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