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