net/sched/act_api.c

   1 /*
   2  * net/sched/act_api.c  Packet action API.
   3  *
   4  *              This program is free software; you can redistribute it and/or
   5  *              modify it under the terms of the GNU General Public License
   6  *              as published by the Free Software Foundation; either version
   7  *              2 of the License, or (at your option) any later version.
   8  *
   9  * Author:      Jamal Hadi Salim
  10  *
  11  *
  12  */
  13
  14 #include <linux/types.h>
  15 #include <linux/kernel.h>
  16 #include <linux/string.h>
  17 #include <linux/errno.h>
  18 #include <linux/slab.h>
  19 #include <linux/skbuff.h>
  20 #include <linux/init.h>
  21 #include <linux/kmod.h>
  22 #include <linux/err.h>
  23 #include <net/net_namespace.h>
  24 #include <net/sock.h>
  25 #include <net/sch_generic.h>
  26 #include <net/act_api.h>
  27 #include <net/netlink.h>
  28
  29 static void tcf_common_free_rcu(struct rcu_head *head)
  30 {
  31         kfree(container_of(head, struct tcf_common, tcfc_rcu));
  32 }
  33
  34 void tcf_hash_destroy(struct tcf_common *p, struct tcf_hashinfo *hinfo)
  35 {
  36         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
  37         struct tcf_common **p1p;
  38
  39         for (p1p = &hinfo->htab[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
  40                 if (*p1p == p) {
  41                         write_lock_bh(hinfo->lock);
  42                         *p1p = p->tcfc_next;
  43                         write_unlock_bh(hinfo->lock);
  44                         gen_kill_estimator(&p->tcfc_bstats,
  45                                            &p->tcfc_rate_est);
  46                         /*
  47                          * gen_estimator est_timer() might access p->tcfc_lock
  48                          * or bstats, wait a RCU grace period before freeing p
  49                          */
  50                         call_rcu(&p->tcfc_rcu, tcf_common_free_rcu);
  51                         return;
  52                 }
  53         }
  54         WARN_ON(1);
  55 }
  56 EXPORT_SYMBOL(tcf_hash_destroy);
  57
  58 int tcf_hash_release(struct tcf_common *p, int bind,
  59                      struct tcf_hashinfo *hinfo)
  60 {
  61         int ret = 0;
  62
  63         if (p) {
  64                 if (bind)
  65                         p->tcfc_bindcnt--;
  66
  67                 p->tcfc_refcnt--;
  68                 if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
  69                         tcf_hash_destroy(p, hinfo);
  70                         ret = 1;
  71                 }
  72         }
  73         return ret;
  74 }
  75 EXPORT_SYMBOL(tcf_hash_release);
  76
  77 static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
  78                            struct tc_action *a, struct tcf_hashinfo *hinfo)
  79 {
  80         struct tcf_common *p;
  81         int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
  82         struct nlattr *nest;
  83
  84         read_lock_bh(hinfo->lock);
  85
  86         s_i = cb->args[0];
  87
  88         for (i = 0; i < (hinfo->hmask + 1); i++) {
  89                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
  90
  91                 for (; p; p = p->tcfc_next) {
  92                         index++;
  93                         if (index < s_i)
  94                                 continue;
  95                         a->priv = p;
  96                         a->order = n_i;
  97
  98                         nest = nla_nest_start(skb, a->order);
  99                         if (nest == NULL)
 100                                 goto nla_put_failure;
 101                         err = tcf_action_dump_1(skb, a, 0, 0);
 102                         if (err < 0) {
 103                                 index--;
 104                                 nlmsg_trim(skb, nest);
 105                                 goto done;
 106                         }
 107                         nla_nest_end(skb, nest);
 108                         n_i++;
 109                         if (n_i >= TCA_ACT_MAX_PRIO)
 110                                 goto done;
 111                 }
 112         }
 113 done:
 114         read_unlock_bh(hinfo->lock);
 115         if (n_i)
 116                 cb->args[0] += n_i;
 117         return n_i;
 118
 119 nla_put_failure:
 120         nla_nest_cancel(skb, nest);
 121         goto done;
 122 }
 123
 124 static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a,
 125                           struct tcf_hashinfo *hinfo)
 126 {
 127         struct tcf_common *p, *s_p;
 128         struct nlattr *nest;
 129         int i = 0, n_i = 0;
 130
 131         nest = nla_nest_start(skb, a->order);
 132         if (nest == NULL)
 133                 goto nla_put_failure;
 134         NLA_PUT_STRING(skb, TCA_KIND, a->ops->kind);
 135         for (i = 0; i < (hinfo->hmask + 1); i++) {
 136                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
 137
 138                 while (p != NULL) {
 139                         s_p = p->tcfc_next;
 140                         if (ACT_P_DELETED == tcf_hash_release(p, 0, hinfo))
 141                                 module_put(a->ops->owner);
 142                         n_i++;
 143                         p = s_p;
 144                 }
 145         }
 146         NLA_PUT_U32(skb, TCA_FCNT, n_i);
 147         nla_nest_end(skb, nest);
 148
 149         return n_i;
 150 nla_put_failure:
 151         nla_nest_cancel(skb, nest);
 152         return -EINVAL;
 153 }
 154
 155 int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
 156                        int type, struct tc_action *a)
 157 {
 158         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 159
 160         if (type == RTM_DELACTION) {
 161                 return tcf_del_walker(skb, a, hinfo);
 162         } else if (type == RTM_GETACTION) {
 163                 return tcf_dump_walker(skb, cb, a, hinfo);
 164         } else {
 165                 WARN(1, "tcf_generic_walker: unknown action %d\n", type);
 166                 return -EINVAL;
 167         }
 168 }
 169 EXPORT_SYMBOL(tcf_generic_walker);
 170
 171 struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 172 {
 173         struct tcf_common *p;
 174
 175         read_lock_bh(hinfo->lock);
 176         for (p = hinfo->htab[tcf_hash(index, hinfo->hmask)]; p;
 177              p = p->tcfc_next) {
 178                 if (p->tcfc_index == index)
 179                         break;
 180         }
 181         read_unlock_bh(hinfo->lock);
 182
 183         return p;
 184 }
 185 EXPORT_SYMBOL(tcf_hash_lookup);
 186
 187 u32 tcf_hash_new_index(u32 *idx_gen, struct tcf_hashinfo *hinfo)
 188 {
 189         u32 val = *idx_gen;
 190
 191         do {
 192                 if (++val == 0)
 193                         val = 1;
 194         } while (tcf_hash_lookup(val, hinfo));
 195
 196         return (*idx_gen = val);
 197 }
 198 EXPORT_SYMBOL(tcf_hash_new_index);
 199
 200 int tcf_hash_search(struct tc_action *a, u32 index)
 201 {
 202         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 203         struct tcf_common *p = tcf_hash_lookup(index, hinfo);
 204
 205         if (p) {
 206                 a->priv = p;
 207                 return 1;
 208         }
 209         return 0;
 210 }
 211 EXPORT_SYMBOL(tcf_hash_search);
 212
 213 struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
 214                                   struct tcf_hashinfo *hinfo)
 215 {
 216         struct tcf_common *p = NULL;
 217         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 218                 if (bind)
 219                         p->tcfc_bindcnt++;
 220                 p->tcfc_refcnt++;
 221                 a->priv = p;
 222         }
 223         return p;
 224 }
 225 EXPORT_SYMBOL(tcf_hash_check);
 226
 227 struct tcf_common *tcf_hash_create(u32 index, struct nlattr *est,
 228                                    struct tc_action *a, int size, int bind,
 229                                    u32 *idx_gen, struct tcf_hashinfo *hinfo)
 230 {
 231         struct tcf_common *p = kzalloc(size, GFP_KERNEL);
 232
 233         if (unlikely(!p))
 234                 return ERR_PTR(-ENOMEM);
 235         p->tcfc_refcnt = 1;
 236         if (bind)
 237                 p->tcfc_bindcnt = 1;
 238
 239         spin_lock_init(&p->tcfc_lock);
 240         p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
 241         p->tcfc_tm.install = jiffies;
 242         p->tcfc_tm.lastuse = jiffies;
 243         if (est) {
 244                 int err = gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
 245                                             &p->tcfc_lock, est);
 246                 if (err) {
 247                         kfree(p);
 248                         return ERR_PTR(err);
 249                 }
 250         }
 251
 252         a->priv = (void *) p;
 253         return p;
 254 }
 255 EXPORT_SYMBOL(tcf_hash_create);
 256
 257 void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
 258 {
 259         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
 260
 261         write_lock_bh(hinfo->lock);
 262         p->tcfc_next = hinfo->htab[h];
 263         hinfo->htab[h] = p;
 264         write_unlock_bh(hinfo->lock);
 265 }
 266 EXPORT_SYMBOL(tcf_hash_insert);
 267
 268 static struct tc_action_ops *act_base = NULL;
 269 static DEFINE_RWLOCK(act_mod_lock);
 270
 271 int tcf_register_action(struct tc_action_ops *act)
 272 {
 273         struct tc_action_ops *a, **ap;
 274
 275         write_lock(&act_mod_lock);
 276         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
 277                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 278                         write_unlock(&act_mod_lock);
 279                         return -EEXIST;
 280                 }
 281         }
 282         act->next = NULL;
 283         *ap = act;
 284         write_unlock(&act_mod_lock);
 285         return 0;
 286 }
 287 EXPORT_SYMBOL(tcf_register_action);
 288
 289 int tcf_unregister_action(struct tc_action_ops *act)
 290 {
 291         struct tc_action_ops *a, **ap;
 292         int err = -ENOENT;
 293
 294         write_lock(&act_mod_lock);
 295         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
 296                 if (a == act)
 297                         break;
 298         if (a) {
 299                 *ap = a->next;
 300                 a->next = NULL;
 301                 err = 0;
 302         }
 303         write_unlock(&act_mod_lock);
 304         return err;
 305 }
 306 EXPORT_SYMBOL(tcf_unregister_action);
 307
 308 /* lookup by name */
 309 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 310 {
 311         struct tc_action_ops *a = NULL;
 312
 313         if (kind) {
 314                 read_lock(&act_mod_lock);
 315                 for (a = act_base; a; a = a->next) {
 316                         if (strcmp(kind, a->kind) == 0) {
 317                                 if (!try_module_get(a->owner)) {
 318                                         read_unlock(&act_mod_lock);
 319                                         return NULL;
 320                                 }
 321                                 break;
 322                         }
 323                 }
 324                 read_unlock(&act_mod_lock);
 325         }
 326         return a;
 327 }
 328
 329 /* lookup by nlattr */
 330 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 331 {
 332         struct tc_action_ops *a = NULL;
 333
 334         if (kind) {
 335                 read_lock(&act_mod_lock);
 336                 for (a = act_base; a; a = a->next) {
 337                         if (nla_strcmp(kind, a->kind) == 0) {
 338                                 if (!try_module_get(a->owner)) {
 339                                         read_unlock(&act_mod_lock);
 340                                         return NULL;
 341                                 }
 342                                 break;
 343                         }
 344                 }
 345                 read_unlock(&act_mod_lock);
 346         }
 347         return a;
 348 }
 349
 350 #if 0
 351 /* lookup by id */
 352 static struct tc_action_ops *tc_lookup_action_id(u32 type)
 353 {
 354         struct tc_action_ops *a = NULL;
 355
 356         if (type) {
 357                 read_lock(&act_mod_lock);
 358                 for (a = act_base; a; a = a->next) {
 359                         if (a->type == type) {
 360                                 if (!try_module_get(a->owner)) {
 361                                         read_unlock(&act_mod_lock);
 362                                         return NULL;
 363                                 }
 364                                 break;
 365                         }
 366                 }
 367                 read_unlock(&act_mod_lock);
 368         }
 369         return a;
 370 }
 371 #endif
 372
 373 int tcf_action_exec(struct sk_buff *skb, struct tc_action *act,
 374                     struct tcf_result *res)
 375 {
 376         struct tc_action *a;
 377         int ret = -1;
 378
 379         if (skb->tc_verd & TC_NCLS) {
 380                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 381                 ret = TC_ACT_OK;
 382                 goto exec_done;
 383         }
 384         while ((a = act) != NULL) {
 385 repeat:
 386                 if (a->ops && a->ops->act) {
 387                         ret = a->ops->act(skb, a, res);
 388                         if (TC_MUNGED & skb->tc_verd) {
 389                                 /* copied already, allow trampling */
 390                                 skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
 391                                 skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
 392                         }
 393                         if (ret == TC_ACT_REPEAT)
 394                                 goto repeat;    /* we need a ttl - JHS */
 395                         if (ret != TC_ACT_PIPE)
 396                                 goto exec_done;
 397                 }
 398                 act = a->next;
 399         }
 400 exec_done:
 401         return ret;
 402 }
 403 EXPORT_SYMBOL(tcf_action_exec);
 404
 405 void tcf_action_destroy(struct tc_action *act, int bind)
 406 {
 407         struct tc_action *a;
 408
 409         for (a = act; a; a = act) {
 410                 if (a->ops && a->ops->cleanup) {
 411                         if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
 412                                 module_put(a->ops->owner);
 413                         act = act->next;
 414                         kfree(a);
 415                 } else {
 416                         /*FIXME: Remove later - catch insertion bugs*/
 417                         WARN(1, "tcf_action_destroy: BUG? destroying NULL ops\n");
 418                         act = act->next;
 419                         kfree(a);
 420                 }
 421         }
 422 }
 423
 424 int
 425 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 426 {
 427         int err = -EINVAL;
 428
 429         if (a->ops == NULL || a->ops->dump == NULL)
 430                 return err;
 431         return a->ops->dump(skb, a, bind, ref);
 432 }
 433
 434 int
 435 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 436 {
 437         int err = -EINVAL;
 438         unsigned char *b = skb_tail_pointer(skb);
 439         struct nlattr *nest;
 440
 441         if (a->ops == NULL || a->ops->dump == NULL)
 442                 return err;
 443
 444         NLA_PUT_STRING(skb, TCA_KIND, a->ops->kind);
 445         if (tcf_action_copy_stats(skb, a, 0))
 446                 goto nla_put_failure;
 447         nest = nla_nest_start(skb, TCA_OPTIONS);
 448         if (nest == NULL)
 449                 goto nla_put_failure;
 450         err = tcf_action_dump_old(skb, a, bind, ref);
 451         if (err > 0) {
 452                 nla_nest_end(skb, nest);
 453                 return err;
 454         }
 455
 456 nla_put_failure:
 457         nlmsg_trim(skb, b);
 458         return -1;
 459 }
 460 EXPORT_SYMBOL(tcf_action_dump_1);
 461
 462 int
 463 tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
 464 {
 465         struct tc_action *a;
 466         int err = -EINVAL;
 467         struct nlattr *nest;
 468
 469         while ((a = act) != NULL) {
 470                 act = a->next;
 471                 nest = nla_nest_start(skb, a->order);
 472                 if (nest == NULL)
 473                         goto nla_put_failure;
 474                 err = tcf_action_dump_1(skb, a, bind, ref);
 475                 if (err < 0)
 476                         goto errout;
 477                 nla_nest_end(skb, nest);
 478         }
 479
 480         return 0;
 481
 482 nla_put_failure:
 483         err = -EINVAL;
 484 errout:
 485         nla_nest_cancel(skb, nest);
 486         return err;
 487 }
 488
 489 struct tc_action *tcf_action_init_1(struct nlattr *nla, struct nlattr *est,
 490                                     char *name, int ovr, int bind)
 491 {
 492         struct tc_action *a;
 493         struct tc_action_ops *a_o;
 494         char act_name[IFNAMSIZ];
 495         struct nlattr *tb[TCA_ACT_MAX + 1];
 496         struct nlattr *kind;
 497         int err;
 498
 499         if (name == NULL) {
 500                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 501                 if (err < 0)
 502                         goto err_out;
 503                 err = -EINVAL;
 504                 kind = tb[TCA_ACT_KIND];
 505                 if (kind == NULL)
 506                         goto err_out;
 507                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 508                         goto err_out;
 509         } else {
 510                 err = -EINVAL;
 511                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 512                         goto err_out;
 513         }
 514
 515         a_o = tc_lookup_action_n(act_name);
 516         if (a_o == NULL) {
 517 #ifdef CONFIG_MODULES
 518                 rtnl_unlock();
 519                 request_module("act_%s", act_name);
 520                 rtnl_lock();
 521
 522                 a_o = tc_lookup_action_n(act_name);
 523
 524                 /* We dropped the RTNL semaphore in order to
 525                  * perform the module load.  So, even if we
 526                  * succeeded in loading the module we have to
 527                  * tell the caller to replay the request.  We
 528                  * indicate this using -EAGAIN.
 529                  */
 530                 if (a_o != NULL) {
 531                         err = -EAGAIN;
 532                         goto err_mod;
 533                 }
 534 #endif
 535                 err = -ENOENT;
 536                 goto err_out;
 537         }
 538
 539         err = -ENOMEM;
 540         a = kzalloc(sizeof(*a), GFP_KERNEL);
 541         if (a == NULL)
 542                 goto err_mod;
 543
 544         /* backward compatibility for policer */
 545         if (name == NULL)
 546                 err = a_o->init(tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
 547         else
 548                 err = a_o->init(nla, est, a, ovr, bind);
 549         if (err < 0)
 550                 goto err_free;
 551
 552         /* module count goes up only when brand new policy is created
 553          * if it exists and is only bound to in a_o->init() then
 554          * ACT_P_CREATED is not returned (a zero is).
 555          */
 556         if (err != ACT_P_CREATED)
 557                 module_put(a_o->owner);
 558         a->ops = a_o;
 559
 560         return a;
 561
 562 err_free:
 563         kfree(a);
 564 err_mod:
 565         module_put(a_o->owner);
 566 err_out:
 567         return ERR_PTR(err);
 568 }
 569
 570 struct tc_action *tcf_action_init(struct nlattr *nla, struct nlattr *est,
 571                                   char *name, int ovr, int bind)
 572 {
 573         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 574         struct tc_action *head = NULL, *act, *act_prev = NULL;
 575         int err;
 576         int i;
 577
 578         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 579         if (err < 0)
 580                 return ERR_PTR(err);
 581
 582         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 583                 act = tcf_action_init_1(tb[i], est, name, ovr, bind);
 584                 if (IS_ERR(act))
 585                         goto err;
 586                 act->order = i;
 587
 588                 if (head == NULL)
 589                         head = act;
 590                 else
 591                         act_prev->next = act;
 592                 act_prev = act;
 593         }
 594         return head;
 595
 596 err:
 597         if (head != NULL)
 598                 tcf_action_destroy(head, bind);
 599         return act;
 600 }
 601
 602 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 603                           int compat_mode)
 604 {
 605         int err = 0;
 606         struct gnet_dump d;
 607         struct tcf_act_hdr *h = a->priv;
 608
 609         if (h == NULL)
 610                 goto errout;
 611
 612         /* compat_mode being true specifies a call that is supposed
 613          * to add additional backward compatibility statistic TLVs.
 614          */
 615         if (compat_mode) {
 616                 if (a->type == TCA_OLD_COMPAT)
 617                         err = gnet_stats_start_copy_compat(skb, 0,
 618                                 TCA_STATS, TCA_XSTATS, &h->tcf_lock, &d);
 619                 else
 620                         return 0;
 621         } else
 622                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 623                                             &h->tcf_lock, &d);
 624
 625         if (err < 0)
 626                 goto errout;
 627
 628         if (a->ops != NULL && a->ops->get_stats != NULL)
 629                 if (a->ops->get_stats(skb, a) < 0)
 630                         goto errout;
 631
 632         if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
 633             gnet_stats_copy_rate_est(&d, &h->tcf_bstats,
 634                                      &h->tcf_rate_est) < 0 ||
 635             gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
 636                 goto errout;
 637
 638         if (gnet_stats_finish_copy(&d) < 0)
 639                 goto errout;
 640
 641         return 0;
 642
 643 errout:
 644         return -1;
 645 }
 646
 647 static int
 648 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 pid, u32 seq,
 649              u16 flags, int event, int bind, int ref)
 650 {
 651         struct tcamsg *t;
 652         struct nlmsghdr *nlh;
 653         unsigned char *b = skb_tail_pointer(skb);
 654         struct nlattr *nest;
 655
 656         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 657
 658         t = NLMSG_DATA(nlh);
 659         t->tca_family = AF_UNSPEC;
 660         t->tca__pad1 = 0;
 661         t->tca__pad2 = 0;
 662
 663         nest = nla_nest_start(skb, TCA_ACT_TAB);
 664         if (nest == NULL)
 665                 goto nla_put_failure;
 666
 667         if (tcf_action_dump(skb, a, bind, ref) < 0)
 668                 goto nla_put_failure;
 669
 670         nla_nest_end(skb, nest);
 671
 672         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 673         return skb->len;
 674
 675 nla_put_failure:
 676 nlmsg_failure:
 677         nlmsg_trim(skb, b);
 678         return -1;
 679 }
 680
 681 static int
 682 act_get_notify(struct net *net, u32 pid, struct nlmsghdr *n,
 683                struct tc_action *a, int event)
 684 {
 685         struct sk_buff *skb;
 686
 687         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 688         if (!skb)
 689                 return -ENOBUFS;
 690         if (tca_get_fill(skb, a, pid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 691                 kfree_skb(skb);
 692                 return -EINVAL;
 693         }
 694
 695         return rtnl_unicast(skb, net, pid);
 696 }
 697
 698 static struct tc_action *
 699 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 pid)
 700 {
 701         struct nlattr *tb[TCA_ACT_MAX + 1];
 702         struct tc_action *a;
 703         int index;
 704         int err;
 705
 706         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 707         if (err < 0)
 708                 goto err_out;
 709
 710         err = -EINVAL;
 711         if (tb[TCA_ACT_INDEX] == NULL ||
 712             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 713                 goto err_out;
 714         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 715
 716         err = -ENOMEM;
 717         a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
 718         if (a == NULL)
 719                 goto err_out;
 720
 721         err = -EINVAL;
 722         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 723         if (a->ops == NULL)
 724                 goto err_free;
 725         if (a->ops->lookup == NULL)
 726                 goto err_mod;
 727         err = -ENOENT;
 728         if (a->ops->lookup(a, index) == 0)
 729                 goto err_mod;
 730
 731         module_put(a->ops->owner);
 732         return a;
 733
 734 err_mod:
 735         module_put(a->ops->owner);
 736 err_free:
 737         kfree(a);
 738 err_out:
 739         return ERR_PTR(err);
 740 }
 741
 742 static void cleanup_a(struct tc_action *act)
 743 {
 744         struct tc_action *a;
 745
 746         for (a = act; a; a = act) {
 747                 act = a->next;
 748                 kfree(a);
 749         }
 750 }
 751
 752 static struct tc_action *create_a(int i)
 753 {
 754         struct tc_action *act;
 755
 756         act = kzalloc(sizeof(*act), GFP_KERNEL);
 757         if (act == NULL) {
 758                 pr_debug("create_a: failed to alloc!\n");
 759                 return NULL;
 760         }
 761         act->order = i;
 762         return act;
 763 }
 764
 765 static int tca_action_flush(struct net *net, struct nlattr *nla,
 766                             struct nlmsghdr *n, u32 pid)
 767 {
 768         struct sk_buff *skb;
 769         unsigned char *b;
 770         struct nlmsghdr *nlh;
 771         struct tcamsg *t;
 772         struct netlink_callback dcb;
 773         struct nlattr *nest;
 774         struct nlattr *tb[TCA_ACT_MAX + 1];
 775         struct nlattr *kind;
 776         struct tc_action *a = create_a(0);
 777         int err = -ENOMEM;
 778
 779         if (a == NULL) {
 780                 pr_debug("tca_action_flush: couldnt create tc_action\n");
 781                 return err;
 782         }
 783
 784         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 785         if (!skb) {
 786                 pr_debug("tca_action_flush: failed skb alloc\n");
 787                 kfree(a);
 788                 return err;
 789         }
 790
 791         b = skb_tail_pointer(skb);
 792
 793         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 794         if (err < 0)
 795                 goto err_out;
 796
 797         err = -EINVAL;
 798         kind = tb[TCA_ACT_KIND];
 799         a->ops = tc_lookup_action(kind);
 800         if (a->ops == NULL)
 801                 goto err_out;
 802
 803         nlh = NLMSG_PUT(skb, pid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t));
 804         t = NLMSG_DATA(nlh);
 805         t->tca_family = AF_UNSPEC;
 806         t->tca__pad1 = 0;
 807         t->tca__pad2 = 0;
 808
 809         nest = nla_nest_start(skb, TCA_ACT_TAB);
 810         if (nest == NULL)
 811                 goto nla_put_failure;
 812
 813         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 814         if (err < 0)
 815                 goto nla_put_failure;
 816         if (err == 0)
 817                 goto noflush_out;
 818
 819         nla_nest_end(skb, nest);
 820
 821         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 822         nlh->nlmsg_flags |= NLM_F_ROOT;
 823         module_put(a->ops->owner);
 824         kfree(a);
 825         err = rtnetlink_send(skb, net, pid, RTNLGRP_TC,
 826                              n->nlmsg_flags & NLM_F_ECHO);
 827         if (err > 0)
 828                 return 0;
 829
 830         return err;
 831
 832 nla_put_failure:
 833 nlmsg_failure:
 834         module_put(a->ops->owner);
 835 err_out:
 836 noflush_out:
 837         kfree_skb(skb);
 838         kfree(a);
 839         return err;
 840 }
 841
 842 static int
 843 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 844               u32 pid, int event)
 845 {
 846         int i, ret;
 847         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 848         struct tc_action *head = NULL, *act, *act_prev = NULL;
 849
 850         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 851         if (ret < 0)
 852                 return ret;
 853
 854         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
 855                 if (tb[1] != NULL)
 856                         return tca_action_flush(net, tb[1], n, pid);
 857                 else
 858                         return -EINVAL;
 859         }
 860
 861         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 862                 act = tcf_action_get_1(tb[i], n, pid);
 863                 if (IS_ERR(act)) {
 864                         ret = PTR_ERR(act);
 865                         goto err;
 866                 }
 867                 act->order = i;
 868
 869                 if (head == NULL)
 870                         head = act;
 871                 else
 872                         act_prev->next = act;
 873                 act_prev = act;
 874         }
 875
 876         if (event == RTM_GETACTION)
 877                 ret = act_get_notify(net, pid, n, head, event);
 878         else { /* delete */
 879                 struct sk_buff *skb;
 880
 881                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 882                 if (!skb) {
 883                         ret = -ENOBUFS;
 884                         goto err;
 885                 }
 886
 887                 if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
 888                                  0, 1) <= 0) {
 889                         kfree_skb(skb);
 890                         ret = -EINVAL;
 891                         goto err;
 892                 }
 893
 894                 /* now do the delete */
 895                 tcf_action_destroy(head, 0);
 896                 ret = rtnetlink_send(skb, net, pid, RTNLGRP_TC,
 897                                      n->nlmsg_flags & NLM_F_ECHO);
 898                 if (ret > 0)
 899                         return 0;
 900                 return ret;
 901         }
 902 err:
 903         cleanup_a(head);
 904         return ret;
 905 }
 906
 907 static int tcf_add_notify(struct net *net, struct tc_action *a,
 908                           u32 pid, u32 seq, int event, u16 flags)
 909 {
 910         struct tcamsg *t;
 911         struct nlmsghdr *nlh;
 912         struct sk_buff *skb;
 913         struct nlattr *nest;
 914         unsigned char *b;
 915         int err = 0;
 916
 917         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 918         if (!skb)
 919                 return -ENOBUFS;
 920
 921         b = skb_tail_pointer(skb);
 922
 923         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 924         t = NLMSG_DATA(nlh);
 925         t->tca_family = AF_UNSPEC;
 926         t->tca__pad1 = 0;
 927         t->tca__pad2 = 0;
 928
 929         nest = nla_nest_start(skb, TCA_ACT_TAB);
 930         if (nest == NULL)
 931                 goto nla_put_failure;
 932
 933         if (tcf_action_dump(skb, a, 0, 0) < 0)
 934                 goto nla_put_failure;
 935
 936         nla_nest_end(skb, nest);
 937
 938         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 939         NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 940
 941         err = rtnetlink_send(skb, net, pid, RTNLGRP_TC, flags & NLM_F_ECHO);
 942         if (err > 0)
 943                 err = 0;
 944         return err;
 945
 946 nla_put_failure:
 947 nlmsg_failure:
 948         kfree_skb(skb);
 949         return -1;
 950 }
 951
 952
 953 static int
 954 tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 955                u32 pid, int ovr)
 956 {
 957         int ret = 0;
 958         struct tc_action *act;
 959         struct tc_action *a;
 960         u32 seq = n->nlmsg_seq;
 961
 962         act = tcf_action_init(nla, NULL, NULL, ovr, 0);
 963         if (act == NULL)
 964                 goto done;
 965         if (IS_ERR(act)) {
 966                 ret = PTR_ERR(act);
 967                 goto done;
 968         }
 969
 970         /* dump then free all the actions after update; inserted policy
 971          * stays intact
 972          */
 973         ret = tcf_add_notify(net, act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
 974         for (a = act; a; a = act) {
 975                 act = a->next;
 976                 kfree(a);
 977         }
 978 done:
 979         return ret;
 980 }
 981
 982 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 983 {
 984         struct net *net = sock_net(skb->sk);
 985         struct nlattr *tca[TCA_ACT_MAX + 1];
 986         u32 pid = skb ? NETLINK_CB(skb).pid : 0;
 987         int ret = 0, ovr = 0;
 988
 989         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
 990         if (ret < 0)
 991                 return ret;
 992
 993         if (tca[TCA_ACT_TAB] == NULL) {
 994                 pr_notice("tc_ctl_action: received NO action attribs\n");
 995                 return -EINVAL;
 996         }
 997
 998         /* n->nlmsg_flags & NLM_F_CREATE */
 999         switch (n->nlmsg_type) {
1000         case RTM_NEWACTION:
1001                 /* we are going to assume all other flags
1002                  * imply create only if it doesn't exist
1003                  * Note that CREATE | EXCL implies that
1004                  * but since we want avoid ambiguity (eg when flags
1005                  * is zero) then just set this
1006                  */
1007                 if (n->nlmsg_flags & NLM_F_REPLACE)
1008                         ovr = 1;
1009 replay:
1010                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, pid, ovr);
1011                 if (ret == -EAGAIN)
1012                         goto replay;
1013                 break;
1014         case RTM_DELACTION:
1015                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1016                                     pid, RTM_DELACTION);
1017                 break;
1018         case RTM_GETACTION:
1019                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1020                                     pid, RTM_GETACTION);
1021                 break;
1022         default:
1023                 BUG();
1024         }
1025
1026         return ret;
1027 }
1028
1029 static struct nlattr *
1030 find_dump_kind(const struct nlmsghdr *n)
1031 {
1032         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1033         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1034         struct nlattr *nla[TCAA_MAX + 1];
1035         struct nlattr *kind;
1036
1037         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1038                 return NULL;
1039         tb1 = nla[TCA_ACT_TAB];
1040         if (tb1 == NULL)
1041                 return NULL;
1042
1043         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1044                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1045                 return NULL;
1046
1047         if (tb[1] == NULL)
1048                 return NULL;
1049         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1050                       nla_len(tb[1]), NULL) < 0)
1051                 return NULL;
1052         kind = tb2[TCA_ACT_KIND];
1053
1054         return kind;
1055 }
1056
1057 static int
1058 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1059 {
1060         struct nlmsghdr *nlh;
1061         unsigned char *b = skb_tail_pointer(skb);
1062         struct nlattr *nest;
1063         struct tc_action_ops *a_o;
1064         struct tc_action a;
1065         int ret = 0;
1066         struct tcamsg *t = (struct tcamsg *) NLMSG_DATA(cb->nlh);
1067         struct nlattr *kind = find_dump_kind(cb->nlh);
1068
1069         if (kind == NULL) {
1070                 pr_info("tc_dump_action: action bad kind\n");
1071                 return 0;
1072         }
1073
1074         a_o = tc_lookup_action(kind);
1075         if (a_o == NULL)
1076                 return 0;
1077
1078         memset(&a, 0, sizeof(struct tc_action));
1079         a.ops = a_o;
1080
1081         if (a_o->walk == NULL) {
1082                 WARN(1, "tc_dump_action: %s !capable of dumping table\n",
1083                      a_o->kind);
1084                 goto nla_put_failure;
1085         }
1086
1087         nlh = NLMSG_PUT(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
1088                         cb->nlh->nlmsg_type, sizeof(*t));
1089         t = NLMSG_DATA(nlh);
1090         t->tca_family = AF_UNSPEC;
1091         t->tca__pad1 = 0;
1092         t->tca__pad2 = 0;
1093
1094         nest = nla_nest_start(skb, TCA_ACT_TAB);
1095         if (nest == NULL)
1096                 goto nla_put_failure;
1097
1098         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1099         if (ret < 0)
1100                 goto nla_put_failure;
1101
1102         if (ret > 0) {
1103                 nla_nest_end(skb, nest);
1104                 ret = skb->len;
1105         } else
1106                 nla_nest_cancel(skb, nest);
1107
1108         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1109         if (NETLINK_CB(cb->skb).pid && ret)
1110                 nlh->nlmsg_flags |= NLM_F_MULTI;
1111         module_put(a_o->owner);
1112         return skb->len;
1113
1114 nla_put_failure:
1115 nlmsg_failure:
1116         module_put(a_o->owner);
1117         nlmsg_trim(skb, b);
1118         return skb->len;
1119 }
1120
1121 static int __init tc_action_init(void)
1122 {
1123         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL);
1124         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL);
1125         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action);
1126
1127         return 0;
1128 }
1129
1130 subsys_initcall(tc_action_init);