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 tc_action *act,
 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         while ((a = act) != NULL) {
 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                 act = a->next;
 408         }
 409 exec_done:
 410         return ret;
 411 }
 412 EXPORT_SYMBOL(tcf_action_exec);
 413
 414 void tcf_action_destroy(struct tc_action *act, int bind)
 415 {
 416         struct tc_action *a;
 417
 418         for (a = act; a; a = act) {
 419                 if (a->ops) {
 420                         if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
 421                                 module_put(a->ops->owner);
 422                         act = act->next;
 423                         kfree(a);
 424                 } else {
 425                         /*FIXME: Remove later - catch insertion bugs*/
 426                         WARN(1, "tcf_action_destroy: BUG? destroying NULL ops\n");
 427                         act = act->next;
 428                         kfree(a);
 429                 }
 430         }
 431 }
 432
 433 int
 434 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 435 {
 436         int err = -EINVAL;
 437
 438         if (a->ops == NULL)
 439                 return err;
 440         return a->ops->dump(skb, a, bind, ref);
 441 }
 442
 443 int
 444 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 445 {
 446         int err = -EINVAL;
 447         unsigned char *b = skb_tail_pointer(skb);
 448         struct nlattr *nest;
 449
 450         if (a->ops == NULL)
 451                 return err;
 452
 453         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 454                 goto nla_put_failure;
 455         if (tcf_action_copy_stats(skb, a, 0))
 456                 goto nla_put_failure;
 457         nest = nla_nest_start(skb, TCA_OPTIONS);
 458         if (nest == NULL)
 459                 goto nla_put_failure;
 460         err = tcf_action_dump_old(skb, a, bind, ref);
 461         if (err > 0) {
 462                 nla_nest_end(skb, nest);
 463                 return err;
 464         }
 465
 466 nla_put_failure:
 467         nlmsg_trim(skb, b);
 468         return -1;
 469 }
 470 EXPORT_SYMBOL(tcf_action_dump_1);
 471
 472 int
 473 tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
 474 {
 475         struct tc_action *a;
 476         int err = -EINVAL;
 477         struct nlattr *nest;
 478
 479         while ((a = act) != NULL) {
 480                 act = a->next;
 481                 nest = nla_nest_start(skb, a->order);
 482                 if (nest == NULL)
 483                         goto nla_put_failure;
 484                 err = tcf_action_dump_1(skb, a, bind, ref);
 485                 if (err < 0)
 486                         goto errout;
 487                 nla_nest_end(skb, nest);
 488         }
 489
 490         return 0;
 491
 492 nla_put_failure:
 493         err = -EINVAL;
 494 errout:
 495         nla_nest_cancel(skb, nest);
 496         return err;
 497 }
 498
 499 struct tc_action *tcf_action_init_1(struct net *net, struct nlattr *nla,
 500                                     struct nlattr *est, char *name, int ovr,
 501                                     int bind)
 502 {
 503         struct tc_action *a;
 504         struct tc_action_ops *a_o;
 505         char act_name[IFNAMSIZ];
 506         struct nlattr *tb[TCA_ACT_MAX + 1];
 507         struct nlattr *kind;
 508         int err;
 509
 510         if (name == NULL) {
 511                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 512                 if (err < 0)
 513                         goto err_out;
 514                 err = -EINVAL;
 515                 kind = tb[TCA_ACT_KIND];
 516                 if (kind == NULL)
 517                         goto err_out;
 518                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 519                         goto err_out;
 520         } else {
 521                 err = -EINVAL;
 522                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 523                         goto err_out;
 524         }
 525
 526         a_o = tc_lookup_action_n(act_name);
 527         if (a_o == NULL) {
 528 #ifdef CONFIG_MODULES
 529                 rtnl_unlock();
 530                 request_module("act_%s", act_name);
 531                 rtnl_lock();
 532
 533                 a_o = tc_lookup_action_n(act_name);
 534
 535                 /* We dropped the RTNL semaphore in order to
 536                  * perform the module load.  So, even if we
 537                  * succeeded in loading the module we have to
 538                  * tell the caller to replay the request.  We
 539                  * indicate this using -EAGAIN.
 540                  */
 541                 if (a_o != NULL) {
 542                         err = -EAGAIN;
 543                         goto err_mod;
 544                 }
 545 #endif
 546                 err = -ENOENT;
 547                 goto err_out;
 548         }
 549
 550         err = -ENOMEM;
 551         a = kzalloc(sizeof(*a), GFP_KERNEL);
 552         if (a == NULL)
 553                 goto err_mod;
 554
 555         /* backward compatibility for policer */
 556         if (name == NULL)
 557                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
 558         else
 559                 err = a_o->init(net, nla, est, a, ovr, bind);
 560         if (err < 0)
 561                 goto err_free;
 562
 563         /* module count goes up only when brand new policy is created
 564          * if it exists and is only bound to in a_o->init() then
 565          * ACT_P_CREATED is not returned (a zero is).
 566          */
 567         if (err != ACT_P_CREATED)
 568                 module_put(a_o->owner);
 569         a->ops = a_o;
 570
 571         return a;
 572
 573 err_free:
 574         kfree(a);
 575 err_mod:
 576         module_put(a_o->owner);
 577 err_out:
 578         return ERR_PTR(err);
 579 }
 580
 581 struct tc_action *tcf_action_init(struct net *net, struct nlattr *nla,
 582                                   struct nlattr *est, char *name, int ovr,
 583                                   int bind)
 584 {
 585         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 586         struct tc_action *head = NULL, *act, *act_prev = NULL;
 587         int err;
 588         int i;
 589
 590         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 591         if (err < 0)
 592                 return ERR_PTR(err);
 593
 594         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 595                 act = tcf_action_init_1(net, tb[i], est, name, ovr, bind);
 596                 if (IS_ERR(act))
 597                         goto err;
 598                 act->order = i;
 599
 600                 if (head == NULL)
 601                         head = act;
 602                 else
 603                         act_prev->next = act;
 604                 act_prev = act;
 605         }
 606         return head;
 607
 608 err:
 609         if (head != NULL)
 610                 tcf_action_destroy(head, bind);
 611         return act;
 612 }
 613
 614 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 615                           int compat_mode)
 616 {
 617         int err = 0;
 618         struct gnet_dump d;
 619         struct tcf_act_hdr *h = a->priv;
 620
 621         if (h == NULL)
 622                 goto errout;
 623
 624         /* compat_mode being true specifies a call that is supposed
 625          * to add additional backward compatibility statistic TLVs.
 626          */
 627         if (compat_mode) {
 628                 if (a->type == TCA_OLD_COMPAT)
 629                         err = gnet_stats_start_copy_compat(skb, 0,
 630                                 TCA_STATS, TCA_XSTATS, &h->tcf_lock, &d);
 631                 else
 632                         return 0;
 633         } else
 634                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 635                                             &h->tcf_lock, &d);
 636
 637         if (err < 0)
 638                 goto errout;
 639
 640         if (a->ops != NULL && a->ops->get_stats != NULL)
 641                 if (a->ops->get_stats(skb, a) < 0)
 642                         goto errout;
 643
 644         if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
 645             gnet_stats_copy_rate_est(&d, &h->tcf_bstats,
 646                                      &h->tcf_rate_est) < 0 ||
 647             gnet_stats_copy_queue(&d, &h->tcf_qstats) < 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 tc_action *a, 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, a, 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 tc_action *a, 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, a, 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 *
 711 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 portid)
 712 {
 713         struct nlattr *tb[TCA_ACT_MAX + 1];
 714         struct tc_action *a;
 715         int index;
 716         int err;
 717
 718         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 719         if (err < 0)
 720                 goto err_out;
 721
 722         err = -EINVAL;
 723         if (tb[TCA_ACT_INDEX] == NULL ||
 724             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 725                 goto err_out;
 726         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 727
 728         err = -ENOMEM;
 729         a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
 730         if (a == NULL)
 731                 goto err_out;
 732
 733         err = -EINVAL;
 734         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 735         if (a->ops == NULL)
 736                 goto err_free;
 737         err = -ENOENT;
 738         if (a->ops->lookup(a, index) == 0)
 739                 goto err_mod;
 740
 741         module_put(a->ops->owner);
 742         return a;
 743
 744 err_mod:
 745         module_put(a->ops->owner);
 746 err_free:
 747         kfree(a);
 748 err_out:
 749         return ERR_PTR(err);
 750 }
 751
 752 static void cleanup_a(struct tc_action *act)
 753 {
 754         struct tc_action *a;
 755
 756         for (a = act; a; a = act) {
 757                 act = a->next;
 758                 kfree(a);
 759         }
 760 }
 761
 762 static struct tc_action *create_a(int i)
 763 {
 764         struct tc_action *act;
 765
 766         act = kzalloc(sizeof(*act), GFP_KERNEL);
 767         if (act == NULL) {
 768                 pr_debug("create_a: failed to alloc!\n");
 769                 return NULL;
 770         }
 771         act->order = i;
 772         return act;
 773 }
 774
 775 static int tca_action_flush(struct net *net, struct nlattr *nla,
 776                             struct nlmsghdr *n, u32 portid)
 777 {
 778         struct sk_buff *skb;
 779         unsigned char *b;
 780         struct nlmsghdr *nlh;
 781         struct tcamsg *t;
 782         struct netlink_callback dcb;
 783         struct nlattr *nest;
 784         struct nlattr *tb[TCA_ACT_MAX + 1];
 785         struct nlattr *kind;
 786         struct tc_action *a = create_a(0);
 787         int err = -ENOMEM;
 788
 789         if (a == NULL) {
 790                 pr_debug("tca_action_flush: couldnt create tc_action\n");
 791                 return err;
 792         }
 793
 794         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 795         if (!skb) {
 796                 pr_debug("tca_action_flush: failed skb alloc\n");
 797                 kfree(a);
 798                 return err;
 799         }
 800
 801         b = skb_tail_pointer(skb);
 802
 803         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 804         if (err < 0)
 805                 goto err_out;
 806
 807         err = -EINVAL;
 808         kind = tb[TCA_ACT_KIND];
 809         a->ops = tc_lookup_action(kind);
 810         if (a->ops == NULL)
 811                 goto err_out;
 812
 813         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t), 0);
 814         if (!nlh)
 815                 goto out_module_put;
 816         t = nlmsg_data(nlh);
 817         t->tca_family = AF_UNSPEC;
 818         t->tca__pad1 = 0;
 819         t->tca__pad2 = 0;
 820
 821         nest = nla_nest_start(skb, TCA_ACT_TAB);
 822         if (nest == NULL)
 823                 goto out_module_put;
 824
 825         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 826         if (err < 0)
 827                 goto out_module_put;
 828         if (err == 0)
 829                 goto noflush_out;
 830
 831         nla_nest_end(skb, nest);
 832
 833         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 834         nlh->nlmsg_flags |= NLM_F_ROOT;
 835         module_put(a->ops->owner);
 836         kfree(a);
 837         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 838                              n->nlmsg_flags & NLM_F_ECHO);
 839         if (err > 0)
 840                 return 0;
 841
 842         return err;
 843
 844 out_module_put:
 845         module_put(a->ops->owner);
 846 err_out:
 847 noflush_out:
 848         kfree_skb(skb);
 849         kfree(a);
 850         return err;
 851 }
 852
 853 static int
 854 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 855               u32 portid, int event)
 856 {
 857         int i, ret;
 858         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 859         struct tc_action *head = NULL, *act, *act_prev = NULL;
 860
 861         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 862         if (ret < 0)
 863                 return ret;
 864
 865         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
 866                 if (tb[1] != NULL)
 867                         return tca_action_flush(net, tb[1], n, portid);
 868                 else
 869                         return -EINVAL;
 870         }
 871
 872         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 873                 act = tcf_action_get_1(tb[i], n, portid);
 874                 if (IS_ERR(act)) {
 875                         ret = PTR_ERR(act);
 876                         goto err;
 877                 }
 878                 act->order = i;
 879
 880                 if (head == NULL)
 881                         head = act;
 882                 else
 883                         act_prev->next = act;
 884                 act_prev = act;
 885         }
 886
 887         if (event == RTM_GETACTION)
 888                 ret = act_get_notify(net, portid, n, head, event);
 889         else { /* delete */
 890                 struct sk_buff *skb;
 891
 892                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 893                 if (!skb) {
 894                         ret = -ENOBUFS;
 895                         goto err;
 896                 }
 897
 898                 if (tca_get_fill(skb, head, portid, n->nlmsg_seq, 0, event,
 899                                  0, 1) <= 0) {
 900                         kfree_skb(skb);
 901                         ret = -EINVAL;
 902                         goto err;
 903                 }
 904
 905                 /* now do the delete */
 906                 tcf_action_destroy(head, 0);
 907                 ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 908                                      n->nlmsg_flags & NLM_F_ECHO);
 909                 if (ret > 0)
 910                         return 0;
 911                 return ret;
 912         }
 913 err:
 914         cleanup_a(head);
 915         return ret;
 916 }
 917
 918 static int tcf_add_notify(struct net *net, struct tc_action *a,
 919                           u32 portid, u32 seq, int event, u16 flags)
 920 {
 921         struct tcamsg *t;
 922         struct nlmsghdr *nlh;
 923         struct sk_buff *skb;
 924         struct nlattr *nest;
 925         unsigned char *b;
 926         int err = 0;
 927
 928         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 929         if (!skb)
 930                 return -ENOBUFS;
 931
 932         b = skb_tail_pointer(skb);
 933
 934         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
 935         if (!nlh)
 936                 goto out_kfree_skb;
 937         t = nlmsg_data(nlh);
 938         t->tca_family = AF_UNSPEC;
 939         t->tca__pad1 = 0;
 940         t->tca__pad2 = 0;
 941
 942         nest = nla_nest_start(skb, TCA_ACT_TAB);
 943         if (nest == NULL)
 944                 goto out_kfree_skb;
 945
 946         if (tcf_action_dump(skb, a, 0, 0) < 0)
 947                 goto out_kfree_skb;
 948
 949         nla_nest_end(skb, nest);
 950
 951         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 952         NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 953
 954         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
 955         if (err > 0)
 956                 err = 0;
 957         return err;
 958
 959 out_kfree_skb:
 960         kfree_skb(skb);
 961         return -1;
 962 }
 963
 964
 965 static int
 966 tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 967                u32 portid, int ovr)
 968 {
 969         int ret = 0;
 970         struct tc_action *act;
 971         struct tc_action *a;
 972         u32 seq = n->nlmsg_seq;
 973
 974         act = tcf_action_init(net, nla, NULL, NULL, ovr, 0);
 975         if (act == NULL)
 976                 goto done;
 977         if (IS_ERR(act)) {
 978                 ret = PTR_ERR(act);
 979                 goto done;
 980         }
 981
 982         /* dump then free all the actions after update; inserted policy
 983          * stays intact
 984          */
 985         ret = tcf_add_notify(net, act, portid, seq, RTM_NEWACTION, n->nlmsg_flags);
 986         for (a = act; a; a = act) {
 987                 act = a->next;
 988                 kfree(a);
 989         }
 990 done:
 991         return ret;
 992 }
 993
 994 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n)
 995 {
 996         struct net *net = sock_net(skb->sk);
 997         struct nlattr *tca[TCA_ACT_MAX + 1];
 998         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
 999         int ret = 0, ovr = 0;
1000
1001         if ((n->nlmsg_type != RTM_GETACTION) && !capable(CAP_NET_ADMIN))
1002                 return -EPERM;
1003
1004         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
1005         if (ret < 0)
1006                 return ret;
1007
1008         if (tca[TCA_ACT_TAB] == NULL) {
1009                 pr_notice("tc_ctl_action: received NO action attribs\n");
1010                 return -EINVAL;
1011         }
1012
1013         /* n->nlmsg_flags & NLM_F_CREATE */
1014         switch (n->nlmsg_type) {
1015         case RTM_NEWACTION:
1016                 /* we are going to assume all other flags
1017                  * imply create only if it doesn't exist
1018                  * Note that CREATE | EXCL implies that
1019                  * but since we want avoid ambiguity (eg when flags
1020                  * is zero) then just set this
1021                  */
1022                 if (n->nlmsg_flags & NLM_F_REPLACE)
1023                         ovr = 1;
1024 replay:
1025                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr);
1026                 if (ret == -EAGAIN)
1027                         goto replay;
1028                 break;
1029         case RTM_DELACTION:
1030                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1031                                     portid, RTM_DELACTION);
1032                 break;
1033         case RTM_GETACTION:
1034                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1035                                     portid, RTM_GETACTION);
1036                 break;
1037         default:
1038                 BUG();
1039         }
1040
1041         return ret;
1042 }
1043
1044 static struct nlattr *
1045 find_dump_kind(const struct nlmsghdr *n)
1046 {
1047         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1048         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1049         struct nlattr *nla[TCAA_MAX + 1];
1050         struct nlattr *kind;
1051
1052         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1053                 return NULL;
1054         tb1 = nla[TCA_ACT_TAB];
1055         if (tb1 == NULL)
1056                 return NULL;
1057
1058         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1059                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1060                 return NULL;
1061
1062         if (tb[1] == NULL)
1063                 return NULL;
1064         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1065                       nla_len(tb[1]), NULL) < 0)
1066                 return NULL;
1067         kind = tb2[TCA_ACT_KIND];
1068
1069         return kind;
1070 }
1071
1072 static int
1073 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1074 {
1075         struct nlmsghdr *nlh;
1076         unsigned char *b = skb_tail_pointer(skb);
1077         struct nlattr *nest;
1078         struct tc_action_ops *a_o;
1079         struct tc_action a;
1080         int ret = 0;
1081         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1082         struct nlattr *kind = find_dump_kind(cb->nlh);
1083
1084         if (kind == NULL) {
1085                 pr_info("tc_dump_action: action bad kind\n");
1086                 return 0;
1087         }
1088
1089         a_o = tc_lookup_action(kind);
1090         if (a_o == NULL)
1091                 return 0;
1092
1093         memset(&a, 0, sizeof(struct tc_action));
1094         a.ops = a_o;
1095
1096         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1097                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1098         if (!nlh)
1099                 goto out_module_put;
1100         t = nlmsg_data(nlh);
1101         t->tca_family = AF_UNSPEC;
1102         t->tca__pad1 = 0;
1103         t->tca__pad2 = 0;
1104
1105         nest = nla_nest_start(skb, TCA_ACT_TAB);
1106         if (nest == NULL)
1107                 goto out_module_put;
1108
1109         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1110         if (ret < 0)
1111                 goto out_module_put;
1112
1113         if (ret > 0) {
1114                 nla_nest_end(skb, nest);
1115                 ret = skb->len;
1116         } else
1117                 nla_nest_cancel(skb, nest);
1118
1119         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1120         if (NETLINK_CB(cb->skb).portid && ret)
1121                 nlh->nlmsg_flags |= NLM_F_MULTI;
1122         module_put(a_o->owner);
1123         return skb->len;
1124
1125 out_module_put:
1126         module_put(a_o->owner);
1127         nlmsg_trim(skb, b);
1128         return skb->len;
1129 }
1130
1131 static int __init tc_action_init(void)
1132 {
1133         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
1134         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
1135         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1136                       NULL);
1137
1138         return 0;
1139 }
1140
1141 subsys_initcall(tc_action_init);