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