 exec_done:
 407         return ret;
 408 }
 409 EXPORT_SYMBOL(tcf_action_exec);
 410
 411 int tcf_action_destroy(struct list_head *actions, int bind)
 412 {
 413         struct tc_action *a, *tmp;
 414         int ret = 0;
 415
 416         list_for_each_entry_safe(a, tmp, actions, list) {
 417                 ret = __tcf_hash_release(a, bind, true);
 418                 if (ret == ACT_P_DELETED)
 419                         module_put(a->ops->owner);
 420                 else if (ret < 0)
 421                         return ret;
 422                 list_del(&a->list);
 423                 kfree(a);
 424         }
 425         return ret;
 426 }
 427
 428 int
 429 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 430 {
 431         return a->ops->dump(skb, a, bind, ref);
 432 }
 433
 434 int
 435 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 436 {
 437         int err = -EINVAL;
 438         unsigned char *b = skb_tail_pointer(skb);
 439         struct nlattr *nest;
 440
 441         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 442                 goto nla_put_failure;
 443         if (tcf_action_copy_stats(skb, a, 0))
 444                 goto nla_put_failure;
 445         nest = nla_nest_start(skb, TCA_OPTIONS);
 446         if (nest == NULL)
 447                 goto nla_put_failure;
 448         err = tcf_action_dump_old(skb, a, bind, ref);
 449         if (err > 0) {
 450                 nla_nest_end(skb, nest);
 451                 return err;
 452         }
 453
 454 nla_put_failure:
 455         nlmsg_trim(skb, b);
 456         return -1;
 457 }
 458 EXPORT_SYMBOL(tcf_action_dump_1);
 459
 460 int
 461 tcf_action_dump(struct sk_buff *skb, struct list_head *actions, int bind, int ref)
 462 {
 463         struct tc_action *a;
 464         int err = -EINVAL;
 465         struct nlattr *nest;
 466
 467         list_for_each_entry(a, actions, list) {
 468                 nest = nla_nest_start(skb, a->order);
 469                 if (nest == NULL)
 470                         goto nla_put_failure;
 471                 err = tcf_action_dump_1(skb, a, bind, ref);
 472                 if (err < 0)
 473                         goto errout;
 474                 nla_nest_end(skb, nest);
 475         }
 476
 477         return 0;
 478
 479 nla_put_failure:
 480         err = -EINVAL;
 481 errout:
 482         nla_nest_cancel(skb, nest);
 483         return err;
 484 }
 485
 486 struct tc_action *tcf_action_init_1(struct net *net, struct nlattr *nla,
 487                                     struct nlattr *est, char *name, int ovr,
 488                                     int bind)
 489 {
 490         struct tc_action *a;
 491         struct tc_action_ops *a_o;
 492         char act_name[IFNAMSIZ];
 493         struct nlattr *tb[TCA_ACT_MAX + 1];
 494         struct nlattr *kind;
 495         int err;
 496
 497         if (name == NULL) {
 498                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 499                 if (err < 0)
 500                         goto err_out;
 501                 err = -EINVAL;
 502                 kind = tb[TCA_ACT_KIND];
 503                 if (kind == NULL)
 504                         goto err_out;
 505                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 506                         goto err_out;
 507         } else {
 508                 err = -EINVAL;
 509                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 510                         goto err_out;
 511         }
 512
 513         a_o = tc_lookup_action_n(act_name);
 514         if (a_o == NULL) {
 515 #ifdef CONFIG_MODULES
 516                 rtnl_unlock();
 517                 request_module("act_%s", act_name);
 518                 rtnl_lock();
 519
 520                 a_o = tc_lookup_action_n(act_name);
 521
 522                 /* We dropped the RTNL semaphore in order to
 523                  * perform the module load.  So, even if we
 524                  * succeeded in loading the module we have to
 525                  * tell the caller to replay the request.  We
 526                  * indicate this using -EAGAIN.
 527                  */
 528                 if (a_o != NULL) {
 529                         err = -EAGAIN;
 530                         goto err_mod;
 531                 }
 532 #endif
 533                 err = -ENOENT;
 534                 goto err_out;
 535         }
 536
 537         err = -ENOMEM;
 538         a = kzalloc(sizeof(*a), GFP_KERNEL);
 539         if (a == NULL)
 540                 goto err_mod;
 541
 542         a->ops = a_o;
 543         INIT_LIST_HEAD(&a->list);
 544         /* backward compatibility for policer */
 545         if (name == NULL)
 546                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
 547         else
 548                 err = a_o->init(net, nla, est, a, ovr, bind);
 549         if (err < 0)
 550                 goto err_free;
 551
 552         /* module count goes up only when brand new policy is created
 553          * if it exists and is only bound to in a_o->init() then
 554          * ACT_P_CREATED is not returned (a zero is).
 555          */
 556         if (err != ACT_P_CREATED)
 557                 module_put(a_o->owner);
 558
 559         return a;
 560
 561 err_free:
 562         kfree(a);
 563 err_mod:
 564         module_put(a_o->owner);
 565 err_out:
 566         return ERR_PTR(err);
 567 }
 568
 569 int tcf_action_init(struct net *net, struct nlattr *nla,
 570                                   struct nlattr *est, char *name, int ovr,
 571                                   int bind, struct list_head *actions)
 572 {
 573         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 574         struct tc_action *act;
 575         int err;
 576         int i;
 577
 578         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 579         if (err < 0)
 580                 return err;
 581
 582         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 583                 act = tcf_action_init_1(net, tb[i], est, name, ovr, bind);
 584                 if (IS_ERR(act)) {
 585                         err = PTR_ERR(act);
 586                         goto err;
 587                 }
 588                 act->order = i;
 589                 list_add_tail(&act->list, actions);
 590         }
 591         return 0;
 592
 593 err:
 594         tcf_action_destroy(actions, bind);
 595         return err;
 596 }
 597
 598 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 599                           int compat_mode)
 600 {
 601         int err = 0;
 602         struct gnet_dump d;
 603         struct tcf_common *p = a->priv;
 604
 605         if (p == NULL)
 606                 goto errout;
 607
 608         /* compat_mode being true specifies a call that is supposed
 609          * to add additional backward compatibility statistic TLVs.
 610          */
 611         if (compat_mode) {
 612                 if (a->type == TCA_OLD_COMPAT)
 613                         err = gnet_stats_start_copy_compat(skb, 0,
 614                                 TCA_STATS, TCA_XSTATS, &p->tcfc_lock, &d);
 615                 else
 616                         return 0;
 617         } else
 618                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 619                                             &p->tcfc_lock, &d);
 620
 621         if (err < 0)
 622                 goto errout;
 623
 624         if (gnet_stats_copy_basic(&d, NULL, &p->tcfc_bstats) < 0 ||
 625             gnet_stats_copy_rate_est(&d, &p->tcfc_bstats,
 626                                      &p->tcfc_rate_est) < 0 ||
 627             gnet_stats_copy_queue(&d, NULL,
 628                                   &p->tcfc_qstats,
 629                                   p->tcfc_qstats.qlen) < 0)
 630                 goto errout;
 631
 632         if (gnet_stats_finish_copy(&d) < 0)
 633                 goto errout;
 634
 635         return 0;
 636
 637 errout:
 638         return -1;
 639 }
 640
 641 static int
 642 tca_get_fill(struct sk_buff *skb, struct list_head *actions, u32 portid, u32 seq,
 643              u16 flags, int event, int bind, int ref)
 644 {
 645         struct tcamsg *t;
 646         struct nlmsghdr *nlh;
 647         unsigned char *b = skb_tail_pointer(skb);
 648         struct nlattr *nest;
 649
 650         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
 651         if (!nlh)
 652                 goto out_nlmsg_trim;
 653         t = nlmsg_data(nlh);
 654         t->tca_family = AF_UNSPEC;
 655         t->tca__pad1 = 0;
 656         t->tca__pad2 = 0;
 657
 658         nest = nla_nest_start(skb, TCA_ACT_TAB);
 659         if (nest == NULL)
 660                 goto out_nlmsg_trim;
 661
 662         if (tcf_action_dump(skb, actions, bind, ref) < 0)
 663                 goto out_nlmsg_trim;
 664
 665         nla_nest_end(skb, nest);
 666
 667         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 668         return skb->len;
 669
 670 out_nlmsg_trim:
 671         nlmsg_trim(skb, b);
 672         return -1;
 673 }
 674
 675 static int
 676 act_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
 677                struct list_head *actions, int event)
 678 {
 679         struct sk_buff *skb;
 680
 681         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 682         if (!skb)
 683                 return -ENOBUFS;
 684         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 685                 kfree_skb(skb);
 686                 return -EINVAL;
 687         }
 688
 689         return rtnl_unicast(skb, net, portid);
 690 }
 691
 692 static struct tc_action *create_a(int i)
 693 {
 694         struct tc_action *act;
 695
 696         act = kzalloc(sizeof(*act), GFP_KERNEL);
 697         if (act == NULL) {
 698                 pr_debug("create_a: failed to alloc!\n");
 699                 return NULL;
 700         }
 701         act->order = i;
 702         INIT_LIST_HEAD(&act->list);
 703         return act;
 704 }
 705
 706 static struct tc_action *
 707 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 portid)
 708 {
 709         struct nlattr *tb[TCA_ACT_MAX + 1];
 710         struct tc_action *a;
 711         int index;
 712         int err;
 713
 714         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 715         if (err < 0)
 716                 goto err_out;
 717
 718         err = -EINVAL;
 719         if (tb[TCA_ACT_INDEX] == NULL ||
 720             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 721                 goto err_out;
 722         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 723
 724         err = -ENOMEM;
 725         a = create_a(0);
 726         if (a == NULL)
 727                 goto err_out;
 728
 729         err = -EINVAL;
 730         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 731         if (a->ops == NULL) /* could happen in batch of actions */
 732                 goto err_free;
 733         err = -ENOENT;
 734         if (a->ops->lookup(a, index) == 0)
 735                 goto err_mod;
 736
 737         module_put(a->ops->owner);
 738         return a;
 739
 740 err_mod:
 741         module_put(a->ops->owner);
 742 err_free:
 743         kfree(a);
 744 err_out:
 745         return ERR_PTR(err);
 746 }
 747
 748 static void cleanup_a(struct list_head *actions)
 749 {
 750         struct tc_action *a, *tmp;
 751
 752         list_for_each_entry_safe(a, tmp, actions, list) {
 753                 list_del(&a->list);
 754                 kfree(a);
 755         }
 756 }
 757
 758 static int tca_action_flush(struct net *net, struct nlattr *nla,
 759                             struct nlmsghdr *n, u32 portid)
 760 {
 761         struct sk_buff *skb;
 762         unsigned char *b;
 763         struct nlmsghdr *nlh;
 764         struct tcamsg *t;
 765         struct netlink_callback dcb;
 766         struct nlattr *nest;
 767         struct nlattr *tb[TCA_ACT_MAX + 1];
 768         struct nlattr *kind;
 769         struct tc_action a;
 770         int err = -ENOMEM;
 771
 772         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 773         if (!skb) {
 774                 pr_debug("tca_action_flush: failed skb alloc\n");
 775                 return err;
 776         }
 777
 778         b = skb_tail_pointer(skb);
 779
 780         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 781         if (err < 0)
 782                 goto err_out;
 783
 784         err = -EINVAL;
 785         kind = tb[TCA_ACT_KIND];
 786         memset(&a, 0, sizeof(struct tc_action));
 787         INIT_LIST_HEAD(&a.list);
 788         a.ops = tc_lookup_action(kind);
 789         if (a.ops == NULL) /*some idjot trying to flush unknown action */
 790                 goto err_out;
 791
 792         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t), 0);
 793         if (!nlh)
 794                 goto out_module_put;
 795         t = nlmsg_data(nlh);
 796         t->tca_family = AF_UNSPEC;
 797         t->tca__pad1 = 0;
 798         t->tca__pad2 = 0;
 799
 800         nest = nla_nest_start(skb, TCA_ACT_TAB);
 801         if (nest == NULL)
 802                 goto out_module_put;
 803
 804         err = a.ops->walk(skb, &dcb, RTM_DELACTION, &a);
 805         if (err < 0)
 806                 goto out_module_put;
 807         if (err == 0)
 808                 goto noflush_out;
 809
 810         nla_nest_end(skb, nest);
 811
 812         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 813         nlh->nlmsg_flags |= NLM_F_ROOT;
 814         module_put(a.ops->owner);
 815         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 816                              n->nlmsg_flags & NLM_F_ECHO);
 817         if (err > 0)
 818                 return 0;
 819
 820         return err;
 821
 822 out_module_put:
 823         module_put(a.ops->owner);
 824 err_out:
 825 noflush_out:
 826         kfree_skb(skb);
 827         return err;
 828 }
 829
 830 static int
 831 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
 832                u32 portid)
 833 {
 834         int ret;
 835         struct sk_buff *skb;
 836
 837         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 838         if (!skb)
 839                 return -ENOBUFS;
 840
 841         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
 842                          0, 1) <= 0) {
 843                 kfree_skb(skb);
 844                 return -EINVAL;
 845         }
 846
 847         /* now do the delete */
 848         ret = tcf_action_destroy(actions, 0);
 849         if (ret < 0) {
 850                 kfree_skb(skb);
 851                 return ret;
 852         }
 853
 854         ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 855                              n->nlmsg_flags & NLM_F_ECHO);
 856         if (ret > 0)
 857                 return 0;
 858         return ret;
 859 }
 860
 861 static int
 862 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 863               u32 portid, int event)
 864 {
 865         int i, ret;
 866         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 867         struct tc_action *act;
 868         LIST_HEAD(actions);
 869
 870         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 871         if (ret < 0)
 872                 return ret;
 873
 874         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
 875                 if (tb[1] != NULL)
 876                         return tca_action_flush(net, tb[1], n, portid);
 877                 else
 878                         return -EINVAL;
 879         }
 880
 881         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 882                 act = tcf_action_get_1(tb[i], n, portid);
 883                 if (IS_ERR(act)) {
 884                         ret = PTR_ERR(act);
 885                         goto err;
 886                 }
 887                 act->order = i;
 888                 list_add_tail(&act->list, &actions);
 889         }
 890
 891         if (event == RTM_GETACTION)
 892                 ret = act_get_notify(net, portid, n, &actions, event);
 893         else { /* delete */
 894                 ret = tcf_del_notify(net, n, &actions, portid);
 895                 if (ret)
 896                         goto err;
 897                 return ret;
 898         }
 899 err:
 900         cleanup_a(&actions);
 901         return ret;
 902 }
 903
 904 static int
 905 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
 906                u32 portid)
 907 {
 908         struct sk_buff *skb;
 909         int err = 0;
 910
 911         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 912         if (!skb)
 913                 return -ENOBUFS;
 914
 915         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
 916                          RTM_NEWACTION, 0, 0) <= 0) {
 917                 kfree_skb(skb);
 918                 return -EINVAL;
 919         }
 920
 921         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 922                              n->nlmsg_flags & NLM_F_ECHO);
 923         if (err > 0)
 924                 err = 0;
 925         return err;
 926 }
 927
 928 static int
 929 tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 930                u32 portid, int ovr)
 931 {
 932         int ret = 0;
 933         LIST_HEAD(actions);
 934
 935         ret = tcf_action_init(net, nla, NULL, NULL, ovr, 0, &actions);
 936         if (ret)
 937                 goto done;
 938
 939         /* dump then free all the actions after update; inserted policy
 940          * stays intact
 941          */
 942         ret = tcf_add_notify(net, n, &actions, portid);
 943         cleanup_a(&actions);
 944 done:
 945         return ret;
 946 }
 947
 948 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n)
 949 {
 950         struct net *net = sock_net(skb->sk);
 951         struct nlattr *tca[TCA_ACT_MAX + 1];
 952         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
 953         int ret = 0, ovr = 0;
 954
 955         if ((n->nlmsg_type != RTM_GETACTION) && !netlink_capable(skb, CAP_NET_ADMIN))
 956                 return -EPERM;
 957
 958         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
 959         if (ret < 0)
 960                 return ret;
 961
 962         if (tca[TCA_ACT_TAB] == NULL) {
 963                 pr_notice("tc_ctl_action: received NO action attribs\n");
 964                 return -EINVAL;
 965         }
 966
 967         /* n->nlmsg_flags & NLM_F_CREATE */
 968         switch (n->nlmsg_type) {
 969         case RTM_NEWACTION:
 970                 /* we are going to assume all other flags
 971                  * imply create only if it doesn't exist
 972                  * Note that CREATE | EXCL implies that
 973                  * but since we want avoid ambiguity (eg when flags
 974                  * is zero) then just set this
 975                  */
 976                 if (n->nlmsg_flags & NLM_F_REPLACE)
 977                         ovr = 1;
 978 replay:
 979                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr);
 980                 if (ret == -EAGAIN)
 981                         goto replay;
 982                 break;
 983         case RTM_DELACTION:
 984                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
 985                                     portid, RTM_DELACTION);
 986                 break;
 987         case RTM_GETACTION:
 988                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
 989                                     portid, RTM_GETACTION);
 990                 break;
 991         default:
 992                 BUG();
 993         }
 994
 995         return ret;
 996 }
 997
 998 static struct nlattr *
 999 find_dump_kind(const struct nlmsghdr *n)
1000 {
1001         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1002         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1003         struct nlattr *nla[TCAA_MAX + 1];
1004         struct nlattr *kind;
1005
1006         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1007                 return NULL;
1008         tb1 = nla[TCA_ACT_TAB];
1009         if (tb1 == NULL)
1010                 return NULL;
1011
1012         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1013                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1014                 return NULL;
1015
1016         if (tb[1] == NULL)
1017                 return NULL;
1018         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1019                       nla_len(tb[1]), NULL) < 0)
1020                 return NULL;
1021         kind = tb2[TCA_ACT_KIND];
1022
1023         return kind;
1024 }
1025
1026 static int
1027 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1028 {
1029         struct nlmsghdr *nlh;
1030         unsigned char *b = skb_tail_pointer(skb);
1031         struct nlattr *nest;
1032         struct tc_action_ops *a_o;
1033         struct tc_action a;
1034         int ret = 0;
1035         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1036         struct nlattr *kind = find_dump_kind(cb->nlh);
1037
1038         if (kind == NULL) {
1039                 pr_info("tc_dump_action: action bad kind\n");
1040                 return 0;
1041         }
1042
1043         a_o = tc_lookup_action(kind);
1044         if (a_o == NULL)
1045                 return 0;
1046
1047         memset(&a, 0, sizeof(struct tc_action));
1048         a.ops = a_o;
1049
1050         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1051                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1052         if (!nlh)
1053                 goto out_module_put;
1054         t = nlmsg_data(nlh);
1055         t->tca_family = AF_UNSPEC;
1056         t->tca__pad1 = 0;
1057         t->tca__pad2 = 0;
1058
1059         nest = nla_nest_start(skb, TCA_ACT_TAB);
1060         if (nest == NULL)
1061                 goto out_module_put;
1062
1063         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1064         if (ret < 0)
1065                 goto out_module_put;
1066
1067         if (ret > 0) {
1068                 nla_nest_end(skb, nest);
1069                 ret = skb->len;
1070         } else
1071                 nla_nest_cancel(skb, nest);
1072
1073         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1074         if (NETLINK_CB(cb->skb).portid && ret)
1075                 nlh->nlmsg_flags |= NLM_F_MULTI;
1076         module_put(a_o->owner);
1077         return skb->len;
1078
1079 out_module_put:
1080         module_put(a_o->owner);
1081         nlmsg_trim(skb, b);
1082         return skb->len;
1083 }
1084
1085 static int __init tc_action_init(void)
1086 {
1087         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
1088         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
1089         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1090                       NULL);
1091
1092         return 0;
1093 }
1094
1095 subsys_initcall(tc_action_init);