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         NLA_PUT_STRING(skb, TCA_KIND, a->ops->kind);
 131         for (i = 0; i < (hinfo->hmask + 1); i++) {
 132                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
 133
 134                 while (p != NULL) {
 135                         s_p = p->tcfc_next;
 136                         if (ACT_P_DELETED == tcf_hash_release(p, 0, hinfo))
 137                                 module_put(a->ops->owner);
 138                         n_i++;
 139                         p = s_p;
 140                 }
 141         }
 142         NLA_PUT_U32(skb, TCA_FCNT, n_i);
 143         nla_nest_end(skb, nest);
 144
 145         return n_i;
 146 nla_put_failure:
 147         nla_nest_cancel(skb, nest);
 148         return -EINVAL;
 149 }
 150
 151 int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
 152                        int type, struct tc_action *a)
 153 {
 154         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 155
 156         if (type == RTM_DELACTION) {
 157                 return tcf_del_walker(skb, a, hinfo);
 158         } else if (type == RTM_GETACTION) {
 159                 return tcf_dump_walker(skb, cb, a, hinfo);
 160         } else {
 161                 WARN(1, "tcf_generic_walker: unknown action %d\n", type);
 162                 return -EINVAL;
 163         }
 164 }
 165 EXPORT_SYMBOL(tcf_generic_walker);
 166
 167 struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 168 {
 169         struct tcf_common *p;
 170
 171         read_lock_bh(hinfo->lock);
 172         for (p = hinfo->htab[tcf_hash(index, hinfo->hmask)]; p;
 173              p = p->tcfc_next) {
 174                 if (p->tcfc_index == index)
 175                         break;
 176         }
 177         read_unlock_bh(hinfo->lock);
 178
 179         return p;
 180 }
 181 EXPORT_SYMBOL(tcf_hash_lookup);
 182
 183 u32 tcf_hash_new_index(u32 *idx_gen, struct tcf_hashinfo *hinfo)
 184 {
 185         u32 val = *idx_gen;
 186
 187         do {
 188                 if (++val == 0)
 189                         val = 1;
 190         } while (tcf_hash_lookup(val, hinfo));
 191
 192         return (*idx_gen = val);
 193 }
 194 EXPORT_SYMBOL(tcf_hash_new_index);
 195
 196 int tcf_hash_search(struct tc_action *a, u32 index)
 197 {
 198         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 199         struct tcf_common *p = tcf_hash_lookup(index, hinfo);
 200
 201         if (p) {
 202                 a->priv = p;
 203                 return 1;
 204         }
 205         return 0;
 206 }
 207 EXPORT_SYMBOL(tcf_hash_search);
 208
 209 struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
 210                                   struct tcf_hashinfo *hinfo)
 211 {
 212         struct tcf_common *p = NULL;
 213         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 214                 if (bind)
 215                         p->tcfc_bindcnt++;
 216                 p->tcfc_refcnt++;
 217                 a->priv = p;
 218         }
 219         return p;
 220 }
 221 EXPORT_SYMBOL(tcf_hash_check);
 222
 223 struct tcf_common *tcf_hash_create(u32 index, struct nlattr *est,
 224                                    struct tc_action *a, int size, int bind,
 225                                    u32 *idx_gen, struct tcf_hashinfo *hinfo)
 226 {
 227         struct tcf_common *p = kzalloc(size, GFP_KERNEL);
 228
 229         if (unlikely(!p))
 230                 return ERR_PTR(-ENOMEM);
 231         p->tcfc_refcnt = 1;
 232         if (bind)
 233                 p->tcfc_bindcnt = 1;
 234
 235         spin_lock_init(&p->tcfc_lock);
 236         p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
 237         p->tcfc_tm.install = jiffies;
 238         p->tcfc_tm.lastuse = jiffies;
 239         if (est) {
 240                 int err = gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
 241                                             &p->tcfc_lock, est);
 242                 if (err) {
 243                         kfree(p);
 244                         return ERR_PTR(err);
 245                 }
 246         }
 247
 248         a->priv = (void *) p;
 249         return p;
 250 }
 251 EXPORT_SYMBOL(tcf_hash_create);
 252
 253 void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
 254 {
 255         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
 256
 257         write_lock_bh(hinfo->lock);
 258         p->tcfc_next = hinfo->htab[h];
 259         hinfo->htab[h] = p;
 260         write_unlock_bh(hinfo->lock);
 261 }
 262 EXPORT_SYMBOL(tcf_hash_insert);
 263
 264 static struct tc_action_ops *act_base = NULL;
 265 static DEFINE_RWLOCK(act_mod_lock);
 266
 267 int tcf_register_action(struct tc_action_ops *act)
 268 {
 269         struct tc_action_ops *a, **ap;
 270
 271         write_lock(&act_mod_lock);
 272         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
 273                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 274                         write_unlock(&act_mod_lock);
 275                         return -EEXIST;
 276                 }
 277         }
 278         act->next = NULL;
 279         *ap = act;
 280         write_unlock(&act_mod_lock);
 281         return 0;
 282 }
 283 EXPORT_SYMBOL(tcf_register_action);
 284
 285 int tcf_unregister_action(struct tc_action_ops *act)
 286 {
 287         struct tc_action_ops *a, **ap;
 288         int err = -ENOENT;
 289
 290         write_lock(&act_mod_lock);
 291         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
 292                 if (a == act)
 293                         break;
 294         if (a) {
 295                 *ap = a->next;
 296                 a->next = NULL;
 297                 err = 0;
 298         }
 299         write_unlock(&act_mod_lock);
 300         return err;
 301 }
 302 EXPORT_SYMBOL(tcf_unregister_action);
 303
 304 /* lookup by name */
 305 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 306 {
 307         struct tc_action_ops *a = NULL;
 308
 309         if (kind) {
 310                 read_lock(&act_mod_lock);
 311                 for (a = act_base; a; a = a->next) {
 312                         if (strcmp(kind, a->kind) == 0) {
 313                                 if (!try_module_get(a->owner)) {
 314                                         read_unlock(&act_mod_lock);
 315                                         return NULL;
 316                                 }
 317                                 break;
 318                         }
 319                 }
 320                 read_unlock(&act_mod_lock);
 321         }
 322         return a;
 323 }
 324
 325 /* lookup by nlattr */
 326 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 327 {
 328         struct tc_action_ops *a = NULL;
 329
 330         if (kind) {
 331                 read_lock(&act_mod_lock);
 332                 for (a = act_base; a; a = a->next) {
 333                         if (nla_strcmp(kind, a->kind) == 0) {
 334                                 if (!try_module_get(a->owner)) {
 335                                         read_unlock(&act_mod_lock);
 336                                         return NULL;
 337                                 }
 338                                 break;
 339                         }
 340                 }
 341                 read_unlock(&act_mod_lock);
 342         }
 343         return a;
 344 }
 345
 346 #if 0
 347 /* lookup by id */
 348 static struct tc_action_ops *tc_lookup_action_id(u32 type)
 349 {
 350         struct tc_action_ops *a = NULL;
 351
 352         if (type) {
 353                 read_lock(&act_mod_lock);
 354                 for (a = act_base; a; a = a->next) {
 355                         if (a->type == type) {
 356                                 if (!try_module_get(a->owner)) {
 357                                         read_unlock(&act_mod_lock);
 358                                         return NULL;
 359                                 }
 360                                 break;
 361                         }
 362                 }
 363                 read_unlock(&act_mod_lock);
 364         }
 365         return a;
 366 }
 367 #endif
 368
 369 int tcf_action_exec(struct sk_buff *skb, const struct tc_action *act,
 370                     struct tcf_result *res)
 371 {
 372         const struct tc_action *a;
 373         int ret = -1;
 374
 375         if (skb->tc_verd & TC_NCLS) {
 376                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 377                 ret = TC_ACT_OK;
 378                 goto exec_done;
 379         }
 380         while ((a = act) != NULL) {
 381 repeat:
 382                 if (a->ops && a->ops->act) {
 383                         ret = a->ops->act(skb, a, res);
 384                         if (TC_MUNGED & skb->tc_verd) {
 385                                 /* copied already, allow trampling */
 386                                 skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
 387                                 skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
 388                         }
 389                         if (ret == TC_ACT_REPEAT)
 390                                 goto repeat;    /* we need a ttl - JHS */
 391                         if (ret != TC_ACT_PIPE)
 392                                 goto exec_done;
 393                 }
 394                 act = a->next;
 395         }
 396 exec_done:
 397         return ret;
 398 }
 399 EXPORT_SYMBOL(tcf_action_exec);
 400
 401 void tcf_action_destroy(struct tc_action *act, int bind)
 402 {
 403         struct tc_action *a;
 404
 405         for (a = act; a; a = act) {
 406                 if (a->ops && a->ops->cleanup) {
 407                         if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
 408                                 module_put(a->ops->owner);
 409                         act = act->next;
 410                         kfree(a);
 411                 } else {
 412                         /*FIXME: Remove later - catch insertion bugs*/
 413                         WARN(1, "tcf_action_destroy: BUG? destroying NULL ops\n");
 414                         act = act->next;
 415                         kfree(a);
 416                 }
 417         }
 418 }
 419
 420 int
 421 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 422 {
 423         int err = -EINVAL;
 424
 425         if (a->ops == NULL || a->ops->dump == NULL)
 426                 return err;
 427         return a->ops->dump(skb, a, bind, ref);
 428 }
 429
 430 int
 431 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 432 {
 433         int err = -EINVAL;
 434         unsigned char *b = skb_tail_pointer(skb);
 435         struct nlattr *nest;
 436
 437         if (a->ops == NULL || a->ops->dump == NULL)
 438                 return err;
 439
 440         NLA_PUT_STRING(skb, TCA_KIND, a->ops->kind);
 441         if (tcf_action_copy_stats(skb, a, 0))
 442                 goto nla_put_failure;
 443         nest = nla_nest_start(skb, TCA_OPTIONS);
 444         if (nest == NULL)
 445                 goto nla_put_failure;
 446         err = tcf_action_dump_old(skb, a, bind, ref);
 447         if (err > 0) {
 448                 nla_nest_end(skb, nest);
 449                 return err;
 450         }
 451
 452 nla_put_failure:
 453         nlmsg_trim(skb, b);
 454         return -1;
 455 }
 456 EXPORT_SYMBOL(tcf_action_dump_1);
 457
 458 int
 459 tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
 460 {
 461         struct tc_action *a;
 462         int err = -EINVAL;
 463         struct nlattr *nest;
 464
 465         while ((a = act) != NULL) {
 466                 act = a->next;
 467                 nest = nla_nest_start(skb, a->order);
 468                 if (nest == NULL)
 469                         goto nla_put_failure;
 470                 err = tcf_action_dump_1(skb, a, bind, ref);
 471                 if (err < 0)
 472                         goto errout;
 473                 nla_nest_end(skb, nest);
 474         }
 475
 476         return 0;
 477
 478 nla_put_failure:
 479         err = -EINVAL;
 480 errout:
 481         nla_nest_cancel(skb, nest);
 482         return err;
 483 }
 484
 485 struct tc_action *tcf_action_init_1(struct nlattr *nla, struct nlattr *est,
 486                                     char *name, int ovr, int bind)
 487 {
 488         struct tc_action *a;
 489         struct tc_action_ops *a_o;
 490         char act_name[IFNAMSIZ];
 491         struct nlattr *tb[TCA_ACT_MAX + 1];
 492         struct nlattr *kind;
 493         int err;
 494
 495         if (name == NULL) {
 496                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 497                 if (err < 0)
 498                         goto err_out;
 499                 err = -EINVAL;
 500                 kind = tb[TCA_ACT_KIND];
 501                 if (kind == NULL)
 502                         goto err_out;
 503                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 504                         goto err_out;
 505         } else {
 506                 err = -EINVAL;
 507                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 508                         goto err_out;
 509         }
 510
 511         a_o = tc_lookup_action_n(act_name);
 512         if (a_o == NULL) {
 513 #ifdef CONFIG_MODULES
 514                 rtnl_unlock();
 515                 request_module("act_%s", act_name);
 516                 rtnl_lock();
 517
 518                 a_o = tc_lookup_action_n(act_name);
 519
 520                 /* We dropped the RTNL semaphore in order to
 521                  * perform the module load.  So, even if we
 522                  * succeeded in loading the module we have to
 523                  * tell the caller to replay the request.  We
 524                  * indicate this using -EAGAIN.
 525                  */
 526                 if (a_o != NULL) {
 527                         err = -EAGAIN;
 528                         goto err_mod;
 529                 }
 530 #endif
 531                 err = -ENOENT;
 532                 goto err_out;
 533         }
 534
 535         err = -ENOMEM;
 536         a = kzalloc(sizeof(*a), GFP_KERNEL);
 537         if (a == NULL)
 538                 goto err_mod;
 539
 540         /* backward compatibility for policer */
 541         if (name == NULL)
 542                 err = a_o->init(tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
 543         else
 544                 err = a_o->init(nla, est, a, ovr, bind);
 545         if (err < 0)
 546                 goto err_free;
 547
 548         /* module count goes up only when brand new policy is created
 549          * if it exists and is only bound to in a_o->init() then
 550          * ACT_P_CREATED is not returned (a zero is).
 551          */
 552         if (err != ACT_P_CREATED)
 553                 module_put(a_o->owner);
 554         a->ops = a_o;
 555
 556         return a;
 557
 558 err_free:
 559         kfree(a);
 560 err_mod:
 561         module_put(a_o->owner);
 562 err_out:
 563         return ERR_PTR(err);
 564 }
 565
 566 struct tc_action *tcf_action_init(struct nlattr *nla, struct nlattr *est,
 567                                   char *name, int ovr, int bind)
 568 {
 569         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 570         struct tc_action *head = NULL, *act, *act_prev = NULL;
 571         int err;
 572         int i;
 573
 574         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 575         if (err < 0)
 576                 return ERR_PTR(err);
 577
 578         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 579                 act = tcf_action_init_1(tb[i], est, name, ovr, bind);
 580                 if (IS_ERR(act))
 581                         goto err;
 582                 act->order = i;
 583
 584                 if (head == NULL)
 585                         head = act;
 586                 else
 587                         act_prev->next = act;
 588                 act_prev = act;
 589         }
 590         return head;
 591
 592 err:
 593         if (head != NULL)
 594                 tcf_action_destroy(head, bind);
 595         return act;
 596 }
 597
 598 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 599                           int compat_mode)
 600 {
 601         int err = 0;
 602         struct gnet_dump d;
 603         struct tcf_act_hdr *h = a->priv;
 604
 605         if (h == NULL)
 606                 goto errout;
 607
 608         /* compat_mode being true specifies a call that is supposed
 609          * to add additional backward compatibility statistic TLVs.
 610          */
 611         if (compat_mode) {
 612                 if (a->type == TCA_OLD_COMPAT)
 613                         err = gnet_stats_start_copy_compat(skb, 0,
 614                                 TCA_STATS, TCA_XSTATS, &h->tcf_lock, &d);
 615                 else
 616                         return 0;
 617         } else
 618                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 619                                             &h->tcf_lock, &d);
 620
 621         if (err < 0)
 622                 goto errout;
 623
 624         if (a->ops != NULL && a->ops->get_stats != NULL)
 625                 if (a->ops->get_stats(skb, a) < 0)
 626                         goto errout;
 627
 628         if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
 629             gnet_stats_copy_rate_est(&d, &h->tcf_bstats,
 630                                      &h->tcf_rate_est) < 0 ||
 631             gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
 632                 goto errout;
 633
 634         if (gnet_stats_finish_copy(&d) < 0)
 635                 goto errout;
 636
 637         return 0;
 638
 639 errout:
 640         return -1;
 641 }
 642
 643 static int
 644 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 pid, u32 seq,
 645              u16 flags, int event, int bind, int ref)
 646 {
 647         struct tcamsg *t;
 648         struct nlmsghdr *nlh;
 649         unsigned char *b = skb_tail_pointer(skb);
 650         struct nlattr *nest;
 651
 652         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 653
 654         t = NLMSG_DATA(nlh);
 655         t->tca_family = AF_UNSPEC;
 656         t->tca__pad1 = 0;
 657         t->tca__pad2 = 0;
 658
 659         nest = nla_nest_start(skb, TCA_ACT_TAB);
 660         if (nest == NULL)
 661                 goto nla_put_failure;
 662
 663         if (tcf_action_dump(skb, a, bind, ref) < 0)
 664                 goto nla_put_failure;
 665
 666         nla_nest_end(skb, nest);
 667
 668         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 669         return skb->len;
 670
 671 nla_put_failure:
 672 nlmsg_failure:
 673         nlmsg_trim(skb, b);
 674         return -1;
 675 }
 676
 677 static int
 678 act_get_notify(struct net *net, u32 pid, struct nlmsghdr *n,
 679                struct tc_action *a, int event)
 680 {
 681         struct sk_buff *skb;
 682
 683         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 684         if (!skb)
 685                 return -ENOBUFS;
 686         if (tca_get_fill(skb, a, pid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 687                 kfree_skb(skb);
 688                 return -EINVAL;
 689         }
 690
 691         return rtnl_unicast(skb, net, pid);
 692 }
 693
 694 static struct tc_action *
 695 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 pid)
 696 {
 697         struct nlattr *tb[TCA_ACT_MAX + 1];
 698         struct tc_action *a;
 699         int index;
 700         int err;
 701
 702         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 703         if (err < 0)
 704                 goto err_out;
 705
 706         err = -EINVAL;
 707         if (tb[TCA_ACT_INDEX] == NULL ||
 708             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 709                 goto err_out;
 710         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 711
 712         err = -ENOMEM;
 713         a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
 714         if (a == NULL)
 715                 goto err_out;
 716
 717         err = -EINVAL;
 718         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 719         if (a->ops == NULL)
 720                 goto err_free;
 721         if (a->ops->lookup == NULL)
 722                 goto err_mod;
 723         err = -ENOENT;
 724         if (a->ops->lookup(a, index) == 0)
 725                 goto err_mod;
 726
 727         module_put(a->ops->owner);
 728         return a;
 729
 730 err_mod:
 731         module_put(a->ops->owner);
 732 err_free:
 733         kfree(a);
 734 err_out:
 735         return ERR_PTR(err);
 736 }
 737
 738 static void cleanup_a(struct tc_action *act)
 739 {
 740         struct tc_action *a;
 741
 742         for (a = act; a; a = act) {
 743                 act = a->next;
 744                 kfree(a);
 745         }
 746 }
 747
 748 static struct tc_action *create_a(int i)
 749 {
 750         struct tc_action *act;
 751
 752         act = kzalloc(sizeof(*act), GFP_KERNEL);
 753         if (act == NULL) {
 754                 pr_debug("create_a: failed to alloc!\n");
 755                 return NULL;
 756         }
 757         act->order = i;
 758         return act;
 759 }
 760
 761 static int tca_action_flush(struct net *net, struct nlattr *nla,
 762                             struct nlmsghdr *n, u32 pid)
 763 {
 764         struct sk_buff *skb;
 765         unsigned char *b;
 766         struct nlmsghdr *nlh;
 767         struct tcamsg *t;
 768         struct netlink_callback dcb;
 769         struct nlattr *nest;
 770         struct nlattr *tb[TCA_ACT_MAX + 1];
 771         struct nlattr *kind;
 772         struct tc_action *a = create_a(0);
 773         int err = -ENOMEM;
 774
 775         if (a == NULL) {
 776                 pr_debug("tca_action_flush: couldnt create tc_action\n");
 777                 return err;
 778         }
 779
 780         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 781         if (!skb) {
 782                 pr_debug("tca_action_flush: failed skb alloc\n");
 783                 kfree(a);
 784                 return err;
 785         }
 786
 787         b = skb_tail_pointer(skb);
 788
 789         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 790         if (err < 0)
 791                 goto err_out;
 792
 793         err = -EINVAL;
 794         kind = tb[TCA_ACT_KIND];
 795         a->ops = tc_lookup_action(kind);
 796         if (a->ops == NULL)
 797                 goto err_out;
 798
 799         nlh = NLMSG_PUT(skb, pid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t));
 800         t = NLMSG_DATA(nlh);
 801         t->tca_family = AF_UNSPEC;
 802         t->tca__pad1 = 0;
 803         t->tca__pad2 = 0;
 804
 805         nest = nla_nest_start(skb, TCA_ACT_TAB);
 806         if (nest == NULL)
 807                 goto nla_put_failure;
 808
 809         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 810         if (err < 0)
 811                 goto nla_put_failure;
 812         if (err == 0)
 813                 goto noflush_out;
 814
 815         nla_nest_end(skb, nest);
 816
 817         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 818         nlh->nlmsg_flags |= NLM_F_ROOT;
 819         module_put(a->ops->owner);
 820         kfree(a);
 821         err = rtnetlink_send(skb, net, pid, RTNLGRP_TC,
 822                              n->nlmsg_flags & NLM_F_ECHO);
 823         if (err > 0)
 824                 return 0;
 825
 826         return err;
 827
 828 nla_put_failure:
 829 nlmsg_failure:
 830         module_put(a->ops->owner);
 831 err_out:
 832 noflush_out:
 833         kfree_skb(skb);
 834         kfree(a);
 835         return err;
 836 }
 837
 838 static int
 839 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 840               u32 pid, int event)
 841 {
 842         int i, ret;
 843         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 844         struct tc_action *head = NULL, *act, *act_prev = NULL;
 845
 846         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 847         if (ret < 0)
 848                 return ret;
 849
 850         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
 851                 if (tb[1] != NULL)
 852                         return tca_action_flush(net, tb[1], n, pid);
 853                 else
 854                         return -EINVAL;
 855         }
 856
 857         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 858                 act = tcf_action_get_1(tb[i], n, pid);
 859                 if (IS_ERR(act)) {
 860                         ret = PTR_ERR(act);
 861                         goto err;
 862                 }
 863                 act->order = i;
 864
 865                 if (head == NULL)
 866                         head = act;
 867                 else
 868                         act_prev->next = act;
 869                 act_prev = act;
 870         }
 871
 872         if (event == RTM_GETACTION)
 873                 ret = act_get_notify(net, pid, n, head, event);
 874         else { /* delete */
 875                 struct sk_buff *skb;
 876
 877                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 878                 if (!skb) {
 879                         ret = -ENOBUFS;
 880                         goto err;
 881                 }
 882
 883                 if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
 884                                  0, 1) <= 0) {
 885                         kfree_skb(skb);
 886                         ret = -EINVAL;
 887                         goto err;
 888                 }
 889
 890                 /* now do the delete */
 891                 tcf_action_destroy(head, 0);
 892                 ret = rtnetlink_send(skb, net, pid, RTNLGRP_TC,
 893                                      n->nlmsg_flags & NLM_F_ECHO);
 894                 if (ret > 0)
 895                         return 0;
 896                 return ret;
 897         }
 898 err:
 899         cleanup_a(head);
 900         return ret;
 901 }
 902
 903 static int tcf_add_notify(struct net *net, struct tc_action *a,
 904                           u32 pid, u32 seq, int event, u16 flags)
 905 {
 906         struct tcamsg *t;
 907         struct nlmsghdr *nlh;
 908         struct sk_buff *skb;
 909         struct nlattr *nest;
 910         unsigned char *b;
 911         int err = 0;
 912
 913         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 914         if (!skb)
 915                 return -ENOBUFS;
 916
 917         b = skb_tail_pointer(skb);
 918
 919         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 920         t = NLMSG_DATA(nlh);
 921         t->tca_family = AF_UNSPEC;
 922         t->tca__pad1 = 0;
 923         t->tca__pad2 = 0;
 924
 925         nest = nla_nest_start(skb, TCA_ACT_TAB);
 926         if (nest == NULL)
 927                 goto nla_put_failure;
 928
 929         if (tcf_action_dump(skb, a, 0, 0) < 0)
 930                 goto nla_put_failure;
 931
 932         nla_nest_end(skb, nest);
 933
 934         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 935         NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 936
 937         err = rtnetlink_send(skb, net, pid, RTNLGRP_TC, flags & NLM_F_ECHO);
 938         if (err > 0)
 939                 err = 0;
 940         return err;
 941
 942 nla_put_failure:
 943 nlmsg_failure:
 944         kfree_skb(skb);
 945         return -1;
 946 }
 947
 948
 949 static int
 950 tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 951                u32 pid, int ovr)
 952 {
 953         int ret = 0;
 954         struct tc_action *act;
 955         struct tc_action *a;
 956         u32 seq = n->nlmsg_seq;
 957
 958         act = tcf_action_init(nla, NULL, NULL, ovr, 0);
 959         if (act == NULL)
 960                 goto done;
 961         if (IS_ERR(act)) {
 962                 ret = PTR_ERR(act);
 963                 goto done;
 964         }
 965
 966         /* dump then free all the actions after update; inserted policy
 967          * stays intact
 968          */
 969         ret = tcf_add_notify(net, act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
 970         for (a = act; a; a = act) {
 971                 act = a->next;
 972                 kfree(a);
 973         }
 974 done:
 975         return ret;
 976 }
 977
 978 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 979 {
 980         struct net *net = sock_net(skb->sk);
 981         struct nlattr *tca[TCA_ACT_MAX + 1];
 982         u32 pid = skb ? NETLINK_CB(skb).pid : 0;
 983         int ret = 0, ovr = 0;
 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, pid, 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                                     pid, RTM_DELACTION);
1013                 break;
1014         case RTM_GETACTION:
1015                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1016                                     pid, 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         if (a_o->walk == NULL) {
1078                 WARN(1, "tc_dump_action: %s !capable of dumping table\n",
1079                      a_o->kind);
1080                 goto nla_put_failure;
1081         }
1082
1083         nlh = NLMSG_PUT(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
1084                         cb->nlh->nlmsg_type, sizeof(*t));
1085         t = NLMSG_DATA(nlh);
1086         t->tca_family = AF_UNSPEC;
1087         t->tca__pad1 = 0;
1088         t->tca__pad2 = 0;
1089
1090         nest = nla_nest_start(skb, TCA_ACT_TAB);
1091         if (nest == NULL)
1092                 goto nla_put_failure;
1093
1094         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1095         if (ret < 0)
1096                 goto nla_put_failure;
1097
1098         if (ret > 0) {
1099                 nla_nest_end(skb, nest);
1100                 ret = skb->len;
1101         } else
1102                 nla_nest_cancel(skb, nest);
1103
1104         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1105         if (NETLINK_CB(cb->skb).pid && ret)
1106                 nlh->nlmsg_flags |= NLM_F_MULTI;
1107         module_put(a_o->owner);
1108         return skb->len;
1109
1110 nla_put_failure:
1111 nlmsg_failure:
1112         module_put(a_o->owner);
1113         nlmsg_trim(skb, b);
1114         return skb->len;
1115 }
1116
1117 static int __init tc_action_init(void)
1118 {
1119         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
1120         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
1121         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1122                       NULL);
1123
1124         return 0;
1125 }
1126
1127 subsys_initcall(tc_action_init);