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