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 (ret == TC_ACT_REPEAT)
 397                         goto repeat;    /* we need a ttl - JHS */
 398                 if (ret != TC_ACT_PIPE)
 399                         goto exec_done;
 400         }
 401 exec_done:
 402         return ret;
 403 }
 404 EXPORT_SYMBOL(tcf_action_exec);
 405
 406 int tcf_action_destroy(struct list_head *actions, int bind)
 407 {
 408         struct tc_action *a, *tmp;
 409         int ret = 0;
 410
 411         list_for_each_entry_safe(a, tmp, actions, list) {
 412                 ret = __tcf_hash_release(a, bind, true);
 413                 if (ret == ACT_P_DELETED)
 414                         module_put(a->ops->owner);
 415                 else if (ret < 0)
 416                         return ret;
 417                 list_del(&a->list);
 418                 kfree(a);
 419         }
 420         return ret;
 421 }
 422
 423 int
 424 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 425 {
 426         return a->ops->dump(skb, a, bind, ref);
 427 }
 428
 429 int
 430 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 431 {
 432         int err = -EINVAL;
 433         unsigned char *b = skb_tail_pointer(skb);
 434         struct nlattr *nest;
 435
 436         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 437                 goto nla_put_failure;
 438         if (tcf_action_copy_stats(skb, a, 0))
 439                 goto nla_put_failure;
 440         nest = nla_nest_start(skb, TCA_OPTIONS);
 441         if (nest == NULL)
 442                 goto nla_put_failure;
 443         err = tcf_action_dump_old(skb, a, bind, ref);
 444         if (err > 0) {
 445                 nla_nest_end(skb, nest);
 446                 return err;
 447         }
 448
 449 nla_put_failure:
 450         nlmsg_trim(skb, b);
 451         return -1;
 452 }
 453 EXPORT_SYMBOL(tcf_action_dump_1);
 454
 455 int
 456 tcf_action_dump(struct sk_buff *skb, struct list_head *actions, int bind, int ref)
 457 {
 458         struct tc_action *a;
 459         int err = -EINVAL;
 460         struct nlattr *nest;
 461
 462         list_for_each_entry(a, actions, list) {
 463                 nest = nla_nest_start(skb, a->order);
 464                 if (nest == NULL)
 465                         goto nla_put_failure;
 466                 err = tcf_action_dump_1(skb, a, bind, ref);
 467                 if (err < 0)
 468                         goto errout;
 469                 nla_nest_end(skb, nest);
 470         }
 471
 472         return 0;
 473
 474 nla_put_failure:
 475         err = -EINVAL;
 476 errout:
 477         nla_nest_cancel(skb, nest);
 478         return err;
 479 }
 480
 481 struct tc_action *tcf_action_init_1(struct net *net, struct nlattr *nla,
 482                                     struct nlattr *est, char *name, int ovr,
 483                                     int bind)
 484 {
 485         struct tc_action *a;
 486         struct tc_action_ops *a_o;
 487         char act_name[IFNAMSIZ];
 488         struct nlattr *tb[TCA_ACT_MAX + 1];
 489         struct nlattr *kind;
 490         int err;
 491
 492         if (name == NULL) {
 493                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 494                 if (err < 0)
 495                         goto err_out;
 496                 err = -EINVAL;
 497                 kind = tb[TCA_ACT_KIND];
 498                 if (kind == NULL)
 499                         goto err_out;
 500                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 501                         goto err_out;
 502         } else {
 503                 err = -EINVAL;
 504                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 505                         goto err_out;
 506         }
 507
 508         a_o = tc_lookup_action_n(act_name);
 509         if (a_o == NULL) {
 510 #ifdef CONFIG_MODULES
 511                 rtnl_unlock();
 512                 request_module("act_%s", act_name);
 513                 rtnl_lock();
 514
 515                 a_o = tc_lookup_action_n(act_name);
 516
 517                 /* We dropped the RTNL semaphore in order to
 518                  * perform the module load.  So, even if we
 519                  * succeeded in loading the module we have to
 520                  * tell the caller to replay the request.  We
 521                  * indicate this using -EAGAIN.
 522                  */
 523                 if (a_o != NULL) {
 524                         err = -EAGAIN;
 525                         goto err_mod;
 526                 }
 527 #endif
 528                 err = -ENOENT;
 529                 goto err_out;
 530         }
 531
 532         err = -ENOMEM;
 533         a = kzalloc(sizeof(*a), GFP_KERNEL);
 534         if (a == NULL)
 535                 goto err_mod;
 536
 537         a->ops = a_o;
 538         INIT_LIST_HEAD(&a->list);
 539         /* backward compatibility for policer */
 540         if (name == NULL)
 541                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
 542         else
 543                 err = a_o->init(net, nla, est, a, ovr, bind);
 544         if (err < 0)
 545                 goto err_free;
 546
 547         /* module count goes up only when brand new policy is created
 548          * if it exists and is only bound to in a_o->init() then
 549          * ACT_P_CREATED is not returned (a zero is).
 550          */
 551         if (err != ACT_P_CREATED)
 552                 module_put(a_o->owner);
 553
 554         return a;
 555
 556 err_free:
 557         kfree(a);
 558 err_mod:
 559         module_put(a_o->owner);
 560 err_out:
 561         return ERR_PTR(err);
 562 }
 563
 564 int tcf_action_init(struct net *net, struct nlattr *nla,
 565                                   struct nlattr *est, char *name, int ovr,
 566                                   int bind, struct list_head *actions)
 567 {
 568         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 569         struct tc_action *act;
 570         int err;
 571         int i;
 572
 573         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 574         if (err < 0)
 575                 return err;
 576
 577         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 578                 act = tcf_action_init_1(net, tb[i], est, name, ovr, bind);
 579                 if (IS_ERR(act)) {
 580                         err = PTR_ERR(act);
 581                         goto err;
 582                 }
 583                 act->order = i;
 584                 list_add_tail(&act->list, actions);
 585         }
 586         return 0;
 587
 588 err:
 589         tcf_action_destroy(actions, bind);
 590         return err;
 591 }
 592
 593 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 594                           int compat_mode)
 595 {
 596         int err = 0;
 597         struct gnet_dump d;
 598         struct tcf_common *p = a->priv;
 599
 600         if (p == NULL)
 601                 goto errout;
 602
 603         /* compat_mode being true specifies a call that is supposed
 604          * to add additional backward compatibility statistic TLVs.
 605          */
 606         if (compat_mode) {
 607                 if (a->type == TCA_OLD_COMPAT)
 608                         err = gnet_stats_start_copy_compat(skb, 0,
 609                                 TCA_STATS, TCA_XSTATS, &p->tcfc_lock, &d);
 610                 else
 611                         return 0;
 612         } else
 613                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 614                                             &p->tcfc_lock, &d);
 615
 616         if (err < 0)
 617                 goto errout;
 618
 619         if (gnet_stats_copy_basic(&d, NULL, &p->tcfc_bstats) < 0 ||
 620             gnet_stats_copy_rate_est(&d, &p->tcfc_bstats,
 621                                      &p->tcfc_rate_est) < 0 ||
 622             gnet_stats_copy_queue(&d, NULL,
 623                                   &p->tcfc_qstats,
 624                                   p->tcfc_qstats.qlen) < 0)
 625                 goto errout;
 626
 627         if (gnet_stats_finish_copy(&d) < 0)
 628                 goto errout;
 629
 630         return 0;
 631
 632 errout:
 633         return -1;
 634 }
 635
 636 static int
 637 tca_get_fill(struct sk_buff *skb, struct list_head *actions, u32 portid, u32 seq,
 638              u16 flags, int event, int bind, int ref)
 639 {
 640         struct tcamsg *t;
 641         struct nlmsghdr *nlh;
 642         unsigned char *b = skb_tail_pointer(skb);
 643         struct nlattr *nest;
 644
 645         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
 646         if (!nlh)
 647                 goto out_nlmsg_trim;
 648         t = nlmsg_data(nlh);
 649         t->tca_family = AF_UNSPEC;
 650         t->tca__pad1 = 0;
 651         t->tca__pad2 = 0;
 652
 653         nest = nla_nest_start(skb, TCA_ACT_TAB);
 654         if (nest == NULL)
 655                 goto out_nlmsg_trim;
 656
 657         if (tcf_action_dump(skb, actions, bind, ref) < 0)
 658                 goto out_nlmsg_trim;
 659
 660         nla_nest_end(skb, nest);
 661
 662         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 663         return skb->len;
 664
 665 out_nlmsg_trim:
 666         nlmsg_trim(skb, b);
 667         return -1;
 668 }
 669
 670 static int
 671 act_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
 672                struct list_head *actions, int event)
 673 {
 674         struct sk_buff *skb;
 675
 676         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 677         if (!skb)
 678                 return -ENOBUFS;
 679         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 680                 kfree_skb(skb);
 681                 return -EINVAL;
 682         }
 683
 684         return rtnl_unicast(skb, net, portid);
 685 }
 686
 687 static struct tc_action *create_a(int i)
 688 {
 689         struct tc_action *act;
 690
 691         act = kzalloc(sizeof(*act), GFP_KERNEL);
 692         if (act == NULL) {
 693                 pr_debug("create_a: failed to alloc!\n");
 694                 return NULL;
 695         }
 696         act->order = i;
 697         INIT_LIST_HEAD(&act->list);
 698         return act;
 699 }
 700
 701 static struct tc_action *
 702 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 portid)
 703 {
 704         struct nlattr *tb[TCA_ACT_MAX + 1];
 705         struct tc_action *a;
 706         int index;
 707         int err;
 708
 709         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 710         if (err < 0)
 711                 goto err_out;
 712
 713         err = -EINVAL;
 714         if (tb[TCA_ACT_INDEX] == NULL ||
 715             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 716                 goto err_out;
 717         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 718
 719         err = -ENOMEM;
 720         a = create_a(0);
 721         if (a == NULL)
 722                 goto err_out;
 723
 724         err = -EINVAL;
 725         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 726         if (a->ops == NULL) /* could happen in batch of actions */
 727                 goto err_free;
 728         err = -ENOENT;
 729         if (a->ops->lookup(a, index) == 0)
 730                 goto err_mod;
 731
 732         module_put(a->ops->owner);
 733         return a;
 734
 735 err_mod:
 736         module_put(a->ops->owner);
 737 err_free:
 738         kfree(a);
 739 err_out:
 740         return ERR_PTR(err);
 741 }
 742
 743 static void cleanup_a(struct list_head *actions)
 744 {
 745         struct tc_action *a, *tmp;
 746
 747         list_for_each_entry_safe(a, tmp, actions, list) {
 748                 list_del(&a->list);
 749                 kfree(a);
 750         }
 751 }
 752
 753 static int tca_action_flush(struct net *net, struct nlattr *nla,
 754                             struct nlmsghdr *n, u32 portid)
 755 {
 756         struct sk_buff *skb;
 757         unsigned char *b;
 758         struct nlmsghdr *nlh;
 759         struct tcamsg *t;
 760         struct netlink_callback dcb;
 761         struct nlattr *nest;
 762         struct nlattr *tb[TCA_ACT_MAX + 1];
 763         struct nlattr *kind;
 764         struct tc_action a;
 765         int err = -ENOMEM;
 766
 767         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 768         if (!skb) {
 769                 pr_debug("tca_action_flush: failed skb alloc\n");
 770                 return err;
 771         }
 772
 773         b = skb_tail_pointer(skb);
 774
 775         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 776         if (err < 0)
 777                 goto err_out;
 778
 779         err = -EINVAL;
 780         kind = tb[TCA_ACT_KIND];
 781         memset(&a, 0, sizeof(struct tc_action));
 782         INIT_LIST_HEAD(&a.list);
 783         a.ops = tc_lookup_action(kind);
 784         if (a.ops == NULL) /*some idjot trying to flush unknown action */
 785                 goto err_out;
 786
 787         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t), 0);
 788         if (!nlh)
 789                 goto out_module_put;
 790         t = nlmsg_data(nlh);
 791         t->tca_family = AF_UNSPEC;
 792         t->tca__pad1 = 0;
 793         t->tca__pad2 = 0;
 794
 795         nest = nla_nest_start(skb, TCA_ACT_TAB);
 796         if (nest == NULL)
 797                 goto out_module_put;
 798
 799         err = a.ops->walk(skb, &dcb, RTM_DELACTION, &a);
 800         if (err < 0)
 801                 goto out_module_put;
 802         if (err == 0)
 803                 goto noflush_out;
 804
 805         nla_nest_end(skb, nest);
 806
 807         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 808         nlh->nlmsg_flags |= NLM_F_ROOT;
 809         module_put(a.ops->owner);
 810         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 811                              n->nlmsg_flags & NLM_F_ECHO);
 812         if (err > 0)
 813                 return 0;
 814
 815         return err;
 816
 817 out_module_put:
 818         module_put(a.ops->owner);
 819 err_out:
 820 noflush_out:
 821         kfree_skb(skb);
 822         return err;
 823 }
 824
 825 static int
 826 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
 827                u32 portid)
 828 {
 829         int ret;
 830         struct sk_buff *skb;
 831
 832         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 833         if (!skb)
 834                 return -ENOBUFS;
 835
 836         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
 837                          0, 1) <= 0) {
 838                 kfree_skb(skb);
 839                 return -EINVAL;
 840         }
 841
 842         /* now do the delete */
 843         ret = tcf_action_destroy(actions, 0);
 844         if (ret < 0) {
 845                 kfree_skb(skb);
 846                 return ret;
 847         }
 848
 849         ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 850                              n->nlmsg_flags & NLM_F_ECHO);
 851         if (ret > 0)
 852                 return 0;
 853         return ret;
 854 }
 855
 856 static int
 857 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 858               u32 portid, int event)
 859 {
 860         int i, ret;
 861         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 862         struct tc_action *act;
 863         LIST_HEAD(actions);
 864
 865         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 866         if (ret < 0)
 867                 return ret;
 868
 869         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
 870                 if (tb[1] != NULL)
 871                         return tca_action_flush(net, tb[1], n, portid);
 872                 else
 873                         return -EINVAL;
 874         }
 875
 876         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 877                 act = tcf_action_get_1(tb[i], n, portid);
 878                 if (IS_ERR(act)) {
 879                         ret = PTR_ERR(act);
 880                         goto err;
 881                 }
 882                 act->order = i;
 883                 list_add_tail(&act->list, &actions);
 884         }
 885
 886         if (event == RTM_GETACTION)
 887                 ret = act_get_notify(net, portid, n, &actions, event);
 888         else { /* delete */
 889                 ret = tcf_del_notify(net, n, &actions, portid);
 890                 if (ret)
 891                         goto err;
 892                 return ret;
 893         }
 894 err:
 895         cleanup_a(&actions);
 896         return ret;
 897 }
 898
 899 static int
 900 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
 901                u32 portid)
 902 {
 903         struct sk_buff *skb;
 904         int err = 0;
 905
 906         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 907         if (!skb)
 908                 return -ENOBUFS;
 909
 910         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
 911                          RTM_NEWACTION, 0, 0) <= 0) {
 912                 kfree_skb(skb);
 913                 return -EINVAL;
 914         }
 915
 916         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 917                              n->nlmsg_flags & NLM_F_ECHO);
 918         if (err > 0)
 919                 err = 0;
 920         return err;
 921 }
 922
 923 static int
 924 tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 925                u32 portid, int ovr)
 926 {
 927         int ret = 0;
 928         LIST_HEAD(actions);
 929
 930         ret = tcf_action_init(net, nla, NULL, NULL, ovr, 0, &actions);
 931         if (ret)
 932                 goto done;
 933
 934         /* dump then free all the actions after update; inserted policy
 935          * stays intact
 936          */
 937         ret = tcf_add_notify(net, n, &actions, portid);
 938         cleanup_a(&actions);
 939 done:
 940         return ret;
 941 }
 942
 943 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n)
 944 {
 945         struct net *net = sock_net(skb->sk);
 946         struct nlattr *tca[TCA_ACT_MAX + 1];
 947         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
 948         int ret = 0, ovr = 0;
 949
 950         if ((n->nlmsg_type != RTM_GETACTION) && !netlink_capable(skb, CAP_NET_ADMIN))
 951                 return -EPERM;
 952
 953         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
 954         if (ret < 0)
 955                 return ret;
 956
 957         if (tca[TCA_ACT_TAB] == NULL) {
 958                 pr_notice("tc_ctl_action: received NO action attribs\n");
 959                 return -EINVAL;
 960         }
 961
 962         /* n->nlmsg_flags & NLM_F_CREATE */
 963         switch (n->nlmsg_type) {
 964         case RTM_NEWACTION:
 965                 /* we are going to assume all other flags
 966                  * imply create only if it doesn't exist
 967                  * Note that CREATE | EXCL implies that
 968                  * but since we want avoid ambiguity (eg when flags
 969                  * is zero) then just set this
 970                  */
 971                 if (n->nlmsg_flags & NLM_F_REPLACE)
 972                         ovr = 1;
 973 replay:
 974                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr);
 975                 if (ret == -EAGAIN)
 976                         goto replay;
 977                 break;
 978         case RTM_DELACTION:
 979                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
 980                                     portid, RTM_DELACTION);
 981                 break;
 982         case RTM_GETACTION:
 983                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
 984                                     portid, RTM_GETACTION);
 985                 break;
 986         default:
 987                 BUG();
 988         }
 989
 990         return ret;
 991 }
 992
 993 static struct nlattr *
 994 find_dump_kind(const struct nlmsghdr *n)
 995 {
 996         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
 997         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 998         struct nlattr *nla[TCAA_MAX + 1];
 999         struct nlattr *kind;
1000
1001         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1002                 return NULL;
1003         tb1 = nla[TCA_ACT_TAB];
1004         if (tb1 == NULL)
1005                 return NULL;
1006
1007         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1008                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1009                 return NULL;
1010
1011         if (tb[1] == NULL)
1012                 return NULL;
1013         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1014                       nla_len(tb[1]), NULL) < 0)
1015                 return NULL;
1016         kind = tb2[TCA_ACT_KIND];
1017
1018         return kind;
1019 }
1020
1021 static int
1022 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1023 {
1024         struct nlmsghdr *nlh;
1025         unsigned char *b = skb_tail_pointer(skb);
1026         struct nlattr *nest;
1027         struct tc_action_ops *a_o;
1028         struct tc_action a;
1029         int ret = 0;
1030         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1031         struct nlattr *kind = find_dump_kind(cb->nlh);
1032
1033         if (kind == NULL) {
1034                 pr_info("tc_dump_action: action bad kind\n");
1035                 return 0;
1036         }
1037
1038         a_o = tc_lookup_action(kind);
1039         if (a_o == NULL)
1040                 return 0;
1041
1042         memset(&a, 0, sizeof(struct tc_action));
1043         a.ops = a_o;
1044
1045         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1046                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1047         if (!nlh)
1048                 goto out_module_put;
1049         t = nlmsg_data(nlh);
1050         t->tca_family = AF_UNSPEC;
1051         t->tca__pad1 = 0;
1052         t->tca__pad2 = 0;
1053
1054         nest = nla_nest_start(skb, TCA_ACT_TAB);
1055         if (nest == NULL)
1056                 goto out_module_put;
1057
1058         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1059         if (ret < 0)
1060                 goto out_module_put;
1061
1062         if (ret > 0) {
1063                 nla_nest_end(skb, nest);
1064                 ret = skb->len;
1065         } else
1066                 nla_nest_cancel(skb, nest);
1067
1068         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1069         if (NETLINK_CB(cb->skb).portid && ret)
1070                 nlh->nlmsg_flags |= NLM_F_MULTI;
1071         module_put(a_o->owner);
1072         return skb->len;
1073
1074 out_module_put:
1075         module_put(a_o->owner);
1076         nlmsg_trim(skb, b);
1077         return skb->len;
1078 }
1079
1080 static int __init tc_action_init(void)
1081 {
1082         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
1083         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
1084         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1085                       NULL);
1086
1087         return 0;
1088 }
1089
1090 subsys_initcall(tc_action_init);