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 void tcf_hash_destroy(struct tcf_common *p, struct tcf_hashinfo *hinfo)
  30 {
  31         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
  32         struct tcf_common **p1p;
  33
  34         for (p1p = &hinfo->htab[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
  35                 if (*p1p == p) {
  36                         write_lock_bh(hinfo->lock);
  37                         *p1p = p->tcfc_next;
  38                         write_unlock_bh(hinfo->lock);
  39                         gen_kill_estimator(&p->tcfc_bstats,
  40                                            &p->tcfc_rate_est);
  41                         kfree(p);
  42                         return;
  43                 }
  44         }
  45         WARN_ON(1);
  46 }
  47 EXPORT_SYMBOL(tcf_hash_destroy);
  48
  49 int tcf_hash_release(struct tcf_common *p, int bind,
  50                      struct tcf_hashinfo *hinfo)
  51 {
  52         int ret = 0;
  53
  54         if (p) {
  55                 if (bind)
  56                         p->tcfc_bindcnt--;
  57
  58                 p->tcfc_refcnt--;
  59                 if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
  60                         tcf_hash_destroy(p, hinfo);
  61                         ret = 1;
  62                 }
  63         }
  64         return ret;
  65 }
  66 EXPORT_SYMBOL(tcf_hash_release);
  67
  68 static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
  69                            struct tc_action *a, struct tcf_hashinfo *hinfo)
  70 {
  71         struct tcf_common *p;
  72         int err = 0, index = -1,i = 0, s_i = 0, n_i = 0;
  73         struct nlattr *nest;
  74
  75         read_lock_bh(hinfo->lock);
  76
  77         s_i = cb->args[0];
  78
  79         for (i = 0; i < (hinfo->hmask + 1); i++) {
  80                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
  81
  82                 for (; p; p = p->tcfc_next) {
  83                         index++;
  84                         if (index < s_i)
  85                                 continue;
  86                         a->priv = p;
  87                         a->order = n_i;
  88
  89                         nest = nla_nest_start(skb, a->order);
  90                         if (nest == NULL)
  91                                 goto nla_put_failure;
  92                         err = tcf_action_dump_1(skb, a, 0, 0);
  93                         if (err < 0) {
  94                                 index--;
  95                                 nlmsg_trim(skb, nest);
  96                                 goto done;
  97                         }
  98                         nla_nest_end(skb, nest);
  99                         n_i++;
 100                         if (n_i >= TCA_ACT_MAX_PRIO)
 101                                 goto done;
 102                 }
 103         }
 104 done:
 105         read_unlock_bh(hinfo->lock);
 106         if (n_i)
 107                 cb->args[0] += n_i;
 108         return n_i;
 109
 110 nla_put_failure:
 111         nla_nest_cancel(skb, nest);
 112         goto done;
 113 }
 114
 115 static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a,
 116                           struct tcf_hashinfo *hinfo)
 117 {
 118         struct tcf_common *p, *s_p;
 119         struct nlattr *nest;
 120         int i= 0, n_i = 0;
 121
 122         nest = nla_nest_start(skb, a->order);
 123         if (nest == NULL)
 124                 goto nla_put_failure;
 125         NLA_PUT_STRING(skb, TCA_KIND, a->ops->kind);
 126         for (i = 0; i < (hinfo->hmask + 1); i++) {
 127                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
 128
 129                 while (p != NULL) {
 130                         s_p = p->tcfc_next;
 131                         if (ACT_P_DELETED == tcf_hash_release(p, 0, hinfo))
 132                                  module_put(a->ops->owner);
 133                         n_i++;
 134                         p = s_p;
 135                 }
 136         }
 137         NLA_PUT_U32(skb, TCA_FCNT, n_i);
 138         nla_nest_end(skb, nest);
 139
 140         return n_i;
 141 nla_put_failure:
 142         nla_nest_cancel(skb, nest);
 143         return -EINVAL;
 144 }
 145
 146 int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
 147                        int type, struct tc_action *a)
 148 {
 149         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 150
 151         if (type == RTM_DELACTION) {
 152                 return tcf_del_walker(skb, a, hinfo);
 153         } else if (type == RTM_GETACTION) {
 154                 return tcf_dump_walker(skb, cb, a, hinfo);
 155         } else {
 156                 WARN(1, "tcf_generic_walker: unknown action %d\n", type);
 157                 return -EINVAL;
 158         }
 159 }
 160 EXPORT_SYMBOL(tcf_generic_walker);
 161
 162 struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 163 {
 164         struct tcf_common *p;
 165
 166         read_lock_bh(hinfo->lock);
 167         for (p = hinfo->htab[tcf_hash(index, hinfo->hmask)]; p;
 168              p = p->tcfc_next) {
 169                 if (p->tcfc_index == index)
 170                         break;
 171         }
 172         read_unlock_bh(hinfo->lock);
 173
 174         return p;
 175 }
 176 EXPORT_SYMBOL(tcf_hash_lookup);
 177
 178 u32 tcf_hash_new_index(u32 *idx_gen, struct tcf_hashinfo *hinfo)
 179 {
 180         u32 val = *idx_gen;
 181
 182         do {
 183                 if (++val == 0)
 184                         val = 1;
 185         } while (tcf_hash_lookup(val, hinfo));
 186
 187         return (*idx_gen = val);
 188 }
 189 EXPORT_SYMBOL(tcf_hash_new_index);
 190
 191 int tcf_hash_search(struct tc_action *a, u32 index)
 192 {
 193         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 194         struct tcf_common *p = tcf_hash_lookup(index, hinfo);
 195
 196         if (p) {
 197                 a->priv = p;
 198                 return 1;
 199         }
 200         return 0;
 201 }
 202 EXPORT_SYMBOL(tcf_hash_search);
 203
 204 struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
 205                                   struct tcf_hashinfo *hinfo)
 206 {
 207         struct tcf_common *p = NULL;
 208         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 209                 if (bind)
 210                         p->tcfc_bindcnt++;
 211                 p->tcfc_refcnt++;
 212                 a->priv = p;
 213         }
 214         return p;
 215 }
 216 EXPORT_SYMBOL(tcf_hash_check);
 217
 218 struct tcf_common *tcf_hash_create(u32 index, struct nlattr *est,
 219                                    struct tc_action *a, int size, int bind,
 220                                    u32 *idx_gen, struct tcf_hashinfo *hinfo)
 221 {
 222         struct tcf_common *p = kzalloc(size, GFP_KERNEL);
 223
 224         if (unlikely(!p))
 225                 return ERR_PTR(-ENOMEM);
 226         p->tcfc_refcnt = 1;
 227         if (bind)
 228                 p->tcfc_bindcnt = 1;
 229
 230         spin_lock_init(&p->tcfc_lock);
 231         p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
 232         p->tcfc_tm.install = jiffies;
 233         p->tcfc_tm.lastuse = jiffies;
 234         if (est) {
 235                 int err = gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
 236                                             &p->tcfc_lock, est);
 237                 if (err) {
 238                         kfree(p);
 239                         return ERR_PTR(err);
 240                 }
 241         }
 242
 243         a->priv = (void *) p;
 244         return p;
 245 }
 246 EXPORT_SYMBOL(tcf_hash_create);
 247
 248 void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
 249 {
 250         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
 251
 252         write_lock_bh(hinfo->lock);
 253         p->tcfc_next = hinfo->htab[h];
 254         hinfo->htab[h] = p;
 255         write_unlock_bh(hinfo->lock);
 256 }
 257 EXPORT_SYMBOL(tcf_hash_insert);
 258
 259 static struct tc_action_ops *act_base = NULL;
 260 static DEFINE_RWLOCK(act_mod_lock);
 261
 262 int tcf_register_action(struct tc_action_ops *act)
 263 {
 264         struct tc_action_ops *a, **ap;
 265
 266         write_lock(&act_mod_lock);
 267         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
 268                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 269                         write_unlock(&act_mod_lock);
 270                         return -EEXIST;
 271                 }
 272         }
 273         act->next = NULL;
 274         *ap = act;
 275         write_unlock(&act_mod_lock);
 276         return 0;
 277 }
 278 EXPORT_SYMBOL(tcf_register_action);
 279
 280 int tcf_unregister_action(struct tc_action_ops *act)
 281 {
 282         struct tc_action_ops *a, **ap;
 283         int err = -ENOENT;
 284
 285         write_lock(&act_mod_lock);
 286         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
 287                 if (a == act)
 288                         break;
 289         if (a) {
 290                 *ap = a->next;
 291                 a->next = NULL;
 292                 err = 0;
 293         }
 294         write_unlock(&act_mod_lock);
 295         return err;
 296 }
 297 EXPORT_SYMBOL(tcf_unregister_action);
 298
 299 /* lookup by name */
 300 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 301 {
 302         struct tc_action_ops *a = NULL;
 303
 304         if (kind) {
 305                 read_lock(&act_mod_lock);
 306                 for (a = act_base; a; a = a->next) {
 307                         if (strcmp(kind, a->kind) == 0) {
 308                                 if (!try_module_get(a->owner)) {
 309                                         read_unlock(&act_mod_lock);
 310                                         return NULL;
 311                                 }
 312                                 break;
 313                         }
 314                 }
 315                 read_unlock(&act_mod_lock);
 316         }
 317         return a;
 318 }
 319
 320 /* lookup by nlattr */
 321 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 322 {
 323         struct tc_action_ops *a = NULL;
 324
 325         if (kind) {
 326                 read_lock(&act_mod_lock);
 327                 for (a = act_base; a; a = a->next) {
 328                         if (nla_strcmp(kind, a->kind) == 0) {
 329                                 if (!try_module_get(a->owner)) {
 330                                         read_unlock(&act_mod_lock);
 331                                         return NULL;
 332                                 }
 333                                 break;
 334                         }
 335                 }
 336                 read_unlock(&act_mod_lock);
 337         }
 338         return a;
 339 }
 340
 341 #if 0
 342 /* lookup by id */
 343 static struct tc_action_ops *tc_lookup_action_id(u32 type)
 344 {
 345         struct tc_action_ops *a = NULL;
 346
 347         if (type) {
 348                 read_lock(&act_mod_lock);
 349                 for (a = act_base; a; a = a->next) {
 350                         if (a->type == type) {
 351                                 if (!try_module_get(a->owner)) {
 352                                         read_unlock(&act_mod_lock);
 353                                         return NULL;
 354                                 }
 355                                 break;
 356                         }
 357                 }
 358                 read_unlock(&act_mod_lock);
 359         }
 360         return a;
 361 }
 362 #endif
 363
 364 int tcf_action_exec(struct sk_buff *skb, struct tc_action *act,
 365                     struct tcf_result *res)
 366 {
 367         struct tc_action *a;
 368         int ret = -1;
 369
 370         if (skb->tc_verd & TC_NCLS) {
 371                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 372                 ret = TC_ACT_OK;
 373                 goto exec_done;
 374         }
 375         while ((a = act) != NULL) {
 376 repeat:
 377                 if (a->ops && a->ops->act) {
 378                         ret = a->ops->act(skb, a, res);
 379                         if (TC_MUNGED & skb->tc_verd) {
 380                                 /* copied already, allow trampling */
 381                                 skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
 382                                 skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
 383                         }
 384                         if (ret == TC_ACT_REPEAT)
 385                                 goto repeat;    /* we need a ttl - JHS */
 386                         if (ret != TC_ACT_PIPE)
 387                                 goto exec_done;
 388                 }
 389                 act = a->next;
 390         }
 391 exec_done:
 392         return ret;
 393 }
 394 EXPORT_SYMBOL(tcf_action_exec);
 395
 396 void tcf_action_destroy(struct tc_action *act, int bind)
 397 {
 398         struct tc_action *a;
 399
 400         for (a = act; a; a = act) {
 401                 if (a->ops && a->ops->cleanup) {
 402                         if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
 403                                 module_put(a->ops->owner);
 404                         act = act->next;
 405                         kfree(a);
 406                 } else {
 407                         /*FIXME: Remove later - catch insertion bugs*/
 408                         WARN(1, "tcf_action_destroy: BUG? destroying NULL ops\n");
 409                         act = act->next;
 410                         kfree(a);
 411                 }
 412         }
 413 }
 414
 415 int
 416 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 417 {
 418         int err = -EINVAL;
 419
 420         if (a->ops == NULL || a->ops->dump == NULL)
 421                 return err;
 422         return a->ops->dump(skb, a, bind, ref);
 423 }
 424
 425 int
 426 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 427 {
 428         int err = -EINVAL;
 429         unsigned char *b = skb_tail_pointer(skb);
 430         struct nlattr *nest;
 431
 432         if (a->ops == NULL || a->ops->dump == NULL)
 433                 return err;
 434
 435         NLA_PUT_STRING(skb, TCA_KIND, a->ops->kind);
 436         if (tcf_action_copy_stats(skb, a, 0))
 437                 goto nla_put_failure;
 438         nest = nla_nest_start(skb, TCA_OPTIONS);
 439         if (nest == NULL)
 440                 goto nla_put_failure;
 441         if ((err = tcf_action_dump_old(skb, a, bind, ref)) > 0) {
 442                 nla_nest_end(skb, nest);
 443                 return err;
 444         }
 445
 446 nla_put_failure:
 447         nlmsg_trim(skb, b);
 448         return -1;
 449 }
 450 EXPORT_SYMBOL(tcf_action_dump_1);
 451
 452 int
 453 tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
 454 {
 455         struct tc_action *a;
 456         int err = -EINVAL;
 457         struct nlattr *nest;
 458
 459         while ((a = act) != NULL) {
 460                 act = a->next;
 461                 nest = nla_nest_start(skb, a->order);
 462                 if (nest == NULL)
 463                         goto nla_put_failure;
 464                 err = tcf_action_dump_1(skb, a, bind, ref);
 465                 if (err < 0)
 466                         goto errout;
 467                 nla_nest_end(skb, nest);
 468         }
 469
 470         return 0;
 471
 472 nla_put_failure:
 473         err = -EINVAL;
 474 errout:
 475         nla_nest_cancel(skb, nest);
 476         return err;
 477 }
 478
 479 struct tc_action *tcf_action_init_1(struct nlattr *nla, struct nlattr *est,
 480                                     char *name, int ovr, int bind)
 481 {
 482         struct tc_action *a;
 483         struct tc_action_ops *a_o;
 484         char act_name[IFNAMSIZ];
 485         struct nlattr *tb[TCA_ACT_MAX+1];
 486         struct nlattr *kind;
 487         int err;
 488
 489         if (name == NULL) {
 490                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 491                 if (err < 0)
 492                         goto err_out;
 493                 err = -EINVAL;
 494                 kind = tb[TCA_ACT_KIND];
 495                 if (kind == NULL)
 496                         goto err_out;
 497                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 498                         goto err_out;
 499         } else {
 500                 err = -EINVAL;
 501                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 502                         goto err_out;
 503         }
 504
 505         a_o = tc_lookup_action_n(act_name);
 506         if (a_o == NULL) {
 507 #ifdef CONFIG_MODULES
 508                 rtnl_unlock();
 509                 request_module("act_%s", act_name);
 510                 rtnl_lock();
 511
 512                 a_o = tc_lookup_action_n(act_name);
 513
 514                 /* We dropped the RTNL semaphore in order to
 515                  * perform the module load.  So, even if we
 516                  * succeeded in loading the module we have to
 517                  * tell the caller to replay the request.  We
 518                  * indicate this using -EAGAIN.
 519                  */
 520                 if (a_o != NULL) {
 521                         err = -EAGAIN;
 522                         goto err_mod;
 523                 }
 524 #endif
 525                 err = -ENOENT;
 526                 goto err_out;
 527         }
 528
 529         err = -ENOMEM;
 530         a = kzalloc(sizeof(*a), GFP_KERNEL);
 531         if (a == NULL)
 532                 goto err_mod;
 533
 534         /* backward compatibility for policer */
 535         if (name == NULL)
 536                 err = a_o->init(tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
 537         else
 538                 err = a_o->init(nla, est, a, ovr, bind);
 539         if (err < 0)
 540                 goto err_free;
 541
 542         /* module count goes up only when brand new policy is created
 543            if it exists and is only bound to in a_o->init() then
 544            ACT_P_CREATED is not returned (a zero is).
 545         */
 546         if (err != ACT_P_CREATED)
 547                 module_put(a_o->owner);
 548         a->ops = a_o;
 549
 550         return a;
 551
 552 err_free:
 553         kfree(a);
 554 err_mod:
 555         module_put(a_o->owner);
 556 err_out:
 557         return ERR_PTR(err);
 558 }
 559
 560 struct tc_action *tcf_action_init(struct nlattr *nla, struct nlattr *est,
 561                                   char *name, int ovr, int bind)
 562 {
 563         struct nlattr *tb[TCA_ACT_MAX_PRIO+1];
 564         struct tc_action *head = NULL, *act, *act_prev = NULL;
 565         int err;
 566         int i;
 567
 568         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 569         if (err < 0)
 570                 return ERR_PTR(err);
 571
 572         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 573                 act = tcf_action_init_1(tb[i], est, name, ovr, bind);
 574                 if (IS_ERR(act))
 575                         goto err;
 576                 act->order = i;
 577
 578                 if (head == NULL)
 579                         head = act;
 580                 else
 581                         act_prev->next = act;
 582                 act_prev = act;
 583         }
 584         return head;
 585
 586 err:
 587         if (head != NULL)
 588                 tcf_action_destroy(head, bind);
 589         return act;
 590 }
 591
 592 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 593                           int compat_mode)
 594 {
 595         int err = 0;
 596         struct gnet_dump d;
 597         struct tcf_act_hdr *h = a->priv;
 598
 599         if (h == NULL)
 600                 goto errout;
 601
 602         /* compat_mode being true specifies a call that is supposed
 603          * to add additional backward compatibility statistic TLVs.
 604          */
 605         if (compat_mode) {
 606                 if (a->type == TCA_OLD_COMPAT)
 607                         err = gnet_stats_start_copy_compat(skb, 0,
 608                                 TCA_STATS, TCA_XSTATS, &h->tcf_lock, &d);
 609                 else
 610                         return 0;
 611         } else
 612                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 613                                             &h->tcf_lock, &d);
 614
 615         if (err < 0)
 616                 goto errout;
 617
 618         if (a->ops != NULL && a->ops->get_stats != NULL)
 619                 if (a->ops->get_stats(skb, a) < 0)
 620                         goto errout;
 621
 622         if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
 623             gnet_stats_copy_rate_est(&d, &h->tcf_bstats,
 624                                      &h->tcf_rate_est) < 0 ||
 625             gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
 626                 goto errout;
 627
 628         if (gnet_stats_finish_copy(&d) < 0)
 629                 goto errout;
 630
 631         return 0;
 632
 633 errout:
 634         return -1;
 635 }
 636
 637 static int
 638 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 pid, u32 seq,
 639              u16 flags, int event, int bind, int ref)
 640 {
 641         struct tcamsg *t;
 642         struct nlmsghdr *nlh;
 643         unsigned char *b = skb_tail_pointer(skb);
 644         struct nlattr *nest;
 645
 646         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 647
 648         t = NLMSG_DATA(nlh);
 649         t->tca_family = AF_UNSPEC;
 650         t->tca__pad1 = 0;
 651         t->tca__pad2 = 0;
 652
 653         nest = nla_nest_start(skb, TCA_ACT_TAB);
 654         if (nest == NULL)
 655                 goto nla_put_failure;
 656
 657         if (tcf_action_dump(skb, a, bind, ref) < 0)
 658                 goto nla_put_failure;
 659
 660         nla_nest_end(skb, nest);
 661
 662         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 663         return skb->len;
 664
 665 nla_put_failure:
 666 nlmsg_failure:
 667         nlmsg_trim(skb, b);
 668         return -1;
 669 }
 670
 671 static int
 672 act_get_notify(struct net *net, u32 pid, struct nlmsghdr *n,
 673                struct tc_action *a, int event)
 674 {
 675         struct sk_buff *skb;
 676
 677         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 678         if (!skb)
 679                 return -ENOBUFS;
 680         if (tca_get_fill(skb, a, pid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 681                 kfree_skb(skb);
 682                 return -EINVAL;
 683         }
 684
 685         return rtnl_unicast(skb, net, pid);
 686 }
 687
 688 static struct tc_action *
 689 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 pid)
 690 {
 691         struct nlattr *tb[TCA_ACT_MAX+1];
 692         struct tc_action *a;
 693         int index;
 694         int err;
 695
 696         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 697         if (err < 0)
 698                 goto err_out;
 699
 700         err = -EINVAL;
 701         if (tb[TCA_ACT_INDEX] == NULL ||
 702             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 703                 goto err_out;
 704         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 705
 706         err = -ENOMEM;
 707         a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
 708         if (a == NULL)
 709                 goto err_out;
 710
 711         err = -EINVAL;
 712         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 713         if (a->ops == NULL)
 714                 goto err_free;
 715         if (a->ops->lookup == NULL)
 716                 goto err_mod;
 717         err = -ENOENT;
 718         if (a->ops->lookup(a, index) == 0)
 719                 goto err_mod;
 720
 721         module_put(a->ops->owner);
 722         return a;
 723
 724 err_mod:
 725         module_put(a->ops->owner);
 726 err_free:
 727         kfree(a);
 728 err_out:
 729         return ERR_PTR(err);
 730 }
 731
 732 static void cleanup_a(struct tc_action *act)
 733 {
 734         struct tc_action *a;
 735
 736         for (a = act; a; a = act) {
 737                 act = a->next;
 738                 kfree(a);
 739         }
 740 }
 741
 742 static struct tc_action *create_a(int i)
 743 {
 744         struct tc_action *act;
 745
 746         act = kzalloc(sizeof(*act), GFP_KERNEL);
 747         if (act == NULL) {
 748                 pr_debug("create_a: failed to alloc!\n");
 749                 return NULL;
 750         }
 751         act->order = i;
 752         return act;
 753 }
 754
 755 static int tca_action_flush(struct net *net, struct nlattr *nla,
 756                             struct nlmsghdr *n, u32 pid)
 757 {
 758         struct sk_buff *skb;
 759         unsigned char *b;
 760         struct nlmsghdr *nlh;
 761         struct tcamsg *t;
 762         struct netlink_callback dcb;
 763         struct nlattr *nest;
 764         struct nlattr *tb[TCA_ACT_MAX+1];
 765         struct nlattr *kind;
 766         struct tc_action *a = create_a(0);
 767         int err = -ENOMEM;
 768
 769         if (a == NULL) {
 770                 pr_debug("tca_action_flush: couldnt create tc_action\n");
 771                 return err;
 772         }
 773
 774         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 775         if (!skb) {
 776                 pr_debug("tca_action_flush: failed skb alloc\n");
 777                 kfree(a);
 778                 return err;
 779         }
 780
 781         b = skb_tail_pointer(skb);
 782
 783         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 784         if (err < 0)
 785                 goto err_out;
 786
 787         err = -EINVAL;
 788         kind = tb[TCA_ACT_KIND];
 789         a->ops = tc_lookup_action(kind);
 790         if (a->ops == NULL)
 791                 goto err_out;
 792
 793         nlh = NLMSG_PUT(skb, pid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t));
 794         t = NLMSG_DATA(nlh);
 795         t->tca_family = AF_UNSPEC;
 796         t->tca__pad1 = 0;
 797         t->tca__pad2 = 0;
 798
 799         nest = nla_nest_start(skb, TCA_ACT_TAB);
 800         if (nest == NULL)
 801                 goto nla_put_failure;
 802
 803         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 804         if (err < 0)
 805                 goto nla_put_failure;
 806         if (err == 0)
 807                 goto noflush_out;
 808
 809         nla_nest_end(skb, nest);
 810
 811         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 812         nlh->nlmsg_flags |= NLM_F_ROOT;
 813         module_put(a->ops->owner);
 814         kfree(a);
 815         err = rtnetlink_send(skb, net, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO);
 816         if (err > 0)
 817                 return 0;
 818
 819         return err;
 820
 821 nla_put_failure:
 822 nlmsg_failure:
 823         module_put(a->ops->owner);
 824 err_out:
 825 noflush_out:
 826         kfree_skb(skb);
 827         kfree(a);
 828         return err;
 829 }
 830
 831 static int
 832 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 833               u32 pid, int event)
 834 {
 835         int i, ret;
 836         struct nlattr *tb[TCA_ACT_MAX_PRIO+1];
 837         struct tc_action *head = NULL, *act, *act_prev = NULL;
 838
 839         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 840         if (ret < 0)
 841                 return ret;
 842
 843         if (event == RTM_DELACTION && n->nlmsg_flags&NLM_F_ROOT) {
 844                 if (tb[1] != NULL)
 845                         return tca_action_flush(net, tb[1], n, pid);
 846                 else
 847                         return -EINVAL;
 848         }
 849
 850         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 851                 act = tcf_action_get_1(tb[i], n, pid);
 852                 if (IS_ERR(act)) {
 853                         ret = PTR_ERR(act);
 854                         goto err;
 855                 }
 856                 act->order = i;
 857
 858                 if (head == NULL)
 859                         head = act;
 860                 else
 861                         act_prev->next = act;
 862                 act_prev = act;
 863         }
 864
 865         if (event == RTM_GETACTION)
 866                 ret = act_get_notify(net, pid, n, head, event);
 867         else { /* delete */
 868                 struct sk_buff *skb;
 869
 870                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 871                 if (!skb) {
 872                         ret = -ENOBUFS;
 873                         goto err;
 874                 }
 875
 876                 if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
 877                                  0, 1) <= 0) {
 878                         kfree_skb(skb);
 879                         ret = -EINVAL;
 880                         goto err;
 881                 }
 882
 883                 /* now do the delete */
 884                 tcf_action_destroy(head, 0);
 885                 ret = rtnetlink_send(skb, net, pid, RTNLGRP_TC,
 886                                      n->nlmsg_flags&NLM_F_ECHO);
 887                 if (ret > 0)
 888                         return 0;
 889                 return ret;
 890         }
 891 err:
 892         cleanup_a(head);
 893         return ret;
 894 }
 895
 896 static int tcf_add_notify(struct net *net, struct tc_action *a,
 897                           u32 pid, u32 seq, int event, u16 flags)
 898 {
 899         struct tcamsg *t;
 900         struct nlmsghdr *nlh;
 901         struct sk_buff *skb;
 902         struct nlattr *nest;
 903         unsigned char *b;
 904         int err = 0;
 905
 906         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 907         if (!skb)
 908                 return -ENOBUFS;
 909
 910         b = skb_tail_pointer(skb);
 911
 912         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 913         t = NLMSG_DATA(nlh);
 914         t->tca_family = AF_UNSPEC;
 915         t->tca__pad1 = 0;
 916         t->tca__pad2 = 0;
 917
 918         nest = nla_nest_start(skb, TCA_ACT_TAB);
 919         if (nest == NULL)
 920                 goto nla_put_failure;
 921
 922         if (tcf_action_dump(skb, a, 0, 0) < 0)
 923                 goto nla_put_failure;
 924
 925         nla_nest_end(skb, nest);
 926
 927         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 928         NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 929
 930         err = rtnetlink_send(skb, net, pid, RTNLGRP_TC, flags&NLM_F_ECHO);
 931         if (err > 0)
 932                 err = 0;
 933         return err;
 934
 935 nla_put_failure:
 936 nlmsg_failure:
 937         kfree_skb(skb);
 938         return -1;
 939 }
 940
 941
 942 static int
 943 tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 944                u32 pid, int ovr)
 945 {
 946         int ret = 0;
 947         struct tc_action *act;
 948         struct tc_action *a;
 949         u32 seq = n->nlmsg_seq;
 950
 951         act = tcf_action_init(nla, NULL, NULL, ovr, 0);
 952         if (act == NULL)
 953                 goto done;
 954         if (IS_ERR(act)) {
 955                 ret = PTR_ERR(act);
 956                 goto done;
 957         }
 958
 959         /* dump then free all the actions after update; inserted policy
 960          * stays intact
 961          * */
 962         ret = tcf_add_notify(net, act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
 963         for (a = act; a; a = act) {
 964                 act = a->next;
 965                 kfree(a);
 966         }
 967 done:
 968         return ret;
 969 }
 970
 971 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 972 {
 973         struct net *net = sock_net(skb->sk);
 974         struct nlattr *tca[TCA_ACT_MAX + 1];
 975         u32 pid = skb ? NETLINK_CB(skb).pid : 0;
 976         int ret = 0, ovr = 0;
 977
 978         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
 979         if (ret < 0)
 980                 return ret;
 981
 982         if (tca[TCA_ACT_TAB] == NULL) {
 983                 pr_notice("tc_ctl_action: received NO action attribs\n");
 984                 return -EINVAL;
 985         }
 986
 987         /* n->nlmsg_flags&NLM_F_CREATE
 988          * */
 989         switch (n->nlmsg_type) {
 990         case RTM_NEWACTION:
 991                 /* we are going to assume all other flags
 992                  * imply create only if it doesnt exist
 993                  * Note that CREATE | EXCL implies that
 994                  * but since we want avoid ambiguity (eg when flags
 995                  * is zero) then just set this
 996                  */
 997                 if (n->nlmsg_flags&NLM_F_REPLACE)
 998                         ovr = 1;
 999 replay:
1000                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, pid, ovr);
1001                 if (ret == -EAGAIN)
1002                         goto replay;
1003                 break;
1004         case RTM_DELACTION:
1005                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1006                                     pid, RTM_DELACTION);
1007                 break;
1008         case RTM_GETACTION:
1009                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1010                                     pid, RTM_GETACTION);
1011                 break;
1012         default:
1013                 BUG();
1014         }
1015
1016         return ret;
1017 }
1018
1019 static struct nlattr *
1020 find_dump_kind(const struct nlmsghdr *n)
1021 {
1022         struct nlattr *tb1, *tb2[TCA_ACT_MAX+1];
1023         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1024         struct nlattr *nla[TCAA_MAX + 1];
1025         struct nlattr *kind;
1026
1027         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1028                 return NULL;
1029         tb1 = nla[TCA_ACT_TAB];
1030         if (tb1 == NULL)
1031                 return NULL;
1032
1033         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1034                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1035                 return NULL;
1036
1037         if (tb[1] == NULL)
1038                 return NULL;
1039         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1040                       nla_len(tb[1]), NULL) < 0)
1041                 return NULL;
1042         kind = tb2[TCA_ACT_KIND];
1043
1044         return kind;
1045 }
1046
1047 static int
1048 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1049 {
1050         struct nlmsghdr *nlh;
1051         unsigned char *b = skb_tail_pointer(skb);
1052         struct nlattr *nest;
1053         struct tc_action_ops *a_o;
1054         struct tc_action a;
1055         int ret = 0;
1056         struct tcamsg *t = (struct tcamsg *) NLMSG_DATA(cb->nlh);
1057         struct nlattr *kind = find_dump_kind(cb->nlh);
1058
1059         if (kind == NULL) {
1060                 pr_info("tc_dump_action: action bad kind\n");
1061                 return 0;
1062         }
1063
1064         a_o = tc_lookup_action(kind);
1065         if (a_o == NULL) {
1066                 return 0;
1067         }
1068
1069         memset(&a, 0, sizeof(struct tc_action));
1070         a.ops = a_o;
1071
1072         if (a_o->walk == NULL) {
1073                 WARN(1, "tc_dump_action: %s !capable of dumping table\n",
1074                      a_o->kind);
1075                 goto nla_put_failure;
1076         }
1077
1078         nlh = NLMSG_PUT(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
1079                         cb->nlh->nlmsg_type, sizeof(*t));
1080         t = NLMSG_DATA(nlh);
1081         t->tca_family = AF_UNSPEC;
1082         t->tca__pad1 = 0;
1083         t->tca__pad2 = 0;
1084
1085         nest = nla_nest_start(skb, TCA_ACT_TAB);
1086         if (nest == NULL)
1087                 goto nla_put_failure;
1088
1089         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1090         if (ret < 0)
1091                 goto nla_put_failure;
1092
1093         if (ret > 0) {
1094                 nla_nest_end(skb, nest);
1095                 ret = skb->len;
1096         } else
1097                 nla_nest_cancel(skb, nest);
1098
1099         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1100         if (NETLINK_CB(cb->skb).pid && ret)
1101                 nlh->nlmsg_flags |= NLM_F_MULTI;
1102         module_put(a_o->owner);
1103         return skb->len;
1104
1105 nla_put_failure:
1106 nlmsg_failure:
1107         module_put(a_o->owner);
1108         nlmsg_trim(skb, b);
1109         return skb->len;
1110 }
1111
1112 static int __init tc_action_init(void)
1113 {
1114         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL);
1115         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL);
1116         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action);
1117
1118         return 0;
1119 }
1120
1121 subsys_initcall(tc_action_init);