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