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