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         if ((err = tcf_action_dump_old(skb, a, bind, ref)) > 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, n->nlmsg_flags&NLM_F_ECHO);
 825         if (err > 0)
 826                 return 0;
 827
 828         return err;
 829
 830 nla_put_failure:
 831 nlmsg_failure:
 832         module_put(a->ops->owner);
 833 err_out:
 834 noflush_out:
 835         kfree_skb(skb);
 836         kfree(a);
 837         return err;
 838 }
 839
 840 static int
 841 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 842               u32 pid, int event)
 843 {
 844         int i, ret;
 845         struct nlattr *tb[TCA_ACT_MAX_PRIO+1];
 846         struct tc_action *head = NULL, *act, *act_prev = NULL;
 847
 848         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 849         if (ret < 0)
 850                 return ret;
 851
 852         if (event == RTM_DELACTION && n->nlmsg_flags&NLM_F_ROOT) {
 853                 if (tb[1] != NULL)
 854                         return tca_action_flush(net, tb[1], n, pid);
 855                 else
 856                         return -EINVAL;
 857         }
 858
 859         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 860                 act = tcf_action_get_1(tb[i], n, pid);
 861                 if (IS_ERR(act)) {
 862                         ret = PTR_ERR(act);
 863                         goto err;
 864                 }
 865                 act->order = i;
 866
 867                 if (head == NULL)
 868                         head = act;
 869                 else
 870                         act_prev->next = act;
 871                 act_prev = act;
 872         }
 873
 874         if (event == RTM_GETACTION)
 875                 ret = act_get_notify(net, pid, n, head, event);
 876         else { /* delete */
 877                 struct sk_buff *skb;
 878
 879                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 880                 if (!skb) {
 881                         ret = -ENOBUFS;
 882                         goto err;
 883                 }
 884
 885                 if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
 886                                  0, 1) <= 0) {
 887                         kfree_skb(skb);
 888                         ret = -EINVAL;
 889                         goto err;
 890                 }
 891
 892                 /* now do the delete */
 893                 tcf_action_destroy(head, 0);
 894                 ret = rtnetlink_send(skb, net, pid, RTNLGRP_TC,
 895                                      n->nlmsg_flags&NLM_F_ECHO);
 896                 if (ret > 0)
 897                         return 0;
 898                 return ret;
 899         }
 900 err:
 901         cleanup_a(head);
 902         return ret;
 903 }
 904
 905 static int tcf_add_notify(struct net *net, struct tc_action *a,
 906                           u32 pid, u32 seq, int event, u16 flags)
 907 {
 908         struct tcamsg *t;
 909         struct nlmsghdr *nlh;
 910         struct sk_buff *skb;
 911         struct nlattr *nest;
 912         unsigned char *b;
 913         int err = 0;
 914
 915         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 916         if (!skb)
 917                 return -ENOBUFS;
 918
 919         b = skb_tail_pointer(skb);
 920
 921         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 922         t = NLMSG_DATA(nlh);
 923         t->tca_family = AF_UNSPEC;
 924         t->tca__pad1 = 0;
 925         t->tca__pad2 = 0;
 926
 927         nest = nla_nest_start(skb, TCA_ACT_TAB);
 928         if (nest == NULL)
 929                 goto nla_put_failure;
 930
 931         if (tcf_action_dump(skb, a, 0, 0) < 0)
 932                 goto nla_put_failure;
 933
 934         nla_nest_end(skb, nest);
 935
 936         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 937         NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 938
 939         err = rtnetlink_send(skb, net, pid, RTNLGRP_TC, flags&NLM_F_ECHO);
 940         if (err > 0)
 941                 err = 0;
 942         return err;
 943
 944 nla_put_failure:
 945 nlmsg_failure:
 946         kfree_skb(skb);
 947         return -1;
 948 }
 949
 950
 951 static int
 952 tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 953                u32 pid, int ovr)
 954 {
 955         int ret = 0;
 956         struct tc_action *act;
 957         struct tc_action *a;
 958         u32 seq = n->nlmsg_seq;
 959
 960         act = tcf_action_init(nla, NULL, NULL, ovr, 0);
 961         if (act == NULL)
 962                 goto done;
 963         if (IS_ERR(act)) {
 964                 ret = PTR_ERR(act);
 965                 goto done;
 966         }
 967
 968         /* dump then free all the actions after update; inserted policy
 969          * stays intact
 970          * */
 971         ret = tcf_add_notify(net, act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
 972         for (a = act; a; a = act) {
 973                 act = a->next;
 974                 kfree(a);
 975         }
 976 done:
 977         return ret;
 978 }
 979
 980 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 981 {
 982         struct net *net = sock_net(skb->sk);
 983         struct nlattr *tca[TCA_ACT_MAX + 1];
 984         u32 pid = skb ? NETLINK_CB(skb).pid : 0;
 985         int ret = 0, ovr = 0;
 986
 987         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
 988         if (ret < 0)
 989                 return ret;
 990
 991         if (tca[TCA_ACT_TAB] == NULL) {
 992                 pr_notice("tc_ctl_action: received NO action attribs\n");
 993                 return -EINVAL;
 994         }
 995
 996         /* n->nlmsg_flags&NLM_F_CREATE
 997          * */
 998         switch (n->nlmsg_type) {
 999         case RTM_NEWACTION:
1000                 /* we are going to assume all other flags
1001                  * imply create only if it doesnt 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
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);