net/sched/act_api.c

   1 /*
   2  * net/sched/act_api.c  Packet action API.
   3  *
   4  *              This program is free software; you can redistribute it and/or
   5  *              modify it under the terms of the GNU General Public License
   6  *              as published by the Free Software Foundation; either version
   7  *              2 of the License, or (at your option) any later version.
   8  *
   9  * Author:      Jamal Hadi Salim
  10  *
  11  *
  12  */
  13
  14 #include <linux/types.h>
  15 #include <linux/kernel.h>
  16 #include <linux/string.h>
  17 #include <linux/errno.h>
  18 #include <linux/slab.h>
  19 #include <linux/skbuff.h>
  20 #include <linux/init.h>
  21 #include <linux/kmod.h>
  22 #include <linux/err.h>
  23 #include <linux/module.h>
  24 #include <net/net_namespace.h>
  25 #include <net/sock.h>
  26 #include <net/sch_generic.h>
  27 #include <net/act_api.h>
  28 #include <net/netlink.h>
  29
  30 static void free_tcf(struct rcu_head *head)
  31 {
  32         struct tc_action *p = container_of(head, struct tc_action, tcfa_rcu);
  33
  34         free_percpu(p->cpu_bstats);
  35         free_percpu(p->cpu_qstats);
  36         kfree(p);
  37 }
  38
  39 static void tcf_hash_destroy(struct tcf_hashinfo *hinfo, struct tc_action *p)
  40 {
  41         spin_lock_bh(&hinfo->lock);
  42         hlist_del(&p->tcfa_head);
  43         spin_unlock_bh(&hinfo->lock);
  44         gen_kill_estimator(&p->tcfa_bstats,
  45                            &p->tcfa_rate_est);
  46         /*
  47          * gen_estimator est_timer() might access p->tcfa_lock
  48          * or bstats, wait a RCU grace period before freeing p
  49          */
  50         call_rcu(&p->tcfa_rcu, free_tcf);
  51 }
  52
  53 int __tcf_hash_release(struct tc_action *p, bool bind, bool strict)
  54 {
  55         int ret = 0;
  56
  57         if (p) {
  58                 if (bind)
  59                         p->tcfa_bindcnt--;
  60                 else if (strict && p->tcfa_bindcnt > 0)
  61                         return -EPERM;
  62
  63                 p->tcfa_refcnt--;
  64                 if (p->tcfa_bindcnt <= 0 && p->tcfa_refcnt <= 0) {
  65                         if (p->ops->cleanup)
  66                                 p->ops->cleanup(p, bind);
  67                         tcf_hash_destroy(p->hinfo, p);
  68                         ret = ACT_P_DELETED;
  69                 }
  70         }
  71
  72         return ret;
  73 }
  74 EXPORT_SYMBOL(__tcf_hash_release);
  75
  76 static int tcf_dump_walker(struct tcf_hashinfo *hinfo, struct sk_buff *skb,
  77                            struct netlink_callback *cb)
  78 {
  79         int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
  80         struct nlattr *nest;
  81
  82         spin_lock_bh(&hinfo->lock);
  83
  84         s_i = cb->args[0];
  85
  86         for (i = 0; i < (hinfo->hmask + 1); i++) {
  87                 struct hlist_head *head;
  88                 struct tc_action *p;
  89
  90                 head = &hinfo->htab[tcf_hash(i, hinfo->hmask)];
  91
  92                 hlist_for_each_entry_rcu(p, head, tcfa_head) {
  93                         index++;
  94                         if (index < s_i)
  95                                 continue;
  96
  97                         nest = nla_nest_start(skb, n_i);
  98                         if (nest == NULL)
  99                                 goto nla_put_failure;
 100                         err = tcf_action_dump_1(skb, p, 0, 0);
 101                         if (err < 0) {
 102                                 index--;
 103                                 nlmsg_trim(skb, nest);
 104                                 goto done;
 105                         }
 106                         nla_nest_end(skb, nest);
 107                         n_i++;
 108                         if (n_i >= TCA_ACT_MAX_PRIO)
 109                                 goto done;
 110                 }
 111         }
 112 done:
 113         spin_unlock_bh(&hinfo->lock);
 114         if (n_i)
 115                 cb->args[0] += n_i;
 116         return n_i;
 117
 118 nla_put_failure:
 119         nla_nest_cancel(skb, nest);
 120         goto done;
 121 }
 122
 123 static int tcf_del_walker(struct tcf_hashinfo *hinfo, struct sk_buff *skb,
 124                           const struct tc_action_ops *ops)
 125 {
 126         struct nlattr *nest;
 127         int i = 0, n_i = 0;
 128         int ret = -EINVAL;
 129
 130         nest = nla_nest_start(skb, 0);
 131         if (nest == NULL)
 132                 goto nla_put_failure;
 133         if (nla_put_string(skb, TCA_KIND, ops->kind))
 134                 goto nla_put_failure;
 135         for (i = 0; i < (hinfo->hmask + 1); i++) {
 136                 struct hlist_head *head;
 137                 struct hlist_node *n;
 138                 struct tc_action *p;
 139
 140                 head = &hinfo->htab[tcf_hash(i, hinfo->hmask)];
 141                 hlist_for_each_entry_safe(p, n, head, tcfa_head) {
 142                         ret = __tcf_hash_release(p, false, true);
 143                         if (ret == ACT_P_DELETED) {
 144                                 module_put(p->ops->owner);
 145                                 n_i++;
 146                         } else if (ret < 0)
 147                                 goto nla_put_failure;
 148                 }
 149         }
 150         if (nla_put_u32(skb, TCA_FCNT, n_i))
 151                 goto nla_put_failure;
 152         nla_nest_end(skb, nest);
 153
 154         return n_i;
 155 nla_put_failure:
 156         nla_nest_cancel(skb, nest);
 157         return ret;
 158 }
 159
 160 int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
 161                        struct netlink_callback *cb, int type,
 162                        const struct tc_action_ops *ops)
 163 {
 164         struct tcf_hashinfo *hinfo = tn->hinfo;
 165
 166         if (type == RTM_DELACTION) {
 167                 return tcf_del_walker(hinfo, skb, ops);
 168         } else if (type == RTM_GETACTION) {
 169                 return tcf_dump_walker(hinfo, skb, cb);
 170         } else {
 171                 WARN(1, "tcf_generic_walker: unknown action %d\n", type);
 172                 return -EINVAL;
 173         }
 174 }
 175 EXPORT_SYMBOL(tcf_generic_walker);
 176
 177 static struct tc_action *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 178 {
 179         struct tc_action *p = NULL;
 180         struct hlist_head *head;
 181
 182         spin_lock_bh(&hinfo->lock);
 183         head = &hinfo->htab[tcf_hash(index, hinfo->hmask)];
 184         hlist_for_each_entry_rcu(p, head, tcfa_head)
 185                 if (p->tcfa_index == index)
 186                         break;
 187         spin_unlock_bh(&hinfo->lock);
 188
 189         return p;
 190 }
 191
 192 u32 tcf_hash_new_index(struct tc_action_net *tn)
 193 {
 194         struct tcf_hashinfo *hinfo = tn->hinfo;
 195         u32 val = hinfo->index;
 196
 197         do {
 198                 if (++val == 0)
 199                         val = 1;
 200         } while (tcf_hash_lookup(val, hinfo));
 201
 202         hinfo->index = val;
 203         return val;
 204 }
 205 EXPORT_SYMBOL(tcf_hash_new_index);
 206
 207 int tcf_hash_search(struct tc_action_net *tn, struct tc_action **a, u32 index)
 208 {
 209         struct tcf_hashinfo *hinfo = tn->hinfo;
 210         struct tc_action *p = tcf_hash_lookup(index, hinfo);
 211
 212         if (p) {
 213                 *a = p;
 214                 return 1;
 215         }
 216         return 0;
 217 }
 218 EXPORT_SYMBOL(tcf_hash_search);
 219
 220 bool tcf_hash_check(struct tc_action_net *tn, u32 index, struct tc_action **a,
 221                     int bind)
 222 {
 223         struct tcf_hashinfo *hinfo = tn->hinfo;
 224         struct tc_action *p = NULL;
 225
 226         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 227                 if (bind)
 228                         p->tcfa_bindcnt++;
 229                 p->tcfa_refcnt++;
 230                 *a = p;
 231                 return true;
 232         }
 233         return false;
 234 }
 235 EXPORT_SYMBOL(tcf_hash_check);
 236
 237 void tcf_hash_cleanup(struct tc_action *a, struct nlattr *est)
 238 {
 239         if (est)
 240                 gen_kill_estimator(&a->tcfa_bstats,
 241                                    &a->tcfa_rate_est);
 242         call_rcu(&a->tcfa_rcu, free_tcf);
 243 }
 244 EXPORT_SYMBOL(tcf_hash_cleanup);
 245
 246 int tcf_hash_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
 247                     struct tc_action **a, const struct tc_action_ops *ops,
 248                     int bind, bool cpustats)
 249 {
 250         struct tc_action *p = kzalloc(ops->size, GFP_KERNEL);
 251         struct tcf_hashinfo *hinfo = tn->hinfo;
 252         int err = -ENOMEM;
 253
 254         if (unlikely(!p))
 255                 return -ENOMEM;
 256         p->tcfa_refcnt = 1;
 257         if (bind)
 258                 p->tcfa_bindcnt = 1;
 259
 260         if (cpustats) {
 261                 p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
 262                 if (!p->cpu_bstats) {
 263 err1:
 264                         kfree(p);
 265                         return err;
 266                 }
 267                 p->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
 268                 if (!p->cpu_qstats) {
 269 err2:
 270                         free_percpu(p->cpu_bstats);
 271                         goto err1;
 272                 }
 273         }
 274         spin_lock_init(&p->tcfa_lock);
 275         INIT_HLIST_NODE(&p->tcfa_head);
 276         p->tcfa_index = index ? index : tcf_hash_new_index(tn);
 277         p->tcfa_tm.install = jiffies;
 278         p->tcfa_tm.lastuse = jiffies;
 279         p->tcfa_tm.firstuse = 0;
 280         if (est) {
 281                 err = gen_new_estimator(&p->tcfa_bstats, p->cpu_bstats,
 282                                         &p->tcfa_rate_est,
 283                                         &p->tcfa_lock, NULL, est);
 284                 if (err) {
 285                         free_percpu(p->cpu_qstats);
 286                         goto err2;
 287                 }
 288         }
 289
 290         p->hinfo = hinfo;
 291         p->ops = ops;
 292         INIT_LIST_HEAD(&p->list);
 293         *a = p;
 294         return 0;
 295 }
 296 EXPORT_SYMBOL(tcf_hash_create);
 297
 298 void tcf_hash_insert(struct tc_action_net *tn, struct tc_action *a)
 299 {
 300         struct tcf_hashinfo *hinfo = tn->hinfo;
 301         unsigned int h = tcf_hash(a->tcfa_index, hinfo->hmask);
 302
 303         spin_lock_bh(&hinfo->lock);
 304         hlist_add_head(&a->tcfa_head, &hinfo->htab[h]);
 305         spin_unlock_bh(&hinfo->lock);
 306 }
 307 EXPORT_SYMBOL(tcf_hash_insert);
 308
 309 void tcf_hashinfo_destroy(const struct tc_action_ops *ops,
 310                           struct tcf_hashinfo *hinfo)
 311 {
 312         int i;
 313
 314         for (i = 0; i < hinfo->hmask + 1; i++) {
 315                 struct tc_action *p;
 316                 struct hlist_node *n;
 317
 318                 hlist_for_each_entry_safe(p, n, &hinfo->htab[i], tcfa_head) {
 319                         int ret;
 320
 321                         ret = __tcf_hash_release(p, 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 EXPORT_SYMBOL(tcf_hashinfo_destroy);
 331
 332 static LIST_HEAD(act_base);
 333 static DEFINE_RWLOCK(act_mod_lock);
 334
 335 int tcf_register_action(struct tc_action_ops *act,
 336                         struct pernet_operations *ops)
 337 {
 338         struct tc_action_ops *a;
 339         int ret;
 340
 341         if (!act->act || !act->dump || !act->init || !act->walk || !act->lookup)
 342                 return -EINVAL;
 343
 344         write_lock(&act_mod_lock);
 345         list_for_each_entry(a, &act_base, head) {
 346                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 347                         write_unlock(&act_mod_lock);
 348                         return -EEXIST;
 349                 }
 350         }
 351         list_add_tail(&act->head, &act_base);
 352         write_unlock(&act_mod_lock);
 353
 354         ret = register_pernet_subsys(ops);
 355         if (ret) {
 356                 tcf_unregister_action(act, ops);
 357                 return ret;
 358         }
 359
 360         return 0;
 361 }
 362 EXPORT_SYMBOL(tcf_register_action);
 363
 364 int tcf_unregister_action(struct tc_action_ops *act,
 365                           struct pernet_operations *ops)
 366 {
 367         struct tc_action_ops *a;
 368         int err = -ENOENT;
 369
 370         unregister_pernet_subsys(ops);
 371
 372         write_lock(&act_mod_lock);
 373         list_for_each_entry(a, &act_base, head) {
 374                 if (a == act) {
 375                         list_del(&act->head);
 376                         err = 0;
 377                         break;
 378                 }
 379         }
 380         write_unlock(&act_mod_lock);
 381         return err;
 382 }
 383 EXPORT_SYMBOL(tcf_unregister_action);
 384
 385 /* lookup by name */
 386 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 387 {
 388         struct tc_action_ops *a, *res = NULL;
 389
 390         if (kind) {
 391                 read_lock(&act_mod_lock);
 392                 list_for_each_entry(a, &act_base, head) {
 393                         if (strcmp(kind, a->kind) == 0) {
 394                                 if (try_module_get(a->owner))
 395                                         res = a;
 396                                 break;
 397                         }
 398                 }
 399                 read_unlock(&act_mod_lock);
 400         }
 401         return res;
 402 }
 403
 404 /* lookup by nlattr */
 405 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 406 {
 407         struct tc_action_ops *a, *res = NULL;
 408
 409         if (kind) {
 410                 read_lock(&act_mod_lock);
 411                 list_for_each_entry(a, &act_base, head) {
 412                         if (nla_strcmp(kind, a->kind) == 0) {
 413                                 if (try_module_get(a->owner))
 414                                         res = a;
 415                                 break;
 416                         }
 417                 }
 418                 read_unlock(&act_mod_lock);
 419         }
 420         return res;
 421 }
 422
 423 int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,
 424                     int nr_actions, struct tcf_result *res)
 425 {
 426         int ret = -1, i;
 427
 428         if (skb->tc_verd & TC_NCLS) {
 429                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 430                 ret = TC_ACT_OK;
 431                 goto exec_done;
 432         }
 433         for (i = 0; i < nr_actions; i++) {
 434                 const struct tc_action *a = actions[i];
 435
 436 repeat:
 437                 ret = a->ops->act(skb, a, res);
 438                 if (ret == TC_ACT_REPEAT)
 439                         goto repeat;    /* we need a ttl - JHS */
 440                 if (ret != TC_ACT_PIPE)
 441                         goto exec_done;
 442         }
 443 exec_done:
 444         return ret;
 445 }
 446 EXPORT_SYMBOL(tcf_action_exec);
 447
 448 int tcf_action_destroy(struct list_head *actions, int bind)
 449 {
 450         struct tc_action *a, *tmp;
 451         int ret = 0;
 452
 453         list_for_each_entry_safe(a, tmp, actions, list) {
 454                 ret = __tcf_hash_release(a, bind, true);
 455                 if (ret == ACT_P_DELETED)
 456                         module_put(a->ops->owner);
 457                 else if (ret < 0)
 458                         return ret;
 459         }
 460         return ret;
 461 }
 462
 463 int
 464 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 465 {
 466         return a->ops->dump(skb, a, bind, ref);
 467 }
 468
 469 int
 470 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 471 {
 472         int err = -EINVAL;
 473         unsigned char *b = skb_tail_pointer(skb);
 474         struct nlattr *nest;
 475
 476         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 477                 goto nla_put_failure;
 478         if (tcf_action_copy_stats(skb, a, 0))
 479                 goto nla_put_failure;
 480         nest = nla_nest_start(skb, TCA_OPTIONS);
 481         if (nest == NULL)
 482                 goto nla_put_failure;
 483         err = tcf_action_dump_old(skb, a, bind, ref);
 484         if (err > 0) {
 485                 nla_nest_end(skb, nest);
 486                 return err;
 487         }
 488
 489 nla_put_failure:
 490         nlmsg_trim(skb, b);
 491         return -1;
 492 }
 493 EXPORT_SYMBOL(tcf_action_dump_1);
 494
 495 int tcf_action_dump(struct sk_buff *skb, struct list_head *actions,
 496                     int bind, int ref)
 497 {
 498         struct tc_action *a;
 499         int err = -EINVAL;
 500         struct nlattr *nest;
 501
 502         list_for_each_entry(a, actions, list) {
 503                 nest = nla_nest_start(skb, a->order);
 504                 if (nest == NULL)
 505                         goto nla_put_failure;
 506                 err = tcf_action_dump_1(skb, a, bind, ref);
 507                 if (err < 0)
 508                         goto errout;
 509                 nla_nest_end(skb, nest);
 510         }
 511
 512         return 0;
 513
 514 nla_put_failure:
 515         err = -EINVAL;
 516 errout:
 517         nla_nest_cancel(skb, nest);
 518         return err;
 519 }
 520
 521 struct tc_action *tcf_action_init_1(struct net *net, struct nlattr *nla,
 522                                     struct nlattr *est, char *name, int ovr,
 523                                     int bind)
 524 {
 525         struct tc_action *a;
 526         struct tc_action_ops *a_o;
 527         char act_name[IFNAMSIZ];
 528         struct nlattr *tb[TCA_ACT_MAX + 1];
 529         struct nlattr *kind;
 530         int err;
 531
 532         if (name == NULL) {
 533                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 534                 if (err < 0)
 535                         goto err_out;
 536                 err = -EINVAL;
 537                 kind = tb[TCA_ACT_KIND];
 538                 if (kind == NULL)
 539                         goto err_out;
 540                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 541                         goto err_out;
 542         } else {
 543                 err = -EINVAL;
 544                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 545                         goto err_out;
 546         }
 547
 548         a_o = tc_lookup_action_n(act_name);
 549         if (a_o == NULL) {
 550 #ifdef CONFIG_MODULES
 551                 rtnl_unlock();
 552                 request_module("act_%s", act_name);
 553                 rtnl_lock();
 554
 555                 a_o = tc_lookup_action_n(act_name);
 556
 557                 /* We dropped the RTNL semaphore in order to
 558                  * perform the module load.  So, even if we
 559                  * succeeded in loading the module we have to
 560                  * tell the caller to replay the request.  We
 561                  * indicate this using -EAGAIN.
 562                  */
 563                 if (a_o != NULL) {
 564                         err = -EAGAIN;
 565                         goto err_mod;
 566                 }
 567 #endif
 568                 err = -ENOENT;
 569                 goto err_out;
 570         }
 571
 572         /* backward compatibility for policer */
 573         if (name == NULL)
 574                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, &a, ovr, bind);
 575         else
 576                 err = a_o->init(net, nla, est, &a, ovr, bind);
 577         if (err < 0)
 578                 goto err_mod;
 579
 580         /* module count goes up only when brand new policy is created
 581          * if it exists and is only bound to in a_o->init() then
 582          * ACT_P_CREATED is not returned (a zero is).
 583          */
 584         if (err != ACT_P_CREATED)
 585                 module_put(a_o->owner);
 586
 587         return a;
 588
 589 err_mod:
 590         module_put(a_o->owner);
 591 err_out:
 592         return ERR_PTR(err);
 593 }
 594
 595 int tcf_action_init(struct net *net, struct nlattr *nla,
 596                                   struct nlattr *est, char *name, int ovr,
 597                                   int bind, struct list_head *actions)
 598 {
 599         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 600         struct tc_action *act;
 601         int err;
 602         int i;
 603
 604         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 605         if (err < 0)
 606                 return err;
 607
 608         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 609                 act = tcf_action_init_1(net, tb[i], est, name, ovr, bind);
 610                 if (IS_ERR(act)) {
 611                         err = PTR_ERR(act);
 612                         goto err;
 613                 }
 614                 act->order = i;
 615                 list_add_tail(&act->list, actions);
 616         }
 617         return 0;
 618
 619 err:
 620         tcf_action_destroy(actions, bind);
 621         return err;
 622 }
 623
 624 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *p,
 625                           int compat_mode)
 626 {
 627         int err = 0;
 628         struct gnet_dump d;
 629
 630         if (p == NULL)
 631                 goto errout;
 632
 633         /* compat_mode being true specifies a call that is supposed
 634          * to add additional backward compatibility statistic TLVs.
 635          */
 636         if (compat_mode) {
 637                 if (p->type == TCA_OLD_COMPAT)
 638                         err = gnet_stats_start_copy_compat(skb, 0,
 639                                                            TCA_STATS,
 640                                                            TCA_XSTATS,
 641                                                            &p->tcfa_lock, &d,
 642                                                            TCA_PAD);
 643                 else
 644                         return 0;
 645         } else
 646                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 647                                             &p->tcfa_lock, &d, TCA_ACT_PAD);
 648
 649         if (err < 0)
 650                 goto errout;
 651
 652         if (gnet_stats_copy_basic(NULL, &d, p->cpu_bstats, &p->tcfa_bstats) < 0 ||
 653             gnet_stats_copy_rate_est(&d, &p->tcfa_bstats,
 654                                      &p->tcfa_rate_est) < 0 ||
 655             gnet_stats_copy_queue(&d, p->cpu_qstats,
 656                                   &p->tcfa_qstats,
 657                                   p->tcfa_qstats.qlen) < 0)
 658                 goto errout;
 659
 660         if (gnet_stats_finish_copy(&d) < 0)
 661                 goto errout;
 662
 663         return 0;
 664
 665 errout:
 666         return -1;
 667 }
 668
 669 static int tca_get_fill(struct sk_buff *skb, struct list_head *actions,
 670                         u32 portid, u32 seq, u16 flags, int event, int bind,
 671                         int ref)
 672 {
 673         struct tcamsg *t;
 674         struct nlmsghdr *nlh;
 675         unsigned char *b = skb_tail_pointer(skb);
 676         struct nlattr *nest;
 677
 678         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
 679         if (!nlh)
 680                 goto out_nlmsg_trim;
 681         t = nlmsg_data(nlh);
 682         t->tca_family = AF_UNSPEC;
 683         t->tca__pad1 = 0;
 684         t->tca__pad2 = 0;
 685
 686         nest = nla_nest_start(skb, TCA_ACT_TAB);
 687         if (nest == NULL)
 688                 goto out_nlmsg_trim;
 689
 690         if (tcf_action_dump(skb, actions, bind, ref) < 0)
 691                 goto out_nlmsg_trim;
 692
 693         nla_nest_end(skb, nest);
 694
 695         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 696         return skb->len;
 697
 698 out_nlmsg_trim:
 699         nlmsg_trim(skb, b);
 700         return -1;
 701 }
 702
 703 static int
 704 act_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
 705                struct list_head *actions, int event)
 706 {
 707         struct sk_buff *skb;
 708
 709         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 710         if (!skb)
 711                 return -ENOBUFS;
 712         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event,
 713                          0, 0) <= 0) {
 714                 kfree_skb(skb);
 715                 return -EINVAL;
 716         }
 717
 718         return rtnl_unicast(skb, net, portid);
 719 }
 720
 721 static struct tc_action *tcf_action_get_1(struct net *net, struct nlattr *nla,
 722                                           struct nlmsghdr *n, u32 portid)
 723 {
 724         struct nlattr *tb[TCA_ACT_MAX + 1];
 725         const struct tc_action_ops *ops;
 726         struct tc_action *a;
 727         int index;
 728         int err;
 729
 730         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 731         if (err < 0)
 732                 goto err_out;
 733
 734         err = -EINVAL;
 735         if (tb[TCA_ACT_INDEX] == NULL ||
 736             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 737                 goto err_out;
 738         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 739
 740         err = -EINVAL;
 741         ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 742         if (!ops) /* could happen in batch of actions */
 743                 goto err_out;
 744         err = -ENOENT;
 745         if (ops->lookup(net, &a, index) == 0)
 746                 goto err_mod;
 747
 748         module_put(ops->owner);
 749         return a;
 750
 751 err_mod:
 752         module_put(ops->owner);
 753 err_out:
 754         return ERR_PTR(err);
 755 }
 756
 757 static int tca_action_flush(struct net *net, struct nlattr *nla,
 758                             struct nlmsghdr *n, u32 portid)
 759 {
 760         struct sk_buff *skb;
 761         unsigned char *b;
 762         struct nlmsghdr *nlh;
 763         struct tcamsg *t;
 764         struct netlink_callback dcb;
 765         struct nlattr *nest;
 766         struct nlattr *tb[TCA_ACT_MAX + 1];
 767         const struct tc_action_ops *ops;
 768         struct nlattr *kind;
 769         int err = -ENOMEM;
 770
 771         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 772         if (!skb) {
 773                 pr_debug("tca_action_flush: failed skb alloc\n");
 774                 return err;
 775         }
 776
 777         b = skb_tail_pointer(skb);
 778
 779         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 780         if (err < 0)
 781                 goto err_out;
 782
 783         err = -EINVAL;
 784         kind = tb[TCA_ACT_KIND];
 785         ops = tc_lookup_action(kind);
 786         if (!ops) /*some idjot trying to flush unknown action */
 787                 goto err_out;
 788
 789         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION,
 790                         sizeof(*t), 0);
 791         if (!nlh)
 792                 goto out_module_put;
 793         t = nlmsg_data(nlh);
 794         t->tca_family = AF_UNSPEC;
 795         t->tca__pad1 = 0;
 796         t->tca__pad2 = 0;
 797
 798         nest = nla_nest_start(skb, TCA_ACT_TAB);
 799         if (nest == NULL)
 800                 goto out_module_put;
 801
 802         err = ops->walk(net, skb, &dcb, RTM_DELACTION, ops);
 803         if (err < 0)
 804                 goto out_module_put;
 805         if (err == 0)
 806                 goto noflush_out;
 807
 808         nla_nest_end(skb, nest);
 809
 810         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 811         nlh->nlmsg_flags |= NLM_F_ROOT;
 812         module_put(ops->owner);
 813         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 814                              n->nlmsg_flags & NLM_F_ECHO);
 815         if (err > 0)
 816                 return 0;
 817
 818         return err;
 819
 820 out_module_put:
 821         module_put(ops->owner);
 822 err_out:
 823 noflush_out:
 824         kfree_skb(skb);
 825         return err;
 826 }
 827
 828 static int
 829 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
 830                u32 portid)
 831 {
 832         int ret;
 833         struct sk_buff *skb;
 834
 835         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 836         if (!skb)
 837                 return -ENOBUFS;
 838
 839         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
 840                          0, 1) <= 0) {
 841                 kfree_skb(skb);
 842                 return -EINVAL;
 843         }
 844
 845         /* now do the delete */
 846         ret = tcf_action_destroy(actions, 0);
 847         if (ret < 0) {
 848                 kfree_skb(skb);
 849                 return ret;
 850         }
 851
 852         ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 853                              n->nlmsg_flags & NLM_F_ECHO);
 854         if (ret > 0)
 855                 return 0;
 856         return ret;
 857 }
 858
 859 static int
 860 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 861               u32 portid, int event)
 862 {
 863         int i, ret;
 864         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 865         struct tc_action *act;
 866         LIST_HEAD(actions);
 867
 868         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 869         if (ret < 0)
 870                 return ret;
 871
 872         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
 873                 if (tb[1] != NULL)
 874                         return tca_action_flush(net, tb[1], n, portid);
 875                 else
 876                         return -EINVAL;
 877         }
 878
 879         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 880                 act = tcf_action_get_1(net, tb[i], n, portid);
 881                 if (IS_ERR(act)) {
 882                         ret = PTR_ERR(act);
 883                         goto err;
 884                 }
 885                 act->order = i;
 886                 list_add_tail(&act->list, &actions);
 887         }
 888
 889         if (event == RTM_GETACTION)
 890                 ret = act_get_notify(net, portid, n, &actions, event);
 891         else { /* delete */
 892                 ret = tcf_del_notify(net, n, &actions, portid);
 893                 if (ret)
 894                         goto err;
 895                 return ret;
 896         }
 897 err:
 898         tcf_action_destroy(&actions, 0);
 899         return ret;
 900 }
 901
 902 static int
 903 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
 904                u32 portid)
 905 {
 906         struct sk_buff *skb;
 907         int err = 0;
 908
 909         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 910         if (!skb)
 911                 return -ENOBUFS;
 912
 913         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
 914                          RTM_NEWACTION, 0, 0) <= 0) {
 915                 kfree_skb(skb);
 916                 return -EINVAL;
 917         }
 918
 919         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 920                              n->nlmsg_flags & NLM_F_ECHO);
 921         if (err > 0)
 922                 err = 0;
 923         return err;
 924 }
 925
 926 static int
 927 tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 928                u32 portid, int ovr)
 929 {
 930         int ret = 0;
 931         LIST_HEAD(actions);
 932
 933         ret = tcf_action_init(net, nla, NULL, NULL, ovr, 0, &actions);
 934         if (ret)
 935                 return ret;
 936
 937         return tcf_add_notify(net, n, &actions, portid);
 938 }
 939
 940 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n)
 941 {
 942         struct net *net = sock_net(skb->sk);
 943         struct nlattr *tca[TCA_ACT_MAX + 1];
 944         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
 945         int ret = 0, ovr = 0;
 946
 947         if ((n->nlmsg_type != RTM_GETACTION) &&
 948             !netlink_capable(skb, CAP_NET_ADMIN))
 949                 return -EPERM;
 950
 951         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
 952         if (ret < 0)
 953                 return ret;
 954
 955         if (tca[TCA_ACT_TAB] == NULL) {
 956                 pr_notice("tc_ctl_action: received NO action attribs\n");
 957                 return -EINVAL;
 958         }
 959
 960         /* n->nlmsg_flags & NLM_F_CREATE */
 961         switch (n->nlmsg_type) {
 962         case RTM_NEWACTION:
 963                 /* we are going to assume all other flags
 964                  * imply create only if it doesn't exist
 965                  * Note that CREATE | EXCL implies that
 966                  * but since we want avoid ambiguity (eg when flags
 967                  * is zero) then just set this
 968                  */
 969                 if (n->nlmsg_flags & NLM_F_REPLACE)
 970                         ovr = 1;
 971 replay:
 972                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr);
 973                 if (ret == -EAGAIN)
 974                         goto replay;
 975                 break;
 976         case RTM_DELACTION:
 977                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
 978                                     portid, RTM_DELACTION);
 979                 break;
 980         case RTM_GETACTION:
 981                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
 982                                     portid, RTM_GETACTION);
 983                 break;
 984         default:
 985                 BUG();
 986         }
 987
 988         return ret;
 989 }
 990
 991 static struct nlattr *
 992 find_dump_kind(const struct nlmsghdr *n)
 993 {
 994         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
 995         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 996         struct nlattr *nla[TCAA_MAX + 1];
 997         struct nlattr *kind;
 998
 999         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1000                 return NULL;
1001         tb1 = nla[TCA_ACT_TAB];
1002         if (tb1 == NULL)
1003                 return NULL;
1004
1005         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1006                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1007                 return NULL;
1008
1009         if (tb[1] == NULL)
1010                 return NULL;
1011         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1012                       nla_len(tb[1]), NULL) < 0)
1013                 return NULL;
1014         kind = tb2[TCA_ACT_KIND];
1015
1016         return kind;
1017 }
1018
1019 static int
1020 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1021 {
1022         struct net *net = sock_net(skb->sk);
1023         struct nlmsghdr *nlh;
1024         unsigned char *b = skb_tail_pointer(skb);
1025         struct nlattr *nest;
1026         struct tc_action_ops *a_o;
1027         int ret = 0;
1028         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1029         struct nlattr *kind = find_dump_kind(cb->nlh);
1030
1031         if (kind == NULL) {
1032                 pr_info("tc_dump_action: action bad kind\n");
1033                 return 0;
1034         }
1035
1036         a_o = tc_lookup_action(kind);
1037         if (a_o == NULL)
1038                 return 0;
1039
1040         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1041                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1042         if (!nlh)
1043                 goto out_module_put;
1044         t = nlmsg_data(nlh);
1045         t->tca_family = AF_UNSPEC;
1046         t->tca__pad1 = 0;
1047         t->tca__pad2 = 0;
1048
1049         nest = nla_nest_start(skb, TCA_ACT_TAB);
1050         if (nest == NULL)
1051                 goto out_module_put;
1052
1053         ret = a_o->walk(net, skb, cb, RTM_GETACTION, a_o);
1054         if (ret < 0)
1055                 goto out_module_put;
1056
1057         if (ret > 0) {
1058                 nla_nest_end(skb, nest);
1059                 ret = skb->len;
1060         } else
1061                 nlmsg_trim(skb, b);
1062
1063         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1064         if (NETLINK_CB(cb->skb).portid && ret)
1065                 nlh->nlmsg_flags |= NLM_F_MULTI;
1066         module_put(a_o->owner);
1067         return skb->len;
1068
1069 out_module_put:
1070         module_put(a_o->owner);
1071         nlmsg_trim(skb, b);
1072         return skb->len;
1073 }
1074
1075 static int __init tc_action_init(void)
1076 {
1077         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
1078         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
1079         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1080                       NULL);
1081
1082         return 0;
1083 }
1084
1085 subsys_initcall(tc_action_init);