net/sched/act_api.c

   1 /*
   2  * net/sched/act_api.c  Packet action API.
   3  *
   4  *              This program is free software; you can redistribute it and/or
   5  *              modify it under the terms of the GNU General Public License
   6  *              as published by the Free Software Foundation; either version
   7  *              2 of the License, or (at your option) any later version.
   8  *
   9  * Author:      Jamal Hadi Salim
  10  *
  11  *
  12  */
  13
  14 #include <linux/types.h>
  15 #include <linux/kernel.h>
  16 #include <linux/string.h>
  17 #include <linux/errno.h>
  18 #include <linux/slab.h>
  19 #include <linux/skbuff.h>
  20 #include <linux/init.h>
  21 #include <linux/kmod.h>
  22 #include <linux/err.h>
  23 #include <linux/module.h>
  24 #include <net/net_namespace.h>
  25 #include <net/sock.h>
  26 #include <net/sch_generic.h>
  27 #include <net/act_api.h>
  28 #include <net/netlink.h>
  29
  30 void tcf_hash_destroy(struct tcf_common *p, struct tcf_hashinfo *hinfo)
  31 {
  32         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
  33         struct tcf_common **p1p;
  34
  35         for (p1p = &hinfo->htab[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
  36                 if (*p1p == p) {
  37                         write_lock_bh(hinfo->lock);
  38                         *p1p = p->tcfc_next;
  39                         write_unlock_bh(hinfo->lock);
  40                         gen_kill_estimator(&p->tcfc_bstats,
  41                                            &p->tcfc_rate_est);
  42                         /*
  43                          * gen_estimator est_timer() might access p->tcfc_lock
  44                          * or bstats, wait a RCU grace period before freeing p
  45                          */
  46                         kfree_rcu(p, tcfc_rcu);
  47                         return;
  48                 }
  49         }
  50         WARN_ON(1);
  51 }
  52 EXPORT_SYMBOL(tcf_hash_destroy);
  53
  54 int tcf_hash_release(struct tcf_common *p, int bind,
  55                      struct tcf_hashinfo *hinfo)
  56 {
  57         int ret = 0;
  58
  59         if (p) {
  60                 if (bind)
  61                         p->tcfc_bindcnt--;
  62
  63                 p->tcfc_refcnt--;
  64                 if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
  65                         tcf_hash_destroy(p, hinfo);
  66                         ret = 1;
  67                 }
  68         }
  69         return ret;
  70 }
  71 EXPORT_SYMBOL(tcf_hash_release);
  72
  73 static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
  74                            struct tc_action *a, struct tcf_hashinfo *hinfo)
  75 {
  76         struct tcf_common *p;
  77         int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
  78         struct nlattr *nest;
  79
  80         read_lock_bh(hinfo->lock);
  81
  82         s_i = cb->args[0];
  83
  84         for (i = 0; i < (hinfo->hmask + 1); i++) {
  85                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
  86
  87                 for (; p; p = p->tcfc_next) {
  88                         index++;
  89                         if (index < s_i)
  90                                 continue;
  91                         a->priv = p;
  92                         a->order = n_i;
  93
  94                         nest = nla_nest_start(skb, a->order);
  95                         if (nest == NULL)
  96                                 goto nla_put_failure;
  97                         err = tcf_action_dump_1(skb, a, 0, 0);
  98                         if (err < 0) {
  99                                 index--;
 100                                 nlmsg_trim(skb, nest);
 101                                 goto done;
 102                         }
 103                         nla_nest_end(skb, nest);
 104                         n_i++;
 105                         if (n_i >= TCA_ACT_MAX_PRIO)
 106                                 goto done;
 107                 }
 108         }
 109 done:
 110         read_unlock_bh(hinfo->lock);
 111         if (n_i)
 112                 cb->args[0] += n_i;
 113         return n_i;
 114
 115 nla_put_failure:
 116         nla_nest_cancel(skb, nest);
 117         goto done;
 118 }
 119
 120 static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a,
 121                           struct tcf_hashinfo *hinfo)
 122 {
 123         struct tcf_common *p, *s_p;
 124         struct nlattr *nest;
 125         int i = 0, n_i = 0;
 126
 127         nest = nla_nest_start(skb, a->order);
 128         if (nest == NULL)
 129                 goto nla_put_failure;
 130         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 131                 goto nla_put_failure;
 132         for (i = 0; i < (hinfo->hmask + 1); i++) {
 133                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
 134
 135                 while (p != NULL) {
 136                         s_p = p->tcfc_next;
 137                         if (ACT_P_DELETED == tcf_hash_release(p, 0, hinfo))
 138                                 module_put(a->ops->owner);
 139                         n_i++;
 140                         p = s_p;
 141                 }
 142         }
 143         if (nla_put_u32(skb, TCA_FCNT, n_i))
 144                 goto nla_put_failure;
 145         nla_nest_end(skb, nest);
 146
 147         return n_i;
 148 nla_put_failure:
 149         nla_nest_cancel(skb, nest);
 150         return -EINVAL;
 151 }
 152
 153 int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
 154                        int type, struct tc_action *a)
 155 {
 156         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 157
 158         if (type == RTM_DELACTION) {
 159                 return tcf_del_walker(skb, a, hinfo);
 160         } else if (type == RTM_GETACTION) {
 161                 return tcf_dump_walker(skb, cb, a, hinfo);
 162         } else {
 163                 WARN(1, "tcf_generic_walker: unknown action %d\n", type);
 164                 return -EINVAL;
 165         }
 166 }
 167 EXPORT_SYMBOL(tcf_generic_walker);
 168
 169 struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 170 {
 171         struct tcf_common *p;
 172
 173         read_lock_bh(hinfo->lock);
 174         for (p = hinfo->htab[tcf_hash(index, hinfo->hmask)]; p;
 175              p = p->tcfc_next) {
 176                 if (p->tcfc_index == index)
 177                         break;
 178         }
 179         read_unlock_bh(hinfo->lock);
 180
 181         return p;
 182 }
 183 EXPORT_SYMBOL(tcf_hash_lookup);
 184
 185 u32 tcf_hash_new_index(u32 *idx_gen, struct tcf_hashinfo *hinfo)
 186 {
 187         u32 val = *idx_gen;
 188
 189         do {
 190                 if (++val == 0)
 191                         val = 1;
 192         } while (tcf_hash_lookup(val, hinfo));
 193
 194         return (*idx_gen = val);
 195 }
 196 EXPORT_SYMBOL(tcf_hash_new_index);
 197
 198 int tcf_hash_search(struct tc_action *a, u32 index)
 199 {
 200         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 201         struct tcf_common *p = tcf_hash_lookup(index, hinfo);
 202
 203         if (p) {
 204                 a->priv = p;
 205                 return 1;
 206         }
 207         return 0;
 208 }
 209 EXPORT_SYMBOL(tcf_hash_search);
 210
 211 struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
 212                                   struct tcf_hashinfo *hinfo)
 213 {
 214         struct tcf_common *p = NULL;
 215         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 216                 if (bind)
 217                         p->tcfc_bindcnt++;
 218                 p->tcfc_refcnt++;
 219                 a->priv = p;
 220         }
 221         return p;
 222 }
 223 EXPORT_SYMBOL(tcf_hash_check);
 224
 225 struct tcf_common *tcf_hash_create(u32 index, struct nlattr *est,
 226                                    struct tc_action *a, int size, int bind,
 227                                    u32 *idx_gen, struct tcf_hashinfo *hinfo)
 228 {
 229         struct tcf_common *p = kzalloc(size, GFP_KERNEL);
 230
 231         if (unlikely(!p))
 232                 return ERR_PTR(-ENOMEM);
 233         p->tcfc_refcnt = 1;
 234         if (bind)
 235                 p->tcfc_bindcnt = 1;
 236
 237         spin_lock_init(&p->tcfc_lock);
 238         p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
 239         p->tcfc_tm.install = jiffies;
 240         p->tcfc_tm.lastuse = jiffies;
 241         if (est) {
 242                 int err = gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
 243                                             &p->tcfc_lock, est);
 244                 if (err) {
 245                         kfree(p);
 246                         return ERR_PTR(err);
 247                 }
 248         }
 249
 250         a->priv = (void *) p;
 251         return p;
 252 }
 253 EXPORT_SYMBOL(tcf_hash_create);
 254
 255 void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
 256 {
 257         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
 258
 259         write_lock_bh(hinfo->lock);
 260         p->tcfc_next = hinfo->htab[h];
 261         hinfo->htab[h] = p;
 262         write_unlock_bh(hinfo->lock);
 263 }
 264 EXPORT_SYMBOL(tcf_hash_insert);
 265
 266 static struct tc_action_ops *act_base = NULL;
 267 static DEFINE_RWLOCK(act_mod_lock);
 268
 269 int tcf_register_action(struct tc_action_ops *act)
 270 {
 271         struct tc_action_ops *a, **ap;
 272
 273         write_lock(&act_mod_lock);
 274         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
 275                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 276                         write_unlock(&act_mod_lock);
 277                         return -EEXIST;
 278                 }
 279         }
 280         act->next = NULL;
 281         *ap = act;
 282         write_unlock(&act_mod_lock);
 283         return 0;
 284 }
 285 EXPORT_SYMBOL(tcf_register_action);
 286
 287 int tcf_unregister_action(struct tc_action_ops *act)
 288 {
 289         struct tc_action_ops *a, **ap;
 290         int err = -ENOENT;
 291
 292         write_lock(&act_mod_lock);
 293         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
 294                 if (a == act)
 295                         break;
 296         if (a) {
 297                 *ap = a->next;
 298                 a->next = NULL;
 299                 err = 0;
 300         }
 301         write_unlock(&act_mod_lock);
 302         return err;
 303 }
 304 EXPORT_SYMBOL(tcf_unregister_action);
 305
 306 /* lookup by name */
 307 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 308 {
 309         struct tc_action_ops *a = NULL;
 310
 311         if (kind) {
 312                 read_lock(&act_mod_lock);
 313                 for (a = act_base; a; a = a->next) {
 314                         if (strcmp(kind, a->kind) == 0) {
 315                                 if (!try_module_get(a->owner)) {
 316                                         read_unlock(&act_mod_lock);
 317                                         return NULL;
 318                                 }
 319                                 break;
 320                         }
 321                 }
 322                 read_unlock(&act_mod_lock);
 323         }
 324         return a;
 325 }
 326
 327 /* lookup by nlattr */
 328 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 329 {
 330         struct tc_action_ops *a = NULL;
 331
 332         if (kind) {
 333                 read_lock(&act_mod_lock);
 334                 for (a = act_base; a; a = a->next) {
 335                         if (nla_strcmp(kind, a->kind) == 0) {
 336                                 if (!try_module_get(a->owner)) {
 337                                         read_unlock(&act_mod_lock);
 338                                         return NULL;
 339                                 }
 340                                 break;
 341                         }
 342                 }
 343                 read_unlock(&act_mod_lock);
 344         }
 345         return a;
 346 }
 347
 348 #if 0
 349 /* lookup by id */
 350 static struct tc_action_ops *tc_lookup_action_id(u32 type)
 351 {
 352         struct tc_action_ops *a = NULL;
 353
 354         if (type) {
 355                 read_lock(&act_mod_lock);
 356                 for (a = act_base; a; a = a->next) {
 357                         if (a->type == type) {
 358                                 if (!try_module_get(a->owner)) {
 359                                         read_unlock(&act_mod_lock);
 360                                         return NULL;
 361                                 }
 362                                 break;
 363                         }
 364                 }
 365                 read_unlock(&act_mod_lock);
 366         }
 367         return a;
 368 }
 369 #endif
 370
 371 int tcf_action_exec(struct sk_buff *skb, const struct tc_action *act,
 372                     struct tcf_result *res)
 373 {
 374         const struct tc_action *a;
 375         int ret = -1;
 376
 377         if (skb->tc_verd & TC_NCLS) {
 378                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 379                 ret = TC_ACT_OK;
 380                 goto exec_done;
 381         }
 382         while ((a = act) != NULL) {
 383 repeat:
 384                 if (a->ops && a->ops->act) {
 385                         ret = a->ops->act(skb, a, res);
 386                         if (TC_MUNGED & skb->tc_verd) {
 387                                 /* copied already, allow trampling */
 388                                 skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
 389                                 skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
 390                         }
 391                         if (ret == TC_ACT_REPEAT)
 392                                 goto repeat;    /* we need a ttl - JHS */
 393                         if (ret != TC_ACT_PIPE)
 394                                 goto exec_done;
 395                 }
 396                 act = a->next;
 397         }
 398 exec_done:
 399         return ret;
 400 }
 401 EXPORT_SYMBOL(tcf_action_exec);
 402
 403 void tcf_action_destroy(struct tc_action *act, int bind)
 404 {
 405         struct tc_action *a;
 406
 407         for (a = act; a; a = act) {
 408                 if (a->ops && a->ops->cleanup) {
 409                         if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
 410                                 module_put(a->ops->owner);
 411                         act = act->next;
 412                         kfree(a);
 413                 } else {
 414                         /*FIXME: Remove later - catch insertion bugs*/
 415                         WARN(1, "tcf_action_destroy: BUG? destroying NULL ops\n");
 416                         act = act->next;
 417                         kfree(a);
 418                 }
 419         }
 420 }
 421
 422 int
 423 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 424 {
 425         int err = -EINVAL;
 426
 427         if (a->ops == NULL || a->ops->dump == NULL)
 428                 return err;
 429         return a->ops->dump(skb, a, bind, ref);
 430 }
 431
 432 int
 433 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 434 {
 435         int err = -EINVAL;
 436         unsigned char *b = skb_tail_pointer(skb);
 437         struct nlattr *nest;
 438
 439         if (a->ops == NULL || a->ops->dump == NULL)
 440                 return err;
 441
 442         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 443                 goto nla_put_failure;
 444         if (tcf_action_copy_stats(skb, a, 0))
 445                 goto nla_put_failure;
 446         nest = nla_nest_start(skb, TCA_OPTIONS);
 447         if (nest == NULL)
 448                 goto nla_put_failure;
 449         err = tcf_action_dump_old(skb, a, bind, ref);
 450         if (err > 0) {
 451                 nla_nest_end(skb, nest);
 452                 return err;
 453         }
 454
 455 nla_put_failure:
 456         nlmsg_trim(skb, b);
 457         return -1;
 458 }
 459 EXPORT_SYMBOL(tcf_action_dump_1);
 460
 461 int
 462 tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
 463 {
 464         struct tc_action *a;
 465         int err = -EINVAL;
 466         struct nlattr *nest;
 467
 468         while ((a = act) != NULL) {
 469                 act = a->next;
 470                 nest = nla_nest_start(skb, a->order);
 471                 if (nest == NULL)
 472                         goto nla_put_failure;
 473                 err = tcf_action_dump_1(skb, a, bind, ref);
 474                 if (err < 0)
 475                         goto errout;
 476                 nla_nest_end(skb, nest);
 477         }
 478
 479         return 0;
 480
 481 nla_put_failure:
 482         err = -EINVAL;
 483 errout:
 484         nla_nest_cancel(skb, nest);
 485         return err;
 486 }
 487
 488 struct tc_action *tcf_action_init_1(struct nlattr *nla, struct nlattr *est,
 489                                     char *name, int ovr, int bind)
 490 {
 491         struct tc_action *a;
 492         struct tc_action_ops *a_o;
 493         char act_name[IFNAMSIZ];
 494         struct nlattr *tb[TCA_ACT_MAX + 1];
 495         struct nlattr *kind;
 496         int err;
 497
 498         if (name == NULL) {
 499                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 500                 if (err < 0)
 501                         goto err_out;
 502                 err = -EINVAL;
 503                 kind = tb[TCA_ACT_KIND];
 504                 if (kind == NULL)
 505                         goto err_out;
 506                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 507                         goto err_out;
 508         } else {
 509                 err = -EINVAL;
 510                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 511                         goto err_out;
 512         }
 513
 514         a_o = tc_lookup_action_n(act_name);
 515         if (a_o == NULL) {
 516 #ifdef CONFIG_MODULES
 517                 rtnl_unlock();
 518                 request_module("act_%s", act_name);
 519                 rtnl_lock();
 520
 521                 a_o = tc_lookup_action_n(act_name);
 522
 523                 /* We dropped the RTNL semaphore in order to
 524                  * perform the module load.  So, even if we
 525                  * succeeded in loading the module we have to
 526                  * tell the caller to replay the request.  We
 527                  * indicate this using -EAGAIN.
 528                  */
 529                 if (a_o != NULL) {
 530                         err = -EAGAIN;
 531                         goto err_mod;
 532                 }
 533 #endif
 534                 err = -ENOENT;
 535                 goto err_out;
 536         }
 537
 538         err = -ENOMEM;
 539         a = kzalloc(sizeof(*a), GFP_KERNEL);
 540         if (a == NULL)
 541                 goto err_mod;
 542
 543         /* backward compatibility for policer */
 544         if (name == NULL)
 545                 err = a_o->init(tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
 546         else
 547                 err = a_o->init(nla, est, a, ovr, bind);
 548         if (err < 0)
 549                 goto err_free;
 550
 551         /* module count goes up only when brand new policy is created
 552          * if it exists and is only bound to in a_o->init() then
 553          * ACT_P_CREATED is not returned (a zero is).
 554          */
 555         if (err != ACT_P_CREATED)
 556                 module_put(a_o->owner);
 557         a->ops = a_o;
 558
 559         return a;
 560
 561 err_free:
 562         kfree(a);
 563 err_mod:
 564         module_put(a_o->owner);
 565 err_out:
 566         return ERR_PTR(err);
 567 }
 568
 569 struct tc_action *tcf_action_init(struct nlattr *nla, struct nlattr *est,
 570                                   char *name, int ovr, int bind)
 571 {
 572         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 573         struct tc_action *head = NULL, *act, *act_prev = NULL;
 574         int err;
 575         int i;
 576
 577         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 578         if (err < 0)
 579                 return ERR_PTR(err);
 580
 581         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 582                 act = tcf_action_init_1(tb[i], est, name, ovr, bind);
 583                 if (IS_ERR(act))
 584                         goto err;
 585                 act->order = i;
 586
 587                 if (head == NULL)
 588                         head = act;
 589                 else
 590                         act_prev->next = act;
 591                 act_prev = act;
 592         }
 593         return head;
 594
 595 err:
 596         if (head != NULL)
 597                 tcf_action_destroy(head, bind);
 598         return act;
 599 }
 600
 601 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 602                           int compat_mode)
 603 {
 604         int err = 0;
 605         struct gnet_dump d;
 606         struct tcf_act_hdr *h = a->priv;
 607
 608         if (h == NULL)
 609                 goto errout;
 610
 611         /* compat_mode being true specifies a call that is supposed
 612          * to add additional backward compatibility statistic TLVs.
 613          */
 614         if (compat_mode) {
 615                 if (a->type == TCA_OLD_COMPAT)
 616                         err = gnet_stats_start_copy_compat(skb, 0,
 617                                 TCA_STATS, TCA_XSTATS, &h->tcf_lock, &d);
 618                 else
 619                         return 0;
 620         } else
 621                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 622                                             &h->tcf_lock, &d);
 623
 624         if (err < 0)
 625                 goto errout;
 626
 627         if (a->ops != NULL && a->ops->get_stats != NULL)
 628                 if (a->ops->get_stats(skb, a) < 0)
 629                         goto errout;
 630
 631         if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
 632             gnet_stats_copy_rate_est(&d, &h->tcf_bstats,
 633                                      &h->tcf_rate_est) < 0 ||
 634             gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
 635                 goto errout;
 636
 637         if (gnet_stats_finish_copy(&d) < 0)
 638                 goto errout;
 639
 640         return 0;
 641
 642 errout:
 643         return -1;
 644 }
 645
 646 static int
 647 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 pid, u32 seq,
 648              u16 flags, int event, int bind, int ref)
 649 {
 650         struct tcamsg *t;
 651         struct nlmsghdr *nlh;
 652         unsigned char *b = skb_tail_pointer(skb);
 653         struct nlattr *nest;
 654
 655         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 656
 657         t = NLMSG_DATA(nlh);
 658         t->tca_family = AF_UNSPEC;
 659         t->tca__pad1 = 0;
 660         t->tca__pad2 = 0;
 661
 662         nest = nla_nest_start(skb, TCA_ACT_TAB);
 663         if (nest == NULL)
 664                 goto nla_put_failure;
 665
 666         if (tcf_action_dump(skb, a, bind, ref) < 0)
 667                 goto nla_put_failure;
 668
 669         nla_nest_end(skb, nest);
 670
 671         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 672         return skb->len;
 673
 674 nla_put_failure:
 675 nlmsg_failure:
 676         nlmsg_trim(skb, b);
 677         return -1;
 678 }
 679
 680 static int
 681 act_get_notify(struct net *net, u32 pid, struct nlmsghdr *n,
 682                struct tc_action *a, int event)
 683 {
 684         struct sk_buff *skb;
 685
 686         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 687         if (!skb)
 688                 return -ENOBUFS;
 689         if (tca_get_fill(skb, a, pid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 690                 kfree_skb(skb);
 691                 return -EINVAL;
 692         }
 693
 694         return rtnl_unicast(skb, net, pid);
 695 }
 696
 697 static struct tc_action *
 698 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 pid)
 699 {
 700         struct nlattr *tb[TCA_ACT_MAX + 1];
 701         struct tc_action *a;
 702         int index;
 703         int err;
 704
 705         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 706         if (err < 0)
 707                 goto err_out;
 708
 709         err = -EINVAL;
 710         if (tb[TCA_ACT_INDEX] == NULL ||
 711             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 712                 goto err_out;
 713         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 714
 715         err = -ENOMEM;
 716         a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
 717         if (a == NULL)
 718                 goto err_out;
 719
 720         err = -EINVAL;
 721         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 722         if (a->ops == NULL)
 723                 goto err_free;
 724         if (a->ops->lookup == NULL)
 725                 goto err_mod;
 726         err = -ENOENT;
 727         if (a->ops->lookup(a, index) == 0)
 728                 goto err_mod;
 729
 730         module_put(a->ops->owner);
 731         return a;
 732
 733 err_mod:
 734         module_put(a->ops->owner);
 735 err_free:
 736         kfree(a);
 737 err_out:
 738         return ERR_PTR(err);
 739 }
 740
 741 static void cleanup_a(struct tc_action *act)
 742 {
 743         struct tc_action *a;
 744
 745         for (a = act; a; a = act) {
 746                 act = a->next;
 747                 kfree(a);
 748         }
 749 }
 750
 751 static struct tc_action *create_a(int i)
 752 {
 753         struct tc_action *act;
 754
 755         act = kzalloc(sizeof(*act), GFP_KERNEL);
 756         if (act == NULL) {
 757                 pr_debug("create_a: failed to alloc!\n");
 758                 return NULL;
 759         }
 760         act->order = i;
 761         return act;
 762 }
 763
 764 static int tca_action_flush(struct net *net, struct nlattr *nla,
 765                             struct nlmsghdr *n, u32 pid)
 766 {
 767         struct sk_buff *skb;
 768         unsigned char *b;
 769         struct nlmsghdr *nlh;
 770         struct tcamsg *t;
 771         struct netlink_callback dcb;
 772         struct nlattr *nest;
 773         struct nlattr *tb[TCA_ACT_MAX + 1];
 774         struct nlattr *kind;
 775         struct tc_action *a = create_a(0);
 776         int err = -ENOMEM;
 777
 778         if (a == NULL) {
 779                 pr_debug("tca_action_flush: couldnt create tc_action\n");
 780                 return err;
 781         }
 782
 783         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 784         if (!skb) {
 785                 pr_debug("tca_action_flush: failed skb alloc\n");
 786                 kfree(a);
 787                 return err;
 788         }
 789
 790         b = skb_tail_pointer(skb);
 791
 792         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 793         if (err < 0)
 794                 goto err_out;
 795
 796         err = -EINVAL;
 797         kind = tb[TCA_ACT_KIND];
 798         a->ops = tc_lookup_action(kind);
 799         if (a->ops == NULL)
 800                 goto err_out;
 801
 802         nlh = NLMSG_PUT(skb, pid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t));
 803         t = NLMSG_DATA(nlh);
 804         t->tca_family = AF_UNSPEC;
 805         t->tca__pad1 = 0;
 806         t->tca__pad2 = 0;
 807
 808         nest = nla_nest_start(skb, TCA_ACT_TAB);
 809         if (nest == NULL)
 810                 goto nla_put_failure;
 811
 812         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 813         if (err < 0)
 814                 goto nla_put_failure;
 815         if (err == 0)
 816                 goto noflush_out;
 817
 818         nla_nest_end(skb, nest);
 819
 820         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 821         nlh->nlmsg_flags |= NLM_F_ROOT;
 822         module_put(a->ops->owner);
 823         kfree(a);
 824         err = rtnetlink_send(skb, net, pid, RTNLGRP_TC,
 825                              n->nlmsg_flags & NLM_F_ECHO);
 826         if (err > 0)
 827                 return 0;
 828
 829         return err;
 830
 831 nla_put_failure:
 832 nlmsg_failure:
 833         module_put(a->ops->owner);
 834 err_out:
 835 noflush_out:
 836         kfree_skb(skb);
 837         kfree(a);
 838         return err;
 839 }
 840
 841 static int
 842 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 843               u32 pid, int event)
 844 {
 845         int i, ret;
 846         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 847         struct tc_action *head = NULL, *act, *act_prev = NULL;
 848
 849         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 850         if (ret < 0)
 851                 return ret;
 852
 853         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
 854                 if (tb[1] != NULL)
 855                         return tca_action_flush(net, tb[1], n, pid);
 856                 else
 857                         return -EINVAL;
 858         }
 859
 860         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 861                 act = tcf_action_get_1(tb[i], n, pid);
 862                 if (IS_ERR(act)) {
 863                         ret = PTR_ERR(act);
 864                         goto err;
 865                 }
 866                 act->order = i;
 867
 868                 if (head == NULL)
 869                         head = act;
 870                 else
 871                         act_prev->next = act;
 872                 act_prev = act;
 873         }
 874
 875         if (event == RTM_GETACTION)
 876                 ret = act_get_notify(net, pid, n, head, event);
 877         else { /* delete */
 878                 struct sk_buff *skb;
 879
 880                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 881                 if (!skb) {
 882                         ret = -ENOBUFS;
 883                         goto err;
 884                 }
 885
 886                 if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
 887                                  0, 1) <= 0) {
 888                         kfree_skb(skb);
 889                         ret = -EINVAL;
 890                         goto err;
 891                 }
 892
 893                 /* now do the delete */
 894                 tcf_action_destroy(head, 0);
 895                 ret = rtnetlink_send(skb, net, pid, RTNLGRP_TC,
 896                                      n->nlmsg_flags & NLM_F_ECHO);
 897                 if (ret > 0)
 898                         return 0;
 899                 return ret;
 900         }
 901 err:
 902         cleanup_a(head);
 903         return ret;
 904 }
 905
 906 static int tcf_add_notify(struct net *net, struct tc_action *a,
 907                           u32 pid, u32 seq, int event, u16 flags)
 908 {
 909         struct tcamsg *t;
 910         struct nlmsghdr *nlh;
 911         struct sk_buff *skb;
 912         struct nlattr *nest;
 913         unsigned char *b;
 914         int err = 0;
 915
 916         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 917         if (!skb)
 918                 return -ENOBUFS;
 919
 920         b = skb_tail_pointer(skb);
 921
 922         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 923         t = NLMSG_DATA(nlh);
 924         t->tca_family = AF_UNSPEC;
 925         t->tca__pad1 = 0;
 926         t->tca__pad2 = 0;
 927
 928         nest = nla_nest_start(skb, TCA_ACT_TAB);
 929         if (nest == NULL)
 930                 goto nla_put_failure;
 931
 932         if (tcf_action_dump(skb, a, 0, 0) < 0)
 933                 goto nla_put_failure;
 934
 935         nla_nest_end(skb, nest);
 936
 937         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 938         NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 939
 940         err = rtnetlink_send(skb, net, pid, RTNLGRP_TC, flags & NLM_F_ECHO);
 941         if (err > 0)
 942                 err = 0;
 943         return err;
 944
 945 nla_put_failure:
 946 nlmsg_failure:
 947         kfree_skb(skb);
 948         return -1;
 949 }
 950
 951
 952 static int
 953 tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 954                u32 pid, int ovr)
 955 {
 956         int ret = 0;
 957         struct tc_action *act;
 958         struct tc_action *a;
 959         u32 seq = n->nlmsg_seq;
 960
 961         act = tcf_action_init(nla, NULL, NULL, ovr, 0);
 962         if (act == NULL)
 963                 goto done;
 964         if (IS_ERR(act)) {
 965                 ret = PTR_ERR(act);
 966                 goto done;
 967         }
 968
 969         /* dump then free all the actions after update; inserted policy
 970          * stays intact
 971          */
 972         ret = tcf_add_notify(net, act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
 973         for (a = act; a; a = act) {
 974                 act = a->next;
 975                 kfree(a);
 976         }
 977 done:
 978         return ret;
 979 }
 980
 981 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 982 {
 983         struct net *net = sock_net(skb->sk);
 984         struct nlattr *tca[TCA_ACT_MAX + 1];
 985         u32 pid = skb ? NETLINK_CB(skb).pid : 0;
 986         int ret = 0, ovr = 0;
 987
 988         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
 989         if (ret < 0)
 990                 return ret;
 991
 992         if (tca[TCA_ACT_TAB] == NULL) {
 993                 pr_notice("tc_ctl_action: received NO action attribs\n");
 994                 return -EINVAL;
 995         }
 996
 997         /* n->nlmsg_flags & NLM_F_CREATE */
 998         switch (n->nlmsg_type) {
 999         case RTM_NEWACTION:
1000                 /* we are going to assume all other flags
1001                  * imply create only if it doesn't exist
1002                  * Note that CREATE | EXCL implies that
1003                  * but since we want avoid ambiguity (eg when flags
1004                  * is zero) then just set this
1005                  */
1006                 if (n->nlmsg_flags & NLM_F_REPLACE)
1007                         ovr = 1;
1008 replay:
1009                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, pid, ovr);
1010                 if (ret == -EAGAIN)
1011                         goto replay;
1012                 break;
1013         case RTM_DELACTION:
1014                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1015                                     pid, RTM_DELACTION);
1016                 break;
1017         case RTM_GETACTION:
1018                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1019                                     pid, RTM_GETACTION);
1020                 break;
1021         default:
1022                 BUG();
1023         }
1024
1025         return ret;
1026 }
1027
1028 static struct nlattr *
1029 find_dump_kind(const struct nlmsghdr *n)
1030 {
1031         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1032         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1033         struct nlattr *nla[TCAA_MAX + 1];
1034         struct nlattr *kind;
1035
1036         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1037                 return NULL;
1038         tb1 = nla[TCA_ACT_TAB];
1039         if (tb1 == NULL)
1040                 return NULL;
1041
1042         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1043                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1044                 return NULL;
1045
1046         if (tb[1] == NULL)
1047                 return NULL;
1048         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1049                       nla_len(tb[1]), NULL) < 0)
1050                 return NULL;
1051         kind = tb2[TCA_ACT_KIND];
1052
1053         return kind;
1054 }
1055
1056 static int
1057 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1058 {
1059         struct nlmsghdr *nlh;
1060         unsigned char *b = skb_tail_pointer(skb);
1061         struct nlattr *nest;
1062         struct tc_action_ops *a_o;
1063         struct tc_action a;
1064         int ret = 0;
1065         struct tcamsg *t = (struct tcamsg *) NLMSG_DATA(cb->nlh);
1066         struct nlattr *kind = find_dump_kind(cb->nlh);
1067
1068         if (kind == NULL) {
1069                 pr_info("tc_dump_action: action bad kind\n");
1070                 return 0;
1071         }
1072
1073         a_o = tc_lookup_action(kind);
1074         if (a_o == NULL)
1075                 return 0;
1076
1077         memset(&a, 0, sizeof(struct tc_action));
1078         a.ops = a_o;
1079
1080         if (a_o->walk == NULL) {
1081                 WARN(1, "tc_dump_action: %s !capable of dumping table\n",
1082                      a_o->kind);
1083                 goto nla_put_failure;
1084         }
1085
1086         nlh = NLMSG_PUT(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
1087                         cb->nlh->nlmsg_type, sizeof(*t));
1088         t = NLMSG_DATA(nlh);
1089         t->tca_family = AF_UNSPEC;
1090         t->tca__pad1 = 0;
1091         t->tca__pad2 = 0;
1092
1093         nest = nla_nest_start(skb, TCA_ACT_TAB);
1094         if (nest == NULL)
1095                 goto nla_put_failure;
1096
1097         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1098         if (ret < 0)
1099                 goto nla_put_failure;
1100
1101         if (ret > 0) {
1102                 nla_nest_end(skb, nest);
1103                 ret = skb->len;
1104         } else
1105                 nla_nest_cancel(skb, nest);
1106
1107         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1108         if (NETLINK_CB(cb->skb).pid && ret)
1109                 nlh->nlmsg_flags |= NLM_F_MULTI;
1110         module_put(a_o->owner);
1111         return skb->len;
1112
1113 nla_put_failure:
1114 nlmsg_failure:
1115         module_put(a_o->owner);
1116         nlmsg_trim(skb, b);
1117         return skb->len;
1118 }
1119
1120 static int __init tc_action_init(void)
1121 {
1122         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
1123         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
1124         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1125                       NULL);
1126
1127         return 0;
1128 }
1129
1130 subsys_initcall(tc_action_init);