net/sched/act_api.c

   1 /*
   2  * net/sched/act_api.c  Packet action API.
   3  *
   4  *              This program is free software; you can redistribute it and/or
   5  *              modify it under the terms of the GNU General Public License
   6  *              as published by the Free Software Foundation; either version
   7  *              2 of the License, or (at your option) any later version.
   8  *
   9  * Author:      Jamal Hadi Salim
  10  *
  11  *
  12  */
  13
  14 #include <linux/types.h>
  15 #include <linux/kernel.h>
  16 #include <linux/string.h>
  17 #include <linux/errno.h>
  18 #include <linux/slab.h>
  19 #include <linux/skbuff.h>
  20 #include <linux/init.h>
  21 #include <linux/kmod.h>
  22 #include <linux/err.h>
  23 #include <linux/module.h>
  24 #include <net/net_namespace.h>
  25 #include <net/sock.h>
  26 #include <net/sch_generic.h>
  27 #include <net/act_api.h>
  28 #include <net/netlink.h>
  29
  30 void tcf_hash_destroy(struct tcf_common *p, struct tcf_hashinfo *hinfo)
  31 {
  32         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
  33         struct tcf_common **p1p;
  34
  35         for (p1p = &hinfo->htab[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
  36                 if (*p1p == p) {
  37                         write_lock_bh(hinfo->lock);
  38                         *p1p = p->tcfc_next;
  39                         write_unlock_bh(hinfo->lock);
  40                         gen_kill_estimator(&p->tcfc_bstats,
  41                                            &p->tcfc_rate_est);
  42                         /*
  43                          * gen_estimator est_timer() might access p->tcfc_lock
  44                          * or bstats, wait a RCU grace period before freeing p
  45                          */
  46                         kfree_rcu(p, tcfc_rcu);
  47                         return;
  48                 }
  49         }
  50         WARN_ON(1);
  51 }
  52 EXPORT_SYMBOL(tcf_hash_destroy);
  53
  54 int tcf_hash_release(struct tcf_common *p, int bind,
  55                      struct tcf_hashinfo *hinfo)
  56 {
  57         int ret = 0;
  58
  59         if (p) {
  60                 if (bind)
  61                         p->tcfc_bindcnt--;
  62
  63                 p->tcfc_refcnt--;
  64                 if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
  65                         tcf_hash_destroy(p, hinfo);
  66                         ret = 1;
  67                 }
  68         }
  69         return ret;
  70 }
  71 EXPORT_SYMBOL(tcf_hash_release);
  72
  73 static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
  74                            struct tc_action *a, struct tcf_hashinfo *hinfo)
  75 {
  76         struct tcf_common *p;
  77         int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
  78         struct nlattr *nest;
  79
  80         read_lock_bh(hinfo->lock);
  81
  82         s_i = cb->args[0];
  83
  84         for (i = 0; i < (hinfo->hmask + 1); i++) {
  85                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
  86
  87                 for (; p; p = p->tcfc_next) {
  88                         index++;
  89                         if (index < s_i)
  90                                 continue;
  91                         a->priv = p;
  92                         a->order = n_i;
  93
  94                         nest = nla_nest_start(skb, a->order);
  95                         if (nest == NULL)
  96                                 goto nla_put_failure;
  97                         err = tcf_action_dump_1(skb, a, 0, 0);
  98                         if (err < 0) {
  99                                 index--;
 100                                 nlmsg_trim(skb, nest);
 101                                 goto done;
 102                         }
 103                         nla_nest_end(skb, nest);
 104                         n_i++;
 105                         if (n_i >= TCA_ACT_MAX_PRIO)
 106                                 goto done;
 107                 }
 108         }
 109 done:
 110         read_unlock_bh(hinfo->lock);
 111         if (n_i)
 112                 cb->args[0] += n_i;
 113         return n_i;
 114
 115 nla_put_failure:
 116         nla_nest_cancel(skb, nest);
 117         goto done;
 118 }
 119
 120 static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a,
 121                           struct tcf_hashinfo *hinfo)
 122 {
 123         struct tcf_common *p, *s_p;
 124         struct nlattr *nest;
 125         int i = 0, n_i = 0;
 126
 127         nest = nla_nest_start(skb, a->order);
 128         if (nest == NULL)
 129                 goto nla_put_failure;
 130         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 131                 goto nla_put_failure;
 132         for (i = 0; i < (hinfo->hmask + 1); i++) {
 133                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
 134
 135                 while (p != NULL) {
 136                         s_p = p->tcfc_next;
 137                         if (ACT_P_DELETED == tcf_hash_release(p, 0, hinfo))
 138                                 module_put(a->ops->owner);
 139                         n_i++;
 140                         p = s_p;
 141                 }
 142         }
 143         if (nla_put_u32(skb, TCA_FCNT, n_i))
 144                 goto nla_put_failure;
 145         nla_nest_end(skb, nest);
 146
 147         return n_i;
 148 nla_put_failure:
 149         nla_nest_cancel(skb, nest);
 150         return -EINVAL;
 151 }
 152
 153 int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
 154                        int type, struct tc_action *a)
 155 {
 156         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 157
 158         if (type == RTM_DELACTION) {
 159                 return tcf_del_walker(skb, a, hinfo);
 160         } else if (type == RTM_GETACTION) {
 161                 return tcf_dump_walker(skb, cb, a, hinfo);
 162         } else {
 163                 WARN(1, "tcf_generic_walker: unknown action %d\n", type);
 164                 return -EINVAL;
 165         }
 166 }
 167 EXPORT_SYMBOL(tcf_generic_walker);
 168
 169 struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 170 {
 171         struct tcf_common *p;
 172
 173         read_lock_bh(hinfo->lock);
 174         for (p = hinfo->htab[tcf_hash(index, hinfo->hmask)]; p;
 175              p = p->tcfc_next) {
 176                 if (p->tcfc_index == index)
 177                         break;
 178         }
 179         read_unlock_bh(hinfo->lock);
 180
 181         return p;
 182 }
 183 EXPORT_SYMBOL(tcf_hash_lookup);
 184
 185 u32 tcf_hash_new_index(u32 *idx_gen, struct tcf_hashinfo *hinfo)
 186 {
 187         u32 val = *idx_gen;
 188
 189         do {
 190                 if (++val == 0)
 191                         val = 1;
 192         } while (tcf_hash_lookup(val, hinfo));
 193
 194         return (*idx_gen = val);
 195 }
 196 EXPORT_SYMBOL(tcf_hash_new_index);
 197
 198 int tcf_hash_search(struct tc_action *a, u32 index)
 199 {
 200         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 201         struct tcf_common *p = tcf_hash_lookup(index, hinfo);
 202
 203         if (p) {
 204                 a->priv = p;
 205                 return 1;
 206         }
 207         return 0;
 208 }
 209 EXPORT_SYMBOL(tcf_hash_search);
 210
 211 struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
 212                                   struct tcf_hashinfo *hinfo)
 213 {
 214         struct tcf_common *p = NULL;
 215         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 216                 if (bind)
 217                         p->tcfc_bindcnt++;
 218                 p->tcfc_refcnt++;
 219                 a->priv = p;
 220         }
 221         return p;
 222 }
 223 EXPORT_SYMBOL(tcf_hash_check);
 224
 225 struct tcf_common *tcf_hash_create(u32 index, struct nlattr *est,
 226                                    struct tc_action *a, int size, int bind,
 227                                    u32 *idx_gen, struct tcf_hashinfo *hinfo)
 228 {
 229         struct tcf_common *p = kzalloc(size, GFP_KERNEL);
 230
 231         if (unlikely(!p))
 232                 return ERR_PTR(-ENOMEM);
 233         p->tcfc_refcnt = 1;
 234         if (bind)
 235                 p->tcfc_bindcnt = 1;
 236
 237         spin_lock_init(&p->tcfc_lock);
 238         p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
 239         p->tcfc_tm.install = jiffies;
 240         p->tcfc_tm.lastuse = jiffies;
 241         if (est) {
 242                 int err = gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
 243                                             &p->tcfc_lock, est);
 244                 if (err) {
 245                         kfree(p);
 246                         return ERR_PTR(err);
 247                 }
 248         }
 249
 250         a->priv = (void *) p;
 251         return p;
 252 }
 253 EXPORT_SYMBOL(tcf_hash_create);
 254
 255 void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
 256 {
 257         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
 258
 259         write_lock_bh(hinfo->lock);
 260         p->tcfc_next = hinfo->htab[h];
 261         hinfo->htab[h] = p;
 262         write_unlock_bh(hinfo->lock);
 263 }
 264 EXPORT_SYMBOL(tcf_hash_insert);
 265
 266 static struct tc_action_ops *act_base = NULL;
 267 static DEFINE_RWLOCK(act_mod_lock);
 268
 269 int tcf_register_action(struct tc_action_ops *act)
 270 {
 271         struct tc_action_ops *a, **ap;
 272
 273         /* Must supply act, dump, cleanup and init */
 274         if (!act->act || !act->dump || !act->cleanup || !act->init)
 275                 return -EINVAL;
 276
 277         /* Supply defaults */
 278         if (!act->lookup)
 279                 act->lookup = tcf_hash_search;
 280         if (!act->walk)
 281                 act->walk = tcf_generic_walker;
 282
 283         write_lock(&act_mod_lock);
 284         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
 285                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 286                         write_unlock(&act_mod_lock);
 287                         return -EEXIST;
 288                 }
 289         }
 290         act->next = NULL;
 291         *ap = act;
 292         write_unlock(&act_mod_lock);
 293         return 0;
 294 }
 295 EXPORT_SYMBOL(tcf_register_action);
 296
 297 int tcf_unregister_action(struct tc_action_ops *act)
 298 {
 299         struct tc_action_ops *a, **ap;
 300         int err = -ENOENT;
 301
 302         write_lock(&act_mod_lock);
 303         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
 304                 if (a == act)
 305                         break;
 306         if (a) {
 307                 *ap = a->next;
 308                 a->next = NULL;
 309                 err = 0;
 310         }
 311         write_unlock(&act_mod_lock);
 312         return err;
 313 }
 314 EXPORT_SYMBOL(tcf_unregister_action);
 315
 316 /* lookup by name */
 317 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 318 {
 319         struct tc_action_ops *a = NULL;
 320
 321         if (kind) {
 322                 read_lock(&act_mod_lock);
 323                 for (a = act_base; a; a = a->next) {
 324                         if (strcmp(kind, a->kind) == 0) {
 325                                 if (!try_module_get(a->owner)) {
 326                                         read_unlock(&act_mod_lock);
 327                                         return NULL;
 328                                 }
 329                                 break;
 330                         }
 331                 }
 332                 read_unlock(&act_mod_lock);
 333         }
 334         return a;
 335 }
 336
 337 /* lookup by nlattr */
 338 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 339 {
 340         struct tc_action_ops *a = NULL;
 341
 342         if (kind) {
 343                 read_lock(&act_mod_lock);
 344                 for (a = act_base; a; a = a->next) {
 345                         if (nla_strcmp(kind, a->kind) == 0) {
 346                                 if (!try_module_get(a->owner)) {
 347                                         read_unlock(&act_mod_lock);
 348                                         return NULL;
 349                                 }
 350                                 break;
 351                         }
 352                 }
 353                 read_unlock(&act_mod_lock);
 354         }
 355         return a;
 356 }
 357
 358 #if 0
 359 /* lookup by id */
 360 static struct tc_action_ops *tc_lookup_action_id(u32 type)
 361 {
 362         struct tc_action_ops *a = NULL;
 363
 364         if (type) {
 365                 read_lock(&act_mod_lock);
 366                 for (a = act_base; a; a = a->next) {
 367                         if (a->type == type) {
 368                                 if (!try_module_get(a->owner)) {
 369                                         read_unlock(&act_mod_lock);
 370                                         return NULL;
 371                                 }
 372                                 break;
 373                         }
 374                 }
 375                 read_unlock(&act_mod_lock);
 376         }
 377         return a;
 378 }
 379 #endif
 380
 381 int tcf_action_exec(struct sk_buff *skb, const struct tc_action *act,
 382                     struct tcf_result *res)
 383 {
 384         const struct tc_action *a;
 385         int ret = -1;
 386
 387         if (skb->tc_verd & TC_NCLS) {
 388                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 389                 ret = TC_ACT_OK;
 390                 goto exec_done;
 391         }
 392         while ((a = act) != NULL) {
 393 repeat:
 394                 if (a->ops) {
 395                         ret = a->ops->act(skb, a, res);
 396                         if (TC_MUNGED & skb->tc_verd) {
 397                                 /* copied already, allow trampling */
 398                                 skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
 399                                 skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
 400                         }
 401                         if (ret == TC_ACT_REPEAT)
 402                                 goto repeat;    /* we need a ttl - JHS */
 403                         if (ret != TC_ACT_PIPE)
 404                                 goto exec_done;
 405                 }
 406                 act = a->next;
 407         }
 408 exec_done:
 409         return ret;
 410 }
 411 EXPORT_SYMBOL(tcf_action_exec);
 412
 413 void tcf_action_destroy(struct tc_action *act, int bind)
 414 {
 415         struct tc_action *a;
 416
 417         for (a = act; a; a = act) {
 418                 if (a->ops) {
 419                         if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
 420                                 module_put(a->ops->owner);
 421                         act = act->next;
 422                         kfree(a);
 423                 } else {
 424                         /*FIXME: Remove later - catch insertion bugs*/
 425                         WARN(1, "tcf_action_destroy: BUG? destroying NULL ops\n");
 426                         act = act->next;
 427                         kfree(a);
 428                 }
 429         }
 430 }
 431
 432 int
 433 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 434 {
 435         int err = -EINVAL;
 436
 437         if (a->ops == NULL)
 438                 return err;
 439         return a->ops->dump(skb, a, bind, ref);
 440 }
 441
 442 int
 443 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 444 {
 445         int err = -EINVAL;
 446         unsigned char *b = skb_tail_pointer(skb);
 447         struct nlattr *nest;
 448
 449         if (a->ops == NULL)
 450                 return err;
 451
 452         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 453                 goto nla_put_failure;
 454         if (tcf_action_copy_stats(skb, a, 0))
 455                 goto nla_put_failure;
 456         nest = nla_nest_start(skb, TCA_OPTIONS);
 457         if (nest == NULL)
 458                 goto nla_put_failure;
 459         err = tcf_action_dump_old(skb, a, bind, ref);
 460         if (err > 0) {
 461                 nla_nest_end(skb, nest);
 462                 return err;
 463         }
 464
 465 nla_put_failure:
 466         nlmsg_trim(skb, b);
 467         return -1;
 468 }
 469 EXPORT_SYMBOL(tcf_action_dump_1);
 470
 471 int
 472 tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
 473 {
 474         struct tc_action *a;
 475         int err = -EINVAL;
 476         struct nlattr *nest;
 477
 478         while ((a = act) != NULL) {
 479                 act = a->next;
 480                 nest = nla_nest_start(skb, a->order);
 481                 if (nest == NULL)
 482                         goto nla_put_failure;
 483                 err = tcf_action_dump_1(skb, a, bind, ref);
 484                 if (err < 0)
 485                         goto errout;
 486                 nla_nest_end(skb, nest);
 487         }
 488
 489         return 0;
 490
 491 nla_put_failure:
 492         err = -EINVAL;
 493 errout:
 494         nla_nest_cancel(skb, nest);
 495         return err;
 496 }
 497
 498 struct tc_action *tcf_action_init_1(struct net *net, struct nlattr *nla,
 499                                     struct nlattr *est, char *name, int ovr,
 500                                     int bind)
 501 {
 502         struct tc_action *a;
 503         struct tc_action_ops *a_o;
 504         char act_name[IFNAMSIZ];
 505         struct nlattr *tb[TCA_ACT_MAX + 1];
 506         struct nlattr *kind;
 507         int err;
 508
 509         if (name == NULL) {
 510                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 511                 if (err < 0)
 512                         goto err_out;
 513                 err = -EINVAL;
 514                 kind = tb[TCA_ACT_KIND];
 515                 if (kind == NULL)
 516                         goto err_out;
 517                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 518                         goto err_out;
 519         } else {
 520                 err = -EINVAL;
 521                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 522                         goto err_out;
 523         }
 524
 525         a_o = tc_lookup_action_n(act_name);
 526         if (a_o == NULL) {
 527 #ifdef CONFIG_MODULES
 528                 rtnl_unlock();
 529                 request_module("act_%s", act_name);
 530                 rtnl_lock();
 531
 532                 a_o = tc_lookup_action_n(act_name);
 533
 534                 /* We dropped the RTNL semaphore in order to
 535                  * perform the module load.  So, even if we
 536                  * succeeded in loading the module we have to
 537                  * tell the caller to replay the request.  We
 538                  * indicate this using -EAGAIN.
 539                  */
 540                 if (a_o != NULL) {
 541                         err = -EAGAIN;
 542                         goto err_mod;
 543                 }
 544 #endif
 545                 err = -ENOENT;
 546                 goto err_out;
 547         }
 548
 549         err = -ENOMEM;
 550         a = kzalloc(sizeof(*a), GFP_KERNEL);
 551         if (a == NULL)
 552                 goto err_mod;
 553
 554         /* backward compatibility for policer */
 555         if (name == NULL)
 556                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
 557         else
 558                 err = a_o->init(net, nla, est, a, ovr, bind);
 559         if (err < 0)
 560                 goto err_free;
 561
 562         /* module count goes up only when brand new policy is created
 563          * if it exists and is only bound to in a_o->init() then
 564          * ACT_P_CREATED is not returned (a zero is).
 565          */
 566         if (err != ACT_P_CREATED)
 567                 module_put(a_o->owner);
 568         a->ops = a_o;
 569
 570         return a;
 571
 572 err_free:
 573         kfree(a);
 574 err_mod:
 575         module_put(a_o->owner);
 576 err_out:
 577         return ERR_PTR(err);
 578 }
 579
 580 struct tc_action *tcf_action_init(struct net *net, struct nlattr *nla,
 581                                   struct nlattr *est, char *name, int ovr,
 582                                   int bind)
 583 {
 584         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 585         struct tc_action *head = NULL, *act, *act_prev = NULL;
 586         int err;
 587         int i;
 588
 589         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 590         if (err < 0)
 591                 return ERR_PTR(err);
 592
 593         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 594                 act = tcf_action_init_1(net, tb[i], est, name, ovr, bind);
 595                 if (IS_ERR(act))
 596                         goto err;
 597                 act->order = i;
 598
 599                 if (head == NULL)
 600                         head = act;
 601                 else
 602                         act_prev->next = act;
 603                 act_prev = act;
 604         }
 605         return head;
 606
 607 err:
 608         if (head != NULL)
 609                 tcf_action_destroy(head, bind);
 610         return act;
 611 }
 612
 613 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 614                           int compat_mode)
 615 {
 616         int err = 0;
 617         struct gnet_dump d;
 618         struct tcf_act_hdr *h = a->priv;
 619
 620         if (h == NULL)
 621                 goto errout;
 622
 623         /* compat_mode being true specifies a call that is supposed
 624          * to add additional backward compatibility statistic TLVs.
 625          */
 626         if (compat_mode) {
 627                 if (a->type == TCA_OLD_COMPAT)
 628                         err = gnet_stats_start_copy_compat(skb, 0,
 629                                 TCA_STATS, TCA_XSTATS, &h->tcf_lock, &d);
 630                 else
 631                         return 0;
 632         } else
 633                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 634                                             &h->tcf_lock, &d);
 635
 636         if (err < 0)
 637                 goto errout;
 638
 639         if (a->ops != NULL && a->ops->get_stats != NULL)
 640                 if (a->ops->get_stats(skb, a) < 0)
 641                         goto errout;
 642
 643         if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
 644             gnet_stats_copy_rate_est(&d, &h->tcf_bstats,
 645                                      &h->tcf_rate_est) < 0 ||
 646             gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
 647                 goto errout;
 648
 649         if (gnet_stats_finish_copy(&d) < 0)
 650                 goto errout;
 651
 652         return 0;
 653
 654 errout:
 655         return -1;
 656 }
 657
 658 static int
 659 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 portid, u32 seq,
 660              u16 flags, int event, int bind, int ref)
 661 {
 662         struct tcamsg *t;
 663         struct nlmsghdr *nlh;
 664         unsigned char *b = skb_tail_pointer(skb);
 665         struct nlattr *nest;
 666
 667         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
 668         if (!nlh)
 669                 goto out_nlmsg_trim;
 670         t = nlmsg_data(nlh);
 671         t->tca_family = AF_UNSPEC;
 672         t->tca__pad1 = 0;
 673         t->tca__pad2 = 0;
 674
 675         nest = nla_nest_start(skb, TCA_ACT_TAB);
 676         if (nest == NULL)
 677                 goto out_nlmsg_trim;
 678
 679         if (tcf_action_dump(skb, a, bind, ref) < 0)
 680                 goto out_nlmsg_trim;
 681
 682         nla_nest_end(skb, nest);
 683
 684         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 685         return skb->len;
 686
 687 out_nlmsg_trim:
 688         nlmsg_trim(skb, b);
 689         return -1;
 690 }
 691
 692 static int
 693 act_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
 694                struct tc_action *a, int event)
 695 {
 696         struct sk_buff *skb;
 697
 698         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 699         if (!skb)
 700                 return -ENOBUFS;
 701         if (tca_get_fill(skb, a, portid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 702                 kfree_skb(skb);
 703                 return -EINVAL;
 704         }
 705
 706         return rtnl_unicast(skb, net, portid);
 707 }
 708
 709 static struct tc_action *
 710 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 portid)
 711 {
 712         struct nlattr *tb[TCA_ACT_MAX + 1];
 713         struct tc_action *a;
 714         int index;
 715         int err;
 716
 717         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 718         if (err < 0)
 719                 goto err_out;
 720
 721         err = -EINVAL;
 722         if (tb[TCA_ACT_INDEX] == NULL ||
 723             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 724                 goto err_out;
 725         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 726
 727         err = -ENOMEM;
 728         a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
 729         if (a == NULL)
 730                 goto err_out;
 731
 732         err = -EINVAL;
 733         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 734         if (a->ops == NULL)
 735                 goto err_free;
 736         err = -ENOENT;
 737         if (a->ops->lookup(a, index) == 0)
 738                 goto err_mod;
 739
 740         module_put(a->ops->owner);
 741         return a;
 742
 743 err_mod:
 744         module_put(a->ops->owner);
 745 err_free:
 746         kfree(a);
 747 err_out:
 748         return ERR_PTR(err);
 749 }
 750
 751 static void cleanup_a(struct tc_action *act)
 752 {
 753         struct tc_action *a;
 754
 755         for (a = act; a; a = act) {
 756                 act = a->next;
 757                 kfree(a);
 758         }
 759 }
 760
 761 static struct tc_action *create_a(int i)
 762 {
 763         struct tc_action *act;
 764
 765         act = kzalloc(sizeof(*act), GFP_KERNEL);
 766         if (act == NULL) {
 767                 pr_debug("create_a: failed to alloc!\n");
 768                 return NULL;
 769         }
 770         act->order = i;
 771         return act;
 772 }
 773
 774 static int tca_action_flush(struct net *net, struct nlattr *nla,
 775                             struct nlmsghdr *n, u32 portid)
 776 {
 777         struct sk_buff *skb;
 778         unsigned char *b;
 779         struct nlmsghdr *nlh;
 780         struct tcamsg *t;
 781         struct netlink_callback dcb;
 782         struct nlattr *nest;
 783         struct nlattr *tb[TCA_ACT_MAX + 1];
 784         struct nlattr *kind;
 785         struct tc_action *a = create_a(0);
 786         int err = -ENOMEM;
 787
 788         if (a == NULL) {
 789                 pr_debug("tca_action_flush: couldnt create tc_action\n");
 790                 return err;
 791         }
 792
 793         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 794         if (!skb) {
 795                 pr_debug("tca_action_flush: failed skb alloc\n");
 796                 kfree(a);
 797                 return err;
 798         }
 799
 800         b = skb_tail_pointer(skb);
 801
 802         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 803         if (err < 0)
 804                 goto err_out;
 805
 806         err = -EINVAL;
 807         kind = tb[TCA_ACT_KIND];
 808         a->ops = tc_lookup_action(kind);
 809         if (a->ops == NULL)
 810                 goto err_out;
 811
 812         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t), 0);
 813         if (!nlh)
 814                 goto out_module_put;
 815         t = nlmsg_data(nlh);
 816         t->tca_family = AF_UNSPEC;
 817         t->tca__pad1 = 0;
 818         t->tca__pad2 = 0;
 819
 820         nest = nla_nest_start(skb, TCA_ACT_TAB);
 821         if (nest == NULL)
 822                 goto out_module_put;
 823
 824         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 825         if (err < 0)
 826                 goto out_module_put;
 827         if (err == 0)
 828                 goto noflush_out;
 829
 830         nla_nest_end(skb, nest);
 831
 832         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 833         nlh->nlmsg_flags |= NLM_F_ROOT;
 834         module_put(a->ops->owner);
 835         kfree(a);
 836         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 837                              n->nlmsg_flags & NLM_F_ECHO);
 838         if (err > 0)
 839                 return 0;
 840
 841         return err;
 842
 843 out_module_put:
 844         module_put(a->ops->owner);
 845 err_out:
 846 noflush_out:
 847         kfree_skb(skb);
 848         kfree(a);
 849         return err;
 850 }
 851
 852 static int
 853 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 854               u32 portid, int event)
 855 {
 856         int i, ret;
 857         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 858         struct tc_action *head = NULL, *act, *act_prev = NULL;
 859
 860         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 861         if (ret < 0)
 862                 return ret;
 863
 864         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
 865                 if (tb[1] != NULL)
 866                         return tca_action_flush(net, tb[1], n, portid);
 867                 else
 868                         return -EINVAL;
 869         }
 870
 871         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 872                 act = tcf_action_get_1(tb[i], n, portid);
 873                 if (IS_ERR(act)) {
 874                         ret = PTR_ERR(act);
 875                         goto err;
 876                 }
 877                 act->order = i;
 878
 879                 if (head == NULL)
 880                         head = act;
 881                 else
 882                         act_prev->next = act;
 883                 act_prev = act;
 884         }
 885
 886         if (event == RTM_GETACTION)
 887                 ret = act_get_notify(net, portid, n, head, event);
 888         else { /* delete */
 889                 struct sk_buff *skb;
 890
 891                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 892                 if (!skb) {
 893                         ret = -ENOBUFS;
 894                         goto err;
 895                 }
 896
 897                 if (tca_get_fill(skb, head, portid, n->nlmsg_seq, 0, event,
 898                                  0, 1) <= 0) {
 899                         kfree_skb(skb);
 900                         ret = -EINVAL;
 901                         goto err;
 902                 }
 903
 904                 /* now do the delete */
 905                 tcf_action_destroy(head, 0);
 906                 ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 907                                      n->nlmsg_flags & NLM_F_ECHO);
 908                 if (ret > 0)
 909                         return 0;
 910                 return ret;
 911         }
 912 err:
 913         cleanup_a(head);
 914         return ret;
 915 }
 916
 917 static int tcf_add_notify(struct net *net, struct tc_action *a,
 918                           u32 portid, u32 seq, int event, u16 flags)
 919 {
 920         struct tcamsg *t;
 921         struct nlmsghdr *nlh;
 922         struct sk_buff *skb;
 923         struct nlattr *nest;
 924         unsigned char *b;
 925         int err = 0;
 926
 927         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 928         if (!skb)
 929                 return -ENOBUFS;
 930
 931         b = skb_tail_pointer(skb);
 932
 933         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
 934         if (!nlh)
 935                 goto out_kfree_skb;
 936         t = nlmsg_data(nlh);
 937         t->tca_family = AF_UNSPEC;
 938         t->tca__pad1 = 0;
 939         t->tca__pad2 = 0;
 940
 941         nest = nla_nest_start(skb, TCA_ACT_TAB);
 942         if (nest == NULL)
 943                 goto out_kfree_skb;
 944
 945         if (tcf_action_dump(skb, a, 0, 0) < 0)
 946                 goto out_kfree_skb;
 947
 948         nla_nest_end(skb, nest);
 949
 950         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 951         NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 952
 953         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
 954         if (err > 0)
 955                 err = 0;
 956         return err;
 957
 958 out_kfree_skb:
 959         kfree_skb(skb);
 960         return -1;
 961 }
 962
 963
 964 static int
 965 tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 966                u32 portid, int ovr)
 967 {
 968         int ret = 0;
 969         struct tc_action *act;
 970         struct tc_action *a;
 971         u32 seq = n->nlmsg_seq;
 972
 973         act = tcf_action_init(net, nla, NULL, NULL, ovr, 0);
 974         if (act == NULL)
 975                 goto done;
 976         if (IS_ERR(act)) {
 977                 ret = PTR_ERR(act);
 978                 goto done;
 979         }
 980
 981         /* dump then free all the actions after update; inserted policy
 982          * stays intact
 983          */
 984         ret = tcf_add_notify(net, act, portid, seq, RTM_NEWACTION, n->nlmsg_flags);
 985         for (a = act; a; a = act) {
 986                 act = a->next;
 987                 kfree(a);
 988         }
 989 done:
 990         return ret;
 991 }
 992
 993 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n)
 994 {
 995         struct net *net = sock_net(skb->sk);
 996         struct nlattr *tca[TCA_ACT_MAX + 1];
 997         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
 998         int ret = 0, ovr = 0;
 999
1000         if ((n->nlmsg_type != RTM_GETACTION) && !capable(CAP_NET_ADMIN))
1001                 return -EPERM;
1002
1003         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
1004         if (ret < 0)
1005                 return ret;
1006
1007         if (tca[TCA_ACT_TAB] == NULL) {
1008                 pr_notice("tc_ctl_action: received NO action attribs\n");
1009                 return -EINVAL;
1010         }
1011
1012         /* n->nlmsg_flags & NLM_F_CREATE */
1013         switch (n->nlmsg_type) {
1014         case RTM_NEWACTION:
1015                 /* we are going to assume all other flags
1016                  * imply create only if it doesn't exist
1017                  * Note that CREATE | EXCL implies that
1018                  * but since we want avoid ambiguity (eg when flags
1019                  * is zero) then just set this
1020                  */
1021                 if (n->nlmsg_flags & NLM_F_REPLACE)
1022                         ovr = 1;
1023 replay:
1024                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr);
1025                 if (ret == -EAGAIN)
1026                         goto replay;
1027                 break;
1028         case RTM_DELACTION:
1029                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1030                                     portid, RTM_DELACTION);
1031                 break;
1032         case RTM_GETACTION:
1033                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1034                                     portid, RTM_GETACTION);
1035                 break;
1036         default:
1037                 BUG();
1038         }
1039
1040         return ret;
1041 }
1042
1043 static struct nlattr *
1044 find_dump_kind(const struct nlmsghdr *n)
1045 {
1046         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1047         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1048         struct nlattr *nla[TCAA_MAX + 1];
1049         struct nlattr *kind;
1050
1051         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1052                 return NULL;
1053         tb1 = nla[TCA_ACT_TAB];
1054         if (tb1 == NULL)
1055                 return NULL;
1056
1057         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1058                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1059                 return NULL;
1060
1061         if (tb[1] == NULL)
1062                 return NULL;
1063         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1064                       nla_len(tb[1]), NULL) < 0)
1065                 return NULL;
1066         kind = tb2[TCA_ACT_KIND];
1067
1068         return kind;
1069 }
1070
1071 static int
1072 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1073 {
1074         struct nlmsghdr *nlh;
1075         unsigned char *b = skb_tail_pointer(skb);
1076         struct nlattr *nest;
1077         struct tc_action_ops *a_o;
1078         struct tc_action a;
1079         int ret = 0;
1080         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1081         struct nlattr *kind = find_dump_kind(cb->nlh);
1082
1083         if (kind == NULL) {
1084                 pr_info("tc_dump_action: action bad kind\n");
1085                 return 0;
1086         }
1087
1088         a_o = tc_lookup_action(kind);
1089         if (a_o == NULL)
1090                 return 0;
1091
1092         memset(&a, 0, sizeof(struct tc_action));
1093         a.ops = a_o;
1094
1095         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1096                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1097         if (!nlh)
1098                 goto out_module_put;
1099         t = nlmsg_data(nlh);
1100         t->tca_family = AF_UNSPEC;
1101         t->tca__pad1 = 0;
1102         t->tca__pad2 = 0;
1103
1104         nest = nla_nest_start(skb, TCA_ACT_TAB);
1105         if (nest == NULL)
1106                 goto out_module_put;
1107
1108         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1109         if (ret < 0)
1110                 goto out_module_put;
1111
1112         if (ret > 0) {
1113                 nla_nest_end(skb, nest);
1114                 ret = skb->len;
1115         } else
1116                 nla_nest_cancel(skb, nest);
1117
1118         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1119         if (NETLINK_CB(cb->skb).portid && ret)
1120                 nlh->nlmsg_flags |= NLM_F_MULTI;
1121         module_put(a_o->owner);
1122         return skb->len;
1123
1124 out_module_put:
1125         module_put(a_o->owner);
1126         nlmsg_trim(skb, b);
1127         return skb->len;
1128 }
1129
1130 static int __init tc_action_init(void)
1131 {
1132         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
1133         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
1134         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1135                       NULL);
1136
1137         return 0;
1138 }
1139
1140 subsys_initcall(tc_action_init);