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         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
  33         struct tcf_common **p1p;
  34
  35         for (p1p = &hinfo->htab[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
  36                 if (*p1p == p) {
  37                         write_lock_bh(hinfo->lock);
  38                         *p1p = p->tcfc_next;
  39                         write_unlock_bh(hinfo->lock);
  40                         gen_kill_estimator(&p->tcfc_bstats,
  41                                            &p->tcfc_rate_est);
  42                         /*
  43                          * gen_estimator est_timer() might access p->tcfc_lock
  44                          * or bstats, wait a RCU grace period before freeing p
  45                          */
  46                         kfree_rcu(p, tcfc_rcu);
  47                         return;
  48                 }
  49         }
  50         WARN_ON(1);
  51 }
  52 EXPORT_SYMBOL(tcf_hash_destroy);
  53
  54 int tcf_hash_release(struct tcf_common *p, int bind,
  55                      struct tcf_hashinfo *hinfo)
  56 {
  57         int ret = 0;
  58
  59         if (p) {
  60                 if (bind)
  61                         p->tcfc_bindcnt--;
  62
  63                 p->tcfc_refcnt--;
  64                 if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
  65                         tcf_hash_destroy(p, hinfo);
  66                         ret = 1;
  67                 }
  68         }
  69         return ret;
  70 }
  71 EXPORT_SYMBOL(tcf_hash_release);
  72
  73 static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
  74                            struct tc_action *a, struct tcf_hashinfo *hinfo)
  75 {
  76         struct tcf_common *p;
  77         int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
  78         struct nlattr *nest;
  79
  80         read_lock_bh(hinfo->lock);
  81
  82         s_i = cb->args[0];
  83
  84         for (i = 0; i < (hinfo->hmask + 1); i++) {
  85                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
  86
  87                 for (; p; p = p->tcfc_next) {
  88                         index++;
  89                         if (index < s_i)
  90                                 continue;
  91                         a->priv = p;
  92                         a->order = n_i;
  93
  94                         nest = nla_nest_start(skb, a->order);
  95                         if (nest == NULL)
  96                                 goto nla_put_failure;
  97                         err = tcf_action_dump_1(skb, a, 0, 0);
  98                         if (err < 0) {
  99                                 index--;
 100                                 nlmsg_trim(skb, nest);
 101                                 goto done;
 102                         }
 103                         nla_nest_end(skb, nest);
 104                         n_i++;
 105                         if (n_i >= TCA_ACT_MAX_PRIO)
 106                                 goto done;
 107                 }
 108         }
 109 done:
 110         read_unlock_bh(hinfo->lock);
 111         if (n_i)
 112                 cb->args[0] += n_i;
 113         return n_i;
 114
 115 nla_put_failure:
 116         nla_nest_cancel(skb, nest);
 117         goto done;
 118 }
 119
 120 static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a,
 121                           struct tcf_hashinfo *hinfo)
 122 {
 123         struct tcf_common *p, *s_p;
 124         struct nlattr *nest;
 125         int i = 0, n_i = 0;
 126
 127         nest = nla_nest_start(skb, a->order);
 128         if (nest == NULL)
 129                 goto nla_put_failure;
 130         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 131                 goto nla_put_failure;
 132         for (i = 0; i < (hinfo->hmask + 1); i++) {
 133                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
 134
 135                 while (p != NULL) {
 136                         s_p = p->tcfc_next;
 137                         if (ACT_P_DELETED == tcf_hash_release(p, 0, hinfo))
 138                                 module_put(a->ops->owner);
 139                         n_i++;
 140                         p = s_p;
 141                 }
 142         }
 143         if (nla_put_u32(skb, TCA_FCNT, n_i))
 144                 goto nla_put_failure;
 145         nla_nest_end(skb, nest);
 146
 147         return n_i;
 148 nla_put_failure:
 149         nla_nest_cancel(skb, nest);
 150         return -EINVAL;
 151 }
 152
 153 int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
 154                        int type, struct tc_action *a)
 155 {
 156         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 157
 158         if (type == RTM_DELACTION) {
 159                 return tcf_del_walker(skb, a, hinfo);
 160         } else if (type == RTM_GETACTION) {
 161                 return tcf_dump_walker(skb, cb, a, hinfo);
 162         } else {
 163                 WARN(1, "tcf_generic_walker: unknown action %d\n", type);
 164                 return -EINVAL;
 165         }
 166 }
 167 EXPORT_SYMBOL(tcf_generic_walker);
 168
 169 struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 170 {
 171         struct tcf_common *p;
 172
 173         read_lock_bh(hinfo->lock);
 174         for (p = hinfo->htab[tcf_hash(index, hinfo->hmask)]; p;
 175              p = p->tcfc_next) {
 176                 if (p->tcfc_index == index)
 177                         break;
 178         }
 179         read_unlock_bh(hinfo->lock);
 180
 181         return p;
 182 }
 183 EXPORT_SYMBOL(tcf_hash_lookup);
 184
 185 u32 tcf_hash_new_index(u32 *idx_gen, struct tcf_hashinfo *hinfo)
 186 {
 187         u32 val = *idx_gen;
 188
 189         do {
 190                 if (++val == 0)
 191                         val = 1;
 192         } while (tcf_hash_lookup(val, hinfo));
 193
 194         *idx_gen = val;
 195         return val;
 196 }
 197 EXPORT_SYMBOL(tcf_hash_new_index);
 198
 199 int tcf_hash_search(struct tc_action *a, u32 index)
 200 {
 201         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 202         struct tcf_common *p = tcf_hash_lookup(index, hinfo);
 203
 204         if (p) {
 205                 a->priv = p;
 206                 return 1;
 207         }
 208         return 0;
 209 }
 210 EXPORT_SYMBOL(tcf_hash_search);
 211
 212 struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
 213                                   struct tcf_hashinfo *hinfo)
 214 {
 215         struct tcf_common *p = NULL;
 216         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 217                 if (bind)
 218                         p->tcfc_bindcnt++;
 219                 p->tcfc_refcnt++;
 220                 a->priv = p;
 221         }
 222         return p;
 223 }
 224 EXPORT_SYMBOL(tcf_hash_check);
 225
 226 struct tcf_common *tcf_hash_create(u32 index, struct nlattr *est,
 227                                    struct tc_action *a, int size, int bind,
 228                                    u32 *idx_gen, struct tcf_hashinfo *hinfo)
 229 {
 230         struct tcf_common *p = kzalloc(size, GFP_KERNEL);
 231
 232         if (unlikely(!p))
 233                 return ERR_PTR(-ENOMEM);
 234         p->tcfc_refcnt = 1;
 235         if (bind)
 236                 p->tcfc_bindcnt = 1;
 237
 238         spin_lock_init(&p->tcfc_lock);
 239         p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
 240         p->tcfc_tm.install = jiffies;
 241         p->tcfc_tm.lastuse = jiffies;
 242         if (est) {
 243                 int err = gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
 244                                             &p->tcfc_lock, est);
 245                 if (err) {
 246                         kfree(p);
 247                         return ERR_PTR(err);
 248                 }
 249         }
 250
 251         a->priv = (void *) p;
 252         return p;
 253 }
 254 EXPORT_SYMBOL(tcf_hash_create);
 255
 256 void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
 257 {
 258         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
 259
 260         write_lock_bh(hinfo->lock);
 261         p->tcfc_next = hinfo->htab[h];
 262         hinfo->htab[h] = p;
 263         write_unlock_bh(hinfo->lock);
 264 }
 265 EXPORT_SYMBOL(tcf_hash_insert);
 266
 267 static struct tc_action_ops *act_base = NULL;
 268 static DEFINE_RWLOCK(act_mod_lock);
 269
 270 int tcf_register_action(struct tc_action_ops *act)
 271 {
 272         struct tc_action_ops *a, **ap;
 273
 274         /* Must supply act, dump, cleanup and init */
 275         if (!act->act || !act->dump || !act->cleanup || !act->init)
 276                 return -EINVAL;
 277
 278         /* Supply defaults */
 279         if (!act->lookup)
 280                 act->lookup = tcf_hash_search;
 281         if (!act->walk)
 282                 act->walk = tcf_generic_walker;
 283
 284         write_lock(&act_mod_lock);
 285         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
 286                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 287                         write_unlock(&act_mod_lock);
 288                         return -EEXIST;
 289                 }
 290         }
 291         act->next = NULL;
 292         *ap = act;
 293         write_unlock(&act_mod_lock);
 294         return 0;
 295 }
 296 EXPORT_SYMBOL(tcf_register_action);
 297
 298 int tcf_unregister_action(struct tc_action_ops *act)
 299 {
 300         struct tc_action_ops *a, **ap;
 301         int err = -ENOENT;
 302
 303         write_lock(&act_mod_lock);
 304         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
 305                 if (a == act)
 306                         break;
 307         if (a) {
 308                 *ap = a->next;
 309                 a->next = NULL;
 310                 err = 0;
 311         }
 312         write_unlock(&act_mod_lock);
 313         return err;
 314 }
 315 EXPORT_SYMBOL(tcf_unregister_action);
 316
 317 /* lookup by name */
 318 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 319 {
 320         struct tc_action_ops *a = NULL;
 321
 322         if (kind) {
 323                 read_lock(&act_mod_lock);
 324                 for (a = act_base; a; a = a->next) {
 325                         if (strcmp(kind, a->kind) == 0) {
 326                                 if (!try_module_get(a->owner)) {
 327                                         read_unlock(&act_mod_lock);
 328                                         return NULL;
 329                                 }
 330                                 break;
 331                         }
 332                 }
 333                 read_unlock(&act_mod_lock);
 334         }
 335         return a;
 336 }
 337
 338 /* lookup by nlattr */
 339 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 340 {
 341         struct tc_action_ops *a = NULL;
 342
 343         if (kind) {
 344                 read_lock(&act_mod_lock);
 345                 for (a = act_base; a; a = a->next) {
 346                         if (nla_strcmp(kind, a->kind) == 0) {
 347                                 if (!try_module_get(a->owner)) {
 348                                         read_unlock(&act_mod_lock);
 349                                         return NULL;
 350                                 }
 351                                 break;
 352                         }
 353                 }
 354                 read_unlock(&act_mod_lock);
 355         }
 356         return a;
 357 }
 358
 359 #if 0
 360 /* lookup by id */
 361 static struct tc_action_ops *tc_lookup_action_id(u32 type)
 362 {
 363         struct tc_action_ops *a = NULL;
 364
 365         if (type) {
 366                 read_lock(&act_mod_lock);
 367                 for (a = act_base; a; a = a->next) {
 368                         if (a->type == type) {
 369                                 if (!try_module_get(a->owner)) {
 370                                         read_unlock(&act_mod_lock);
 371                                         return NULL;
 372                                 }
 373                                 break;
 374                         }
 375                 }
 376                 read_unlock(&act_mod_lock);
 377         }
 378         return a;
 379 }
 380 #endif
 381
 382 int tcf_action_exec(struct sk_buff *skb, const struct list_head *actions,
 383                     struct tcf_result *res)
 384 {
 385         const struct tc_action *a;
 386         int ret = -1;
 387
 388         if (skb->tc_verd & TC_NCLS) {
 389                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 390                 ret = TC_ACT_OK;
 391                 goto exec_done;
 392         }
 393         list_for_each_entry(a, actions, list) {
 394 repeat:
 395                 if (a->ops) {
 396                         ret = a->ops->act(skb, a, res);
 397                         if (TC_MUNGED & skb->tc_verd) {
 398                                 /* copied already, allow trampling */
 399                                 skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
 400                                 skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
 401                         }
 402                         if (ret == TC_ACT_REPEAT)
 403                                 goto repeat;    /* we need a ttl - JHS */
 404                         if (ret != TC_ACT_PIPE)
 405                                 goto exec_done;
 406                 }
 407         }
 408 exec_done:
 409         return ret;
 410 }
 411 EXPORT_SYMBOL(tcf_action_exec);
 412
 413 void tcf_action_destroy(struct list_head *actions, int bind)
 414 {
 415         struct tc_action *a, *tmp;
 416
 417         list_for_each_entry_safe(a, tmp, actions, list) {
 418                 if (a->ops) {
 419                         if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
 420                                 module_put(a->ops->owner);
 421                         list_del(&a->list);
 422                         kfree(a);
 423                 } else {
 424                         /*FIXME: Remove later - catch insertion bugs*/
 425                         WARN(1, "tcf_action_destroy: BUG? destroying NULL ops\n");
 426                         list_del(&a->list);
 427                         kfree(a);
 428                 }
 429         }
 430 }
 431
 432 int
 433 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 434 {
 435         int err = -EINVAL;
 436
 437         if (a->ops == NULL)
 438                 return err;
 439         return a->ops->dump(skb, a, bind, ref);
 440 }
 441
 442 int
 443 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 444 {
 445         int err = -EINVAL;
 446         unsigned char *b = skb_tail_pointer(skb);
 447         struct nlattr *nest;
 448
 449         if (a->ops == NULL)
 450                 return err;
 451
 452         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 453                 goto nla_put_failure;
 454         if (tcf_action_copy_stats(skb, a, 0))
 455                 goto nla_put_failure;
 456         nest = nla_nest_start(skb, TCA_OPTIONS);
 457         if (nest == NULL)
 458                 goto nla_put_failure;
 459         err = tcf_action_dump_old(skb, a, bind, ref);
 460         if (err > 0) {
 461                 nla_nest_end(skb, nest);
 462                 return err;
 463         }
 464
 465 nla_put_failure:
 466         nlmsg_trim(skb, b);
 467         return -1;
 468 }
 469 EXPORT_SYMBOL(tcf_action_dump_1);
 470
 471 int
 472 tcf_action_dump(struct sk_buff *skb, struct list_head *actions, int bind, int ref)
 473 {
 474         struct tc_action *a;
 475         int err = -EINVAL;
 476         struct nlattr *nest;
 477
 478         list_for_each_entry(a, actions, list) {
 479                 nest = nla_nest_start(skb, a->order);
 480                 if (nest == NULL)
 481                         goto nla_put_failure;
 482                 err = tcf_action_dump_1(skb, a, bind, ref);
 483                 if (err < 0)
 484                         goto errout;
 485                 nla_nest_end(skb, nest);
 486         }
 487
 488         return 0;
 489
 490 nla_put_failure:
 491         err = -EINVAL;
 492 errout:
 493         nla_nest_cancel(skb, nest);
 494         return err;
 495 }
 496
 497 struct tc_action *tcf_action_init_1(struct net *net, struct nlattr *nla,
 498                                     struct nlattr *est, char *name, int ovr,
 499                                     int bind)
 500 {
 501         struct tc_action *a;
 502         struct tc_action_ops *a_o;
 503         char act_name[IFNAMSIZ];
 504         struct nlattr *tb[TCA_ACT_MAX + 1];
 505         struct nlattr *kind;
 506         int err;
 507
 508         if (name == NULL) {
 509                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 510                 if (err < 0)
 511                         goto err_out;
 512                 err = -EINVAL;
 513                 kind = tb[TCA_ACT_KIND];
 514                 if (kind == NULL)
 515                         goto err_out;
 516                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 517                         goto err_out;
 518         } else {
 519                 err = -EINVAL;
 520                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 521                         goto err_out;
 522         }
 523
 524         a_o = tc_lookup_action_n(act_name);
 525         if (a_o == NULL) {
 526 #ifdef CONFIG_MODULES
 527                 rtnl_unlock();
 528                 request_module("act_%s", act_name);
 529                 rtnl_lock();
 530
 531                 a_o = tc_lookup_action_n(act_name);
 532
 533                 /* We dropped the RTNL semaphore in order to
 534                  * perform the module load.  So, even if we
 535                  * succeeded in loading the module we have to
 536                  * tell the caller to replay the request.  We
 537                  * indicate this using -EAGAIN.
 538                  */
 539                 if (a_o != NULL) {
 540                         err = -EAGAIN;
 541                         goto err_mod;
 542                 }
 543 #endif
 544                 err = -ENOENT;
 545                 goto err_out;
 546         }
 547
 548         err = -ENOMEM;
 549         a = kzalloc(sizeof(*a), GFP_KERNEL);
 550         if (a == NULL)
 551                 goto err_mod;
 552
 553         INIT_LIST_HEAD(&a->list);
 554         /* backward compatibility for policer */
 555         if (name == NULL)
 556                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
 557         else
 558                 err = a_o->init(net, nla, est, a, ovr, bind);
 559         if (err < 0)
 560                 goto err_free;
 561
 562         /* module count goes up only when brand new policy is created
 563          * if it exists and is only bound to in a_o->init() then
 564          * ACT_P_CREATED is not returned (a zero is).
 565          */
 566         if (err != ACT_P_CREATED)
 567                 module_put(a_o->owner);
 568         a->ops = a_o;
 569
 570         return a;
 571
 572 err_free:
 573         kfree(a);
 574 err_mod:
 575         module_put(a_o->owner);
 576 err_out:
 577         return ERR_PTR(err);
 578 }
 579
 580 int tcf_action_init(struct net *net, struct nlattr *nla,
 581                                   struct nlattr *est, char *name, int ovr,
 582                                   int bind, struct list_head *actions)
 583 {
 584         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 585         struct tc_action *act;
 586         int err;
 587         int i;
 588
 589         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 590         if (err < 0)
 591                 return err;
 592
 593         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 594                 act = tcf_action_init_1(net, tb[i], est, name, ovr, bind);
 595                 if (IS_ERR(act)) {
 596                         err = PTR_ERR(act);
 597                         goto err;
 598                 }
 599                 act->order = i;
 600                 list_add_tail(&act->list, actions);
 601         }
 602         return 0;
 603
 604 err:
 605         tcf_action_destroy(actions, bind);
 606         return err;
 607 }
 608
 609 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 610                           int compat_mode)
 611 {
 612         int err = 0;
 613         struct gnet_dump d;
 614         struct tcf_act_hdr *h = a->priv;
 615
 616         if (h == NULL)
 617                 goto errout;
 618
 619         /* compat_mode being true specifies a call that is supposed
 620          * to add additional backward compatibility statistic TLVs.
 621          */
 622         if (compat_mode) {
 623                 if (a->type == TCA_OLD_COMPAT)
 624                         err = gnet_stats_start_copy_compat(skb, 0,
 625                                 TCA_STATS, TCA_XSTATS, &h->tcf_lock, &d);
 626                 else
 627                         return 0;
 628         } else
 629                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 630                                             &h->tcf_lock, &d);
 631
 632         if (err < 0)
 633                 goto errout;
 634
 635         if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
 636             gnet_stats_copy_rate_est(&d, &h->tcf_bstats,
 637                                      &h->tcf_rate_est) < 0 ||
 638             gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
 639                 goto errout;
 640
 641         if (gnet_stats_finish_copy(&d) < 0)
 642                 goto errout;
 643
 644         return 0;
 645
 646 errout:
 647         return -1;
 648 }
 649
 650 static int
 651 tca_get_fill(struct sk_buff *skb, struct list_head *actions, u32 portid, u32 seq,
 652              u16 flags, int event, int bind, int ref)
 653 {
 654         struct tcamsg *t;
 655         struct nlmsghdr *nlh;
 656         unsigned char *b = skb_tail_pointer(skb);
 657         struct nlattr *nest;
 658
 659         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
 660         if (!nlh)
 661                 goto out_nlmsg_trim;
 662         t = nlmsg_data(nlh);
 663         t->tca_family = AF_UNSPEC;
 664         t->tca__pad1 = 0;
 665         t->tca__pad2 = 0;
 666
 667         nest = nla_nest_start(skb, TCA_ACT_TAB);
 668         if (nest == NULL)
 669                 goto out_nlmsg_trim;
 670
 671         if (tcf_action_dump(skb, actions, bind, ref) < 0)
 672                 goto out_nlmsg_trim;
 673
 674         nla_nest_end(skb, nest);
 675
 676         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 677         return skb->len;
 678
 679 out_nlmsg_trim:
 680         nlmsg_trim(skb, b);
 681         return -1;
 682 }
 683
 684 static int
 685 act_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
 686                struct list_head *actions, int event)
 687 {
 688         struct sk_buff *skb;
 689
 690         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 691         if (!skb)
 692                 return -ENOBUFS;
 693         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 694                 kfree_skb(skb);
 695                 return -EINVAL;
 696         }
 697
 698         return rtnl_unicast(skb, net, portid);
 699 }
 700
 701 static struct tc_action *
 702 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 portid)
 703 {
 704         struct nlattr *tb[TCA_ACT_MAX + 1];
 705         struct tc_action *a;
 706         int index;
 707         int err;
 708
 709         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 710         if (err < 0)
 711                 goto err_out;
 712
 713         err = -EINVAL;
 714         if (tb[TCA_ACT_INDEX] == NULL ||
 715             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 716                 goto err_out;
 717         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 718
 719         err = -ENOMEM;
 720         a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
 721         if (a == NULL)
 722                 goto err_out;
 723
 724         INIT_LIST_HEAD(&a->list);
 725         err = -EINVAL;
 726         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 727         if (a->ops == NULL)
 728                 goto err_free;
 729         err = -ENOENT;
 730         if (a->ops->lookup(a, index) == 0)
 731                 goto err_mod;
 732
 733         module_put(a->ops->owner);
 734         return a;
 735
 736 err_mod:
 737         module_put(a->ops->owner);
 738 err_free:
 739         kfree(a);
 740 err_out:
 741         return ERR_PTR(err);
 742 }
 743
 744 static void cleanup_a(struct list_head *actions)
 745 {
 746         struct tc_action *a, *tmp;
 747
 748         list_for_each_entry_safe(a, tmp, actions, list) {
 749                 list_del(&a->list);
 750                 kfree(a);
 751         }
 752 }
 753
 754 static struct tc_action *create_a(int i)
 755 {
 756         struct tc_action *act;
 757
 758         act = kzalloc(sizeof(*act), GFP_KERNEL);
 759         if (act == NULL) {
 760                 pr_debug("create_a: failed to alloc!\n");
 761                 return NULL;
 762         }
 763         act->order = i;
 764         INIT_LIST_HEAD(&act->list);
 765         return act;
 766 }
 767
 768 static int tca_action_flush(struct net *net, struct nlattr *nla,
 769                             struct nlmsghdr *n, u32 portid)
 770 {
 771         struct sk_buff *skb;
 772         unsigned char *b;
 773         struct nlmsghdr *nlh;
 774         struct tcamsg *t;
 775         struct netlink_callback dcb;
 776         struct nlattr *nest;
 777         struct nlattr *tb[TCA_ACT_MAX + 1];
 778         struct nlattr *kind;
 779         struct tc_action *a = create_a(0);
 780         int err = -ENOMEM;
 781
 782         if (a == NULL) {
 783                 pr_debug("tca_action_flush: couldnt create tc_action\n");
 784                 return err;
 785         }
 786
 787         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 788         if (!skb) {
 789                 pr_debug("tca_action_flush: failed skb alloc\n");
 790                 kfree(a);
 791                 return err;
 792         }
 793
 794         b = skb_tail_pointer(skb);
 795
 796         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 797         if (err < 0)
 798                 goto err_out;
 799
 800         err = -EINVAL;
 801         kind = tb[TCA_ACT_KIND];
 802         a->ops = tc_lookup_action(kind);
 803         if (a->ops == NULL)
 804                 goto err_out;
 805
 806         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t), 0);
 807         if (!nlh)
 808                 goto out_module_put;
 809         t = nlmsg_data(nlh);
 810         t->tca_family = AF_UNSPEC;
 811         t->tca__pad1 = 0;
 812         t->tca__pad2 = 0;
 813
 814         nest = nla_nest_start(skb, TCA_ACT_TAB);
 815         if (nest == NULL)
 816                 goto out_module_put;
 817
 818         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 819         if (err < 0)
 820                 goto out_module_put;
 821         if (err == 0)
 822                 goto noflush_out;
 823
 824         nla_nest_end(skb, nest);
 825
 826         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 827         nlh->nlmsg_flags |= NLM_F_ROOT;
 828         module_put(a->ops->owner);
 829         kfree(a);
 830         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 831                              n->nlmsg_flags & NLM_F_ECHO);
 832         if (err > 0)
 833                 return 0;
 834
 835         return err;
 836
 837 out_module_put:
 838         module_put(a->ops->owner);
 839 err_out:
 840 noflush_out:
 841         kfree_skb(skb);
 842         kfree(a);
 843         return err;
 844 }
 845
 846 static int
 847 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 848               u32 portid, int event)
 849 {
 850         int i, ret;
 851         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 852         struct tc_action *act;
 853         LIST_HEAD(actions);
 854
 855         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 856         if (ret < 0)
 857                 return ret;
 858
 859         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
 860                 if (tb[1] != NULL)
 861                         return tca_action_flush(net, tb[1], n, portid);
 862                 else
 863                         return -EINVAL;
 864         }
 865
 866         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 867                 act = tcf_action_get_1(tb[i], n, portid);
 868                 if (IS_ERR(act)) {
 869                         ret = PTR_ERR(act);
 870                         goto err;
 871                 }
 872                 act->order = i;
 873                 list_add_tail(&act->list, &actions);
 874         }
 875
 876         if (event == RTM_GETACTION)
 877                 ret = act_get_notify(net, portid, n, &actions, event);
 878         else { /* delete */
 879                 struct sk_buff *skb;
 880
 881                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 882                 if (!skb) {
 883                         ret = -ENOBUFS;
 884                         goto err;
 885                 }
 886
 887                 if (tca_get_fill(skb, &actions, portid, n->nlmsg_seq, 0, event,
 888                                  0, 1) <= 0) {
 889                         kfree_skb(skb);
 890                         ret = -EINVAL;
 891                         goto err;
 892                 }
 893
 894                 /* now do the delete */
 895                 tcf_action_destroy(&actions, 0);
 896                 ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 897                                      n->nlmsg_flags & NLM_F_ECHO);
 898                 if (ret > 0)
 899                         return 0;
 900                 return ret;
 901         }
 902 err:
 903         cleanup_a(&actions);
 904         return ret;
 905 }
 906
 907 static int tcf_add_notify(struct net *net, struct list_head *actions,
 908                           u32 portid, u32 seq, int event, u16 flags)
 909 {
 910         struct tcamsg *t;
 911         struct nlmsghdr *nlh;
 912         struct sk_buff *skb;
 913         struct nlattr *nest;
 914         unsigned char *b;
 915         int err = 0;
 916
 917         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 918         if (!skb)
 919                 return -ENOBUFS;
 920
 921         b = skb_tail_pointer(skb);
 922
 923         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
 924         if (!nlh)
 925                 goto out_kfree_skb;
 926         t = nlmsg_data(nlh);
 927         t->tca_family = AF_UNSPEC;
 928         t->tca__pad1 = 0;
 929         t->tca__pad2 = 0;
 930
 931         nest = nla_nest_start(skb, TCA_ACT_TAB);
 932         if (nest == NULL)
 933                 goto out_kfree_skb;
 934
 935         if (tcf_action_dump(skb, actions, 0, 0) < 0)
 936                 goto out_kfree_skb;
 937
 938         nla_nest_end(skb, nest);
 939
 940         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 941         NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 942
 943         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
 944         if (err > 0)
 945                 err = 0;
 946         return err;
 947
 948 out_kfree_skb:
 949         kfree_skb(skb);
 950         return -1;
 951 }
 952
 953
 954 static int
 955 tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 956                u32 portid, int ovr)
 957 {
 958         int ret = 0;
 959         LIST_HEAD(actions);
 960         u32 seq = n->nlmsg_seq;
 961
 962         ret = tcf_action_init(net, nla, NULL, NULL, ovr, 0, &actions);
 963         if (ret)
 964                 goto done;
 965
 966         /* dump then free all the actions after update; inserted policy
 967          * stays intact
 968          */
 969         ret = tcf_add_notify(net, &actions, portid, seq, RTM_NEWACTION, n->nlmsg_flags);
 970         cleanup_a(&actions);
 971 done:
 972         return ret;
 973 }
 974
 975 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n)
 976 {
 977         struct net *net = sock_net(skb->sk);
 978         struct nlattr *tca[TCA_ACT_MAX + 1];
 979         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
 980         int ret = 0, ovr = 0;
 981
 982         if ((n->nlmsg_type != RTM_GETACTION) && !capable(CAP_NET_ADMIN))
 983                 return -EPERM;
 984
 985         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
 986         if (ret < 0)
 987                 return ret;
 988
 989         if (tca[TCA_ACT_TAB] == NULL) {
 990                 pr_notice("tc_ctl_action: received NO action attribs\n");
 991                 return -EINVAL;
 992         }
 993
 994         /* n->nlmsg_flags & NLM_F_CREATE */
 995         switch (n->nlmsg_type) {
 996         case RTM_NEWACTION:
 997                 /* we are going to assume all other flags
 998                  * imply create only if it doesn't exist
 999                  * Note that CREATE | EXCL implies that
1000                  * but since we want avoid ambiguity (eg when flags
1001                  * is zero) then just set this
1002                  */
1003                 if (n->nlmsg_flags & NLM_F_REPLACE)
1004                         ovr = 1;
1005 replay:
1006                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr);
1007                 if (ret == -EAGAIN)
1008                         goto replay;
1009                 break;
1010         case RTM_DELACTION:
1011                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1012                                     portid, RTM_DELACTION);
1013                 break;
1014         case RTM_GETACTION:
1015                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1016                                     portid, RTM_GETACTION);
1017                 break;
1018         default:
1019                 BUG();
1020         }
1021
1022         return ret;
1023 }
1024
1025 static struct nlattr *
1026 find_dump_kind(const struct nlmsghdr *n)
1027 {
1028         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1029         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1030         struct nlattr *nla[TCAA_MAX + 1];
1031         struct nlattr *kind;
1032
1033         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1034                 return NULL;
1035         tb1 = nla[TCA_ACT_TAB];
1036         if (tb1 == NULL)
1037                 return NULL;
1038
1039         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1040                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1041                 return NULL;
1042
1043         if (tb[1] == NULL)
1044                 return NULL;
1045         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1046                       nla_len(tb[1]), NULL) < 0)
1047                 return NULL;
1048         kind = tb2[TCA_ACT_KIND];
1049
1050         return kind;
1051 }
1052
1053 static int
1054 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1055 {
1056         struct nlmsghdr *nlh;
1057         unsigned char *b = skb_tail_pointer(skb);
1058         struct nlattr *nest;
1059         struct tc_action_ops *a_o;
1060         struct tc_action a;
1061         int ret = 0;
1062         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1063         struct nlattr *kind = find_dump_kind(cb->nlh);
1064
1065         if (kind == NULL) {
1066                 pr_info("tc_dump_action: action bad kind\n");
1067                 return 0;
1068         }
1069
1070         a_o = tc_lookup_action(kind);
1071         if (a_o == NULL)
1072                 return 0;
1073
1074         memset(&a, 0, sizeof(struct tc_action));
1075         a.ops = a_o;
1076
1077         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1078                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1079         if (!nlh)
1080                 goto out_module_put;
1081         t = nlmsg_data(nlh);
1082         t->tca_family = AF_UNSPEC;
1083         t->tca__pad1 = 0;
1084         t->tca__pad2 = 0;
1085
1086         nest = nla_nest_start(skb, TCA_ACT_TAB);
1087         if (nest == NULL)
1088                 goto out_module_put;
1089
1090         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1091         if (ret < 0)
1092                 goto out_module_put;
1093
1094         if (ret > 0) {
1095                 nla_nest_end(skb, nest);
1096                 ret = skb->len;
1097         } else
1098                 nla_nest_cancel(skb, nest);
1099
1100         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1101         if (NETLINK_CB(cb->skb).portid && ret)
1102                 nlh->nlmsg_flags |= NLM_F_MULTI;
1103         module_put(a_o->owner);
1104         return skb->len;
1105
1106 out_module_put:
1107         module_put(a_o->owner);
1108         nlmsg_trim(skb, b);
1109         return skb->len;
1110 }
1111
1112 static int __init tc_action_init(void)
1113 {
1114         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
1115         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
1116         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1117                       NULL);
1118
1119         return 0;
1120 }
1121
1122 subsys_initcall(tc_action_init);