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         return (*idx_gen = val);
 195 }
 196 EXPORT_SYMBOL(tcf_hash_new_index);
 197
 198 int tcf_hash_search(struct tc_action *a, u32 index)
 199 {
 200         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 201         struct tcf_common *p = tcf_hash_lookup(index, hinfo);
 202
 203         if (p) {
 204                 a->priv = p;
 205                 return 1;
 206         }
 207         return 0;
 208 }
 209 EXPORT_SYMBOL(tcf_hash_search);
 210
 211 struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
 212                                   struct tcf_hashinfo *hinfo)
 213 {
 214         struct tcf_common *p = NULL;
 215         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 216                 if (bind)
 217                         p->tcfc_bindcnt++;
 218                 p->tcfc_refcnt++;
 219                 a->priv = p;
 220         }
 221         return p;
 222 }
 223 EXPORT_SYMBOL(tcf_hash_check);
 224
 225 struct tcf_common *tcf_hash_create(u32 index, struct nlattr *est,
 226                                    struct tc_action *a, int size, int bind,
 227                                    u32 *idx_gen, struct tcf_hashinfo *hinfo)
 228 {
 229         struct tcf_common *p = kzalloc(size, GFP_KERNEL);
 230
 231         if (unlikely(!p))
 232                 return ERR_PTR(-ENOMEM);
 233         p->tcfc_refcnt = 1;
 234         if (bind)
 235                 p->tcfc_bindcnt = 1;
 236
 237         spin_lock_init(&p->tcfc_lock);
 238         p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
 239         p->tcfc_tm.install = jiffies;
 240         p->tcfc_tm.lastuse = jiffies;
 241         if (est) {
 242                 int err = gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
 243                                             &p->tcfc_lock, est);
 244                 if (err) {
 245                         kfree(p);
 246                         return ERR_PTR(err);
 247                 }
 248         }
 249
 250         a->priv = (void *) p;
 251         return p;
 252 }
 253 EXPORT_SYMBOL(tcf_hash_create);
 254
 255 void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
 256 {
 257         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
 258
 259         write_lock_bh(hinfo->lock);
 260         p->tcfc_next = hinfo->htab[h];
 261         hinfo->htab[h] = p;
 262         write_unlock_bh(hinfo->lock);
 263 }
 264 EXPORT_SYMBOL(tcf_hash_insert);
 265
 266 static struct tc_action_ops *act_base = NULL;
 267 static DEFINE_RWLOCK(act_mod_lock);
 268
 269 int tcf_register_action(struct tc_action_ops *act)
 270 {
 271         struct tc_action_ops *a, **ap;
 272
 273         /* Must supply act, dump, cleanup and init */
 274         if (!act->act || !act->dump || !act->cleanup || !act->init)
 275                 return -EINVAL;
 276
 277         if (!act->lookup)
 278                 act->lookup = tcf_hash_search;
 279
 280         write_lock(&act_mod_lock);
 281         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
 282                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 283                         write_unlock(&act_mod_lock);
 284                         return -EEXIST;
 285                 }
 286         }
 287         act->next = NULL;
 288         *ap = act;
 289         write_unlock(&act_mod_lock);
 290         return 0;
 291 }
 292 EXPORT_SYMBOL(tcf_register_action);
 293
 294 int tcf_unregister_action(struct tc_action_ops *act)
 295 {
 296         struct tc_action_ops *a, **ap;
 297         int err = -ENOENT;
 298
 299         write_lock(&act_mod_lock);
 300         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
 301                 if (a == act)
 302                         break;
 303         if (a) {
 304                 *ap = a->next;
 305                 a->next = NULL;
 306                 err = 0;
 307         }
 308         write_unlock(&act_mod_lock);
 309         return err;
 310 }
 311 EXPORT_SYMBOL(tcf_unregister_action);
 312
 313 /* lookup by name */
 314 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 315 {
 316         struct tc_action_ops *a = NULL;
 317
 318         if (kind) {
 319                 read_lock(&act_mod_lock);
 320                 for (a = act_base; a; a = a->next) {
 321                         if (strcmp(kind, a->kind) == 0) {
 322                                 if (!try_module_get(a->owner)) {
 323                                         read_unlock(&act_mod_lock);
 324                                         return NULL;
 325                                 }
 326                                 break;
 327                         }
 328                 }
 329                 read_unlock(&act_mod_lock);
 330         }
 331         return a;
 332 }
 333
 334 /* lookup by nlattr */
 335 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 336 {
 337         struct tc_action_ops *a = NULL;
 338
 339         if (kind) {
 340                 read_lock(&act_mod_lock);
 341                 for (a = act_base; a; a = a->next) {
 342                         if (nla_strcmp(kind, a->kind) == 0) {
 343                                 if (!try_module_get(a->owner)) {
 344                                         read_unlock(&act_mod_lock);
 345                                         return NULL;
 346                                 }
 347                                 break;
 348                         }
 349                 }
 350                 read_unlock(&act_mod_lock);
 351         }
 352         return a;
 353 }
 354
 355 #if 0
 356 /* lookup by id */
 357 static struct tc_action_ops *tc_lookup_action_id(u32 type)
 358 {
 359         struct tc_action_ops *a = NULL;
 360
 361         if (type) {
 362                 read_lock(&act_mod_lock);
 363                 for (a = act_base; a; a = a->next) {
 364                         if (a->type == type) {
 365                                 if (!try_module_get(a->owner)) {
 366                                         read_unlock(&act_mod_lock);
 367                                         return NULL;
 368                                 }
 369                                 break;
 370                         }
 371                 }
 372                 read_unlock(&act_mod_lock);
 373         }
 374         return a;
 375 }
 376 #endif
 377
 378 int tcf_action_exec(struct sk_buff *skb, const struct tc_action *act,
 379                     struct tcf_result *res)
 380 {
 381         const struct tc_action *a;
 382         int ret = -1;
 383
 384         if (skb->tc_verd & TC_NCLS) {
 385                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 386                 ret = TC_ACT_OK;
 387                 goto exec_done;
 388         }
 389         while ((a = act) != NULL) {
 390 repeat:
 391                 if (a->ops) {
 392                         ret = a->ops->act(skb, a, res);
 393                         if (TC_MUNGED & skb->tc_verd) {
 394                                 /* copied already, allow trampling */
 395                                 skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
 396                                 skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
 397                         }
 398                         if (ret == TC_ACT_REPEAT)
 399                                 goto repeat;    /* we need a ttl - JHS */
 400                         if (ret != TC_ACT_PIPE)
 401                                 goto exec_done;
 402                 }
 403                 act = a->next;
 404         }
 405 exec_done:
 406         return ret;
 407 }
 408 EXPORT_SYMBOL(tcf_action_exec);
 409
 410 void tcf_action_destroy(struct tc_action *act, int bind)
 411 {
 412         struct tc_action *a;
 413
 414         for (a = act; a; a = act) {
 415                 if (a->ops) {
 416                         if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
 417                                 module_put(a->ops->owner);
 418                         act = act->next;
 419                         kfree(a);
 420                 } else {
 421                         /*FIXME: Remove later - catch insertion bugs*/
 422                         WARN(1, "tcf_action_destroy: BUG? destroying NULL ops\n");
 423                         act = act->next;
 424                         kfree(a);
 425                 }
 426         }
 427 }
 428
 429 int
 430 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 431 {
 432         int err = -EINVAL;
 433
 434         if (a->ops == NULL)
 435                 return err;
 436         return a->ops->dump(skb, a, bind, ref);
 437 }
 438
 439 int
 440 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 441 {
 442         int err = -EINVAL;
 443         unsigned char *b = skb_tail_pointer(skb);
 444         struct nlattr *nest;
 445
 446         if (a->ops == NULL)
 447                 return err;
 448
 449         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 450                 goto nla_put_failure;
 451         if (tcf_action_copy_stats(skb, a, 0))
 452                 goto nla_put_failure;
 453         nest = nla_nest_start(skb, TCA_OPTIONS);
 454         if (nest == NULL)
 455                 goto nla_put_failure;
 456         err = tcf_action_dump_old(skb, a, bind, ref);
 457         if (err > 0) {
 458                 nla_nest_end(skb, nest);
 459                 return err;
 460         }
 461
 462 nla_put_failure:
 463         nlmsg_trim(skb, b);
 464         return -1;
 465 }
 466 EXPORT_SYMBOL(tcf_action_dump_1);
 467
 468 int
 469 tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
 470 {
 471         struct tc_action *a;
 472         int err = -EINVAL;
 473         struct nlattr *nest;
 474
 475         while ((a = act) != NULL) {
 476                 act = a->next;
 477                 nest = nla_nest_start(skb, a->order);
 478                 if (nest == NULL)
 479                         goto nla_put_failure;
 480                 err = tcf_action_dump_1(skb, a, bind, ref);
 481                 if (err < 0)
 482                         goto errout;
 483                 nla_nest_end(skb, nest);
 484         }
 485
 486         return 0;
 487
 488 nla_put_failure:
 489         err = -EINVAL;
 490 errout:
 491         nla_nest_cancel(skb, nest);
 492         return err;
 493 }
 494
 495 struct tc_action *tcf_action_init_1(struct net *net, struct nlattr *nla,
 496                                     struct nlattr *est, char *name, int ovr,
 497                                     int bind)
 498 {
 499         struct tc_action *a;
 500         struct tc_action_ops *a_o;
 501         char act_name[IFNAMSIZ];
 502         struct nlattr *tb[TCA_ACT_MAX + 1];
 503         struct nlattr *kind;
 504         int err;
 505
 506         if (name == NULL) {
 507                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 508                 if (err < 0)
 509                         goto err_out;
 510                 err = -EINVAL;
 511                 kind = tb[TCA_ACT_KIND];
 512                 if (kind == NULL)
 513                         goto err_out;
 514                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 515                         goto err_out;
 516         } else {
 517                 err = -EINVAL;
 518                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 519                         goto err_out;
 520         }
 521
 522         a_o = tc_lookup_action_n(act_name);
 523         if (a_o == NULL) {
 524 #ifdef CONFIG_MODULES
 525                 rtnl_unlock();
 526                 request_module("act_%s", act_name);
 527                 rtnl_lock();
 528
 529                 a_o = tc_lookup_action_n(act_name);
 530
 531                 /* We dropped the RTNL semaphore in order to
 532                  * perform the module load.  So, even if we
 533                  * succeeded in loading the module we have to
 534                  * tell the caller to replay the request.  We
 535                  * indicate this using -EAGAIN.
 536                  */
 537                 if (a_o != NULL) {
 538                         err = -EAGAIN;
 539                         goto err_mod;
 540                 }
 541 #endif
 542                 err = -ENOENT;
 543                 goto err_out;
 544         }
 545
 546         err = -ENOMEM;
 547         a = kzalloc(sizeof(*a), GFP_KERNEL);
 548         if (a == NULL)
 549                 goto err_mod;
 550
 551         /* backward compatibility for policer */
 552         if (name == NULL)
 553                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
 554         else
 555                 err = a_o->init(net, nla, est, a, ovr, bind);
 556         if (err < 0)
 557                 goto err_free;
 558
 559         /* module count goes up only when brand new policy is created
 560          * if it exists and is only bound to in a_o->init() then
 561          * ACT_P_CREATED is not returned (a zero is).
 562          */
 563         if (err != ACT_P_CREATED)
 564                 module_put(a_o->owner);
 565         a->ops = a_o;
 566
 567         return a;
 568
 569 err_free:
 570         kfree(a);
 571 err_mod:
 572         module_put(a_o->owner);
 573 err_out:
 574         return ERR_PTR(err);
 575 }
 576
 577 struct tc_action *tcf_action_init(struct net *net, struct nlattr *nla,
 578                                   struct nlattr *est, char *name, int ovr,
 579                                   int bind)
 580 {
 581         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 582         struct tc_action *head = NULL, *act, *act_prev = NULL;
 583         int err;
 584         int i;
 585
 586         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 587         if (err < 0)
 588                 return ERR_PTR(err);
 589
 590         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 591                 act = tcf_action_init_1(net, tb[i], est, name, ovr, bind);
 592                 if (IS_ERR(act))
 593                         goto err;
 594                 act->order = i;
 595
 596                 if (head == NULL)
 597                         head = act;
 598                 else
 599                         act_prev->next = act;
 600                 act_prev = act;
 601         }
 602         return head;
 603
 604 err:
 605         if (head != NULL)
 606                 tcf_action_destroy(head, bind);
 607         return act;
 608 }
 609
 610 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 611                           int compat_mode)
 612 {
 613         int err = 0;
 614         struct gnet_dump d;
 615         struct tcf_act_hdr *h = a->priv;
 616
 617         if (h == NULL)
 618                 goto errout;
 619
 620         /* compat_mode being true specifies a call that is supposed
 621          * to add additional backward compatibility statistic TLVs.
 622          */
 623         if (compat_mode) {
 624                 if (a->type == TCA_OLD_COMPAT)
 625                         err = gnet_stats_start_copy_compat(skb, 0,
 626                                 TCA_STATS, TCA_XSTATS, &h->tcf_lock, &d);
 627                 else
 628                         return 0;
 629         } else
 630                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 631                                             &h->tcf_lock, &d);
 632
 633         if (err < 0)
 634                 goto errout;
 635
 636         if (a->ops != NULL && a->ops->get_stats != NULL)
 637                 if (a->ops->get_stats(skb, a) < 0)
 638                         goto errout;
 639
 640         if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
 641             gnet_stats_copy_rate_est(&d, &h->tcf_bstats,
 642                                      &h->tcf_rate_est) < 0 ||
 643             gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
 644                 goto errout;
 645
 646         if (gnet_stats_finish_copy(&d) < 0)
 647                 goto errout;
 648
 649         return 0;
 650
 651 errout:
 652         return -1;
 653 }
 654
 655 static int
 656 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 portid, u32 seq,
 657              u16 flags, int event, int bind, int ref)
 658 {
 659         struct tcamsg *t;
 660         struct nlmsghdr *nlh;
 661         unsigned char *b = skb_tail_pointer(skb);
 662         struct nlattr *nest;
 663
 664         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
 665         if (!nlh)
 666                 goto out_nlmsg_trim;
 667         t = nlmsg_data(nlh);
 668         t->tca_family = AF_UNSPEC;
 669         t->tca__pad1 = 0;
 670         t->tca__pad2 = 0;
 671
 672         nest = nla_nest_start(skb, TCA_ACT_TAB);
 673         if (nest == NULL)
 674                 goto out_nlmsg_trim;
 675
 676         if (tcf_action_dump(skb, a, bind, ref) < 0)
 677                 goto out_nlmsg_trim;
 678
 679         nla_nest_end(skb, nest);
 680
 681         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 682         return skb->len;
 683
 684 out_nlmsg_trim:
 685         nlmsg_trim(skb, b);
 686         return -1;
 687 }
 688
 689 static int
 690 act_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
 691                struct tc_action *a, int event)
 692 {
 693         struct sk_buff *skb;
 694
 695         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 696         if (!skb)
 697                 return -ENOBUFS;
 698         if (tca_get_fill(skb, a, portid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 699                 kfree_skb(skb);
 700                 return -EINVAL;
 701         }
 702
 703         return rtnl_unicast(skb, net, portid);
 704 }
 705
 706 static struct tc_action *
 707 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 portid)
 708 {
 709         struct nlattr *tb[TCA_ACT_MAX + 1];
 710         struct tc_action *a;
 711         int index;
 712         int err;
 713
 714         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 715         if (err < 0)
 716                 goto err_out;
 717
 718         err = -EINVAL;
 719         if (tb[TCA_ACT_INDEX] == NULL ||
 720             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 721                 goto err_out;
 722         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 723
 724         err = -ENOMEM;
 725         a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
 726         if (a == NULL)
 727                 goto err_out;
 728
 729         err = -EINVAL;
 730         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 731         if (a->ops == NULL)
 732                 goto err_free;
 733         err = -ENOENT;
 734         if (a->ops->lookup(a, index) == 0)
 735                 goto err_mod;
 736
 737         module_put(a->ops->owner);
 738         return a;
 739
 740 err_mod:
 741         module_put(a->ops->owner);
 742 err_free:
 743         kfree(a);
 744 err_out:
 745         return ERR_PTR(err);
 746 }
 747
 748 static void cleanup_a(struct tc_action *act)
 749 {
 750         struct tc_action *a;
 751
 752         for (a = act; a; a = act) {
 753                 act = a->next;
 754                 kfree(a);
 755         }
 756 }
 757
 758 static struct tc_action *create_a(int i)
 759 {
 760         struct tc_action *act;
 761
 762         act = kzalloc(sizeof(*act), GFP_KERNEL);
 763         if (act == NULL) {
 764                 pr_debug("create_a: failed to alloc!\n");
 765                 return NULL;
 766         }
 767         act->order = i;
 768         return act;
 769 }
 770
 771 static int tca_action_flush(struct net *net, struct nlattr *nla,
 772                             struct nlmsghdr *n, u32 portid)
 773 {
 774         struct sk_buff *skb;
 775         unsigned char *b;
 776         struct nlmsghdr *nlh;
 777         struct tcamsg *t;
 778         struct netlink_callback dcb;
 779         struct nlattr *nest;
 780         struct nlattr *tb[TCA_ACT_MAX + 1];
 781         struct nlattr *kind;
 782         struct tc_action *a = create_a(0);
 783         int err = -ENOMEM;
 784
 785         if (a == NULL) {
 786                 pr_debug("tca_action_flush: couldnt create tc_action\n");
 787                 return err;
 788         }
 789
 790         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 791         if (!skb) {
 792                 pr_debug("tca_action_flush: failed skb alloc\n");
 793                 kfree(a);
 794                 return err;
 795         }
 796
 797         b = skb_tail_pointer(skb);
 798
 799         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 800         if (err < 0)
 801                 goto err_out;
 802
 803         err = -EINVAL;
 804         kind = tb[TCA_ACT_KIND];
 805         a->ops = tc_lookup_action(kind);
 806         if (a->ops == NULL)
 807                 goto err_out;
 808
 809         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t), 0);
 810         if (!nlh)
 811                 goto out_module_put;
 812         t = nlmsg_data(nlh);
 813         t->tca_family = AF_UNSPEC;
 814         t->tca__pad1 = 0;
 815         t->tca__pad2 = 0;
 816
 817         nest = nla_nest_start(skb, TCA_ACT_TAB);
 818         if (nest == NULL)
 819                 goto out_module_put;
 820
 821         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 822         if (err < 0)
 823                 goto out_module_put;
 824         if (err == 0)
 825                 goto noflush_out;
 826
 827         nla_nest_end(skb, nest);
 828
 829         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 830         nlh->nlmsg_flags |= NLM_F_ROOT;
 831         module_put(a->ops->owner);
 832         kfree(a);
 833         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 834                              n->nlmsg_flags & NLM_F_ECHO);
 835         if (err > 0)
 836                 return 0;
 837
 838         return err;
 839
 840 out_module_put:
 841         module_put(a->ops->owner);
 842 err_out:
 843 noflush_out:
 844         kfree_skb(skb);
 845         kfree(a);
 846         return err;
 847 }
 848
 849 static int
 850 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 851               u32 portid, int event)
 852 {
 853         int i, ret;
 854         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 855         struct tc_action *head = NULL, *act, *act_prev = NULL;
 856
 857         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 858         if (ret < 0)
 859                 return ret;
 860
 861         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
 862                 if (tb[1] != NULL)
 863                         return tca_action_flush(net, tb[1], n, portid);
 864                 else
 865                         return -EINVAL;
 866         }
 867
 868         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 869                 act = tcf_action_get_1(tb[i], n, portid);
 870                 if (IS_ERR(act)) {
 871                         ret = PTR_ERR(act);
 872                         goto err;
 873                 }
 874                 act->order = i;
 875
 876                 if (head == NULL)
 877                         head = act;
 878                 else
 879                         act_prev->next = act;
 880                 act_prev = act;
 881         }
 882
 883         if (event == RTM_GETACTION)
 884                 ret = act_get_notify(net, portid, n, head, event);
 885         else { /* delete */
 886                 struct sk_buff *skb;
 887
 888                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 889                 if (!skb) {
 890                         ret = -ENOBUFS;
 891                         goto err;
 892                 }
 893
 894                 if (tca_get_fill(skb, head, portid, n->nlmsg_seq, 0, event,
 895                                  0, 1) <= 0) {
 896                         kfree_skb(skb);
 897                         ret = -EINVAL;
 898                         goto err;
 899                 }
 900
 901                 /* now do the delete */
 902                 tcf_action_destroy(head, 0);
 903                 ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 904                                      n->nlmsg_flags & NLM_F_ECHO);
 905                 if (ret > 0)
 906                         return 0;
 907                 return ret;
 908         }
 909 err:
 910         cleanup_a(head);
 911         return ret;
 912 }
 913
 914 static int tcf_add_notify(struct net *net, struct tc_action *a,
 915                           u32 portid, u32 seq, int event, u16 flags)
 916 {
 917         struct tcamsg *t;
 918         struct nlmsghdr *nlh;
 919         struct sk_buff *skb;
 920         struct nlattr *nest;
 921         unsigned char *b;
 922         int err = 0;
 923
 924         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 925         if (!skb)
 926                 return -ENOBUFS;
 927
 928         b = skb_tail_pointer(skb);
 929
 930         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
 931         if (!nlh)
 932                 goto out_kfree_skb;
 933         t = nlmsg_data(nlh);
 934         t->tca_family = AF_UNSPEC;
 935         t->tca__pad1 = 0;
 936         t->tca__pad2 = 0;
 937
 938         nest = nla_nest_start(skb, TCA_ACT_TAB);
 939         if (nest == NULL)
 940                 goto out_kfree_skb;
 941
 942         if (tcf_action_dump(skb, a, 0, 0) < 0)
 943                 goto out_kfree_skb;
 944
 945         nla_nest_end(skb, nest);
 946
 947         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 948         NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 949
 950         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
 951         if (err > 0)
 952                 err = 0;
 953         return err;
 954
 955 out_kfree_skb:
 956         kfree_skb(skb);
 957         return -1;
 958 }
 959
 960
 961 static int
 962 tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 963                u32 portid, int ovr)
 964 {
 965         int ret = 0;
 966         struct tc_action *act;
 967         struct tc_action *a;
 968         u32 seq = n->nlmsg_seq;
 969
 970         act = tcf_action_init(net, nla, NULL, NULL, ovr, 0);
 971         if (act == NULL)
 972                 goto done;
 973         if (IS_ERR(act)) {
 974                 ret = PTR_ERR(act);
 975                 goto done;
 976         }
 977
 978         /* dump then free all the actions after update; inserted policy
 979          * stays intact
 980          */
 981         ret = tcf_add_notify(net, act, portid, seq, RTM_NEWACTION, n->nlmsg_flags);
 982         for (a = act; a; a = act) {
 983                 act = a->next;
 984                 kfree(a);
 985         }
 986 done:
 987         return ret;
 988 }
 989
 990 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n)
 991 {
 992         struct net *net = sock_net(skb->sk);
 993         struct nlattr *tca[TCA_ACT_MAX + 1];
 994         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
 995         int ret = 0, ovr = 0;
 996
 997         if ((n->nlmsg_type != RTM_GETACTION) && !capable(CAP_NET_ADMIN))
 998                 return -EPERM;
 999
1000         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
1001         if (ret < 0)
1002                 return ret;
1003
1004         if (tca[TCA_ACT_TAB] == NULL) {
1005                 pr_notice("tc_ctl_action: received NO action attribs\n");
1006                 return -EINVAL;
1007         }
1008
1009         /* n->nlmsg_flags & NLM_F_CREATE */
1010         switch (n->nlmsg_type) {
1011         case RTM_NEWACTION:
1012                 /* we are going to assume all other flags
1013                  * imply create only if it doesn't exist
1014                  * Note that CREATE | EXCL implies that
1015                  * but since we want avoid ambiguity (eg when flags
1016                  * is zero) then just set this
1017                  */
1018                 if (n->nlmsg_flags & NLM_F_REPLACE)
1019                         ovr = 1;
1020 replay:
1021                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr);
1022                 if (ret == -EAGAIN)
1023                         goto replay;
1024                 break;
1025         case RTM_DELACTION:
1026                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1027                                     portid, RTM_DELACTION);
1028                 break;
1029         case RTM_GETACTION:
1030                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1031                                     portid, RTM_GETACTION);
1032                 break;
1033         default:
1034                 BUG();
1035         }
1036
1037         return ret;
1038 }
1039
1040 static struct nlattr *
1041 find_dump_kind(const struct nlmsghdr *n)
1042 {
1043         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1044         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1045         struct nlattr *nla[TCAA_MAX + 1];
1046         struct nlattr *kind;
1047
1048         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1049                 return NULL;
1050         tb1 = nla[TCA_ACT_TAB];
1051         if (tb1 == NULL)
1052                 return NULL;
1053
1054         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1055                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1056                 return NULL;
1057
1058         if (tb[1] == NULL)
1059                 return NULL;
1060         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1061                       nla_len(tb[1]), NULL) < 0)
1062                 return NULL;
1063         kind = tb2[TCA_ACT_KIND];
1064
1065         return kind;
1066 }
1067
1068 static int
1069 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1070 {
1071         struct nlmsghdr *nlh;
1072         unsigned char *b = skb_tail_pointer(skb);
1073         struct nlattr *nest;
1074         struct tc_action_ops *a_o;
1075         struct tc_action a;
1076         int ret = 0;
1077         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1078         struct nlattr *kind = find_dump_kind(cb->nlh);
1079
1080         if (kind == NULL) {
1081                 pr_info("tc_dump_action: action bad kind\n");
1082                 return 0;
1083         }
1084
1085         a_o = tc_lookup_action(kind);
1086         if (a_o == NULL)
1087                 return 0;
1088
1089         memset(&a, 0, sizeof(struct tc_action));
1090         a.ops = a_o;
1091
1092         if (a_o->walk == NULL) {
1093                 WARN(1, "tc_dump_action: %s !capable of dumping table\n",
1094                      a_o->kind);
1095                 goto out_module_put;
1096         }
1097
1098         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1099                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1100         if (!nlh)
1101                 goto out_module_put;
1102         t = nlmsg_data(nlh);
1103         t->tca_family = AF_UNSPEC;
1104         t->tca__pad1 = 0;
1105         t->tca__pad2 = 0;
1106
1107         nest = nla_nest_start(skb, TCA_ACT_TAB);
1108         if (nest == NULL)
1109                 goto out_module_put;
1110
1111         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1112         if (ret < 0)
1113                 goto out_module_put;
1114
1115         if (ret > 0) {
1116                 nla_nest_end(skb, nest);
1117                 ret = skb->len;
1118         } else
1119                 nla_nest_cancel(skb, nest);
1120
1121         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1122         if (NETLINK_CB(cb->skb).portid && ret)
1123                 nlh->nlmsg_flags |= NLM_F_MULTI;
1124         module_put(a_o->owner);
1125         return skb->len;
1126
1127 out_module_put:
1128         module_put(a_o->owner);
1129         nlmsg_trim(skb, b);
1130         return skb->len;
1131 }
1132
1133 static int __init tc_action_init(void)
1134 {
1135         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
1136         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
1137         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1138                       NULL);
1139
1140         return 0;
1141 }
1142
1143 subsys_initcall(tc_action_init);