release/src-rt-6.x.4708/linux/linux-2.6.36/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 <net/net_namespace.h>
  24 #include <net/sock.h>
  25 #include <net/sch_generic.h>
  26 #include <net/act_api.h>
  27 #include <net/netlink.h>
  28
  29 static void tcf_common_free_rcu(struct rcu_head *head)
  30 {
  31         kfree(container_of(head, struct tcf_common, tcfc_rcu));
  32 }
  33
  34 void tcf_hash_destroy(struct tcf_common *p, struct tcf_hashinfo *hinfo)
  35 {
  36         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
  37         struct tcf_common **p1p;
  38
  39         for (p1p = &hinfo->htab[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
  40                 if (*p1p == p) {
  41                         write_lock_bh(hinfo->lock);
  42                         *p1p = p->tcfc_next;
  43                         write_unlock_bh(hinfo->lock);
  44                         gen_kill_estimator(&p->tcfc_bstats,
  45                                            &p->tcfc_rate_est);
  46                         /*
  47                          * gen_estimator est_timer() might access p->tcfc_lock
  48                          * or bstats, wait a RCU grace period before freeing p
  49                          */
  50                         call_rcu(&p->tcfc_rcu, tcf_common_free_rcu);
  51                         return;
  52                 }
  53         }
  54         WARN_ON(1);
  55 }
  56 EXPORT_SYMBOL(tcf_hash_destroy);
  57
  58 int tcf_hash_release(struct tcf_common *p, int bind,
  59                      struct tcf_hashinfo *hinfo)
  60 {
  61         int ret = 0;
  62
  63         if (p) {
  64                 if (bind)
  65                         p->tcfc_bindcnt--;
  66
  67                 p->tcfc_refcnt--;
  68                 if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
  69                         tcf_hash_destroy(p, hinfo);
  70                         ret = 1;
  71                 }
  72         }
  73         return ret;
  74 }
  75 EXPORT_SYMBOL(tcf_hash_release);
  76
  77 static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
  78                            struct tc_action *a, struct tcf_hashinfo *hinfo)
  79 {
  80         struct tcf_common *p;
  81         int err = 0, index = -1,i = 0, s_i = 0, n_i = 0;
  82         struct nlattr *nest;
  83
  84         read_lock_bh(hinfo->lock);
  85
  86         s_i = cb->args[0];
  87
  88         for (i = 0; i < (hinfo->hmask + 1); i++) {
  89                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
  90
  91                 for (; p; p = p->tcfc_next) {
  92                         index++;
  93                         if (index < s_i)
  94                                 continue;
  95                         a->priv = p;
  96                         a->order = n_i;
  97
  98                         nest = nla_nest_start(skb, a->order);
  99                         if (nest == NULL)
 100                                 goto nla_put_failure;
 101                         err = tcf_action_dump_1(skb, a, 0, 0);
 102                         if (err < 0) {
 103                                 index--;
 104                                 nlmsg_trim(skb, nest);
 105                                 goto done;
 106                         }
 107                         nla_nest_end(skb, nest);
 108                         n_i++;
 109                         if (n_i >= TCA_ACT_MAX_PRIO)
 110                                 goto done;
 111                 }
 112         }
 113 done:
 114         read_unlock_bh(hinfo->lock);
 115         if (n_i)
 116                 cb->args[0] += n_i;
 117         return n_i;
 118
 119 nla_put_failure:
 120         nla_nest_cancel(skb, nest);
 121         goto done;
 122 }
 123
 124 static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a,
 125                           struct tcf_hashinfo *hinfo)
 126 {
 127         struct tcf_common *p, *s_p;
 128         struct nlattr *nest;
 129         int i= 0, n_i = 0;
 130
 131         nest = nla_nest_start(skb, a->order);
 132         if (nest == NULL)
 133                 goto nla_put_failure;
 134         NLA_PUT_STRING(skb, TCA_KIND, a->ops->kind);
 135         for (i = 0; i < (hinfo->hmask + 1); i++) {
 136                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
 137
 138                 while (p != NULL) {
 139                         s_p = p->tcfc_next;
 140                         if (ACT_P_DELETED == tcf_hash_release(p, 0, hinfo))
 141                                  module_put(a->ops->owner);
 142                         n_i++;
 143                         p = s_p;
 144                 }
 145         }
 146         NLA_PUT_U32(skb, TCA_FCNT, n_i);
 147         nla_nest_end(skb, nest);
 148
 149         return n_i;
 150 nla_put_failure:
 151         nla_nest_cancel(skb, nest);
 152         return -EINVAL;
 153 }
 154
 155 int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
 156                        int type, struct tc_action *a)
 157 {
 158         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 159
 160         if (type == RTM_DELACTION) {
 161                 return tcf_del_walker(skb, a, hinfo);
 162         } else if (type == RTM_GETACTION) {
 163                 return tcf_dump_walker(skb, cb, a, hinfo);
 164         } else {
 165                 WARN(1, "tcf_generic_walker: unknown action %d\n", type);
 166                 return -EINVAL;
 167         }
 168 }
 169 EXPORT_SYMBOL(tcf_generic_walker);
 170
 171 struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 172 {
 173         struct tcf_common *p;
 174
 175         read_lock_bh(hinfo->lock);
 176         for (p = hinfo->htab[tcf_hash(index, hinfo->hmask)]; p;
 177              p = p->tcfc_next) {
 178                 if (p->tcfc_index == index)
 179                         break;
 180         }
 181         read_unlock_bh(hinfo->lock);
 182
 183         return p;
 184 }
 185 EXPORT_SYMBOL(tcf_hash_lookup);
 186
 187 u32 tcf_hash_new_index(u32 *idx_gen, struct tcf_hashinfo *hinfo)
 188 {
 189         u32 val = *idx_gen;
 190
 191         do {
 192                 if (++val == 0)
 193                         val = 1;
 194         } while (tcf_hash_lookup(val, hinfo));
 195
 196         return (*idx_gen = val);
 197 }
 198 EXPORT_SYMBOL(tcf_hash_new_index);
 199
 200 int tcf_hash_search(struct tc_action *a, u32 index)
 201 {
 202         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 203         struct tcf_common *p = tcf_hash_lookup(index, hinfo);
 204
 205         if (p) {
 206                 a->priv = p;
 207                 return 1;
 208         }
 209         return 0;
 210 }
 211 EXPORT_SYMBOL(tcf_hash_search);
 212
 213 struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
 214                                   struct tcf_hashinfo *hinfo)
 215 {
 216         struct tcf_common *p = NULL;
 217         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 218                 if (bind)
 219                         p->tcfc_bindcnt++;
 220                 p->tcfc_refcnt++;
 221                 a->priv = p;
 222         }
 223         return p;
 224 }
 225 EXPORT_SYMBOL(tcf_hash_check);
 226
 227 struct tcf_common *tcf_hash_create(u32 index, struct nlattr *est,
 228                                    struct tc_action *a, int size, int bind,
 229                                    u32 *idx_gen, struct tcf_hashinfo *hinfo)
 230 {
 231         struct tcf_common *p = kzalloc(size, GFP_KERNEL);
 232
 233         if (unlikely(!p))
 234                 return ERR_PTR(-ENOMEM);
 235         p->tcfc_refcnt = 1;
 236         if (bind)
 237                 p->tcfc_bindcnt = 1;
 238
 239         spin_lock_init(&p->tcfc_lock);
 240         p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
 241         p->tcfc_tm.install = jiffies;
 242         p->tcfc_tm.lastuse = jiffies;
 243         if (est) {
 244                 int err = gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
 245                                             &p->tcfc_lock, est);
 246                 if (err) {
 247                         kfree(p);
 248                         return ERR_PTR(err);
 249                 }
 250         }
 251
 252         a->priv = (void *) p;
 253         return p;
 254 }
 255 EXPORT_SYMBOL(tcf_hash_create);
 256
 257 void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
 258 {
 259         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
 260
 261         write_lock_bh(hinfo->lock);
 262         p->tcfc_next = hinfo->htab[h];
 263         hinfo->htab[h] = p;
 264         write_unlock_bh(hinfo->lock);
 265 }
 266 EXPORT_SYMBOL(tcf_hash_insert);
 267
 268 static struct tc_action_ops *act_base = NULL;
 269 static DEFINE_RWLOCK(act_mod_lock);
 270
 271 int tcf_register_action(struct tc_action_ops *act)
 272 {
 273         struct tc_action_ops *a, **ap;
 274
 275         write_lock(&act_mod_lock);
 276         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
 277                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 278                         write_unlock(&act_mod_lock);
 279                         return -EEXIST;
 280                 }
 281         }
 282         act->next = NULL;
 283         *ap = act;
 284         write_unlock(&act_mod_lock);
 285         return 0;
 286 }
 287 EXPORT_SYMBOL(tcf_register_action);
 288
 289 int tcf_unregister_action(struct tc_action_ops *act)
 290 {
 291         struct tc_action_ops *a, **ap;
 292         int err = -ENOENT;
 293
 294         write_lock(&act_mod_lock);
 295         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
 296                 if (a == act)
 297                         break;
 298         if (a) {
 299                 *ap = a->next;
 300                 a->next = NULL;
 301                 err = 0;
 302         }
 303         write_unlock(&act_mod_lock);
 304         return err;
 305 }
 306 EXPORT_SYMBOL(tcf_unregister_action);
 307
 308 /* lookup by name */
 309 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 310 {
 311         struct tc_action_ops *a = NULL;
 312
 313         if (kind) {
 314                 read_lock(&act_mod_lock);
 315                 for (a = act_base; a; a = a->next) {
 316                         if (strcmp(kind, a->kind) == 0) {
 317                                 if (!try_module_get(a->owner)) {
 318                                         read_unlock(&act_mod_lock);
 319                                         return NULL;
 320                                 }
 321                                 break;
 322                         }
 323                 }
 324                 read_unlock(&act_mod_lock);
 325         }
 326         return a;
 327 }
 328
 329 /* lookup by nlattr */
 330 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 331 {
 332         struct tc_action_ops *a = NULL;
 333
 334         if (kind) {
 335                 read_lock(&act_mod_lock);
 336                 for (a = act_base; a; a = a->next) {
 337                         if (nla_strcmp(kind, a->kind) == 0) {
 338                                 if (!try_module_get(a->owner)) {
 339                                         read_unlock(&act_mod_lock);
 340                                         return NULL;
 341                                 }
 342                                 break;
 343                         }
 344                 }
 345                 read_unlock(&act_mod_lock);
 346         }
 347         return a;
 348 }
 349
 350
 351 int tcf_action_exec(struct sk_buff *skb, struct tc_action *act,
 352                     struct tcf_result *res)
 353 {
 354         struct tc_action *a;
 355         int ret = -1;
 356
 357         if (skb->tc_verd & TC_NCLS) {
 358                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 359                 ret = TC_ACT_OK;
 360                 goto exec_done;
 361         }
 362         while ((a = act) != NULL) {
 363 repeat:
 364                 if (a->ops && a->ops->act) {
 365                         ret = a->ops->act(skb, a, res);
 366                         if (TC_MUNGED & skb->tc_verd) {
 367                                 /* copied already, allow trampling */
 368                                 skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
 369                                 skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
 370                         }
 371                         if (ret == TC_ACT_REPEAT)
 372                                 goto repeat;    /* we need a ttl - JHS */
 373                         if (ret != TC_ACT_PIPE)
 374                                 goto exec_done;
 375                 }
 376                 act = a->next;
 377         }
 378 exec_done:
 379         return ret;
 380 }
 381 EXPORT_SYMBOL(tcf_action_exec);
 382
 383 void tcf_action_destroy(struct tc_action *act, int bind)
 384 {
 385         struct tc_action *a;
 386
 387         for (a = act; a; a = act) {
 388                 if (a->ops && a->ops->cleanup) {
 389                         if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
 390                                 module_put(a->ops->owner);
 391                         act = act->next;
 392                         kfree(a);
 393                 } else {
 394                         WARN(1, "tcf_action_destroy: BUG? destroying NULL ops\n");
 395                         act = act->next;
 396                         kfree(a);
 397                 }
 398         }
 399 }
 400
 401 int
 402 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 403 {
 404         int err = -EINVAL;
 405
 406         if (a->ops == NULL || a->ops->dump == NULL)
 407                 return err;
 408         return a->ops->dump(skb, a, bind, ref);
 409 }
 410
 411 int
 412 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 413 {
 414         int err = -EINVAL;
 415         unsigned char *b = skb_tail_pointer(skb);
 416         struct nlattr *nest;
 417
 418         if (a->ops == NULL || a->ops->dump == NULL)
 419                 return err;
 420
 421         NLA_PUT_STRING(skb, TCA_KIND, a->ops->kind);
 422         if (tcf_action_copy_stats(skb, a, 0))
 423                 goto nla_put_failure;
 424         nest = nla_nest_start(skb, TCA_OPTIONS);
 425         if (nest == NULL)
 426                 goto nla_put_failure;
 427         if ((err = tcf_action_dump_old(skb, a, bind, ref)) > 0) {
 428                 nla_nest_end(skb, nest);
 429                 return err;
 430         }
 431
 432 nla_put_failure:
 433         nlmsg_trim(skb, b);
 434         return -1;
 435 }
 436 EXPORT_SYMBOL(tcf_action_dump_1);
 437
 438 int
 439 tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
 440 {
 441         struct tc_action *a;
 442         int err = -EINVAL;
 443         struct nlattr *nest;
 444
 445         while ((a = act) != NULL) {
 446                 act = a->next;
 447                 nest = nla_nest_start(skb, a->order);
 448                 if (nest == NULL)
 449                         goto nla_put_failure;
 450                 err = tcf_action_dump_1(skb, a, bind, ref);
 451                 if (err < 0)
 452                         goto errout;
 453                 nla_nest_end(skb, nest);
 454         }
 455
 456         return 0;
 457
 458 nla_put_failure:
 459         err = -EINVAL;
 460 errout:
 461         nla_nest_cancel(skb, nest);
 462         return err;
 463 }
 464
 465 struct tc_action *tcf_action_init_1(struct nlattr *nla, struct nlattr *est,
 466                                     char *name, int ovr, int bind)
 467 {
 468         struct tc_action *a;
 469         struct tc_action_ops *a_o;
 470         char act_name[IFNAMSIZ];
 471         struct nlattr *tb[TCA_ACT_MAX+1];
 472         struct nlattr *kind;
 473         int err;
 474
 475         if (name == NULL) {
 476                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 477                 if (err < 0)
 478                         goto err_out;
 479                 err = -EINVAL;
 480                 kind = tb[TCA_ACT_KIND];
 481                 if (kind == NULL)
 482                         goto err_out;
 483                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 484                         goto err_out;
 485         } else {
 486                 err = -EINVAL;
 487                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 488                         goto err_out;
 489         }
 490
 491         a_o = tc_lookup_action_n(act_name);
 492         if (a_o == NULL) {
 493 #ifdef CONFIG_MODULES
 494                 rtnl_unlock();
 495                 request_module("act_%s", act_name);
 496                 rtnl_lock();
 497
 498                 a_o = tc_lookup_action_n(act_name);
 499
 500                 /* We dropped the RTNL semaphore in order to
 501                  * perform the module load.  So, even if we
 502                  * succeeded in loading the module we have to
 503                  * tell the caller to replay the request.  We
 504                  * indicate this using -EAGAIN.
 505                  */
 506                 if (a_o != NULL) {
 507                         err = -EAGAIN;
 508                         goto err_mod;
 509                 }
 510 #endif
 511                 err = -ENOENT;
 512                 goto err_out;
 513         }
 514
 515         err = -ENOMEM;
 516         a = kzalloc(sizeof(*a), GFP_KERNEL);
 517         if (a == NULL)
 518                 goto err_mod;
 519
 520         /* backward compatibility for policer */
 521         if (name == NULL)
 522                 err = a_o->init(tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
 523         else
 524                 err = a_o->init(nla, est, a, ovr, bind);
 525         if (err < 0)
 526                 goto err_free;
 527
 528         /* module count goes up only when brand new policy is created
 529            if it exists and is only bound to in a_o->init() then
 530            ACT_P_CREATED is not returned (a zero is).
 531         */
 532         if (err != ACT_P_CREATED)
 533                 module_put(a_o->owner);
 534         a->ops = a_o;
 535
 536         return a;
 537
 538 err_free:
 539         kfree(a);
 540 err_mod:
 541         module_put(a_o->owner);
 542 err_out:
 543         return ERR_PTR(err);
 544 }
 545
 546 struct tc_action *tcf_action_init(struct nlattr *nla, struct nlattr *est,
 547                                   char *name, int ovr, int bind)
 548 {
 549         struct nlattr *tb[TCA_ACT_MAX_PRIO+1];
 550         struct tc_action *head = NULL, *act, *act_prev = NULL;
 551         int err;
 552         int i;
 553
 554         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 555         if (err < 0)
 556                 return ERR_PTR(err);
 557
 558         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 559                 act = tcf_action_init_1(tb[i], est, name, ovr, bind);
 560                 if (IS_ERR(act))
 561                         goto err;
 562                 act->order = i;
 563
 564                 if (head == NULL)
 565                         head = act;
 566                 else
 567                         act_prev->next = act;
 568                 act_prev = act;
 569         }
 570         return head;
 571
 572 err:
 573         if (head != NULL)
 574                 tcf_action_destroy(head, bind);
 575         return act;
 576 }
 577
 578 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 579                           int compat_mode)
 580 {
 581         int err = 0;
 582         struct gnet_dump d;
 583         struct tcf_act_hdr *h = a->priv;
 584
 585         if (h == NULL)
 586                 goto errout;
 587
 588         /* compat_mode being true specifies a call that is supposed
 589          * to add additional backward compatibility statistic TLVs.
 590          */
 591         if (compat_mode) {
 592                 if (a->type == TCA_OLD_COMPAT)
 593                         err = gnet_stats_start_copy_compat(skb, 0,
 594                                 TCA_STATS, TCA_XSTATS, &h->tcf_lock, &d);
 595                 else
 596                         return 0;
 597         } else
 598                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 599                                             &h->tcf_lock, &d);
 600
 601         if (err < 0)
 602                 goto errout;
 603
 604         if (a->ops != NULL && a->ops->get_stats != NULL)
 605                 if (a->ops->get_stats(skb, a) < 0)
 606                         goto errout;
 607
 608         if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
 609             gnet_stats_copy_rate_est(&d, &h->tcf_bstats,
 610                                      &h->tcf_rate_est) < 0 ||
 611             gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
 612                 goto errout;
 613
 614         if (gnet_stats_finish_copy(&d) < 0)
 615                 goto errout;
 616
 617         return 0;
 618
 619 errout:
 620         return -1;
 621 }
 622
 623 static int
 624 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 pid, u32 seq,
 625              u16 flags, int event, int bind, int ref)
 626 {
 627         struct tcamsg *t;
 628         struct nlmsghdr *nlh;
 629         unsigned char *b = skb_tail_pointer(skb);
 630         struct nlattr *nest;
 631
 632         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 633
 634         t = NLMSG_DATA(nlh);
 635         t->tca_family = AF_UNSPEC;
 636         t->tca__pad1 = 0;
 637         t->tca__pad2 = 0;
 638
 639         nest = nla_nest_start(skb, TCA_ACT_TAB);
 640         if (nest == NULL)
 641                 goto nla_put_failure;
 642
 643         if (tcf_action_dump(skb, a, bind, ref) < 0)
 644                 goto nla_put_failure;
 645
 646         nla_nest_end(skb, nest);
 647
 648         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 649         return skb->len;
 650
 651 nla_put_failure:
 652 nlmsg_failure:
 653         nlmsg_trim(skb, b);
 654         return -1;
 655 }
 656
 657 static int
 658 act_get_notify(struct net *net, u32 pid, struct nlmsghdr *n,
 659                struct tc_action *a, int event)
 660 {
 661         struct sk_buff *skb;
 662
 663         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 664         if (!skb)
 665                 return -ENOBUFS;
 666         if (tca_get_fill(skb, a, pid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 667                 kfree_skb(skb);
 668                 return -EINVAL;
 669         }
 670
 671         return rtnl_unicast(skb, net, pid);
 672 }
 673
 674 static struct tc_action *
 675 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 pid)
 676 {
 677         struct nlattr *tb[TCA_ACT_MAX+1];
 678         struct tc_action *a;
 679         int index;
 680         int err;
 681
 682         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 683         if (err < 0)
 684                 goto err_out;
 685
 686         err = -EINVAL;
 687         if (tb[TCA_ACT_INDEX] == NULL ||
 688             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 689                 goto err_out;
 690         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 691
 692         err = -ENOMEM;
 693         a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
 694         if (a == NULL)
 695                 goto err_out;
 696
 697         err = -EINVAL;
 698         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 699         if (a->ops == NULL)
 700                 goto err_free;
 701         if (a->ops->lookup == NULL)
 702                 goto err_mod;
 703         err = -ENOENT;
 704         if (a->ops->lookup(a, index) == 0)
 705                 goto err_mod;
 706
 707         module_put(a->ops->owner);
 708         return a;
 709
 710 err_mod:
 711         module_put(a->ops->owner);
 712 err_free:
 713         kfree(a);
 714 err_out:
 715         return ERR_PTR(err);
 716 }
 717
 718 static void cleanup_a(struct tc_action *act)
 719 {
 720         struct tc_action *a;
 721
 722         for (a = act; a; a = act) {
 723                 act = a->next;
 724                 kfree(a);
 725         }
 726 }
 727
 728 static struct tc_action *create_a(int i)
 729 {
 730         struct tc_action *act;
 731
 732         act = kzalloc(sizeof(*act), GFP_KERNEL);
 733         if (act == NULL) {
 734                 pr_debug("create_a: failed to alloc!\n");
 735                 return NULL;
 736         }
 737         act->order = i;
 738         return act;
 739 }
 740
 741 static int tca_action_flush(struct net *net, struct nlattr *nla,
 742                             struct nlmsghdr *n, u32 pid)
 743 {
 744         struct sk_buff *skb;
 745         unsigned char *b;
 746         struct nlmsghdr *nlh;
 747         struct tcamsg *t;
 748         struct netlink_callback dcb;
 749         struct nlattr *nest;
 750         struct nlattr *tb[TCA_ACT_MAX+1];
 751         struct nlattr *kind;
 752         struct tc_action *a = create_a(0);
 753         int err = -ENOMEM;
 754
 755         if (a == NULL) {
 756                 pr_debug("tca_action_flush: couldnt create tc_action\n");
 757                 return err;
 758         }
 759
 760         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 761         if (!skb) {
 762                 pr_debug("tca_action_flush: failed skb alloc\n");
 763                 kfree(a);
 764                 return err;
 765         }
 766
 767         b = skb_tail_pointer(skb);
 768
 769         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 770         if (err < 0)
 771                 goto err_out;
 772
 773         err = -EINVAL;
 774         kind = tb[TCA_ACT_KIND];
 775         a->ops = tc_lookup_action(kind);
 776         if (a->ops == NULL)
 777                 goto err_out;
 778
 779         nlh = NLMSG_PUT(skb, pid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t));
 780         t = NLMSG_DATA(nlh);
 781         t->tca_family = AF_UNSPEC;
 782         t->tca__pad1 = 0;
 783         t->tca__pad2 = 0;
 784
 785         nest = nla_nest_start(skb, TCA_ACT_TAB);
 786         if (nest == NULL)
 787                 goto nla_put_failure;
 788
 789         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 790         if (err < 0)
 791                 goto nla_put_failure;
 792         if (err == 0)
 793                 goto noflush_out;
 794
 795         nla_nest_end(skb, nest);
 796
 797         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 798         nlh->nlmsg_flags |= NLM_F_ROOT;
 799         module_put(a->ops->owner);
 800         kfree(a);
 801         err = rtnetlink_send(skb, net, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO);
 802         if (err > 0)
 803                 return 0;
 804
 805         return err;
 806
 807 nla_put_failure:
 808 nlmsg_failure:
 809         module_put(a->ops->owner);
 810 err_out:
 811 noflush_out:
 812         kfree_skb(skb);
 813         kfree(a);
 814         return err;
 815 }
 816
 817 static int
 818 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 819               u32 pid, int event)
 820 {
 821         int i, ret;
 822         struct nlattr *tb[TCA_ACT_MAX_PRIO+1];
 823         struct tc_action *head = NULL, *act, *act_prev = NULL;
 824
 825         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 826         if (ret < 0)
 827                 return ret;
 828
 829         if (event == RTM_DELACTION && n->nlmsg_flags&NLM_F_ROOT) {
 830                 if (tb[1] != NULL)
 831                         return tca_action_flush(net, tb[1], n, pid);
 832                 else
 833                         return -EINVAL;
 834         }
 835
 836         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 837                 act = tcf_action_get_1(tb[i], n, pid);
 838                 if (IS_ERR(act)) {
 839                         ret = PTR_ERR(act);
 840                         goto err;
 841                 }
 842                 act->order = i;
 843
 844                 if (head == NULL)
 845                         head = act;
 846                 else
 847                         act_prev->next = act;
 848                 act_prev = act;
 849         }
 850
 851         if (event == RTM_GETACTION)
 852                 ret = act_get_notify(net, pid, n, head, event);
 853         else { /* delete */
 854                 struct sk_buff *skb;
 855
 856                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 857                 if (!skb) {
 858                         ret = -ENOBUFS;
 859                         goto err;
 860                 }
 861
 862                 if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
 863                                  0, 1) <= 0) {
 864                         kfree_skb(skb);
 865                         ret = -EINVAL;
 866                         goto err;
 867                 }
 868
 869                 /* now do the delete */
 870                 tcf_action_destroy(head, 0);
 871                 ret = rtnetlink_send(skb, net, pid, RTNLGRP_TC,
 872                                      n->nlmsg_flags&NLM_F_ECHO);
 873                 if (ret > 0)
 874                         return 0;
 875                 return ret;
 876         }
 877 err:
 878         cleanup_a(head);
 879         return ret;
 880 }
 881
 882 static int tcf_add_notify(struct net *net, struct tc_action *a,
 883                           u32 pid, u32 seq, int event, u16 flags)
 884 {
 885         struct tcamsg *t;
 886         struct nlmsghdr *nlh;
 887         struct sk_buff *skb;
 888         struct nlattr *nest;
 889         unsigned char *b;
 890         int err = 0;
 891
 892         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 893         if (!skb)
 894                 return -ENOBUFS;
 895
 896         b = skb_tail_pointer(skb);
 897
 898         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 899         t = NLMSG_DATA(nlh);
 900         t->tca_family = AF_UNSPEC;
 901         t->tca__pad1 = 0;
 902         t->tca__pad2 = 0;
 903
 904         nest = nla_nest_start(skb, TCA_ACT_TAB);
 905         if (nest == NULL)
 906                 goto nla_put_failure;
 907
 908         if (tcf_action_dump(skb, a, 0, 0) < 0)
 909                 goto nla_put_failure;
 910
 911         nla_nest_end(skb, nest);
 912
 913         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 914         NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 915
 916         err = rtnetlink_send(skb, net, pid, RTNLGRP_TC, flags&NLM_F_ECHO);
 917         if (err > 0)
 918                 err = 0;
 919         return err;
 920
 921 nla_put_failure:
 922 nlmsg_failure:
 923         kfree_skb(skb);
 924         return -1;
 925 }
 926
 927
 928 static int
 929 tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 930                u32 pid, int ovr)
 931 {
 932         int ret = 0;
 933         struct tc_action *act;
 934         struct tc_action *a;
 935         u32 seq = n->nlmsg_seq;
 936
 937         act = tcf_action_init(nla, NULL, NULL, ovr, 0);
 938         if (act == NULL)
 939                 goto done;
 940         if (IS_ERR(act)) {
 941                 ret = PTR_ERR(act);
 942                 goto done;
 943         }
 944
 945         /* dump then free all the actions after update; inserted policy
 946          * stays intact
 947          * */
 948         ret = tcf_add_notify(net, act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
 949         for (a = act; a; a = act) {
 950                 act = a->next;
 951                 kfree(a);
 952         }
 953 done:
 954         return ret;
 955 }
 956
 957 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 958 {
 959         struct net *net = sock_net(skb->sk);
 960         struct nlattr *tca[TCA_ACT_MAX + 1];
 961         u32 pid = skb ? NETLINK_CB(skb).pid : 0;
 962         int ret = 0, ovr = 0;
 963
 964         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
 965         if (ret < 0)
 966                 return ret;
 967
 968         if (tca[TCA_ACT_TAB] == NULL) {
 969                 pr_notice("tc_ctl_action: received NO action attribs\n");
 970                 return -EINVAL;
 971         }
 972
 973         /* n->nlmsg_flags&NLM_F_CREATE
 974          * */
 975         switch (n->nlmsg_type) {
 976         case RTM_NEWACTION:
 977                 /* we are going to assume all other flags
 978                  * imply create only if it doesnt exist
 979                  * Note that CREATE | EXCL implies that
 980                  * but since we want avoid ambiguity (eg when flags
 981                  * is zero) then just set this
 982                  */
 983                 if (n->nlmsg_flags&NLM_F_REPLACE)
 984                         ovr = 1;
 985 replay:
 986                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, pid, ovr);
 987                 if (ret == -EAGAIN)
 988                         goto replay;
 989                 break;
 990         case RTM_DELACTION:
 991                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
 992                                     pid, RTM_DELACTION);
 993                 break;
 994         case RTM_GETACTION:
 995                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
 996                                     pid, RTM_GETACTION);
 997                 break;
 998         default:
 999                 BUG();
1000         }
1001
1002         return ret;
1003 }
1004
1005 static struct nlattr *
1006 find_dump_kind(const struct nlmsghdr *n)
1007 {
1008         struct nlattr *tb1, *tb2[TCA_ACT_MAX+1];
1009         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1010         struct nlattr *nla[TCAA_MAX + 1];
1011         struct nlattr *kind;
1012
1013         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1014                 return NULL;
1015         tb1 = nla[TCA_ACT_TAB];
1016         if (tb1 == NULL)
1017                 return NULL;
1018
1019         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1020                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1021                 return NULL;
1022
1023         if (tb[1] == NULL)
1024                 return NULL;
1025         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1026                       nla_len(tb[1]), NULL) < 0)
1027                 return NULL;
1028         kind = tb2[TCA_ACT_KIND];
1029
1030         return kind;
1031 }
1032
1033 static int
1034 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1035 {
1036         struct nlmsghdr *nlh;
1037         unsigned char *b = skb_tail_pointer(skb);
1038         struct nlattr *nest;
1039         struct tc_action_ops *a_o;
1040         struct tc_action a;
1041         int ret = 0;
1042         struct tcamsg *t = (struct tcamsg *) NLMSG_DATA(cb->nlh);
1043         struct nlattr *kind = find_dump_kind(cb->nlh);
1044
1045         if (kind == NULL) {
1046                 pr_info("tc_dump_action: action bad kind\n");
1047                 return 0;
1048         }
1049
1050         a_o = tc_lookup_action(kind);
1051         if (a_o == NULL) {
1052                 return 0;
1053         }
1054
1055         memset(&a, 0, sizeof(struct tc_action));
1056         a.ops = a_o;
1057
1058         if (a_o->walk == NULL) {
1059                 WARN(1, "tc_dump_action: %s !capable of dumping table\n",
1060                      a_o->kind);
1061                 goto nla_put_failure;
1062         }
1063
1064         nlh = NLMSG_PUT(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
1065                         cb->nlh->nlmsg_type, sizeof(*t));
1066         t = NLMSG_DATA(nlh);
1067         t->tca_family = AF_UNSPEC;
1068         t->tca__pad1 = 0;
1069         t->tca__pad2 = 0;
1070
1071         nest = nla_nest_start(skb, TCA_ACT_TAB);
1072         if (nest == NULL)
1073                 goto nla_put_failure;
1074
1075         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1076         if (ret < 0)
1077                 goto nla_put_failure;
1078
1079         if (ret > 0) {
1080                 nla_nest_end(skb, nest);
1081                 ret = skb->len;
1082         } else
1083                 nla_nest_cancel(skb, nest);
1084
1085         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1086         if (NETLINK_CB(cb->skb).pid && ret)
1087                 nlh->nlmsg_flags |= NLM_F_MULTI;
1088         module_put(a_o->owner);
1089         return skb->len;
1090
1091 nla_put_failure:
1092 nlmsg_failure:
1093         module_put(a_o->owner);
1094         nlmsg_trim(skb, b);
1095         return skb->len;
1096 }
1097
1098 static int __init tc_action_init(void)
1099 {
1100         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL);
1101         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL);
1102         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action);
1103
1104         return 0;
1105 }
1106
1107 subsys_initcall(tc_action_init);