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 static void free_tcf(struct rcu_head *head)
  31 {
  32         struct tcf_common *p = container_of(head, struct tcf_common, tcfc_rcu);
  33
  34         free_percpu(p->cpu_bstats);
  35         free_percpu(p->cpu_qstats);
  36         kfree(p);
  37 }
  38
  39 void tcf_hash_destroy(struct tc_action *a)
  40 {
  41         struct tcf_common *p = a->priv;
  42         struct tcf_hashinfo *hinfo = a->ops->hinfo;
  43
  44         spin_lock_bh(&hinfo->lock);
  45         hlist_del(&p->tcfc_head);
  46         spin_unlock_bh(&hinfo->lock);
  47         gen_kill_estimator(&p->tcfc_bstats,
  48                            &p->tcfc_rate_est);
  49         /*
  50          * gen_estimator est_timer() might access p->tcfc_lock
  51          * or bstats, wait a RCU grace period before freeing p
  52          */
  53         call_rcu(&p->tcfc_rcu, free_tcf);
  54 }
  55 EXPORT_SYMBOL(tcf_hash_destroy);
  56
  57 int __tcf_hash_release(struct tc_action *a, bool bind, bool strict)
  58 {
  59         struct tcf_common *p = a->priv;
  60         int ret = 0;
  61
  62         if (p) {
  63                 if (bind)
  64                         p->tcfc_bindcnt--;
  65                 else if (strict && p->tcfc_bindcnt > 0)
  66                         return -EPERM;
  67
  68                 p->tcfc_refcnt--;
  69                 if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
  70                         if (a->ops->cleanup)
  71                                 a->ops->cleanup(a, bind);
  72                         tcf_hash_destroy(a);
  73                         ret = 1;
  74                 }
  75         }
  76
  77         return ret;
  78 }
  79 EXPORT_SYMBOL(__tcf_hash_release);
  80
  81 static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
  82                            struct tc_action *a)
  83 {
  84         struct tcf_hashinfo *hinfo = a->ops->hinfo;
  85         struct hlist_head *head;
  86         struct tcf_common *p;
  87         int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
  88         struct nlattr *nest;
  89
  90         spin_lock_bh(&hinfo->lock);
  91
  92         s_i = cb->args[0];
  93
  94         for (i = 0; i < (hinfo->hmask + 1); i++) {
  95                 head = &hinfo->htab[tcf_hash(i, hinfo->hmask)];
  96
  97                 hlist_for_each_entry_rcu(p, head, tcfc_head) {
  98                         index++;
  99                         if (index < s_i)
 100                                 continue;
 101                         a->priv = p;
 102                         a->order = n_i;
 103
 104                         nest = nla_nest_start(skb, a->order);
 105                         if (nest == NULL)
 106                                 goto nla_put_failure;
 107                         err = tcf_action_dump_1(skb, a, 0, 0);
 108                         if (err < 0) {
 109                                 index--;
 110                                 nlmsg_trim(skb, nest);
 111                                 goto done;
 112                         }
 113                         nla_nest_end(skb, nest);
 114                         n_i++;
 115                         if (n_i >= TCA_ACT_MAX_PRIO)
 116                                 goto done;
 117                 }
 118         }
 119 done:
 120         spin_unlock_bh(&hinfo->lock);
 121         if (n_i)
 122                 cb->args[0] += n_i;
 123         return n_i;
 124
 125 nla_put_failure:
 126         nla_nest_cancel(skb, nest);
 127         goto done;
 128 }
 129
 130 static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a)
 131 {
 132         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 133         struct hlist_head *head;
 134         struct hlist_node *n;
 135         struct tcf_common *p;
 136         struct nlattr *nest;
 137         int i = 0, n_i = 0;
 138         int ret = -EINVAL;
 139
 140         nest = nla_nest_start(skb, a->order);
 141         if (nest == NULL)
 142                 goto nla_put_failure;
 143         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 144                 goto nla_put_failure;
 145         for (i = 0; i < (hinfo->hmask + 1); i++) {
 146                 head = &hinfo->htab[tcf_hash(i, hinfo->hmask)];
 147                 hlist_for_each_entry_safe(p, n, head, tcfc_head) {
 148                         a->priv = p;
 149                         ret = __tcf_hash_release(a, false, true);
 150                         if (ret == ACT_P_DELETED) {
 151                                 module_put(a->ops->owner);
 152                                 n_i++;
 153                         } else if (ret < 0)
 154                                 goto nla_put_failure;
 155                 }
 156         }
 157         if (nla_put_u32(skb, TCA_FCNT, n_i))
 158                 goto nla_put_failure;
 159         nla_nest_end(skb, nest);
 160
 161         return n_i;
 162 nla_put_failure:
 163         nla_nest_cancel(skb, nest);
 164         return ret;
 165 }
 166
 167 static int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
 168                               int type, struct tc_action *a)
 169 {
 170         if (type == RTM_DELACTION) {
 171                 return tcf_del_walker(skb, a);
 172         } else if (type == RTM_GETACTION) {
 173                 return tcf_dump_walker(skb, cb, a);
 174         } else {
 175                 WARN(1, "tcf_generic_walker: unknown action %d\n", type);
 176                 return -EINVAL;
 177         }
 178 }
 179
 180 static struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 181 {
 182         struct tcf_common *p = NULL;
 183         struct hlist_head *head;
 184
 185         spin_lock_bh(&hinfo->lock);
 186         head = &hinfo->htab[tcf_hash(index, hinfo->hmask)];
 187         hlist_for_each_entry_rcu(p, head, tcfc_head)
 188                 if (p->tcfc_index == index)
 189                         break;
 190         spin_unlock_bh(&hinfo->lock);
 191
 192         return p;
 193 }
 194
 195 u32 tcf_hash_new_index(struct tcf_hashinfo *hinfo)
 196 {
 197         u32 val = hinfo->index;
 198
 199         do {
 200                 if (++val == 0)
 201                         val = 1;
 202         } while (tcf_hash_lookup(val, hinfo));
 203
 204         hinfo->index = val;
 205         return val;
 206 }
 207 EXPORT_SYMBOL(tcf_hash_new_index);
 208
 209 int tcf_hash_search(struct tc_action *a, u32 index)
 210 {
 211         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 212         struct tcf_common *p = tcf_hash_lookup(index, hinfo);
 213
 214         if (p) {
 215                 a->priv = p;
 216                 return 1;
 217         }
 218         return 0;
 219 }
 220 EXPORT_SYMBOL(tcf_hash_search);
 221
 222 int tcf_hash_check(u32 index, struct tc_action *a, int bind)
 223 {
 224         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 225         struct tcf_common *p = NULL;
 226         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 227                 if (bind)
 228                         p->tcfc_bindcnt++;
 229                 p->tcfc_refcnt++;
 230                 a->priv = p;
 231                 return 1;
 232         }
 233         return 0;
 234 }
 235 EXPORT_SYMBOL(tcf_hash_check);
 236
 237 void tcf_hash_cleanup(struct tc_action *a, struct nlattr *est)
 238 {
 239         struct tcf_common *pc = a->priv;
 240         if (est)
 241                 gen_kill_estimator(&pc->tcfc_bstats,
 242                                    &pc->tcfc_rate_est);
 243         call_rcu(&pc->tcfc_rcu, free_tcf);
 244 }
 245 EXPORT_SYMBOL(tcf_hash_cleanup);
 246
 247 int tcf_hash_create(u32 index, struct nlattr *est, struct tc_action *a,
 248                     int size, int bind, bool cpustats)
 249 {
 250         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 251         struct tcf_common *p = kzalloc(size, GFP_KERNEL);
 252         int err = -ENOMEM;
 253
 254         if (unlikely(!p))
 255                 return -ENOMEM;
 256         p->tcfc_refcnt = 1;
 257         if (bind)
 258                 p->tcfc_bindcnt = 1;
 259
 260         if (cpustats) {
 261                 p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
 262                 if (!p->cpu_bstats) {
 263 err1:
 264                         kfree(p);
 265                         return err;
 266                 }
 267                 p->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
 268                 if (!p->cpu_qstats) {
 269 err2:
 270                         free_percpu(p->cpu_bstats);
 271                         goto err1;
 272                 }
 273         }
 274         spin_lock_init(&p->tcfc_lock);
 275         INIT_HLIST_NODE(&p->tcfc_head);
 276         p->tcfc_index = index ? index : tcf_hash_new_index(hinfo);
 277         p->tcfc_tm.install = jiffies;
 278         p->tcfc_tm.lastuse = jiffies;
 279         if (est) {
 280                 err = gen_new_estimator(&p->tcfc_bstats, p->cpu_bstats,
 281                                         &p->tcfc_rate_est,
 282                                         &p->tcfc_lock, est);
 283                 if (err) {
 284                         free_percpu(p->cpu_qstats);
 285                         goto err2;
 286                 }
 287         }
 288
 289         a->priv = (void *) p;
 290         return 0;
 291 }
 292 EXPORT_SYMBOL(tcf_hash_create);
 293
 294 void tcf_hash_insert(struct tc_action *a)
 295 {
 296         struct tcf_common *p = a->priv;
 297         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 298         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
 299
 300         spin_lock_bh(&hinfo->lock);
 301         hlist_add_head(&p->tcfc_head, &hinfo->htab[h]);
 302         spin_unlock_bh(&hinfo->lock);
 303 }
 304 EXPORT_SYMBOL(tcf_hash_insert);
 305
 306 static LIST_HEAD(act_base);
 307 static DEFINE_RWLOCK(act_mod_lock);
 308
 309 int tcf_register_action(struct tc_action_ops *act, unsigned int mask)
 310 {
 311         struct tc_action_ops *a;
 312         int err;
 313
 314         /* Must supply act, dump and init */
 315         if (!act->act || !act->dump || !act->init)
 316                 return -EINVAL;
 317
 318         /* Supply defaults */
 319         if (!act->lookup)
 320                 act->lookup = tcf_hash_search;
 321         if (!act->walk)
 322                 act->walk = tcf_generic_walker;
 323
 324         act->hinfo = kmalloc(sizeof(struct tcf_hashinfo), GFP_KERNEL);
 325         if (!act->hinfo)
 326                 return -ENOMEM;
 327         err = tcf_hashinfo_init(act->hinfo, mask);
 328         if (err) {
 329                 kfree(act->hinfo);
 330                 return err;
 331         }
 332
 333         write_lock(&act_mod_lock);
 334         list_for_each_entry(a, &act_base, head) {
 335                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 336                         write_unlock(&act_mod_lock);
 337                         tcf_hashinfo_destroy(act->hinfo);
 338                         kfree(act->hinfo);
 339                         return -EEXIST;
 340                 }
 341         }
 342         list_add_tail(&act->head, &act_base);
 343         write_unlock(&act_mod_lock);
 344         return 0;
 345 }
 346 EXPORT_SYMBOL(tcf_register_action);
 347
 348 int tcf_unregister_action(struct tc_action_ops *act)
 349 {
 350         struct tc_action_ops *a;
 351         int err = -ENOENT;
 352
 353         write_lock(&act_mod_lock);
 354         list_for_each_entry(a, &act_base, head) {
 355                 if (a == act) {
 356                         list_del(&act->head);
 357                         tcf_hashinfo_destroy(act->hinfo);
 358                         kfree(act->hinfo);
 359                         err = 0;
 360                         break;
 361                 }
 362         }
 363         write_unlock(&act_mod_lock);
 364         return err;
 365 }
 366 EXPORT_SYMBOL(tcf_unregister_action);
 367
 368 /* lookup by name */
 369 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 370 {
 371         struct tc_action_ops *a, *res = NULL;
 372
 373         if (kind) {
 374                 read_lock(&act_mod_lock);
 375                 list_for_each_entry(a, &act_base, head) {
 376                         if (strcmp(kind, a->kind) == 0) {
 377                                 if (try_module_get(a->owner))
 378                                         res = a;
 379                                 break;
 380                         }
 381                 }
 382                 read_unlock(&act_mod_lock);
 383         }
 384         return res;
 385 }
 386
 387 /* lookup by nlattr */
 388 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 389 {
 390         struct tc_action_ops *a, *res = NULL;
 391
 392         if (kind) {
 393                 read_lock(&act_mod_lock);
 394                 list_for_each_entry(a, &act_base, head) {
 395                         if (nla_strcmp(kind, a->kind) == 0) {
 396                                 if (try_module_get(a->owner))
 397                                         res = a;
 398                                 break;
 399                         }
 400                 }
 401                 read_unlock(&act_mod_lock);
 402         }
 403         return res;
 404 }
 405
 406 int tcf_action_exec(struct sk_buff *skb, const struct list_head *actions,
 407                     struct tcf_result *res)
 408 {
 409         const struct tc_action *a;
 410         int ret = -1;
 411
 412         if (skb->tc_verd & TC_NCLS) {
 413                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 414                 ret = TC_ACT_OK;
 415                 goto exec_done;
 416         }
 417         list_for_each_entry(a, actions, list) {
 418 repeat:
 419                 ret = a->ops->act(skb, a, res);
 420                 if (ret == TC_ACT_REPEAT)
 421                         goto repeat;    /* we need a ttl - JHS */
 422                 if (ret != TC_ACT_PIPE)
 423                         goto exec_done;
 424         }
 425 exec_done:
 426         return ret;
 427 }
 428 EXPORT_SYMBOL(tcf_action_exec);
 429
 430 int tcf_action_destroy(struct list_head *actions, int bind)
 431 {
 432         struct tc_action *a, *tmp;
 433         int ret = 0;
 434
 435         list_for_each_entry_safe(a, tmp, actions, list) {
 436                 ret = __tcf_hash_release(a, bind, true);
 437                 if (ret == ACT_P_DELETED)
 438                         module_put(a->ops->owner);
 439                 else if (ret < 0)
 440                         return ret;
 441                 list_del(&a->list);
 442                 kfree(a);
 443         }
 444         return ret;
 445 }
 446
 447 int
 448 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 449 {
 450         return a->ops->dump(skb, a, bind, ref);
 451 }
 452
 453 int
 454 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 455 {
 456         int err = -EINVAL;
 457         unsigned char *b = skb_tail_pointer(skb);
 458         struct nlattr *nest;
 459
 460         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 461                 goto nla_put_failure;
 462         if (tcf_action_copy_stats(skb, a, 0))
 463                 goto nla_put_failure;
 464         nest = nla_nest_start(skb, TCA_OPTIONS);
 465         if (nest == NULL)
 466                 goto nla_put_failure;
 467         err = tcf_action_dump_old(skb, a, bind, ref);
 468         if (err > 0) {
 469                 nla_nest_end(skb, nest);
 470                 return err;
 471         }
 472
 473 nla_put_failure:
 474         nlmsg_trim(skb, b);
 475         return -1;
 476 }
 477 EXPORT_SYMBOL(tcf_action_dump_1);
 478
 479 int
 480 tcf_action_dump(struct sk_buff *skb, struct list_head *actions, int bind, int ref)
 481 {
 482         struct tc_action *a;
 483         int err = -EINVAL;
 484         struct nlattr *nest;
 485
 486         list_for_each_entry(a, actions, list) {
 487                 nest = nla_nest_start(skb, a->order);
 488                 if (nest == NULL)
 489                         goto nla_put_failure;
 490                 err = tcf_action_dump_1(skb, a, bind, ref);
 491                 if (err < 0)
 492                         goto errout;
 493                 nla_nest_end(skb, nest);
 494         }
 495
 496         return 0;
 497
 498 nla_put_failure:
 499         err = -EINVAL;
 500 errout:
 501         nla_nest_cancel(skb, nest);
 502         return err;
 503 }
 504
 505 struct tc_action *tcf_action_init_1(struct net *net, struct nlattr *nla,
 506                                     struct nlattr *est, char *name, int ovr,
 507                                     int bind)
 508 {
 509         struct tc_action *a;
 510         struct tc_action_ops *a_o;
 511         char act_name[IFNAMSIZ];
 512         struct nlattr *tb[TCA_ACT_MAX + 1];
 513         struct nlattr *kind;
 514         int err;
 515
 516         if (name == NULL) {
 517                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 518                 if (err < 0)
 519                         goto err_out;
 520                 err = -EINVAL;
 521                 kind = tb[TCA_ACT_KIND];
 522                 if (kind == NULL)
 523                         goto err_out;
 524                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 525                         goto err_out;
 526         } else {
 527                 err = -EINVAL;
 528                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 529                         goto err_out;
 530         }
 531
 532         a_o = tc_lookup_action_n(act_name);
 533         if (a_o == NULL) {
 534 #ifdef CONFIG_MODULES
 535                 rtnl_unlock();
 536                 request_module("act_%s", act_name);
 537                 rtnl_lock();
 538
 539                 a_o = tc_lookup_action_n(act_name);
 540
 541                 /* We dropped the RTNL semaphore in order to
 542                  * perform the module load.  So, even if we
 543                  * succeeded in loading the module we have to
 544                  * tell the caller to replay the request.  We
 545                  * indicate this using -EAGAIN.
 546                  */
 547                 if (a_o != NULL) {
 548                         err = -EAGAIN;
 549                         goto err_mod;
 550                 }
 551 #endif
 552                 err = -ENOENT;
 553                 goto err_out;
 554         }
 555
 556         err = -ENOMEM;
 557         a = kzalloc(sizeof(*a), GFP_KERNEL);
 558         if (a == NULL)
 559                 goto err_mod;
 560
 561         a->ops = a_o;
 562         INIT_LIST_HEAD(&a->list);
 563         /* backward compatibility for policer */
 564         if (name == NULL)
 565                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
 566         else
 567                 err = a_o->init(net, nla, est, a, ovr, bind);
 568         if (err < 0)
 569                 goto err_free;
 570
 571         /* module count goes up only when brand new policy is created
 572          * if it exists and is only bound to in a_o->init() then
 573          * ACT_P_CREATED is not returned (a zero is).
 574          */
 575         if (err != ACT_P_CREATED)
 576                 module_put(a_o->owner);
 577
 578         return a;
 579
 580 err_free:
 581         kfree(a);
 582 err_mod:
 583         module_put(a_o->owner);
 584 err_out:
 585         return ERR_PTR(err);
 586 }
 587
 588 int tcf_action_init(struct net *net, struct nlattr *nla,
 589                                   struct nlattr *est, char *name, int ovr,
 590                                   int bind, struct list_head *actions)
 591 {
 592         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 593         struct tc_action *act;
 594         int err;
 595         int i;
 596
 597         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 598         if (err < 0)
 599                 return err;
 600
 601         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 602                 act = tcf_action_init_1(net, tb[i], est, name, ovr, bind);
 603                 if (IS_ERR(act)) {
 604                         err = PTR_ERR(act);
 605                         goto err;
 606                 }
 607                 act->order = i;
 608                 list_add_tail(&act->list, actions);
 609         }
 610         return 0;
 611
 612 err:
 613         tcf_action_destroy(actions, bind);
 614         return err;
 615 }
 616
 617 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 618                           int compat_mode)
 619 {
 620         int err = 0;
 621         struct gnet_dump d;
 622         struct tcf_common *p = a->priv;
 623
 624         if (p == NULL)
 625                 goto errout;
 626
 627         /* compat_mode being true specifies a call that is supposed
 628          * to add additional backward compatibility statistic TLVs.
 629          */
 630         if (compat_mode) {
 631                 if (a->type == TCA_OLD_COMPAT)
 632                         err = gnet_stats_start_copy_compat(skb, 0,
 633                                 TCA_STATS, TCA_XSTATS, &p->tcfc_lock, &d);
 634                 else
 635                         return 0;
 636         } else
 637                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 638                                             &p->tcfc_lock, &d);
 639
 640         if (err < 0)
 641                 goto errout;
 642
 643         if (gnet_stats_copy_basic(&d, p->cpu_bstats, &p->tcfc_bstats) < 0 ||
 644             gnet_stats_copy_rate_est(&d, &p->tcfc_bstats,
 645                                      &p->tcfc_rate_est) < 0 ||
 646             gnet_stats_copy_queue(&d, p->cpu_qstats,
 647                                   &p->tcfc_qstats,
 648                                   p->tcfc_qstats.qlen) < 0)
 649                 goto errout;
 650
 651         if (gnet_stats_finish_copy(&d) < 0)
 652                 goto errout;
 653
 654         return 0;
 655
 656 errout:
 657         return -1;
 658 }
 659
 660 static int
 661 tca_get_fill(struct sk_buff *skb, struct list_head *actions, u32 portid, u32 seq,
 662              u16 flags, int event, int bind, int ref)
 663 {
 664         struct tcamsg *t;
 665         struct nlmsghdr *nlh;
 666         unsigned char *b = skb_tail_pointer(skb);
 667         struct nlattr *nest;
 668
 669         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
 670         if (!nlh)
 671                 goto out_nlmsg_trim;
 672         t = nlmsg_data(nlh);
 673         t->tca_family = AF_UNSPEC;
 674         t->tca__pad1 = 0;
 675         t->tca__pad2 = 0;
 676
 677         nest = nla_nest_start(skb, TCA_ACT_TAB);
 678         if (nest == NULL)
 679                 goto out_nlmsg_trim;
 680
 681         if (tcf_action_dump(skb, actions, bind, ref) < 0)
 682                 goto out_nlmsg_trim;
 683
 684         nla_nest_end(skb, nest);
 685
 686         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 687         return skb->len;
 688
 689 out_nlmsg_trim:
 690         nlmsg_trim(skb, b);
 691         return -1;
 692 }
 693
 694 static int
 695 act_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
 696                struct list_head *actions, int event)
 697 {
 698         struct sk_buff *skb;
 699
 700         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 701         if (!skb)
 702                 return -ENOBUFS;
 703         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 704                 kfree_skb(skb);
 705                 return -EINVAL;
 706         }
 707
 708         return rtnl_unicast(skb, net, portid);
 709 }
 710
 711 static struct tc_action *create_a(int i)
 712 {
 713         struct tc_action *act;
 714
 715         act = kzalloc(sizeof(*act), GFP_KERNEL);
 716         if (act == NULL) {
 717                 pr_debug("create_a: failed to alloc!\n");
 718                 return NULL;
 719         }
 720         act->order = i;
 721         INIT_LIST_HEAD(&act->list);
 722         return act;
 723 }
 724
 725 static struct tc_action *
 726 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 portid)
 727 {
 728         struct nlattr *tb[TCA_ACT_MAX + 1];
 729         struct tc_action *a;
 730         int index;
 731         int err;
 732
 733         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 734         if (err < 0)
 735                 goto err_out;
 736
 737         err = -EINVAL;
 738         if (tb[TCA_ACT_INDEX] == NULL ||
 739             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 740                 goto err_out;
 741         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 742
 743         err = -ENOMEM;
 744         a = create_a(0);
 745         if (a == NULL)
 746                 goto err_out;
 747
 748         err = -EINVAL;
 749         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 750         if (a->ops == NULL) /* could happen in batch of actions */
 751                 goto err_free;
 752         err = -ENOENT;
 753         if (a->ops->lookup(a, index) == 0)
 754                 goto err_mod;
 755
 756         module_put(a->ops->owner);
 757         return a;
 758
 759 err_mod:
 760         module_put(a->ops->owner);
 761 err_free:
 762         kfree(a);
 763 err_out:
 764         return ERR_PTR(err);
 765 }
 766
 767 static void cleanup_a(struct list_head *actions)
 768 {
 769         struct tc_action *a, *tmp;
 770
 771         list_for_each_entry_safe(a, tmp, actions, list) {
 772                 list_del(&a->list);
 773                 kfree(a);
 774         }
 775 }
 776
 777 static int tca_action_flush(struct net *net, struct nlattr *nla,
 778                             struct nlmsghdr *n, u32 portid)
 779 {
 780         struct sk_buff *skb;
 781         unsigned char *b;
 782         struct nlmsghdr *nlh;
 783         struct tcamsg *t;
 784         struct netlink_callback dcb;
 785         struct nlattr *nest;
 786         struct nlattr *tb[TCA_ACT_MAX + 1];
 787         struct nlattr *kind;
 788         struct tc_action a;
 789         int err = -ENOMEM;
 790
 791         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 792         if (!skb) {
 793                 pr_debug("tca_action_flush: failed skb alloc\n");
 794                 return err;
 795         }
 796
 797         b = skb_tail_pointer(skb);
 798
 799         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 800         if (err < 0)
 801                 goto err_out;
 802
 803         err = -EINVAL;
 804         kind = tb[TCA_ACT_KIND];
 805         memset(&a, 0, sizeof(struct tc_action));
 806         INIT_LIST_HEAD(&a.list);
 807         a.ops = tc_lookup_action(kind);
 808         if (a.ops == NULL) /*some idjot trying to flush unknown action */
 809                 goto err_out;
 810
 811         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t), 0);
 812         if (!nlh)
 813                 goto out_module_put;
 814         t = nlmsg_data(nlh);
 815         t->tca_family = AF_UNSPEC;
 816         t->tca__pad1 = 0;
 817         t->tca__pad2 = 0;
 818
 819         nest = nla_nest_start(skb, TCA_ACT_TAB);
 820         if (nest == NULL)
 821                 goto out_module_put;
 822
 823         err = a.ops->walk(skb, &dcb, RTM_DELACTION, &a);
 824         if (err < 0)
 825                 goto out_module_put;
 826         if (err == 0)
 827                 goto noflush_out;
 828
 829         nla_nest_end(skb, nest);
 830
 831         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 832         nlh->nlmsg_flags |= NLM_F_ROOT;
 833         module_put(a.ops->owner);
 834         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 835                              n->nlmsg_flags & NLM_F_ECHO);
 836         if (err > 0)
 837                 return 0;
 838
 839         return err;
 840
 841 out_module_put:
 842         module_put(a.ops->owner);
 843 err_out:
 844 noflush_out:
 845         kfree_skb(skb);
 846         return err;
 847 }
 848
 849 static int
 850 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
 851                u32 portid)
 852 {
 853         int ret;
 854         struct sk_buff *skb;
 855
 856         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 857         if (!skb)
 858                 return -ENOBUFS;
 859
 860         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
 861                          0, 1) <= 0) {
 862                 kfree_skb(skb);
 863                 return -EINVAL;
 864         }
 865
 866         /* now do the delete */
 867         ret = tcf_action_destroy(actions, 0);
 868         if (ret < 0) {
 869                 kfree_skb(skb);
 870                 return ret;
 871         }
 872
 873         ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 874                              n->nlmsg_flags & NLM_F_ECHO);
 875         if (ret > 0)
 876                 return 0;
 877         return ret;
 878 }
 879
 880 static int
 881 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 882               u32 portid, int event)
 883 {
 884         int i, ret;
 885         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 886         struct tc_action *act;
 887         LIST_HEAD(actions);
 888
 889         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 890         if (ret < 0)
 891                 return ret;
 892
 893         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
 894                 if (tb[1] != NULL)
 895                         return tca_action_flush(net, tb[1], n, portid);
 896                 else
 897                         return -EINVAL;
 898         }
 899
 900         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 901                 act = tcf_action_get_1(tb[i], n, portid);
 902                 if (IS_ERR(act)) {
 903                         ret = PTR_ERR(act);
 904                         goto err;
 905                 }
 906                 act->order = i;
 907                 list_add_tail(&act->list, &actions);
 908         }
 909
 910         if (event == RTM_GETACTION)
 911                 ret = act_get_notify(net, portid, n, &actions, event);
 912         else { /* delete */
 913                 ret = tcf_del_notify(net, n, &actions, portid);
 914                 if (ret)
 915                         goto err;
 916                 return ret;
 917         }
 918 err:
 919         cleanup_a(&actions);
 920         return ret;
 921 }
 922
 923 static int
 924 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
 925                u32 portid)
 926 {
 927         struct sk_buff *skb;
 928         int err = 0;
 929
 930         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 931         if (!skb)
 932                 return -ENOBUFS;
 933
 934         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
 935                          RTM_NEWACTION, 0, 0) <= 0) {
 936                 kfree_skb(skb);
 937                 return -EINVAL;
 938         }
 939
 940         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 941                              n->nlmsg_flags & NLM_F_ECHO);
 942         if (err > 0)
 943                 err = 0;
 944         return err;
 945 }
 946
 947 static int
 948 tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 949                u32 portid, int ovr)
 950 {
 951         int ret = 0;
 952         LIST_HEAD(actions);
 953
 954         ret = tcf_action_init(net, nla, NULL, NULL, ovr, 0, &actions);
 955         if (ret)
 956                 goto done;
 957
 958         /* dump then free all the actions after update; inserted policy
 959          * stays intact
 960          */
 961         ret = tcf_add_notify(net, n, &actions, portid);
 962         cleanup_a(&actions);
 963 done:
 964         return ret;
 965 }
 966
 967 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n)
 968 {
 969         struct net *net = sock_net(skb->sk);
 970         struct nlattr *tca[TCA_ACT_MAX + 1];
 971         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
 972         int ret = 0, ovr = 0;
 973
 974         if ((n->nlmsg_type != RTM_GETACTION) && !netlink_capable(skb, CAP_NET_ADMIN))
 975                 return -EPERM;
 976
 977         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
 978         if (ret < 0)
 979                 return ret;
 980
 981         if (tca[TCA_ACT_TAB] == NULL) {
 982                 pr_notice("tc_ctl_action: received NO action attribs\n");
 983                 return -EINVAL;
 984         }
 985
 986         /* n->nlmsg_flags & NLM_F_CREATE */
 987         switch (n->nlmsg_type) {
 988         case RTM_NEWACTION:
 989                 /* we are going to assume all other flags
 990                  * imply create only if it doesn't exist
 991                  * Note that CREATE | EXCL implies that
 992                  * but since we want avoid ambiguity (eg when flags
 993                  * is zero) then just set this
 994                  */
 995                 if (n->nlmsg_flags & NLM_F_REPLACE)
 996                         ovr = 1;
 997 replay:
 998                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr);
 999                 if (ret == -EAGAIN)
1000                         goto replay;
1001                 break;
1002         case RTM_DELACTION:
1003                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1004                                     portid, RTM_DELACTION);
1005                 break;
1006         case RTM_GETACTION:
1007                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1008                                     portid, RTM_GETACTION);
1009                 break;
1010         default:
1011                 BUG();
1012         }
1013
1014         return ret;
1015 }
1016
1017 static struct nlattr *
1018 find_dump_kind(const struct nlmsghdr *n)
1019 {
1020         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1021         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1022         struct nlattr *nla[TCAA_MAX + 1];
1023         struct nlattr *kind;
1024
1025         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1026                 return NULL;
1027         tb1 = nla[TCA_ACT_TAB];
1028         if (tb1 == NULL)
1029                 return NULL;
1030
1031         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1032                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1033                 return NULL;
1034
1035         if (tb[1] == NULL)
1036                 return NULL;
1037         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1038                       nla_len(tb[1]), NULL) < 0)
1039                 return NULL;
1040         kind = tb2[TCA_ACT_KIND];
1041
1042         return kind;
1043 }
1044
1045 static int
1046 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1047 {
1048         struct nlmsghdr *nlh;
1049         unsigned char *b = skb_tail_pointer(skb);
1050         struct nlattr *nest;
1051         struct tc_action_ops *a_o;
1052         struct tc_action a;
1053         int ret = 0;
1054         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1055         struct nlattr *kind = find_dump_kind(cb->nlh);
1056
1057         if (kind == NULL) {
1058                 pr_info("tc_dump_action: action bad kind\n");
1059                 return 0;
1060         }
1061
1062         a_o = tc_lookup_action(kind);
1063         if (a_o == NULL)
1064                 return 0;
1065
1066         memset(&a, 0, sizeof(struct tc_action));
1067         a.ops = a_o;
1068
1069         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1070                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1071         if (!nlh)
1072                 goto out_module_put;
1073         t = nlmsg_data(nlh);
1074         t->tca_family = AF_UNSPEC;
1075         t->tca__pad1 = 0;
1076         t->tca__pad2 = 0;
1077
1078         nest = nla_nest_start(skb, TCA_ACT_TAB);
1079         if (nest == NULL)
1080                 goto out_module_put;
1081
1082         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1083         if (ret < 0)
1084                 goto out_module_put;
1085
1086         if (ret > 0) {
1087                 nla_nest_end(skb, nest);
1088                 ret = skb->len;
1089         } else
1090                 nla_nest_cancel(skb, nest);
1091
1092         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1093         if (NETLINK_CB(cb->skb).portid && ret)
1094                 nlh->nlmsg_flags |= NLM_F_MULTI;
1095         module_put(a_o->owner);
1096         return skb->len;
1097
1098 out_module_put:
1099         module_put(a_o->owner);
1100         nlmsg_trim(skb, b);
1101         return skb->len;
1102 }
1103
1104 static int __init tc_action_init(void)
1105 {
1106         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
1107         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
1108         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1109                       NULL);
1110
1111         return 0;
1112 }
1113
1114 subsys_initcall(tc_action_init);