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 void tcf_hash_destroy(struct tc_action *a)
  31 {
  32         struct tcf_common *p = a->priv;
  33         struct tcf_hashinfo *hinfo = a->ops->hinfo;
  34
  35         spin_lock_bh(&hinfo->lock);
  36         hlist_del(&p->tcfc_head);
  37         spin_unlock_bh(&hinfo->lock);
  38         gen_kill_estimator(&p->tcfc_bstats,
  39                            &p->tcfc_rate_est);
  40         /*
  41          * gen_estimator est_timer() might access p->tcfc_lock
  42          * or bstats, wait a RCU grace period before freeing p
  43          */
  44         kfree_rcu(p, tcfc_rcu);
  45 }
  46 EXPORT_SYMBOL(tcf_hash_destroy);
  47
  48 int tcf_hash_release(struct tc_action *a, int bind)
  49 {
  50         struct tcf_common *p = a->priv;
  51         int ret = 0;
  52
  53         if (p) {
  54                 if (bind)
  55                         p->tcfc_bindcnt--;
  56                 else if (p->tcfc_bindcnt > 0)
  57                         return -EPERM;
  58
  59                 p->tcfc_refcnt--;
  60                 if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
  61                         if (a->ops->cleanup)
  62                                 a->ops->cleanup(a, bind);
  63                         tcf_hash_destroy(a);
  64                         ret = 1;
  65                 }
  66         }
  67         return ret;
  68 }
  69 EXPORT_SYMBOL(tcf_hash_release);
  70
  71 static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
  72                            struct tc_action *a)
  73 {
  74         struct tcf_hashinfo *hinfo = a->ops->hinfo;
  75         struct hlist_head *head;
  76         struct tcf_common *p;
  77         int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
  78         struct nlattr *nest;
  79
  80         spin_lock_bh(&hinfo->lock);
  81
  82         s_i = cb->args[0];
  83
  84         for (i = 0; i < (hinfo->hmask + 1); i++) {
  85                 head = &hinfo->htab[tcf_hash(i, hinfo->hmask)];
  86
  87                 hlist_for_each_entry_rcu(p, head, tcfc_head) {
  88                         index++;
  89                         if (index < s_i)
  90                                 continue;
  91                         a->priv = p;
  92                         a->order = n_i;
  93
  94                         nest = nla_nest_start(skb, a->order);
  95                         if (nest == NULL)
  96                                 goto nla_put_failure;
  97                         err = tcf_action_dump_1(skb, a, 0, 0);
  98                         if (err < 0) {
  99                                 index--;
 100                                 nlmsg_trim(skb, nest);
 101                                 goto done;
 102                         }
 103                         nla_nest_end(skb, nest);
 104                         n_i++;
 105                         if (n_i >= TCA_ACT_MAX_PRIO)
 106                                 goto done;
 107                 }
 108         }
 109 done:
 110         spin_unlock_bh(&hinfo->lock);
 111         if (n_i)
 112                 cb->args[0] += n_i;
 113         return n_i;
 114
 115 nla_put_failure:
 116         nla_nest_cancel(skb, nest);
 117         goto done;
 118 }
 119
 120 static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a)
 121 {
 122         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 123         struct hlist_head *head;
 124         struct hlist_node *n;
 125         struct tcf_common *p;
 126         struct nlattr *nest;
 127         int i = 0, n_i = 0;
 128         int ret = -EINVAL;
 129
 130         nest = nla_nest_start(skb, a->order);
 131         if (nest == NULL)
 132                 goto nla_put_failure;
 133         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 134                 goto nla_put_failure;
 135         for (i = 0; i < (hinfo->hmask + 1); i++) {
 136                 head = &hinfo->htab[tcf_hash(i, hinfo->hmask)];
 137                 hlist_for_each_entry_safe(p, n, head, tcfc_head) {
 138                         a->priv = p;
 139                         ret = tcf_hash_release(a, 0);
 140                         if (ret == ACT_P_DELETED) {
 141                                 module_put(a->ops->owner);
 142                                 n_i++;
 143                         } else if (ret < 0)
 144                                 goto nla_put_failure;
 145                 }
 146         }
 147         if (nla_put_u32(skb, TCA_FCNT, n_i))
 148                 goto nla_put_failure;
 149         nla_nest_end(skb, nest);
 150
 151         return n_i;
 152 nla_put_failure:
 153         nla_nest_cancel(skb, nest);
 154         return ret;
 155 }
 156
 157 static int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
 158                               int type, struct tc_action *a)
 159 {
 160         if (type == RTM_DELACTION) {
 161                 return tcf_del_walker(skb, a);
 162         } else if (type == RTM_GETACTION) {
 163                 return tcf_dump_walker(skb, cb, a);
 164         } else {
 165                 WARN(1, "tcf_generic_walker: unknown action %d\n", type);
 166                 return -EINVAL;
 167         }
 168 }
 169
 170 static struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 171 {
 172         struct tcf_common *p = NULL;
 173         struct hlist_head *head;
 174
 175         spin_lock_bh(&hinfo->lock);
 176         head = &hinfo->htab[tcf_hash(index, hinfo->hmask)];
 177         hlist_for_each_entry_rcu(p, head, tcfc_head)
 178                 if (p->tcfc_index == index)
 179                         break;
 180         spin_unlock_bh(&hinfo->lock);
 181
 182         return p;
 183 }
 184
 185 u32 tcf_hash_new_index(struct tcf_hashinfo *hinfo)
 186 {
 187         u32 val = hinfo->index;
 188
 189         do {
 190                 if (++val == 0)
 191                         val = 1;
 192         } while (tcf_hash_lookup(val, hinfo));
 193
 194         hinfo->index = val;
 195         return val;
 196 }
 197 EXPORT_SYMBOL(tcf_hash_new_index);
 198
 199 int tcf_hash_search(struct tc_action *a, u32 index)
 200 {
 201         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 202         struct tcf_common *p = tcf_hash_lookup(index, hinfo);
 203
 204         if (p) {
 205                 a->priv = p;
 206                 return 1;
 207         }
 208         return 0;
 209 }
 210 EXPORT_SYMBOL(tcf_hash_search);
 211
 212 int tcf_hash_check(u32 index, struct tc_action *a, int bind)
 213 {
 214         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 215         struct tcf_common *p = NULL;
 216         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 217                 if (bind)
 218                         p->tcfc_bindcnt++;
 219                 p->tcfc_refcnt++;
 220                 a->priv = p;
 221                 return 1;
 222         }
 223         return 0;
 224 }
 225 EXPORT_SYMBOL(tcf_hash_check);
 226
 227 void tcf_hash_cleanup(struct tc_action *a, struct nlattr *est)
 228 {
 229         struct tcf_common *pc = a->priv;
 230         if (est)
 231                 gen_kill_estimator(&pc->tcfc_bstats,
 232                                    &pc->tcfc_rate_est);
 233         kfree_rcu(pc, tcfc_rcu);
 234 }
 235 EXPORT_SYMBOL(tcf_hash_cleanup);
 236
 237 int tcf_hash_create(u32 index, struct nlattr *est, struct tc_action *a,
 238                     int size, int bind)
 239 {
 240         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 241         struct tcf_common *p = kzalloc(size, GFP_KERNEL);
 242
 243         if (unlikely(!p))
 244                 return -ENOMEM;
 245         p->tcfc_refcnt = 1;
 246         if (bind)
 247                 p->tcfc_bindcnt = 1;
 248
 249         spin_lock_init(&p->tcfc_lock);
 250         INIT_HLIST_NODE(&p->tcfc_head);
 251         p->tcfc_index = index ? index : tcf_hash_new_index(hinfo);
 252         p->tcfc_tm.install = jiffies;
 253         p->tcfc_tm.lastuse = jiffies;
 254         if (est) {
 255                 int err = gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
 256                                             &p->tcfc_lock, est);
 257                 if (err) {
 258                         kfree(p);
 259                         return err;
 260                 }
 261         }
 262
 263         a->priv = (void *) p;
 264         return 0;
 265 }
 266 EXPORT_SYMBOL(tcf_hash_create);
 267
 268 void tcf_hash_insert(struct tc_action *a)
 269 {
 270         struct tcf_common *p = a->priv;
 271         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 272         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
 273
 274         spin_lock_bh(&hinfo->lock);
 275         hlist_add_head(&p->tcfc_head, &hinfo->htab[h]);
 276         spin_unlock_bh(&hinfo->lock);
 277 }
 278 EXPORT_SYMBOL(tcf_hash_insert);
 279
 280 static LIST_HEAD(act_base);
 281 static DEFINE_RWLOCK(act_mod_lock);
 282
 283 int tcf_register_action(struct tc_action_ops *act, unsigned int mask)
 284 {
 285         struct tc_action_ops *a;
 286         int err;
 287
 288         /* Must supply act, dump and init */
 289         if (!act->act || !act->dump || !act->init)
 290                 return -EINVAL;
 291
 292         /* Supply defaults */
 293         if (!act->lookup)
 294                 act->lookup = tcf_hash_search;
 295         if (!act->walk)
 296                 act->walk = tcf_generic_walker;
 297
 298         act->hinfo = kmalloc(sizeof(struct tcf_hashinfo), GFP_KERNEL);
 299         if (!act->hinfo)
 300                 return -ENOMEM;
 301         err = tcf_hashinfo_init(act->hinfo, mask);
 302         if (err) {
 303                 kfree(act->hinfo);
 304                 return err;
 305         }
 306
 307         write_lock(&act_mod_lock);
 308         list_for_each_entry(a, &act_base, head) {
 309                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 310                         write_unlock(&act_mod_lock);
 311                         tcf_hashinfo_destroy(act->hinfo);
 312                         kfree(act->hinfo);
 313                         return -EEXIST;
 314                 }
 315         }
 316         list_add_tail(&act->head, &act_base);
 317         write_unlock(&act_mod_lock);
 318         return 0;
 319 }
 320 EXPORT_SYMBOL(tcf_register_action);
 321
 322 int tcf_unregister_action(struct tc_action_ops *act)
 323 {
 324         struct tc_action_ops *a;
 325         int err = -ENOENT;
 326
 327         write_lock(&act_mod_lock);
 328         list_for_each_entry(a, &act_base, head) {
 329                 if (a == act) {
 330                         list_del(&act->head);
 331                         tcf_hashinfo_destroy(act->hinfo);
 332                         kfree(act->hinfo);
 333                         err = 0;
 334                         break;
 335                 }
 336         }
 337         write_unlock(&act_mod_lock);
 338         return err;
 339 }
 340 EXPORT_SYMBOL(tcf_unregister_action);
 341
 342 /* lookup by name */
 343 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 344 {
 345         struct tc_action_ops *a, *res = NULL;
 346
 347         if (kind) {
 348                 read_lock(&act_mod_lock);
 349                 list_for_each_entry(a, &act_base, head) {
 350                         if (strcmp(kind, a->kind) == 0) {
 351                                 if (try_module_get(a->owner))
 352                                         res = a;
 353                                 break;
 354                         }
 355                 }
 356                 read_unlock(&act_mod_lock);
 357         }
 358         return res;
 359 }
 360
 361 /* lookup by nlattr */
 362 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 363 {
 364         struct tc_action_ops *a, *res = NULL;
 365
 366         if (kind) {
 367                 read_lock(&act_mod_lock);
 368                 list_for_each_entry(a, &act_base, head) {
 369                         if (nla_strcmp(kind, a->kind) == 0) {
 370                                 if (try_module_get(a->owner))
 371                                         res = a;
 372                                 break;
 373                         }
 374                 }
 375                 read_unlock(&act_mod_lock);
 376         }
 377         return res;
 378 }
 379
 380 int tcf_action_exec(struct sk_buff *skb, const struct list_head *actions,
 381                     struct tcf_result *res)
 382 {
 383         const struct tc_action *a;
 384         int ret = -1;
 385
 386         if (skb->tc_verd & TC_NCLS) {
 387                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 388                 ret = TC_ACT_OK;
 389                 goto exec_done;
 390         }
 391         list_for_each_entry(a, actions, list) {
 392 repeat:
 393                 ret = a->ops->act(skb, a, res);
 394                 if (TC_MUNGED & skb->tc_verd) {
 395                         /* copied already, allow trampling */
 396                         skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
 397                         skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
 398                 }
 399                 if (ret == TC_ACT_REPEAT)
 400                         goto repeat;    /* we need a ttl - JHS */
 401                 if (ret != TC_ACT_PIPE)
 402                         goto exec_done;
 403         }
 404 exec_done:
 405         return ret;
 406 }
 407 EXPORT_SYMBOL(tcf_action_exec);
 408
 409 int tcf_action_destroy(struct list_head *actions, int bind)
 410 {
 411         struct tc_action *a, *tmp;
 412         int ret = 0;
 413
 414         list_for_each_entry_safe(a, tmp, actions, list) {
 415                 ret = tcf_hash_release(a, bind);
 416                 if (ret == ACT_P_DELETED)
 417                         module_put(a->ops->owner);
 418                 else if (ret < 0)
 419                         return ret;
 420                 list_del(&a->list);
 421                 kfree(a);
 422         }
 423         return ret;
 424 }
 425
 426 int
 427 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 428 {
 429         return a->ops->dump(skb, a, bind, ref);
 430 }
 431
 432 int
 433 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 434 {
 435         int err = -EINVAL;
 436         unsigned char *b = skb_tail_pointer(skb);
 437         struct nlattr *nest;
 438
 439         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 440                 goto nla_put_failure;
 441         if (tcf_action_copy_stats(skb, a, 0))
 442                 goto nla_put_failure;
 443         nest = nla_nest_start(skb, TCA_OPTIONS);
 444         if (nest == NULL)
 445                 goto nla_put_failure;
 446         err = tcf_action_dump_old(skb, a, bind, ref);
 447         if (err > 0) {
 448                 nla_nest_end(skb, nest);
 449                 return err;
 450         }
 451
 452 nla_put_failure:
 453         nlmsg_trim(skb, b);
 454         return -1;
 455 }
 456 EXPORT_SYMBOL(tcf_action_dump_1);
 457
 458 int
 459 tcf_action_dump(struct sk_buff *skb, struct list_head *actions, int bind, int ref)
 460 {
 461         struct tc_action *a;
 462         int err = -EINVAL;
 463         struct nlattr *nest;
 464
 465         list_for_each_entry(a, actions, list) {
 466                 nest = nla_nest_start(skb, a->order);
 467                 if (nest == NULL)
 468                         goto nla_put_failure;
 469                 err = tcf_action_dump_1(skb, a, bind, ref);
 470                 if (err < 0)
 471                         goto errout;
 472                 nla_nest_end(skb, nest);
 473         }
 474
 475         return 0;
 476
 477 nla_put_failure:
 478         err = -EINVAL;
 479 errout:
 480         nla_nest_cancel(skb, nest);
 481         return err;
 482 }
 483
 484 struct tc_action *tcf_action_init_1(struct net *net, struct nlattr *nla,
 485                                     struct nlattr *est, char *name, int ovr,
 486                                     int bind)
 487 {
 488         struct tc_action *a;
 489         struct tc_action_ops *a_o;
 490         char act_name[IFNAMSIZ];
 491         struct nlattr *tb[TCA_ACT_MAX + 1];
 492         struct nlattr *kind;
 493         int err;
 494
 495         if (name == NULL) {
 496                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 497                 if (err < 0)
 498                         goto err_out;
 499                 err = -EINVAL;
 500                 kind = tb[TCA_ACT_KIND];
 501                 if (kind == NULL)
 502                         goto err_out;
 503                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 504                         goto err_out;
 505         } else {
 506                 err = -EINVAL;
 507                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 508                         goto err_out;
 509         }
 510
 511         a_o = tc_lookup_action_n(act_name);
 512         if (a_o == NULL) {
 513 #ifdef CONFIG_MODULES
 514                 rtnl_unlock();
 515                 request_module("act_%s", act_name);
 516                 rtnl_lock();
 517
 518                 a_o = tc_lookup_action_n(act_name);
 519
 520                 /* We dropped the RTNL semaphore in order to
 521                  * perform the module load.  So, even if we
 522                  * succeeded in loading the module we have to
 523                  * tell the caller to replay the request.  We
 524                  * indicate this using -EAGAIN.
 525                  */
 526                 if (a_o != NULL) {
 527                         err = -EAGAIN;
 528                         goto err_mod;
 529                 }
 530 #endif
 531                 err = -ENOENT;
 532                 goto err_out;
 533         }
 534
 535         err = -ENOMEM;
 536         a = kzalloc(sizeof(*a), GFP_KERNEL);
 537         if (a == NULL)
 538                 goto err_mod;
 539
 540         a->ops = a_o;
 541         INIT_LIST_HEAD(&a->list);
 542         /* backward compatibility for policer */
 543         if (name == NULL)
 544                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
 545         else
 546                 err = a_o->init(net, nla, est, a, ovr, bind);
 547         if (err < 0)
 548                 goto err_free;
 549
 550         /* module count goes up only when brand new policy is created
 551          * if it exists and is only bound to in a_o->init() then
 552          * ACT_P_CREATED is not returned (a zero is).
 553          */
 554         if (err != ACT_P_CREATED)
 555                 module_put(a_o->owner);
 556
 557         return a;
 558
 559 err_free:
 560         kfree(a);
 561 err_mod:
 562         module_put(a_o->owner);
 563 err_out:
 564         return ERR_PTR(err);
 565 }
 566
 567 int tcf_action_init(struct net *net, struct nlattr *nla,
 568                                   struct nlattr *est, char *name, int ovr,
 569                                   int bind, struct list_head *actions)
 570 {
 571         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 572         struct tc_action *act;
 573         int err;
 574         int i;
 575
 576         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 577         if (err < 0)
 578                 return err;
 579
 580         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 581                 act = tcf_action_init_1(net, tb[i], est, name, ovr, bind);
 582                 if (IS_ERR(act)) {
 583                         err = PTR_ERR(act);
 584                         goto err;
 585                 }
 586                 act->order = i;
 587                 list_add_tail(&act->list, actions);
 588         }
 589         return 0;
 590
 591 err:
 592         tcf_action_destroy(actions, bind);
 593         return err;
 594 }
 595
 596 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 597                           int compat_mode)
 598 {
 599         int err = 0;
 600         struct gnet_dump d;
 601         struct tcf_common *p = a->priv;
 602
 603         if (p == NULL)
 604                 goto errout;
 605
 606         /* compat_mode being true specifies a call that is supposed
 607          * to add additional backward compatibility statistic TLVs.
 608          */
 609         if (compat_mode) {
 610                 if (a->type == TCA_OLD_COMPAT)
 611                         err = gnet_stats_start_copy_compat(skb, 0,
 612                                 TCA_STATS, TCA_XSTATS, &p->tcfc_lock, &d);
 613                 else
 614                         return 0;
 615         } else
 616                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 617                                             &p->tcfc_lock, &d);
 618
 619         if (err < 0)
 620                 goto errout;
 621
 622         if (gnet_stats_copy_basic(&d, &p->tcfc_bstats) < 0 ||
 623             gnet_stats_copy_rate_est(&d, &p->tcfc_bstats,
 624                                      &p->tcfc_rate_est) < 0 ||
 625             gnet_stats_copy_queue(&d, &p->tcfc_qstats) < 0)
 626                 goto errout;
 627
 628         if (gnet_stats_finish_copy(&d) < 0)
 629                 goto errout;
 630
 631         return 0;
 632
 633 errout:
 634         return -1;
 635 }
 636
 637 static int
 638 tca_get_fill(struct sk_buff *skb, struct list_head *actions, u32 portid, u32 seq,
 639              u16 flags, int event, int bind, int ref)
 640 {
 641         struct tcamsg *t;
 642         struct nlmsghdr *nlh;
 643         unsigned char *b = skb_tail_pointer(skb);
 644         struct nlattr *nest;
 645
 646         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
 647         if (!nlh)
 648                 goto out_nlmsg_trim;
 649         t = nlmsg_data(nlh);
 650         t->tca_family = AF_UNSPEC;
 651         t->tca__pad1 = 0;
 652         t->tca__pad2 = 0;
 653
 654         nest = nla_nest_start(skb, TCA_ACT_TAB);
 655         if (nest == NULL)
 656                 goto out_nlmsg_trim;
 657
 658         if (tcf_action_dump(skb, actions, bind, ref) < 0)
 659                 goto out_nlmsg_trim;
 660
 661         nla_nest_end(skb, nest);
 662
 663         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 664         return skb->len;
 665
 666 out_nlmsg_trim:
 667         nlmsg_trim(skb, b);
 668         return -1;
 669 }
 670
 671 static int
 672 act_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
 673                struct list_head *actions, int event)
 674 {
 675         struct sk_buff *skb;
 676
 677         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 678         if (!skb)
 679                 return -ENOBUFS;
 680         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 681                 kfree_skb(skb);
 682                 return -EINVAL;
 683         }
 684
 685         return rtnl_unicast(skb, net, portid);
 686 }
 687
 688 static struct tc_action *create_a(int i)
 689 {
 690         struct tc_action *act;
 691
 692         act = kzalloc(sizeof(*act), GFP_KERNEL);
 693         if (act == NULL) {
 694                 pr_debug("create_a: failed to alloc!\n");
 695                 return NULL;
 696         }
 697         act->order = i;
 698         INIT_LIST_HEAD(&act->list);
 699         return act;
 700 }
 701
 702 static struct tc_action *
 703 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 portid)
 704 {
 705         struct nlattr *tb[TCA_ACT_MAX + 1];
 706         struct tc_action *a;
 707         int index;
 708         int err;
 709
 710         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 711         if (err < 0)
 712                 goto err_out;
 713
 714         err = -EINVAL;
 715         if (tb[TCA_ACT_INDEX] == NULL ||
 716             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 717                 goto err_out;
 718         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 719
 720         err = -ENOMEM;
 721         a = create_a(0);
 722         if (a == NULL)
 723                 goto err_out;
 724
 725         err = -EINVAL;
 726         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 727         if (a->ops == NULL) /* could happen in batch of actions */
 728                 goto err_free;
 729         err = -ENOENT;
 730         if (a->ops->lookup(a, index) == 0)
 731                 goto err_mod;
 732
 733         module_put(a->ops->owner);
 734         return a;
 735
 736 err_mod:
 737         module_put(a->ops->owner);
 738 err_free:
 739         kfree(a);
 740 err_out:
 741         return ERR_PTR(err);
 742 }
 743
 744 static void cleanup_a(struct list_head *actions)
 745 {
 746         struct tc_action *a, *tmp;
 747
 748         list_for_each_entry_safe(a, tmp, actions, list) {
 749                 list_del(&a->list);
 750                 kfree(a);
 751         }
 752 }
 753
 754 static int tca_action_flush(struct net *net, struct nlattr *nla,
 755                             struct nlmsghdr *n, u32 portid)
 756 {
 757         struct sk_buff *skb;
 758         unsigned char *b;
 759         struct nlmsghdr *nlh;
 760         struct tcamsg *t;
 761         struct netlink_callback dcb;
 762         struct nlattr *nest;
 763         struct nlattr *tb[TCA_ACT_MAX + 1];
 764         struct nlattr *kind;
 765         struct tc_action a;
 766         int err = -ENOMEM;
 767
 768         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 769         if (!skb) {
 770                 pr_debug("tca_action_flush: failed skb alloc\n");
 771                 return err;
 772         }
 773
 774         b = skb_tail_pointer(skb);
 775
 776         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 777         if (err < 0)
 778                 goto err_out;
 779
 780         err = -EINVAL;
 781         kind = tb[TCA_ACT_KIND];
 782         memset(&a, 0, sizeof(struct tc_action));
 783         INIT_LIST_HEAD(&a.list);
 784         a.ops = tc_lookup_action(kind);
 785         if (a.ops == NULL) /*some idjot trying to flush unknown action */
 786                 goto err_out;
 787
 788         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t), 0);
 789         if (!nlh)
 790                 goto out_module_put;
 791         t = nlmsg_data(nlh);
 792         t->tca_family = AF_UNSPEC;
 793         t->tca__pad1 = 0;
 794         t->tca__pad2 = 0;
 795
 796         nest = nla_nest_start(skb, TCA_ACT_TAB);
 797         if (nest == NULL)
 798                 goto out_module_put;
 799
 800         err = a.ops->walk(skb, &dcb, RTM_DELACTION, &a);
 801         if (err < 0)
 802                 goto out_module_put;
 803         if (err == 0)
 804                 goto noflush_out;
 805
 806         nla_nest_end(skb, nest);
 807
 808         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 809         nlh->nlmsg_flags |= NLM_F_ROOT;
 810         module_put(a.ops->owner);
 811         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 812                              n->nlmsg_flags & NLM_F_ECHO);
 813         if (err > 0)
 814                 return 0;
 815
 816         return err;
 817
 818 out_module_put:
 819         module_put(a.ops->owner);
 820 err_out:
 821 noflush_out:
 822         kfree_skb(skb);
 823         return err;
 824 }
 825
 826 static int
 827 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
 828                u32 portid)
 829 {
 830         int ret;
 831         struct sk_buff *skb;
 832
 833         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 834         if (!skb)
 835                 return -ENOBUFS;
 836
 837         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
 838                          0, 1) <= 0) {
 839                 kfree_skb(skb);
 840                 return -EINVAL;
 841         }
 842
 843         /* now do the delete */
 844         ret = tcf_action_destroy(actions, 0);
 845         if (ret < 0) {
 846                 kfree_skb(skb);
 847                 return ret;
 848         }
 849
 850         ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 851                              n->nlmsg_flags & NLM_F_ECHO);
 852         if (ret > 0)
 853                 return 0;
 854         return ret;
 855 }
 856
 857 static int
 858 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 859               u32 portid, int event)
 860 {
 861         int i, ret;
 862         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 863         struct tc_action *act;
 864         LIST_HEAD(actions);
 865
 866         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 867         if (ret < 0)
 868                 return ret;
 869
 870         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
 871                 if (tb[1] != NULL)
 872                         return tca_action_flush(net, tb[1], n, portid);
 873                 else
 874                         return -EINVAL;
 875         }
 876
 877         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 878                 act = tcf_action_get_1(tb[i], n, portid);
 879                 if (IS_ERR(act)) {
 880                         ret = PTR_ERR(act);
 881                         goto err;
 882                 }
 883                 act->order = i;
 884                 list_add_tail(&act->list, &actions);
 885         }
 886
 887         if (event == RTM_GETACTION)
 888                 ret = act_get_notify(net, portid, n, &actions, event);
 889         else { /* delete */
 890                 ret = tcf_del_notify(net, n, &actions, portid);
 891                 if (ret)
 892                         goto err;
 893                 return ret;
 894         }
 895 err:
 896         cleanup_a(&actions);
 897         return ret;
 898 }
 899
 900 static int
 901 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
 902                u32 portid)
 903 {
 904         struct sk_buff *skb;
 905         int err = 0;
 906
 907         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 908         if (!skb)
 909                 return -ENOBUFS;
 910
 911         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
 912                          RTM_NEWACTION, 0, 0) <= 0) {
 913                 kfree_skb(skb);
 914                 return -EINVAL;
 915         }
 916
 917         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 918                              n->nlmsg_flags & NLM_F_ECHO);
 919         if (err > 0)
 920                 err = 0;
 921         return err;
 922 }
 923
 924 static int
 925 tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 926                u32 portid, int ovr)
 927 {
 928         int ret = 0;
 929         LIST_HEAD(actions);
 930
 931         ret = tcf_action_init(net, nla, NULL, NULL, ovr, 0, &actions);
 932         if (ret)
 933                 goto done;
 934
 935         /* dump then free all the actions after update; inserted policy
 936          * stays intact
 937          */
 938         ret = tcf_add_notify(net, n, &actions, portid);
 939         cleanup_a(&actions);
 940 done:
 941         return ret;
 942 }
 943
 944 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n)
 945 {
 946         struct net *net = sock_net(skb->sk);
 947         struct nlattr *tca[TCA_ACT_MAX + 1];
 948         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
 949         int ret = 0, ovr = 0;
 950
 951         if ((n->nlmsg_type != RTM_GETACTION) && !netlink_capable(skb, CAP_NET_ADMIN))
 952                 return -EPERM;
 953
 954         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
 955         if (ret < 0)
 956                 return ret;
 957
 958         if (tca[TCA_ACT_TAB] == NULL) {
 959                 pr_notice("tc_ctl_action: received NO action attribs\n");
 960                 return -EINVAL;
 961         }
 962
 963         /* n->nlmsg_flags & NLM_F_CREATE */
 964         switch (n->nlmsg_type) {
 965         case RTM_NEWACTION:
 966                 /* we are going to assume all other flags
 967                  * imply create only if it doesn't exist
 968                  * Note that CREATE | EXCL implies that
 969                  * but since we want avoid ambiguity (eg when flags
 970                  * is zero) then just set this
 971                  */
 972                 if (n->nlmsg_flags & NLM_F_REPLACE)
 973                         ovr = 1;
 974 replay:
 975                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr);
 976                 if (ret == -EAGAIN)
 977                         goto replay;
 978                 break;
 979         case RTM_DELACTION:
 980                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
 981                                     portid, RTM_DELACTION);
 982                 break;
 983         case RTM_GETACTION:
 984                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
 985                                     portid, RTM_GETACTION);
 986                 break;
 987         default:
 988                 BUG();
 989         }
 990
 991         return ret;
 992 }
 993
 994 static struct nlattr *
 995 find_dump_kind(const struct nlmsghdr *n)
 996 {
 997         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
 998         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 999         struct nlattr *nla[TCAA_MAX + 1];
1000         struct nlattr *kind;
1001
1002         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1003                 return NULL;
1004         tb1 = nla[TCA_ACT_TAB];
1005         if (tb1 == NULL)
1006                 return NULL;
1007
1008         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1009                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1010                 return NULL;
1011
1012         if (tb[1] == NULL)
1013                 return NULL;
1014         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1015                       nla_len(tb[1]), NULL) < 0)
1016                 return NULL;
1017         kind = tb2[TCA_ACT_KIND];
1018
1019         return kind;
1020 }
1021
1022 static int
1023 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1024 {
1025         struct nlmsghdr *nlh;
1026         unsigned char *b = skb_tail_pointer(skb);
1027         struct nlattr *nest;
1028         struct tc_action_ops *a_o;
1029         struct tc_action a;
1030         int ret = 0;
1031         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1032         struct nlattr *kind = find_dump_kind(cb->nlh);
1033
1034         if (kind == NULL) {
1035                 pr_info("tc_dump_action: action bad kind\n");
1036                 return 0;
1037         }
1038
1039         a_o = tc_lookup_action(kind);
1040         if (a_o == NULL)
1041                 return 0;
1042
1043         memset(&a, 0, sizeof(struct tc_action));
1044         a.ops = a_o;
1045
1046         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1047                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1048         if (!nlh)
1049                 goto out_module_put;
1050         t = nlmsg_data(nlh);
1051         t->tca_family = AF_UNSPEC;
1052         t->tca__pad1 = 0;
1053         t->tca__pad2 = 0;
1054
1055         nest = nla_nest_start(skb, TCA_ACT_TAB);
1056         if (nest == NULL)
1057                 goto out_module_put;
1058
1059         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1060         if (ret < 0)
1061                 goto out_module_put;
1062
1063         if (ret > 0) {
1064                 nla_nest_end(skb, nest);
1065                 ret = skb->len;
1066         } else
1067                 nla_nest_cancel(skb, nest);
1068
1069         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1070         if (NETLINK_CB(cb->skb).portid && ret)
1071                 nlh->nlmsg_flags |= NLM_F_MULTI;
1072         module_put(a_o->owner);
1073         return skb->len;
1074
1075 out_module_put:
1076         module_put(a_o->owner);
1077         nlmsg_trim(skb, b);
1078         return skb->len;
1079 }
1080
1081 static int __init tc_action_init(void)
1082 {
1083         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
1084         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
1085         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1086                       NULL);
1087
1088         return 0;
1089 }
1090
1091 subsys_initcall(tc_action_init);