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