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