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 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 EXPORT_SYMBOL(tcf_generic_walker);
 159
 160 struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 161 {
 162         struct tcf_common *p = NULL;
 163         struct hlist_head *head;
 164
 165         spin_lock_bh(&hinfo->lock);
 166         head = &hinfo->htab[tcf_hash(index, hinfo->hmask)];
 167         hlist_for_each_entry_rcu(p, head, tcfc_head)
 168                 if (p->tcfc_index == index)
 169                         break;
 170         spin_unlock_bh(&hinfo->lock);
 171
 172         return p;
 173 }
 174 EXPORT_SYMBOL(tcf_hash_lookup);
 175
 176 u32 tcf_hash_new_index(u32 *idx_gen, struct tcf_hashinfo *hinfo)
 177 {
 178         u32 val = *idx_gen;
 179
 180         do {
 181                 if (++val == 0)
 182                         val = 1;
 183         } while (tcf_hash_lookup(val, hinfo));
 184
 185         *idx_gen = val;
 186         return val;
 187 }
 188 EXPORT_SYMBOL(tcf_hash_new_index);
 189
 190 int tcf_hash_search(struct tc_action *a, u32 index)
 191 {
 192         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 193         struct tcf_common *p = tcf_hash_lookup(index, hinfo);
 194
 195         if (p) {
 196                 a->priv = p;
 197                 return 1;
 198         }
 199         return 0;
 200 }
 201 EXPORT_SYMBOL(tcf_hash_search);
 202
 203 struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
 204                                   struct tcf_hashinfo *hinfo)
 205 {
 206         struct tcf_common *p = NULL;
 207         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 208                 if (bind)
 209                         p->tcfc_bindcnt++;
 210                 p->tcfc_refcnt++;
 211                 a->priv = p;
 212         }
 213         return p;
 214 }
 215 EXPORT_SYMBOL(tcf_hash_check);
 216
 217 struct tcf_common *tcf_hash_create(u32 index, struct nlattr *est,
 218                                    struct tc_action *a, int size, int bind,
 219                                    u32 *idx_gen, struct tcf_hashinfo *hinfo)
 220 {
 221         struct tcf_common *p = kzalloc(size, GFP_KERNEL);
 222
 223         if (unlikely(!p))
 224                 return ERR_PTR(-ENOMEM);
 225         p->tcfc_refcnt = 1;
 226         if (bind)
 227                 p->tcfc_bindcnt = 1;
 228
 229         spin_lock_init(&p->tcfc_lock);
 230         INIT_HLIST_NODE(&p->tcfc_head);
 231         p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
 232         p->tcfc_tm.install = jiffies;
 233         p->tcfc_tm.lastuse = jiffies;
 234         if (est) {
 235                 int err = gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
 236                                             &p->tcfc_lock, est);
 237                 if (err) {
 238                         kfree(p);
 239                         return ERR_PTR(err);
 240                 }
 241         }
 242
 243         a->priv = (void *) p;
 244         return p;
 245 }
 246 EXPORT_SYMBOL(tcf_hash_create);
 247
 248 void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
 249 {
 250         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
 251
 252         spin_lock_bh(&hinfo->lock);
 253         hlist_add_head(&p->tcfc_head, &hinfo->htab[h]);
 254         spin_unlock_bh(&hinfo->lock);
 255 }
 256 EXPORT_SYMBOL(tcf_hash_insert);
 257
 258 static LIST_HEAD(act_base);
 259 static DEFINE_RWLOCK(act_mod_lock);
 260
 261 int tcf_register_action(struct tc_action_ops *act)
 262 {
 263         struct tc_action_ops *a;
 264
 265         /* Must supply act, dump, cleanup and init */
 266         if (!act->act || !act->dump || !act->cleanup || !act->init)
 267                 return -EINVAL;
 268
 269         /* Supply defaults */
 270         if (!act->lookup)
 271                 act->lookup = tcf_hash_search;
 272         if (!act->walk)
 273                 act->walk = tcf_generic_walker;
 274
 275         write_lock(&act_mod_lock);
 276         list_for_each_entry(a, &act_base, head) {
 277                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 278                         write_unlock(&act_mod_lock);
 279                         return -EEXIST;
 280                 }
 281         }
 282         list_add_tail(&act->head, &act_base);
 283         write_unlock(&act_mod_lock);
 284         return 0;
 285 }
 286 EXPORT_SYMBOL(tcf_register_action);
 287
 288 int tcf_unregister_action(struct tc_action_ops *act)
 289 {
 290         struct tc_action_ops *a;
 291         int err = -ENOENT;
 292
 293         write_lock(&act_mod_lock);
 294         list_for_each_entry(a, &act_base, head)
 295                 if (a == act)
 296                         break;
 297         if (a) {
 298                 list_del(&act->head);
 299                 err = 0;
 300         }
 301         write_unlock(&act_mod_lock);
 302         return err;
 303 }
 304 EXPORT_SYMBOL(tcf_unregister_action);
 305
 306 /* lookup by name */
 307 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 308 {
 309         struct tc_action_ops *a = NULL;
 310
 311         if (kind) {
 312                 read_lock(&act_mod_lock);
 313                 list_for_each_entry(a, &act_base, head) {
 314                         if (strcmp(kind, a->kind) == 0) {
 315                                 if (!try_module_get(a->owner)) {
 316                                         read_unlock(&act_mod_lock);
 317                                         return NULL;
 318                                 }
 319                                 break;
 320                         }
 321                 }
 322                 read_unlock(&act_mod_lock);
 323         }
 324         return a;
 325 }
 326
 327 /* lookup by nlattr */
 328 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 329 {
 330         struct tc_action_ops *a = NULL;
 331
 332         if (kind) {
 333                 read_lock(&act_mod_lock);
 334                 list_for_each_entry(a, &act_base, head) {
 335                         if (nla_strcmp(kind, a->kind) == 0) {
 336                                 if (!try_module_get(a->owner)) {
 337                                         read_unlock(&act_mod_lock);
 338                                         return NULL;
 339                                 }
 340                                 break;
 341                         }
 342                 }
 343                 read_unlock(&act_mod_lock);
 344         }
 345         return a;
 346 }
 347
 348 #if 0
 349 /* lookup by id */
 350 static struct tc_action_ops *tc_lookup_action_id(u32 type)
 351 {
 352         struct tc_action_ops *a = NULL;
 353
 354         if (type) {
 355                 read_lock(&act_mod_lock);
 356                 for (a = act_base; a; a = a->next) {
 357                         if (a->type == type) {
 358                                 if (!try_module_get(a->owner)) {
 359                                         read_unlock(&act_mod_lock);
 360                                         return NULL;
 361                                 }
 362                                 break;
 363                         }
 364                 }
 365                 read_unlock(&act_mod_lock);
 366         }
 367         return a;
 368 }
 369 #endif
 370
 371 int tcf_action_exec(struct sk_buff *skb, const struct list_head *actions,
 372                     struct tcf_result *res)
 373 {
 374         const struct tc_action *a;
 375         int ret = -1;
 376
 377         if (skb->tc_verd & TC_NCLS) {
 378                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 379                 ret = TC_ACT_OK;
 380                 goto exec_done;
 381         }
 382         list_for_each_entry(a, actions, list) {
 383 repeat:
 384                 if (a->ops) {
 385                         ret = a->ops->act(skb, a, res);
 386                         if (TC_MUNGED & skb->tc_verd) {
 387                                 /* copied already, allow trampling */
 388                                 skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
 389                                 skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
 390                         }
 391                         if (ret == TC_ACT_REPEAT)
 392                                 goto repeat;    /* we need a ttl - JHS */
 393                         if (ret != TC_ACT_PIPE)
 394                                 goto exec_done;
 395                 }
 396         }
 397 exec_done:
 398         return ret;
 399 }
 400 EXPORT_SYMBOL(tcf_action_exec);
 401
 402 void tcf_action_destroy(struct list_head *actions, int bind)
 403 {
 404         struct tc_action *a, *tmp;
 405
 406         list_for_each_entry_safe(a, tmp, actions, list) {
 407                 if (a->ops) {
 408                         if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
 409                                 module_put(a->ops->owner);
 410                         list_del(&a->list);
 411                         kfree(a);
 412                 } else {
 413                         /*FIXME: Remove later - catch insertion bugs*/
 414                         WARN(1, "tcf_action_destroy: BUG? destroying NULL ops\n");
 415                         list_del(&a->list);
 416                         kfree(a);
 417                 }
 418         }
 419 }
 420
 421 int
 422 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 423 {
 424         int err = -EINVAL;
 425
 426         if (a->ops == NULL)
 427                 return err;
 428         return a->ops->dump(skb, a, bind, ref);
 429 }
 430
 431 int
 432 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 433 {
 434         int err = -EINVAL;
 435         unsigned char *b = skb_tail_pointer(skb);
 436         struct nlattr *nest;
 437
 438         if (a->ops == NULL)
 439                 return err;
 440
 441         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 442                 goto nla_put_failure;
 443         if (tcf_action_copy_stats(skb, a, 0))
 444                 goto nla_put_failure;
 445         nest = nla_nest_start(skb, TCA_OPTIONS);
 446         if (nest == NULL)
 447                 goto nla_put_failure;
 448         err = tcf_action_dump_old(skb, a, bind, ref);
 449         if (err > 0) {
 450                 nla_nest_end(skb, nest);
 451                 return err;
 452         }
 453
 454 nla_put_failure:
 455         nlmsg_trim(skb, b);
 456         return -1;
 457 }
 458 EXPORT_SYMBOL(tcf_action_dump_1);
 459
 460 int
 461 tcf_action_dump(struct sk_buff *skb, struct list_head *actions, int bind, int ref)
 462 {
 463         struct tc_action *a;
 464         int err = -EINVAL;
 465         struct nlattr *nest;
 466
 467         list_for_each_entry(a, actions, list) {
 468                 nest = nla_nest_start(skb, a->order);
 469                 if (nest == NULL)
 470                         goto nla_put_failure;
 471                 err = tcf_action_dump_1(skb, a, bind, ref);
 472                 if (err < 0)
 473                         goto errout;
 474                 nla_nest_end(skb, nest);
 475         }
 476
 477         return 0;
 478
 479 nla_put_failure:
 480         err = -EINVAL;
 481 errout:
 482         nla_nest_cancel(skb, nest);
 483         return err;
 484 }
 485
 486 struct tc_action *tcf_action_init_1(struct net *net, struct nlattr *nla,
 487                                     struct nlattr *est, char *name, int ovr,
 488                                     int bind)
 489 {
 490         struct tc_action *a;
 491         struct tc_action_ops *a_o;
 492         char act_name[IFNAMSIZ];
 493         struct nlattr *tb[TCA_ACT_MAX + 1];
 494         struct nlattr *kind;
 495         int err;
 496
 497         if (name == NULL) {
 498                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 499                 if (err < 0)
 500                         goto err_out;
 501                 err = -EINVAL;
 502                 kind = tb[TCA_ACT_KIND];
 503                 if (kind == NULL)
 504                         goto err_out;
 505                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 506                         goto err_out;
 507         } else {
 508                 err = -EINVAL;
 509                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 510                         goto err_out;
 511         }
 512
 513         a_o = tc_lookup_action_n(act_name);
 514         if (a_o == NULL) {
 515 #ifdef CONFIG_MODULES
 516                 rtnl_unlock();
 517                 request_module("act_%s", act_name);
 518                 rtnl_lock();
 519
 520                 a_o = tc_lookup_action_n(act_name);
 521
 522                 /* We dropped the RTNL semaphore in order to
 523                  * perform the module load.  So, even if we
 524                  * succeeded in loading the module we have to
 525                  * tell the caller to replay the request.  We
 526                  * indicate this using -EAGAIN.
 527                  */
 528                 if (a_o != NULL) {
 529                         err = -EAGAIN;
 530                         goto err_mod;
 531                 }
 532 #endif
 533                 err = -ENOENT;
 534                 goto err_out;
 535         }
 536
 537         err = -ENOMEM;
 538         a = kzalloc(sizeof(*a), GFP_KERNEL);
 539         if (a == NULL)
 540                 goto err_mod;
 541
 542         INIT_LIST_HEAD(&a->list);
 543         /* backward compatibility for policer */
 544         if (name == NULL)
 545                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
 546         else
 547                 err = a_o->init(net, nla, est, a, ovr, bind);
 548         if (err < 0)
 549                 goto err_free;
 550
 551         /* module count goes up only when brand new policy is created
 552          * if it exists and is only bound to in a_o->init() then
 553          * ACT_P_CREATED is not returned (a zero is).
 554          */
 555         if (err != ACT_P_CREATED)
 556                 module_put(a_o->owner);
 557         a->ops = a_o;
 558
 559         return a;
 560
 561 err_free:
 562         kfree(a);
 563 err_mod:
 564         module_put(a_o->owner);
 565 err_out:
 566         return ERR_PTR(err);
 567 }
 568
 569 int tcf_action_init(struct net *net, struct nlattr *nla,
 570                                   struct nlattr *est, char *name, int ovr,
 571                                   int bind, struct list_head *actions)
 572 {
 573         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 574         struct tc_action *act;
 575         int err;
 576         int i;
 577
 578         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 579         if (err < 0)
 580                 return err;
 581
 582         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 583                 act = tcf_action_init_1(net, tb[i], est, name, ovr, bind);
 584                 if (IS_ERR(act)) {
 585                         err = PTR_ERR(act);
 586                         goto err;
 587                 }
 588                 act->order = i;
 589                 list_add_tail(&act->list, actions);
 590         }
 591         return 0;
 592
 593 err:
 594         tcf_action_destroy(actions, bind);
 595         return err;
 596 }
 597
 598 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 599                           int compat_mode)
 600 {
 601         int err = 0;
 602         struct gnet_dump d;
 603         struct tcf_act_hdr *h = a->priv;
 604
 605         if (h == NULL)
 606                 goto errout;
 607
 608         /* compat_mode being true specifies a call that is supposed
 609          * to add additional backward compatibility statistic TLVs.
 610          */
 611         if (compat_mode) {
 612                 if (a->type == TCA_OLD_COMPAT)
 613                         err = gnet_stats_start_copy_compat(skb, 0,
 614                                 TCA_STATS, TCA_XSTATS, &h->tcf_lock, &d);
 615                 else
 616                         return 0;
 617         } else
 618                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 619                                             &h->tcf_lock, &d);
 620
 621         if (err < 0)
 622                 goto errout;
 623
 624         if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
 625             gnet_stats_copy_rate_est(&d, &h->tcf_bstats,
 626                                      &h->tcf_rate_est) < 0 ||
 627             gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
 628                 goto errout;
 629
 630         if (gnet_stats_finish_copy(&d) < 0)
 631                 goto errout;
 632
 633         return 0;
 634
 635 errout:
 636         return -1;
 637 }
 638
 639 static int
 640 tca_get_fill(struct sk_buff *skb, struct list_head *actions, u32 portid, u32 seq,
 641              u16 flags, int event, int bind, int ref)
 642 {
 643         struct tcamsg *t;
 644         struct nlmsghdr *nlh;
 645         unsigned char *b = skb_tail_pointer(skb);
 646         struct nlattr *nest;
 647
 648         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
 649         if (!nlh)
 650                 goto out_nlmsg_trim;
 651         t = nlmsg_data(nlh);
 652         t->tca_family = AF_UNSPEC;
 653         t->tca__pad1 = 0;
 654         t->tca__pad2 = 0;
 655
 656         nest = nla_nest_start(skb, TCA_ACT_TAB);
 657         if (nest == NULL)
 658                 goto out_nlmsg_trim;
 659
 660         if (tcf_action_dump(skb, actions, bind, ref) < 0)
 661                 goto out_nlmsg_trim;
 662
 663         nla_nest_end(skb, nest);
 664
 665         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 666         return skb->len;
 667
 668 out_nlmsg_trim:
 669         nlmsg_trim(skb, b);
 670         return -1;
 671 }
 672
 673 static int
 674 act_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
 675                struct list_head *actions, int event)
 676 {
 677         struct sk_buff *skb;
 678
 679         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 680         if (!skb)
 681                 return -ENOBUFS;
 682         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 683                 kfree_skb(skb);
 684                 return -EINVAL;
 685         }
 686
 687         return rtnl_unicast(skb, net, portid);
 688 }
 689
 690 static struct tc_action *
 691 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 portid)
 692 {
 693         struct nlattr *tb[TCA_ACT_MAX + 1];
 694         struct tc_action *a;
 695         int index;
 696         int err;
 697
 698         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 699         if (err < 0)
 700                 goto err_out;
 701
 702         err = -EINVAL;
 703         if (tb[TCA_ACT_INDEX] == NULL ||
 704             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 705                 goto err_out;
 706         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 707
 708         err = -ENOMEM;
 709         a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
 710         if (a == NULL)
 711                 goto err_out;
 712
 713         INIT_LIST_HEAD(&a->list);
 714         err = -EINVAL;
 715         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 716         if (a->ops == NULL)
 717                 goto err_free;
 718         err = -ENOENT;
 719         if (a->ops->lookup(a, index) == 0)
 720                 goto err_mod;
 721
 722         module_put(a->ops->owner);
 723         return a;
 724
 725 err_mod:
 726         module_put(a->ops->owner);
 727 err_free:
 728         kfree(a);
 729 err_out:
 730         return ERR_PTR(err);
 731 }
 732
 733 static void cleanup_a(struct list_head *actions)
 734 {
 735         struct tc_action *a, *tmp;
 736
 737         list_for_each_entry_safe(a, tmp, actions, list) {
 738                 list_del(&a->list);
 739                 kfree(a);
 740         }
 741 }
 742
 743 static struct tc_action *create_a(int i)
 744 {
 745         struct tc_action *act;
 746
 747         act = kzalloc(sizeof(*act), GFP_KERNEL);
 748         if (act == NULL) {
 749                 pr_debug("create_a: failed to alloc!\n");
 750                 return NULL;
 751         }
 752         act->order = i;
 753         INIT_LIST_HEAD(&act->list);
 754         return act;
 755 }
 756
 757 static int tca_action_flush(struct net *net, struct nlattr *nla,
 758                             struct nlmsghdr *n, u32 portid)
 759 {
 760         struct sk_buff *skb;
 761         unsigned char *b;
 762         struct nlmsghdr *nlh;
 763         struct tcamsg *t;
 764         struct netlink_callback dcb;
 765         struct nlattr *nest;
 766         struct nlattr *tb[TCA_ACT_MAX + 1];
 767         struct nlattr *kind;
 768         struct tc_action *a = create_a(0);
 769         int err = -ENOMEM;
 770
 771         if (a == NULL) {
 772                 pr_debug("tca_action_flush: couldnt create tc_action\n");
 773                 return err;
 774         }
 775
 776         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 777         if (!skb) {
 778                 pr_debug("tca_action_flush: failed skb alloc\n");
 779                 kfree(a);
 780                 return err;
 781         }
 782
 783         b = skb_tail_pointer(skb);
 784
 785         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 786         if (err < 0)
 787                 goto err_out;
 788
 789         err = -EINVAL;
 790         kind = tb[TCA_ACT_KIND];
 791         a->ops = tc_lookup_action(kind);
 792         if (a->ops == NULL)
 793                 goto err_out;
 794
 795         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t), 0);
 796         if (!nlh)
 797                 goto out_module_put;
 798         t = nlmsg_data(nlh);
 799         t->tca_family = AF_UNSPEC;
 800         t->tca__pad1 = 0;
 801         t->tca__pad2 = 0;
 802
 803         nest = nla_nest_start(skb, TCA_ACT_TAB);
 804         if (nest == NULL)
 805                 goto out_module_put;
 806
 807         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 808         if (err < 0)
 809                 goto out_module_put;
 810         if (err == 0)
 811                 goto noflush_out;
 812
 813         nla_nest_end(skb, nest);
 814
 815         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 816         nlh->nlmsg_flags |= NLM_F_ROOT;
 817         module_put(a->ops->owner);
 818         kfree(a);
 819         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 820                              n->nlmsg_flags & NLM_F_ECHO);
 821         if (err > 0)
 822                 return 0;
 823
 824         return err;
 825
 826 out_module_put:
 827         module_put(a->ops->owner);
 828 err_out:
 829 noflush_out:
 830         kfree_skb(skb);
 831         kfree(a);
 832         return err;
 833 }
 834
 835 static int
 836 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 837               u32 portid, int event)
 838 {
 839         int i, ret;
 840         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 841         struct tc_action *act;
 842         LIST_HEAD(actions);
 843
 844         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 845         if (ret < 0)
 846                 return ret;
 847
 848         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
 849                 if (tb[1] != NULL)
 850                         return tca_action_flush(net, tb[1], n, portid);
 851                 else
 852                         return -EINVAL;
 853         }
 854
 855         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 856                 act = tcf_action_get_1(tb[i], n, portid);
 857                 if (IS_ERR(act)) {
 858                         ret = PTR_ERR(act);
 859                         goto err;
 860                 }
 861                 act->order = i;
 862                 list_add_tail(&act->list, &actions);
 863         }
 864
 865         if (event == RTM_GETACTION)
 866                 ret = act_get_notify(net, portid, n, &actions, event);
 867         else { /* delete */
 868                 struct sk_buff *skb;
 869
 870                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 871                 if (!skb) {
 872                         ret = -ENOBUFS;
 873                         goto err;
 874                 }
 875
 876                 if (tca_get_fill(skb, &actions, portid, n->nlmsg_seq, 0, event,
 877                                  0, 1) <= 0) {
 878                         kfree_skb(skb);
 879                         ret = -EINVAL;
 880                         goto err;
 881                 }
 882
 883                 /* now do the delete */
 884                 tcf_action_destroy(&actions, 0);
 885                 ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 886                                      n->nlmsg_flags & NLM_F_ECHO);
 887                 if (ret > 0)
 888                         return 0;
 889                 return ret;
 890         }
 891 err:
 892         cleanup_a(&actions);
 893         return ret;
 894 }
 895
 896 static int tcf_add_notify(struct net *net, struct list_head *actions,
 897                           u32 portid, u32 seq, int event, u16 flags)
 898 {
 899         struct tcamsg *t;
 900         struct nlmsghdr *nlh;
 901         struct sk_buff *skb;
 902         struct nlattr *nest;
 903         unsigned char *b;
 904         int err = 0;
 905
 906         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 907         if (!skb)
 908                 return -ENOBUFS;
 909
 910         b = skb_tail_pointer(skb);
 911
 912         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
 913         if (!nlh)
 914                 goto out_kfree_skb;
 915         t = nlmsg_data(nlh);
 916         t->tca_family = AF_UNSPEC;
 917         t->tca__pad1 = 0;
 918         t->tca__pad2 = 0;
 919
 920         nest = nla_nest_start(skb, TCA_ACT_TAB);
 921         if (nest == NULL)
 922                 goto out_kfree_skb;
 923
 924         if (tcf_action_dump(skb, actions, 0, 0) < 0)
 925                 goto out_kfree_skb;
 926
 927         nla_nest_end(skb, nest);
 928
 929         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 930         NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 931
 932         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
 933         if (err > 0)
 934                 err = 0;
 935         return err;
 936
 937 out_kfree_skb:
 938         kfree_skb(skb);
 939         return -1;
 940 }
 941
 942
 943 static int
 944 tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 945                u32 portid, int ovr)
 946 {
 947         int ret = 0;
 948         LIST_HEAD(actions);
 949         u32 seq = n->nlmsg_seq;
 950
 951         ret = tcf_action_init(net, nla, NULL, NULL, ovr, 0, &actions);
 952         if (ret)
 953                 goto done;
 954
 955         /* dump then free all the actions after update; inserted policy
 956          * stays intact
 957          */
 958         ret = tcf_add_notify(net, &actions, portid, seq, RTM_NEWACTION, n->nlmsg_flags);
 959         cleanup_a(&actions);
 960 done:
 961         return ret;
 962 }
 963
 964 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n)
 965 {
 966         struct net *net = sock_net(skb->sk);
 967         struct nlattr *tca[TCA_ACT_MAX + 1];
 968         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
 969         int ret = 0, ovr = 0;
 970
 971         if ((n->nlmsg_type != RTM_GETACTION) && !capable(CAP_NET_ADMIN))
 972                 return -EPERM;
 973
 974         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
 975         if (ret < 0)
 976                 return ret;
 977
 978         if (tca[TCA_ACT_TAB] == NULL) {
 979                 pr_notice("tc_ctl_action: received NO action attribs\n");
 980                 return -EINVAL;
 981         }
 982
 983         /* n->nlmsg_flags & NLM_F_CREATE */
 984         switch (n->nlmsg_type) {
 985         case RTM_NEWACTION:
 986                 /* we are going to assume all other flags
 987                  * imply create only if it doesn't exist
 988                  * Note that CREATE | EXCL implies that
 989                  * but since we want avoid ambiguity (eg when flags
 990                  * is zero) then just set this
 991                  */
 992                 if (n->nlmsg_flags & NLM_F_REPLACE)
 993                         ovr = 1;
 994 replay:
 995                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr);
 996                 if (ret == -EAGAIN)
 997                         goto replay;
 998                 break;
 999         case RTM_DELACTION:
1000                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1001                                     portid, RTM_DELACTION);
1002                 break;
1003         case RTM_GETACTION:
1004                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1005                                     portid, RTM_GETACTION);
1006                 break;
1007         default:
1008                 BUG();
1009         }
1010
1011         return ret;
1012 }
1013
1014 static struct nlattr *
1015 find_dump_kind(const struct nlmsghdr *n)
1016 {
1017         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1018         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1019         struct nlattr *nla[TCAA_MAX + 1];
1020         struct nlattr *kind;
1021
1022         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1023                 return NULL;
1024         tb1 = nla[TCA_ACT_TAB];
1025         if (tb1 == NULL)
1026                 return NULL;
1027
1028         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1029                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1030                 return NULL;
1031
1032         if (tb[1] == NULL)
1033                 return NULL;
1034         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1035                       nla_len(tb[1]), NULL) < 0)
1036                 return NULL;
1037         kind = tb2[TCA_ACT_KIND];
1038
1039         return kind;
1040 }
1041
1042 static int
1043 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1044 {
1045         struct nlmsghdr *nlh;
1046         unsigned char *b = skb_tail_pointer(skb);
1047         struct nlattr *nest;
1048         struct tc_action_ops *a_o;
1049         struct tc_action a;
1050         int ret = 0;
1051         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1052         struct nlattr *kind = find_dump_kind(cb->nlh);
1053
1054         if (kind == NULL) {
1055                 pr_info("tc_dump_action: action bad kind\n");
1056                 return 0;
1057         }
1058
1059         a_o = tc_lookup_action(kind);
1060         if (a_o == NULL)
1061                 return 0;
1062
1063         memset(&a, 0, sizeof(struct tc_action));
1064         a.ops = a_o;
1065
1066         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1067                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1068         if (!nlh)
1069                 goto out_module_put;
1070         t = nlmsg_data(nlh);
1071         t->tca_family = AF_UNSPEC;
1072         t->tca__pad1 = 0;
1073         t->tca__pad2 = 0;
1074
1075         nest = nla_nest_start(skb, TCA_ACT_TAB);
1076         if (nest == NULL)
1077                 goto out_module_put;
1078
1079         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1080         if (ret < 0)
1081                 goto out_module_put;
1082
1083         if (ret > 0) {
1084                 nla_nest_end(skb, nest);
1085                 ret = skb->len;
1086         } else
1087                 nla_nest_cancel(skb, nest);
1088
1089         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1090         if (NETLINK_CB(cb->skb).portid && ret)
1091                 nlh->nlmsg_flags |= NLM_F_MULTI;
1092         module_put(a_o->owner);
1093         return skb->len;
1094
1095 out_module_put:
1096         module_put(a_o->owner);
1097         nlmsg_trim(skb, b);
1098         return skb->len;
1099 }
1100
1101 static int __init tc_action_init(void)
1102 {
1103         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
1104         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
1105         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1106                       NULL);
1107
1108         return 0;
1109 }
1110
1111 subsys_initcall(tc_action_init);