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 static void tcf_hash_destroy(struct tcf_hashinfo *hinfo, struct tc_action *a)
  40 {
  41         struct tcf_common *p = a->priv;
  42
  43         spin_lock_bh(&hinfo->lock);
  44         hlist_del(&p->tcfc_head);
  45         spin_unlock_bh(&hinfo->lock);
  46         gen_kill_estimator(&p->tcfc_bstats,
  47                            &p->tcfc_rate_est);
  48         /*
  49          * gen_estimator est_timer() might access p->tcfc_lock
  50          * or bstats, wait a RCU grace period before freeing p
  51          */
  52         call_rcu(&p->tcfc_rcu, free_tcf);
  53 }
  54
  55 int __tcf_hash_release(struct tc_action *a, bool bind, bool strict)
  56 {
  57         struct tcf_common *p = a->priv;
  58         int ret = 0;
  59
  60         if (p) {
  61                 if (bind)
  62                         p->tcfc_bindcnt--;
  63                 else if (strict && p->tcfc_bindcnt > 0)
  64                         return -EPERM;
  65
  66                 p->tcfc_refcnt--;
  67                 if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
  68                         if (a->ops->cleanup)
  69                                 a->ops->cleanup(a, bind);
  70                         tcf_hash_destroy(a->hinfo, a);
  71                         ret = ACT_P_DELETED;
  72                 }
  73         }
  74
  75         return ret;
  76 }
  77 EXPORT_SYMBOL(__tcf_hash_release);
  78
  79 static int tcf_dump_walker(struct tcf_hashinfo *hinfo, struct sk_buff *skb,
  80                            struct netlink_callback *cb, struct tc_action *a)
  81 {
  82         struct hlist_head *head;
  83         struct tcf_common *p;
  84         int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
  85         struct nlattr *nest;
  86
  87         spin_lock_bh(&hinfo->lock);
  88
  89         s_i = cb->args[0];
  90
  91         for (i = 0; i < (hinfo->hmask + 1); i++) {
  92                 head = &hinfo->htab[tcf_hash(i, hinfo->hmask)];
  93
  94                 hlist_for_each_entry_rcu(p, head, tcfc_head) {
  95                         index++;
  96                         if (index < s_i)
  97                                 continue;
  98                         a->priv = p;
  99                         a->order = n_i;
 100
 101                         nest = nla_nest_start(skb, a->order);
 102                         if (nest == NULL)
 103                                 goto nla_put_failure;
 104                         err = tcf_action_dump_1(skb, a, 0, 0);
 105                         if (err < 0) {
 106                                 index--;
 107                                 nlmsg_trim(skb, nest);
 108                                 goto done;
 109                         }
 110                         nla_nest_end(skb, nest);
 111                         n_i++;
 112                         if (n_i >= TCA_ACT_MAX_PRIO)
 113                                 goto done;
 114                 }
 115         }
 116 done:
 117         spin_unlock_bh(&hinfo->lock);
 118         if (n_i)
 119                 cb->args[0] += n_i;
 120         return n_i;
 121
 122 nla_put_failure:
 123         nla_nest_cancel(skb, nest);
 124         goto done;
 125 }
 126
 127 static int tcf_del_walker(struct tcf_hashinfo *hinfo, struct sk_buff *skb,
 128                           struct tc_action *a)
 129 {
 130         struct hlist_head *head;
 131         struct hlist_node *n;
 132         struct tcf_common *p;
 133         struct nlattr *nest;
 134         int i = 0, n_i = 0;
 135         int ret = -EINVAL;
 136
 137         nest = nla_nest_start(skb, a->order);
 138         if (nest == NULL)
 139                 goto nla_put_failure;
 140         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 141                 goto nla_put_failure;
 142         for (i = 0; i < (hinfo->hmask + 1); i++) {
 143                 head = &hinfo->htab[tcf_hash(i, hinfo->hmask)];
 144                 hlist_for_each_entry_safe(p, n, head, tcfc_head) {
 145                         a->priv = p;
 146                         ret = __tcf_hash_release(a, false, true);
 147                         if (ret == ACT_P_DELETED) {
 148                                 module_put(a->ops->owner);
 149                                 n_i++;
 150                         } else if (ret < 0)
 151                                 goto nla_put_failure;
 152                 }
 153         }
 154         if (nla_put_u32(skb, TCA_FCNT, n_i))
 155                 goto nla_put_failure;
 156         nla_nest_end(skb, nest);
 157
 158         return n_i;
 159 nla_put_failure:
 160         nla_nest_cancel(skb, nest);
 161         return ret;
 162 }
 163
 164 int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
 165                        struct netlink_callback *cb, int type,
 166                        struct tc_action *a)
 167 {
 168         struct tcf_hashinfo *hinfo = tn->hinfo;
 169
 170         a->hinfo = hinfo;
 171
 172         if (type == RTM_DELACTION) {
 173                 return tcf_del_walker(hinfo, skb, a);
 174         } else if (type == RTM_GETACTION) {
 175                 return tcf_dump_walker(hinfo, skb, cb, a);
 176         } else {
 177                 WARN(1, "tcf_generic_walker: unknown action %d\n", type);
 178                 return -EINVAL;
 179         }
 180 }
 181 EXPORT_SYMBOL(tcf_generic_walker);
 182
 183 static struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 184 {
 185         struct tcf_common *p = NULL;
 186         struct hlist_head *head;
 187
 188         spin_lock_bh(&hinfo->lock);
 189         head = &hinfo->htab[tcf_hash(index, hinfo->hmask)];
 190         hlist_for_each_entry_rcu(p, head, tcfc_head)
 191                 if (p->tcfc_index == index)
 192                         break;
 193         spin_unlock_bh(&hinfo->lock);
 194
 195         return p;
 196 }
 197
 198 u32 tcf_hash_new_index(struct tc_action_net *tn)
 199 {
 200         struct tcf_hashinfo *hinfo = tn->hinfo;
 201         u32 val = hinfo->index;
 202
 203         do {
 204                 if (++val == 0)
 205                         val = 1;
 206         } while (tcf_hash_lookup(val, hinfo));
 207
 208         hinfo->index = val;
 209         return val;
 210 }
 211 EXPORT_SYMBOL(tcf_hash_new_index);
 212
 213 int tcf_hash_search(struct tc_action_net *tn, struct tc_action *a, u32 index)
 214 {
 215         struct tcf_hashinfo *hinfo = tn->hinfo;
 216         struct tcf_common *p = tcf_hash_lookup(index, hinfo);
 217
 218         if (p) {
 219                 a->priv = p;
 220                 a->hinfo = hinfo;
 221                 return 1;
 222         }
 223         return 0;
 224 }
 225 EXPORT_SYMBOL(tcf_hash_search);
 226
 227 int tcf_hash_check(struct tc_action_net *tn, u32 index, struct tc_action *a,
 228                    int bind)
 229 {
 230         struct tcf_hashinfo *hinfo = tn->hinfo;
 231         struct tcf_common *p = NULL;
 232         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 233                 if (bind)
 234                         p->tcfc_bindcnt++;
 235                 p->tcfc_refcnt++;
 236                 a->priv = p;
 237                 a->hinfo = hinfo;
 238                 return 1;
 239         }
 240         return 0;
 241 }
 242 EXPORT_SYMBOL(tcf_hash_check);
 243
 244 void tcf_hash_cleanup(struct tc_action *a, struct nlattr *est)
 245 {
 246         struct tcf_common *pc = a->priv;
 247         if (est)
 248                 gen_kill_estimator(&pc->tcfc_bstats,
 249                                    &pc->tcfc_rate_est);
 250         call_rcu(&pc->tcfc_rcu, free_tcf);
 251 }
 252 EXPORT_SYMBOL(tcf_hash_cleanup);
 253
 254 int tcf_hash_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
 255                     struct tc_action *a, int size, int bind, bool cpustats)
 256 {
 257         struct tcf_common *p = kzalloc(size, GFP_KERNEL);
 258         struct tcf_hashinfo *hinfo = tn->hinfo;
 259         int err = -ENOMEM;
 260
 261         if (unlikely(!p))
 262                 return -ENOMEM;
 263         p->tcfc_refcnt = 1;
 264         if (bind)
 265                 p->tcfc_bindcnt = 1;
 266
 267         if (cpustats) {
 268                 p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
 269                 if (!p->cpu_bstats) {
 270 err1:
 271                         kfree(p);
 272                         return err;
 273                 }
 274                 p->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
 275                 if (!p->cpu_qstats) {
 276 err2:
 277                         free_percpu(p->cpu_bstats);
 278                         goto err1;
 279                 }
 280         }
 281         spin_lock_init(&p->tcfc_lock);
 282         INIT_HLIST_NODE(&p->tcfc_head);
 283         p->tcfc_index = index ? index : tcf_hash_new_index(tn);
 284         p->tcfc_tm.install = jiffies;
 285         p->tcfc_tm.lastuse = jiffies;
 286         p->tcfc_tm.firstuse = 0;
 287         if (est) {
 288                 err = gen_new_estimator(&p->tcfc_bstats, p->cpu_bstats,
 289                                         &p->tcfc_rate_est,
 290                                         &p->tcfc_lock, NULL, est);
 291                 if (err) {
 292                         free_percpu(p->cpu_qstats);
 293                         goto err2;
 294                 }
 295         }
 296
 297         a->priv = (void *) p;
 298         a->hinfo = hinfo;
 299         return 0;
 300 }
 301 EXPORT_SYMBOL(tcf_hash_create);
 302
 303 void tcf_hash_insert(struct tc_action_net *tn, struct tc_action *a)
 304 {
 305         struct tcf_common *p = a->priv;
 306         struct tcf_hashinfo *hinfo = tn->hinfo;
 307         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
 308
 309         spin_lock_bh(&hinfo->lock);
 310         hlist_add_head(&p->tcfc_head, &hinfo->htab[h]);
 311         spin_unlock_bh(&hinfo->lock);
 312 }
 313 EXPORT_SYMBOL(tcf_hash_insert);
 314
 315 void tcf_hashinfo_destroy(const struct tc_action_ops *ops,
 316                           struct tcf_hashinfo *hinfo)
 317 {
 318         struct tc_action a = {
 319                 .ops = ops,
 320                 .hinfo = hinfo,
 321         };
 322         int i;
 323
 324         for (i = 0; i < hinfo->hmask + 1; i++) {
 325                 struct tcf_common *p;
 326                 struct hlist_node *n;
 327
 328                 hlist_for_each_entry_safe(p, n, &hinfo->htab[i], tcfc_head) {
 329                         int ret;
 330
 331                         a.priv = p;
 332                         ret = __tcf_hash_release(&a, false, true);
 333                         if (ret == ACT_P_DELETED)
 334                                 module_put(ops->owner);
 335                         else if (ret < 0)
 336                                 return;
 337                 }
 338         }
 339         kfree(hinfo->htab);
 340 }
 341 EXPORT_SYMBOL(tcf_hashinfo_destroy);
 342
 343 static LIST_HEAD(act_base);
 344 static DEFINE_RWLOCK(act_mod_lock);
 345
 346 int tcf_register_action(struct tc_action_ops *act,
 347                         struct pernet_operations *ops)
 348 {
 349         struct tc_action_ops *a;
 350         int ret;
 351
 352         if (!act->act || !act->dump || !act->init || !act->walk || !act->lookup)
 353                 return -EINVAL;
 354
 355         write_lock(&act_mod_lock);
 356         list_for_each_entry(a, &act_base, head) {
 357                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 358                         write_unlock(&act_mod_lock);
 359                         return -EEXIST;
 360                 }
 361         }
 362         list_add_tail(&act->head, &act_base);
 363         write_unlock(&act_mod_lock);
 364
 365         ret = register_pernet_subsys(ops);
 366         if (ret) {
 367                 tcf_unregister_action(act, ops);
 368                 return ret;
 369         }
 370
 371         return 0;
 372 }
 373 EXPORT_SYMBOL(tcf_register_action);
 374
 375 int tcf_unregister_action(struct tc_action_ops *act,
 376                           struct pernet_operations *ops)
 377 {
 378         struct tc_action_ops *a;
 379         int err = -ENOENT;
 380
 381         unregister_pernet_subsys(ops);
 382
 383         write_lock(&act_mod_lock);
 384         list_for_each_entry(a, &act_base, head) {
 385                 if (a == act) {
 386                         list_del(&act->head);
 387                         err = 0;
 388                         break;
 389                 }
 390         }
 391         write_unlock(&act_mod_lock);
 392         return err;
 393 }
 394 EXPORT_SYMBOL(tcf_unregister_action);
 395
 396 /* lookup by name */
 397 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 398 {
 399         struct tc_action_ops *a, *res = NULL;
 400
 401         if (kind) {
 402                 read_lock(&act_mod_lock);
 403                 list_for_each_entry(a, &act_base, head) {
 404                         if (strcmp(kind, a->kind) == 0) {
 405                                 if (try_module_get(a->owner))
 406                                         res = a;
 407                                 break;
 408                         }
 409                 }
 410                 read_unlock(&act_mod_lock);
 411         }
 412         return res;
 413 }
 414
 415 /* lookup by nlattr */
 416 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 417 {
 418         struct tc_action_ops *a, *res = NULL;
 419
 420         if (kind) {
 421                 read_lock(&act_mod_lock);
 422                 list_for_each_entry(a, &act_base, head) {
 423                         if (nla_strcmp(kind, a->kind) == 0) {
 424                                 if (try_module_get(a->owner))
 425                                         res = a;
 426                                 break;
 427                         }
 428                 }
 429                 read_unlock(&act_mod_lock);
 430         }
 431         return res;
 432 }
 433
 434 int tcf_action_exec(struct sk_buff *skb, const struct list_head *actions,
 435                     struct tcf_result *res)
 436 {
 437         const struct tc_action *a;
 438         int ret = -1;
 439
 440         if (skb->tc_verd & TC_NCLS) {
 441                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 442                 ret = TC_ACT_OK;
 443                 goto exec_done;
 444         }
 445         list_for_each_entry(a, actions, list) {
 446 repeat:
 447                 ret = a->ops->act(skb, a, res);
 448                 if (ret == TC_ACT_REPEAT)
 449                         goto repeat;    /* we need a ttl - JHS */
 450                 if (ret != TC_ACT_PIPE)
 451                         goto exec_done;
 452         }
 453 exec_done:
 454         return ret;
 455 }
 456 EXPORT_SYMBOL(tcf_action_exec);
 457
 458 int tcf_action_destroy(struct list_head *actions, int bind)
 459 {
 460         struct tc_action *a, *tmp;
 461         int ret = 0;
 462
 463         list_for_each_entry_safe(a, tmp, actions, list) {
 464                 ret = __tcf_hash_release(a, bind, true);
 465                 if (ret == ACT_P_DELETED)
 466                         module_put(a->ops->owner);
 467                 else if (ret < 0)
 468                         return ret;
 469                 list_del(&a->list);
 470                 kfree(a);
 471         }
 472         return ret;
 473 }
 474
 475 int
 476 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 477 {
 478         return a->ops->dump(skb, a, bind, ref);
 479 }
 480
 481 int
 482 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 483 {
 484         int err = -EINVAL;
 485         unsigned char *b = skb_tail_pointer(skb);
 486         struct nlattr *nest;
 487
 488         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 489                 goto nla_put_failure;
 490         if (tcf_action_copy_stats(skb, a, 0))
 491                 goto nla_put_failure;
 492         nest = nla_nest_start(skb, TCA_OPTIONS);
 493         if (nest == NULL)
 494                 goto nla_put_failure;
 495         err = tcf_action_dump_old(skb, a, bind, ref);
 496         if (err > 0) {
 497                 nla_nest_end(skb, nest);
 498                 return err;
 499         }
 500
 501 nla_put_failure:
 502         nlmsg_trim(skb, b);
 503         return -1;
 504 }
 505 EXPORT_SYMBOL(tcf_action_dump_1);
 506
 507 int tcf_action_dump(struct sk_buff *skb, struct list_head *actions,
 508                     int bind, int ref)
 509 {
 510         struct tc_action *a;
 511         int err = -EINVAL;
 512         struct nlattr *nest;
 513
 514         list_for_each_entry(a, actions, list) {
 515                 nest = nla_nest_start(skb, a->order);
 516                 if (nest == NULL)
 517                         goto nla_put_failure;
 518                 err = tcf_action_dump_1(skb, a, bind, ref);
 519                 if (err < 0)
 520                         goto errout;
 521                 nla_nest_end(skb, nest);
 522         }
 523
 524         return 0;
 525
 526 nla_put_failure:
 527         err = -EINVAL;
 528 errout:
 529         nla_nest_cancel(skb, nest);
 530         return err;
 531 }
 532
 533 struct tc_action *tcf_action_init_1(struct net *net, struct nlattr *nla,
 534                                     struct nlattr *est, char *name, int ovr,
 535                                     int bind)
 536 {
 537         struct tc_action *a;
 538         struct tc_action_ops *a_o;
 539         char act_name[IFNAMSIZ];
 540         struct nlattr *tb[TCA_ACT_MAX + 1];
 541         struct nlattr *kind;
 542         int err;
 543
 544         if (name == NULL) {
 545                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 546                 if (err < 0)
 547                         goto err_out;
 548                 err = -EINVAL;
 549                 kind = tb[TCA_ACT_KIND];
 550                 if (kind == NULL)
 551                         goto err_out;
 552                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 553                         goto err_out;
 554         } else {
 555                 err = -EINVAL;
 556                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 557                         goto err_out;
 558         }
 559
 560         a_o = tc_lookup_action_n(act_name);
 561         if (a_o == NULL) {
 562 #ifdef CONFIG_MODULES
 563                 rtnl_unlock();
 564                 request_module("act_%s", act_name);
 565                 rtnl_lock();
 566
 567                 a_o = tc_lookup_action_n(act_name);
 568
 569                 /* We dropped the RTNL semaphore in order to
 570                  * perform the module load.  So, even if we
 571                  * succeeded in loading the module we have to
 572                  * tell the caller to replay the request.  We
 573                  * indicate this using -EAGAIN.
 574                  */
 575                 if (a_o != NULL) {
 576                         err = -EAGAIN;
 577                         goto err_mod;
 578                 }
 579 #endif
 580                 err = -ENOENT;
 581                 goto err_out;
 582         }
 583
 584         err = -ENOMEM;
 585         a = kzalloc(sizeof(*a), GFP_KERNEL);
 586         if (a == NULL)
 587                 goto err_mod;
 588
 589         a->ops = a_o;
 590         INIT_LIST_HEAD(&a->list);
 591         /* backward compatibility for policer */
 592         if (name == NULL)
 593                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
 594         else
 595                 err = a_o->init(net, nla, est, a, ovr, bind);
 596         if (err < 0)
 597                 goto err_free;
 598
 599         /* module count goes up only when brand new policy is created
 600          * if it exists and is only bound to in a_o->init() then
 601          * ACT_P_CREATED is not returned (a zero is).
 602          */
 603         if (err != ACT_P_CREATED)
 604                 module_put(a_o->owner);
 605
 606         return a;
 607
 608 err_free:
 609         kfree(a);
 610 err_mod:
 611         module_put(a_o->owner);
 612 err_out:
 613         return ERR_PTR(err);
 614 }
 615
 616 int tcf_action_init(struct net *net, struct nlattr *nla,
 617                                   struct nlattr *est, char *name, int ovr,
 618                                   int bind, struct list_head *actions)
 619 {
 620         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 621         struct tc_action *act;
 622         int err;
 623         int i;
 624
 625         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 626         if (err < 0)
 627                 return err;
 628
 629         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 630                 act = tcf_action_init_1(net, tb[i], est, name, ovr, bind);
 631                 if (IS_ERR(act)) {
 632                         err = PTR_ERR(act);
 633                         goto err;
 634                 }
 635                 act->order = i;
 636                 list_add_tail(&act->list, actions);
 637         }
 638         return 0;
 639
 640 err:
 641         tcf_action_destroy(actions, bind);
 642         return err;
 643 }
 644
 645 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 646                           int compat_mode)
 647 {
 648         int err = 0;
 649         struct gnet_dump d;
 650         struct tcf_common *p = a->priv;
 651
 652         if (p == NULL)
 653                 goto errout;
 654
 655         /* compat_mode being true specifies a call that is supposed
 656          * to add additional backward compatibility statistic TLVs.
 657          */
 658         if (compat_mode) {
 659                 if (a->type == TCA_OLD_COMPAT)
 660                         err = gnet_stats_start_copy_compat(skb, 0,
 661                                                            TCA_STATS,
 662                                                            TCA_XSTATS,
 663                                                            &p->tcfc_lock, &d,
 664                                                            TCA_PAD);
 665                 else
 666                         return 0;
 667         } else
 668                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 669                                             &p->tcfc_lock, &d, TCA_ACT_PAD);
 670
 671         if (err < 0)
 672                 goto errout;
 673
 674         if (gnet_stats_copy_basic(NULL, &d, p->cpu_bstats, &p->tcfc_bstats) < 0 ||
 675             gnet_stats_copy_rate_est(&d, &p->tcfc_bstats,
 676                                      &p->tcfc_rate_est) < 0 ||
 677             gnet_stats_copy_queue(&d, p->cpu_qstats,
 678                                   &p->tcfc_qstats,
 679                                   p->tcfc_qstats.qlen) < 0)
 680                 goto errout;
 681
 682         if (gnet_stats_finish_copy(&d) < 0)
 683                 goto errout;
 684
 685         return 0;
 686
 687 errout:
 688         return -1;
 689 }
 690
 691 static int tca_get_fill(struct sk_buff *skb, struct list_head *actions,
 692                         u32 portid, u32 seq, u16 flags, int event, int bind,
 693                         int ref)
 694 {
 695         struct tcamsg *t;
 696         struct nlmsghdr *nlh;
 697         unsigned char *b = skb_tail_pointer(skb);
 698         struct nlattr *nest;
 699
 700         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
 701         if (!nlh)
 702                 goto out_nlmsg_trim;
 703         t = nlmsg_data(nlh);
 704         t->tca_family = AF_UNSPEC;
 705         t->tca__pad1 = 0;
 706         t->tca__pad2 = 0;
 707
 708         nest = nla_nest_start(skb, TCA_ACT_TAB);
 709         if (nest == NULL)
 710                 goto out_nlmsg_trim;
 711
 712         if (tcf_action_dump(skb, actions, bind, ref) < 0)
 713                 goto out_nlmsg_trim;
 714
 715         nla_nest_end(skb, nest);
 716
 717         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 718         return skb->len;
 719
 720 out_nlmsg_trim:
 721         nlmsg_trim(skb, b);
 722         return -1;
 723 }
 724
 725 static int
 726 act_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
 727                struct list_head *actions, int event)
 728 {
 729         struct sk_buff *skb;
 730
 731         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 732         if (!skb)
 733                 return -ENOBUFS;
 734         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event,
 735                          0, 0) <= 0) {
 736                 kfree_skb(skb);
 737                 return -EINVAL;
 738         }
 739
 740         return rtnl_unicast(skb, net, portid);
 741 }
 742
 743 static struct tc_action *create_a(int i)
 744 {
 745         struct tc_action *act;
 746
 747         act = kzalloc(sizeof(*act), GFP_KERNEL);
 748         if (act == NULL) {
 749                 pr_debug("create_a: failed to alloc!\n");
 750                 return NULL;
 751         }
 752         act->order = i;
 753         INIT_LIST_HEAD(&act->list);
 754         return act;
 755 }
 756
 757 static struct tc_action *tcf_action_get_1(struct net *net, struct nlattr *nla,
 758                                           struct nlmsghdr *n, u32 portid)
 759 {
 760         struct nlattr *tb[TCA_ACT_MAX + 1];
 761         struct tc_action *a;
 762         int index;
 763         int err;
 764
 765         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 766         if (err < 0)
 767                 goto err_out;
 768
 769         err = -EINVAL;
 770         if (tb[TCA_ACT_INDEX] == NULL ||
 771             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 772                 goto err_out;
 773         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 774
 775         err = -ENOMEM;
 776         a = create_a(0);
 777         if (a == NULL)
 778                 goto err_out;
 779
 780         err = -EINVAL;
 781         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 782         if (a->ops == NULL) /* could happen in batch of actions */
 783                 goto err_free;
 784         err = -ENOENT;
 785         if (a->ops->lookup(net, a, index) == 0)
 786                 goto err_mod;
 787
 788         module_put(a->ops->owner);
 789         return a;
 790
 791 err_mod:
 792         module_put(a->ops->owner);
 793 err_free:
 794         kfree(a);
 795 err_out:
 796         return ERR_PTR(err);
 797 }
 798
 799 static void cleanup_a(struct list_head *actions)
 800 {
 801         struct tc_action *a, *tmp;
 802
 803         list_for_each_entry_safe(a, tmp, actions, list) {
 804                 list_del(&a->list);
 805                 kfree(a);
 806         }
 807 }
 808
 809 static int tca_action_flush(struct net *net, struct nlattr *nla,
 810                             struct nlmsghdr *n, u32 portid)
 811 {
 812         struct sk_buff *skb;
 813         unsigned char *b;
 814         struct nlmsghdr *nlh;
 815         struct tcamsg *t;
 816         struct netlink_callback dcb;
 817         struct nlattr *nest;
 818         struct nlattr *tb[TCA_ACT_MAX + 1];
 819         struct nlattr *kind;
 820         struct tc_action a;
 821         int err = -ENOMEM;
 822
 823         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 824         if (!skb) {
 825                 pr_debug("tca_action_flush: failed skb alloc\n");
 826                 return err;
 827         }
 828
 829         b = skb_tail_pointer(skb);
 830
 831         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 832         if (err < 0)
 833                 goto err_out;
 834
 835         err = -EINVAL;
 836         kind = tb[TCA_ACT_KIND];
 837         memset(&a, 0, sizeof(struct tc_action));
 838         INIT_LIST_HEAD(&a.list);
 839         a.ops = tc_lookup_action(kind);
 840         if (a.ops == NULL) /*some idjot trying to flush unknown action */
 841                 goto err_out;
 842
 843         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION,
 844                         sizeof(*t), 0);
 845         if (!nlh)
 846                 goto out_module_put;
 847         t = nlmsg_data(nlh);
 848         t->tca_family = AF_UNSPEC;
 849         t->tca__pad1 = 0;
 850         t->tca__pad2 = 0;
 851
 852         nest = nla_nest_start(skb, TCA_ACT_TAB);
 853         if (nest == NULL)
 854                 goto out_module_put;
 855
 856         err = a.ops->walk(net, skb, &dcb, RTM_DELACTION, &a);
 857         if (err < 0)
 858                 goto out_module_put;
 859         if (err == 0)
 860                 goto noflush_out;
 861
 862         nla_nest_end(skb, nest);
 863
 864         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 865         nlh->nlmsg_flags |= NLM_F_ROOT;
 866         module_put(a.ops->owner);
 867         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 868                              n->nlmsg_flags & NLM_F_ECHO);
 869         if (err > 0)
 870                 return 0;
 871
 872         return err;
 873
 874 out_module_put:
 875         module_put(a.ops->owner);
 876 err_out:
 877 noflush_out:
 878         kfree_skb(skb);
 879         return err;
 880 }
 881
 882 static int
 883 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
 884                u32 portid)
 885 {
 886         int ret;
 887         struct sk_buff *skb;
 888
 889         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 890         if (!skb)
 891                 return -ENOBUFS;
 892
 893         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
 894                          0, 1) <= 0) {
 895                 kfree_skb(skb);
 896                 return -EINVAL;
 897         }
 898
 899         /* now do the delete */
 900         ret = tcf_action_destroy(actions, 0);
 901         if (ret < 0) {
 902                 kfree_skb(skb);
 903                 return ret;
 904         }
 905
 906         ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 907                              n->nlmsg_flags & NLM_F_ECHO);
 908         if (ret > 0)
 909                 return 0;
 910         return ret;
 911 }
 912
 913 static int
 914 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 915               u32 portid, int event)
 916 {
 917         int i, ret;
 918         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 919         struct tc_action *act;
 920         LIST_HEAD(actions);
 921
 922         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 923         if (ret < 0)
 924                 return ret;
 925
 926         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
 927                 if (tb[1] != NULL)
 928                         return tca_action_flush(net, tb[1], n, portid);
 929                 else
 930                         return -EINVAL;
 931         }
 932
 933         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 934                 act = tcf_action_get_1(net, tb[i], n, portid);
 935                 if (IS_ERR(act)) {
 936                         ret = PTR_ERR(act);
 937                         goto err;
 938                 }
 939                 act->order = i;
 940                 list_add_tail(&act->list, &actions);
 941         }
 942
 943         if (event == RTM_GETACTION)
 944                 ret = act_get_notify(net, portid, n, &actions, event);
 945         else { /* delete */
 946                 ret = tcf_del_notify(net, n, &actions, portid);
 947                 if (ret)
 948                         goto err;
 949                 return ret;
 950         }
 951 err:
 952         cleanup_a(&actions);
 953         return ret;
 954 }
 955
 956 static int
 957 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
 958                u32 portid)
 959 {
 960         struct sk_buff *skb;
 961         int err = 0;
 962
 963         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 964         if (!skb)
 965                 return -ENOBUFS;
 966
 967         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
 968                          RTM_NEWACTION, 0, 0) <= 0) {
 969                 kfree_skb(skb);
 970                 return -EINVAL;
 971         }
 972
 973         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 974                              n->nlmsg_flags & NLM_F_ECHO);
 975         if (err > 0)
 976                 err = 0;
 977         return err;
 978 }
 979
 980 static int
 981 tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 982                u32 portid, int ovr)
 983 {
 984         int ret = 0;
 985         LIST_HEAD(actions);
 986
 987         ret = tcf_action_init(net, nla, NULL, NULL, ovr, 0, &actions);
 988         if (ret)
 989                 goto done;
 990
 991         /* dump then free all the actions after update; inserted policy
 992          * stays intact
 993          */
 994         ret = tcf_add_notify(net, n, &actions, portid);
 995         cleanup_a(&actions);
 996 done:
 997         return ret;
 998 }
 999
1000 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n)
1001 {
1002         struct net *net = sock_net(skb->sk);
1003         struct nlattr *tca[TCA_ACT_MAX + 1];
1004         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
1005         int ret = 0, ovr = 0;
1006
1007         if ((n->nlmsg_type != RTM_GETACTION) &&
1008             !netlink_capable(skb, CAP_NET_ADMIN))
1009                 return -EPERM;
1010
1011         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
1012         if (ret < 0)
1013                 return ret;
1014
1015         if (tca[TCA_ACT_TAB] == NULL) {
1016                 pr_notice("tc_ctl_action: received NO action attribs\n");
1017                 return -EINVAL;
1018         }
1019
1020         /* n->nlmsg_flags & NLM_F_CREATE */
1021         switch (n->nlmsg_type) {
1022         case RTM_NEWACTION:
1023                 /* we are going to assume all other flags
1024                  * imply create only if it doesn't exist
1025                  * Note that CREATE | EXCL implies that
1026                  * but since we want avoid ambiguity (eg when flags
1027                  * is zero) then just set this
1028                  */
1029                 if (n->nlmsg_flags & NLM_F_REPLACE)
1030                         ovr = 1;
1031 replay:
1032                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr);
1033                 if (ret == -EAGAIN)
1034                         goto replay;
1035                 break;
1036         case RTM_DELACTION:
1037                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1038                                     portid, RTM_DELACTION);
1039                 break;
1040         case RTM_GETACTION:
1041                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1042                                     portid, RTM_GETACTION);
1043                 break;
1044         default:
1045                 BUG();
1046         }
1047
1048         return ret;
1049 }
1050
1051 static struct nlattr *
1052 find_dump_kind(const struct nlmsghdr *n)
1053 {
1054         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1055         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1056         struct nlattr *nla[TCAA_MAX + 1];
1057         struct nlattr *kind;
1058
1059         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1060                 return NULL;
1061         tb1 = nla[TCA_ACT_TAB];
1062         if (tb1 == NULL)
1063                 return NULL;
1064
1065         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1066                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1067                 return NULL;
1068
1069         if (tb[1] == NULL)
1070                 return NULL;
1071         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1072                       nla_len(tb[1]), NULL) < 0)
1073                 return NULL;
1074         kind = tb2[TCA_ACT_KIND];
1075
1076         return kind;
1077 }
1078
1079 static int
1080 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1081 {
1082         struct net *net = sock_net(skb->sk);
1083         struct nlmsghdr *nlh;
1084         unsigned char *b = skb_tail_pointer(skb);
1085         struct nlattr *nest;
1086         struct tc_action_ops *a_o;
1087         struct tc_action a;
1088         int ret = 0;
1089         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1090         struct nlattr *kind = find_dump_kind(cb->nlh);
1091
1092         if (kind == NULL) {
1093                 pr_info("tc_dump_action: action bad kind\n");
1094                 return 0;
1095         }
1096
1097         a_o = tc_lookup_action(kind);
1098         if (a_o == NULL)
1099                 return 0;
1100
1101         memset(&a, 0, sizeof(struct tc_action));
1102         a.ops = a_o;
1103
1104         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1105                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1106         if (!nlh)
1107                 goto out_module_put;
1108         t = nlmsg_data(nlh);
1109         t->tca_family = AF_UNSPEC;
1110         t->tca__pad1 = 0;
1111         t->tca__pad2 = 0;
1112
1113         nest = nla_nest_start(skb, TCA_ACT_TAB);
1114         if (nest == NULL)
1115                 goto out_module_put;
1116
1117         ret = a_o->walk(net, skb, cb, RTM_GETACTION, &a);
1118         if (ret < 0)
1119                 goto out_module_put;
1120
1121         if (ret > 0) {
1122                 nla_nest_end(skb, nest);
1123                 ret = skb->len;
1124         } else
1125                 nla_nest_cancel(skb, nest);
1126
1127         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1128         if (NETLINK_CB(cb->skb).portid && ret)
1129                 nlh->nlmsg_flags |= NLM_F_MULTI;
1130         module_put(a_o->owner);
1131         return skb->len;
1132
1133 out_module_put:
1134         module_put(a_o->owner);
1135         nlmsg_trim(skb, b);
1136         return skb->len;
1137 }
1138
1139 static int __init tc_action_init(void)
1140 {
1141         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
1142         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
1143         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1144                       NULL);
1145
1146         return 0;
1147 }
1148
1149 subsys_initcall(tc_action_init);