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         write_lock(&act_mod_lock);
 278         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
 279                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 280                         write_unlock(&act_mod_lock);
 281                         return -EEXIST;
 282                 }
 283         }
 284         act->next = NULL;
 285         *ap = act;
 286         write_unlock(&act_mod_lock);
 287         return 0;
 288 }
 289 EXPORT_SYMBOL(tcf_register_action);
 290
 291 int tcf_unregister_action(struct tc_action_ops *act)
 292 {
 293         struct tc_action_ops *a, **ap;
 294         int err = -ENOENT;
 295
 296         write_lock(&act_mod_lock);
 297         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
 298                 if (a == act)
 299                         break;
 300         if (a) {
 301                 *ap = a->next;
 302                 a->next = NULL;
 303                 err = 0;
 304         }
 305         write_unlock(&act_mod_lock);
 306         return err;
 307 }
 308 EXPORT_SYMBOL(tcf_unregister_action);
 309
 310 /* lookup by name */
 311 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 312 {
 313         struct tc_action_ops *a = NULL;
 314
 315         if (kind) {
 316                 read_lock(&act_mod_lock);
 317                 for (a = act_base; a; a = a->next) {
 318                         if (strcmp(kind, a->kind) == 0) {
 319                                 if (!try_module_get(a->owner)) {
 320                                         read_unlock(&act_mod_lock);
 321                                         return NULL;
 322                                 }
 323                                 break;
 324                         }
 325                 }
 326                 read_unlock(&act_mod_lock);
 327         }
 328         return a;
 329 }
 330
 331 /* lookup by nlattr */
 332 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 333 {
 334         struct tc_action_ops *a = NULL;
 335
 336         if (kind) {
 337                 read_lock(&act_mod_lock);
 338                 for (a = act_base; a; a = a->next) {
 339                         if (nla_strcmp(kind, a->kind) == 0) {
 340                                 if (!try_module_get(a->owner)) {
 341                                         read_unlock(&act_mod_lock);
 342                                         return NULL;
 343                                 }
 344                                 break;
 345                         }
 346                 }
 347                 read_unlock(&act_mod_lock);
 348         }
 349         return a;
 350 }
 351
 352 #if 0
 353 /* lookup by id */
 354 static struct tc_action_ops *tc_lookup_action_id(u32 type)
 355 {
 356         struct tc_action_ops *a = NULL;
 357
 358         if (type) {
 359                 read_lock(&act_mod_lock);
 360                 for (a = act_base; a; a = a->next) {
 361                         if (a->type == type) {
 362                                 if (!try_module_get(a->owner)) {
 363                                         read_unlock(&act_mod_lock);
 364                                         return NULL;
 365                                 }
 366                                 break;
 367                         }
 368                 }
 369                 read_unlock(&act_mod_lock);
 370         }
 371         return a;
 372 }
 373 #endif
 374
 375 int tcf_action_exec(struct sk_buff *skb, const struct tc_action *act,
 376                     struct tcf_result *res)
 377 {
 378         const struct tc_action *a;
 379         int ret = -1;
 380
 381         if (skb->tc_verd & TC_NCLS) {
 382                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 383                 ret = TC_ACT_OK;
 384                 goto exec_done;
 385         }
 386         while ((a = act) != NULL) {
 387 repeat:
 388                 if (a->ops) {
 389                         ret = a->ops->act(skb, a, res);
 390                         if (TC_MUNGED & skb->tc_verd) {
 391                                 /* copied already, allow trampling */
 392                                 skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
 393                                 skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
 394                         }
 395                         if (ret == TC_ACT_REPEAT)
 396                                 goto repeat;    /* we need a ttl - JHS */
 397                         if (ret != TC_ACT_PIPE)
 398                                 goto exec_done;
 399                 }
 400                 act = a->next;
 401         }
 402 exec_done:
 403         return ret;
 404 }
 405 EXPORT_SYMBOL(tcf_action_exec);
 406
 407 void tcf_action_destroy(struct tc_action *act, int bind)
 408 {
 409         struct tc_action *a;
 410
 411         for (a = act; a; a = act) {
 412                 if (a->ops) {
 413                         if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
 414                                 module_put(a->ops->owner);
 415                         act = act->next;
 416                         kfree(a);
 417                 } else {
 418                         /*FIXME: Remove later - catch insertion bugs*/
 419                         WARN(1, "tcf_action_destroy: BUG? destroying NULL ops\n");
 420                         act = act->next;
 421                         kfree(a);
 422                 }
 423         }
 424 }
 425
 426 int
 427 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 428 {
 429         int err = -EINVAL;
 430
 431         if (a->ops == NULL)
 432                 return err;
 433         return a->ops->dump(skb, a, bind, ref);
 434 }
 435
 436 int
 437 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 438 {
 439         int err = -EINVAL;
 440         unsigned char *b = skb_tail_pointer(skb);
 441         struct nlattr *nest;
 442
 443         if (a->ops == NULL)
 444                 return err;
 445
 446         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 447                 goto nla_put_failure;
 448         if (tcf_action_copy_stats(skb, a, 0))
 449                 goto nla_put_failure;
 450         nest = nla_nest_start(skb, TCA_OPTIONS);
 451         if (nest == NULL)
 452                 goto nla_put_failure;
 453         err = tcf_action_dump_old(skb, a, bind, ref);
 454         if (err > 0) {
 455                 nla_nest_end(skb, nest);
 456                 return err;
 457         }
 458
 459 nla_put_failure:
 460         nlmsg_trim(skb, b);
 461         return -1;
 462 }
 463 EXPORT_SYMBOL(tcf_action_dump_1);
 464
 465 int
 466 tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
 467 {
 468         struct tc_action *a;
 469         int err = -EINVAL;
 470         struct nlattr *nest;
 471
 472         while ((a = act) != NULL) {
 473                 act = a->next;
 474                 nest = nla_nest_start(skb, a->order);
 475                 if (nest == NULL)
 476                         goto nla_put_failure;
 477                 err = tcf_action_dump_1(skb, a, bind, ref);
 478                 if (err < 0)
 479                         goto errout;
 480                 nla_nest_end(skb, nest);
 481         }
 482
 483         return 0;
 484
 485 nla_put_failure:
 486         err = -EINVAL;
 487 errout:
 488         nla_nest_cancel(skb, nest);
 489         return err;
 490 }
 491
 492 struct tc_action *tcf_action_init_1(struct net *net, struct nlattr *nla,
 493                                     struct nlattr *est, char *name, int ovr,
 494                                     int bind)
 495 {
 496         struct tc_action *a;
 497         struct tc_action_ops *a_o;
 498         char act_name[IFNAMSIZ];
 499         struct nlattr *tb[TCA_ACT_MAX + 1];
 500         struct nlattr *kind;
 501         int err;
 502
 503         if (name == NULL) {
 504                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 505                 if (err < 0)
 506                         goto err_out;
 507                 err = -EINVAL;
 508                 kind = tb[TCA_ACT_KIND];
 509                 if (kind == NULL)
 510                         goto err_out;
 511                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 512                         goto err_out;
 513         } else {
 514                 err = -EINVAL;
 515                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 516                         goto err_out;
 517         }
 518
 519         a_o = tc_lookup_action_n(act_name);
 520         if (a_o == NULL) {
 521 #ifdef CONFIG_MODULES
 522                 rtnl_unlock();
 523                 request_module("act_%s", act_name);
 524                 rtnl_lock();
 525
 526                 a_o = tc_lookup_action_n(act_name);
 527
 528                 /* We dropped the RTNL semaphore in order to
 529                  * perform the module load.  So, even if we
 530                  * succeeded in loading the module we have to
 531                  * tell the caller to replay the request.  We
 532                  * indicate this using -EAGAIN.
 533                  */
 534                 if (a_o != NULL) {
 535                         err = -EAGAIN;
 536                         goto err_mod;
 537                 }
 538 #endif
 539                 err = -ENOENT;
 540                 goto err_out;
 541         }
 542
 543         err = -ENOMEM;
 544         a = kzalloc(sizeof(*a), GFP_KERNEL);
 545         if (a == NULL)
 546                 goto err_mod;
 547
 548         /* backward compatibility for policer */
 549         if (name == NULL)
 550                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
 551         else
 552                 err = a_o->init(net, nla, est, a, ovr, bind);
 553         if (err < 0)
 554                 goto err_free;
 555
 556         /* module count goes up only when brand new policy is created
 557          * if it exists and is only bound to in a_o->init() then
 558          * ACT_P_CREATED is not returned (a zero is).
 559          */
 560         if (err != ACT_P_CREATED)
 561                 module_put(a_o->owner);
 562         a->ops = a_o;
 563
 564         return a;
 565
 566 err_free:
 567         kfree(a);
 568 err_mod:
 569         module_put(a_o->owner);
 570 err_out:
 571         return ERR_PTR(err);
 572 }
 573
 574 struct tc_action *tcf_action_init(struct net *net, struct nlattr *nla,
 575                                   struct nlattr *est, char *name, int ovr,
 576                                   int bind)
 577 {
 578         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 579         struct tc_action *head = NULL, *act, *act_prev = NULL;
 580         int err;
 581         int i;
 582
 583         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 584         if (err < 0)
 585                 return ERR_PTR(err);
 586
 587         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 588                 act = tcf_action_init_1(net, tb[i], est, name, ovr, bind);
 589                 if (IS_ERR(act))
 590                         goto err;
 591                 act->order = i;
 592
 593                 if (head == NULL)
 594                         head = act;
 595                 else
 596                         act_prev->next = act;
 597                 act_prev = act;
 598         }
 599         return head;
 600
 601 err:
 602         if (head != NULL)
 603                 tcf_action_destroy(head, bind);
 604         return act;
 605 }
 606
 607 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 608                           int compat_mode)
 609 {
 610         int err = 0;
 611         struct gnet_dump d;
 612         struct tcf_act_hdr *h = a->priv;
 613
 614         if (h == NULL)
 615                 goto errout;
 616
 617         /* compat_mode being true specifies a call that is supposed
 618          * to add additional backward compatibility statistic TLVs.
 619          */
 620         if (compat_mode) {
 621                 if (a->type == TCA_OLD_COMPAT)
 622                         err = gnet_stats_start_copy_compat(skb, 0,
 623                                 TCA_STATS, TCA_XSTATS, &h->tcf_lock, &d);
 624                 else
 625                         return 0;
 626         } else
 627                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 628                                             &h->tcf_lock, &d);
 629
 630         if (err < 0)
 631                 goto errout;
 632
 633         if (a->ops != NULL && a->ops->get_stats != NULL)
 634                 if (a->ops->get_stats(skb, a) < 0)
 635                         goto errout;
 636
 637         if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
 638             gnet_stats_copy_rate_est(&d, &h->tcf_bstats,
 639                                      &h->tcf_rate_est) < 0 ||
 640             gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
 641                 goto errout;
 642
 643         if (gnet_stats_finish_copy(&d) < 0)
 644                 goto errout;
 645
 646         return 0;
 647
 648 errout:
 649         return -1;
 650 }
 651
 652 static int
 653 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 portid, u32 seq,
 654              u16 flags, int event, int bind, int ref)
 655 {
 656         struct tcamsg *t;
 657         struct nlmsghdr *nlh;
 658         unsigned char *b = skb_tail_pointer(skb);
 659         struct nlattr *nest;
 660
 661         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
 662         if (!nlh)
 663                 goto out_nlmsg_trim;
 664         t = nlmsg_data(nlh);
 665         t->tca_family = AF_UNSPEC;
 666         t->tca__pad1 = 0;
 667         t->tca__pad2 = 0;
 668
 669         nest = nla_nest_start(skb, TCA_ACT_TAB);
 670         if (nest == NULL)
 671                 goto out_nlmsg_trim;
 672
 673         if (tcf_action_dump(skb, a, bind, ref) < 0)
 674                 goto out_nlmsg_trim;
 675
 676         nla_nest_end(skb, nest);
 677
 678         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 679         return skb->len;
 680
 681 out_nlmsg_trim:
 682         nlmsg_trim(skb, b);
 683         return -1;
 684 }
 685
 686 static int
 687 act_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
 688                struct tc_action *a, int event)
 689 {
 690         struct sk_buff *skb;
 691
 692         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 693         if (!skb)
 694                 return -ENOBUFS;
 695         if (tca_get_fill(skb, a, portid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 696                 kfree_skb(skb);
 697                 return -EINVAL;
 698         }
 699
 700         return rtnl_unicast(skb, net, portid);
 701 }
 702
 703 static struct tc_action *
 704 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 portid)
 705 {
 706         struct nlattr *tb[TCA_ACT_MAX + 1];
 707         struct tc_action *a;
 708         int index;
 709         int err;
 710
 711         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 712         if (err < 0)
 713                 goto err_out;
 714
 715         err = -EINVAL;
 716         if (tb[TCA_ACT_INDEX] == NULL ||
 717             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 718                 goto err_out;
 719         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 720
 721         err = -ENOMEM;
 722         a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
 723         if (a == NULL)
 724                 goto err_out;
 725
 726         err = -EINVAL;
 727         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 728         if (a->ops == NULL)
 729                 goto err_free;
 730         if (a->ops->lookup == NULL)
 731                 goto err_mod;
 732         err = -ENOENT;
 733         if (a->ops->lookup(a, index) == 0)
 734                 goto err_mod;
 735
 736         module_put(a->ops->owner);
 737         return a;
 738
 739 err_mod:
 740         module_put(a->ops->owner);
 741 err_free:
 742         kfree(a);
 743 err_out:
 744         return ERR_PTR(err);
 745 }
 746
 747 static void cleanup_a(struct tc_action *act)
 748 {
 749         struct tc_action *a;
 750
 751         for (a = act; a; a = act) {
 752                 act = a->next;
 753                 kfree(a);
 754         }
 755 }
 756
 757 static struct tc_action *create_a(int i)
 758 {
 759         struct tc_action *act;
 760
 761         act = kzalloc(sizeof(*act), GFP_KERNEL);
 762         if (act == NULL) {
 763                 pr_debug("create_a: failed to alloc!\n");
 764                 return NULL;
 765         }
 766         act->order = i;
 767         return act;
 768 }
 769
 770 static int tca_action_flush(struct net *net, struct nlattr *nla,
 771                             struct nlmsghdr *n, u32 portid)
 772 {
 773         struct sk_buff *skb;
 774         unsigned char *b;
 775         struct nlmsghdr *nlh;
 776         struct tcamsg *t;
 777         struct netlink_callback dcb;
 778         struct nlattr *nest;
 779         struct nlattr *tb[TCA_ACT_MAX + 1];
 780         struct nlattr *kind;
 781         struct tc_action *a = create_a(0);
 782         int err = -ENOMEM;
 783
 784         if (a == NULL) {
 785                 pr_debug("tca_action_flush: couldnt create tc_action\n");
 786                 return err;
 787         }
 788
 789         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 790         if (!skb) {
 791                 pr_debug("tca_action_flush: failed skb alloc\n");
 792                 kfree(a);
 793                 return err;
 794         }
 795
 796         b = skb_tail_pointer(skb);
 797
 798         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 799         if (err < 0)
 800                 goto err_out;
 801
 802         err = -EINVAL;
 803         kind = tb[TCA_ACT_KIND];
 804         a->ops = tc_lookup_action(kind);
 805         if (a->ops == NULL)
 806                 goto err_out;
 807
 808         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t), 0);
 809         if (!nlh)
 810                 goto out_module_put;
 811         t = nlmsg_data(nlh);
 812         t->tca_family = AF_UNSPEC;
 813         t->tca__pad1 = 0;
 814         t->tca__pad2 = 0;
 815
 816         nest = nla_nest_start(skb, TCA_ACT_TAB);
 817         if (nest == NULL)
 818                 goto out_module_put;
 819
 820         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 821         if (err < 0)
 822                 goto out_module_put;
 823         if (err == 0)
 824                 goto noflush_out;
 825
 826         nla_nest_end(skb, nest);
 827
 828         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 829         nlh->nlmsg_flags |= NLM_F_ROOT;
 830         module_put(a->ops->owner);
 831         kfree(a);
 832         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 833                              n->nlmsg_flags & NLM_F_ECHO);
 834         if (err > 0)
 835                 return 0;
 836
 837         return err;
 838
 839 out_module_put:
 840         module_put(a->ops->owner);
 841 err_out:
 842 noflush_out:
 843         kfree_skb(skb);
 844         kfree(a);
 845         return err;
 846 }
 847
 848 static int
 849 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 850               u32 portid, int event)
 851 {
 852         int i, ret;
 853         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 854         struct tc_action *head = NULL, *act, *act_prev = NULL;
 855
 856         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 857         if (ret < 0)
 858                 return ret;
 859
 860         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
 861                 if (tb[1] != NULL)
 862                         return tca_action_flush(net, tb[1], n, portid);
 863                 else
 864                         return -EINVAL;
 865         }
 866
 867         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 868                 act = tcf_action_get_1(tb[i], n, portid);
 869                 if (IS_ERR(act)) {
 870                         ret = PTR_ERR(act);
 871                         goto err;
 872                 }
 873                 act->order = i;
 874
 875                 if (head == NULL)
 876                         head = act;
 877                 else
 878                         act_prev->next = act;
 879                 act_prev = act;
 880         }
 881
 882         if (event == RTM_GETACTION)
 883                 ret = act_get_notify(net, portid, n, head, event);
 884         else { /* delete */
 885                 struct sk_buff *skb;
 886
 887                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 888                 if (!skb) {
 889                         ret = -ENOBUFS;
 890                         goto err;
 891                 }
 892
 893                 if (tca_get_fill(skb, head, portid, n->nlmsg_seq, 0, event,
 894                                  0, 1) <= 0) {
 895                         kfree_skb(skb);
 896                         ret = -EINVAL;
 897                         goto err;
 898                 }
 899
 900                 /* now do the delete */
 901                 tcf_action_destroy(head, 0);
 902                 ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 903                                      n->nlmsg_flags & NLM_F_ECHO);
 904                 if (ret > 0)
 905                         return 0;
 906                 return ret;
 907         }
 908 err:
 909         cleanup_a(head);
 910         return ret;
 911 }
 912
 913 static int tcf_add_notify(struct net *net, struct tc_action *a,
 914                           u32 portid, u32 seq, int event, u16 flags)
 915 {
 916         struct tcamsg *t;
 917         struct nlmsghdr *nlh;
 918         struct sk_buff *skb;
 919         struct nlattr *nest;
 920         unsigned char *b;
 921         int err = 0;
 922
 923         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 924         if (!skb)
 925                 return -ENOBUFS;
 926
 927         b = skb_tail_pointer(skb);
 928
 929         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
 930         if (!nlh)
 931                 goto out_kfree_skb;
 932         t = nlmsg_data(nlh);
 933         t->tca_family = AF_UNSPEC;
 934         t->tca__pad1 = 0;
 935         t->tca__pad2 = 0;
 936
 937         nest = nla_nest_start(skb, TCA_ACT_TAB);
 938         if (nest == NULL)
 939                 goto out_kfree_skb;
 940
 941         if (tcf_action_dump(skb, a, 0, 0) < 0)
 942                 goto out_kfree_skb;
 943
 944         nla_nest_end(skb, nest);
 945
 946         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 947         NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 948
 949         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
 950         if (err > 0)
 951                 err = 0;
 952         return err;
 953
 954 out_kfree_skb:
 955         kfree_skb(skb);
 956         return -1;
 957 }
 958
 959
 960 static int
 961 tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 962                u32 portid, int ovr)
 963 {
 964         int ret = 0;
 965         struct tc_action *act;
 966         struct tc_action *a;
 967         u32 seq = n->nlmsg_seq;
 968
 969         act = tcf_action_init(net, nla, NULL, NULL, ovr, 0);
 970         if (act == NULL)
 971                 goto done;
 972         if (IS_ERR(act)) {
 973                 ret = PTR_ERR(act);
 974                 goto done;
 975         }
 976
 977         /* dump then free all the actions after update; inserted policy
 978          * stays intact
 979          */
 980         ret = tcf_add_notify(net, act, portid, seq, RTM_NEWACTION, n->nlmsg_flags);
 981         for (a = act; a; a = act) {
 982                 act = a->next;
 983                 kfree(a);
 984         }
 985 done:
 986         return ret;
 987 }
 988
 989 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n)
 990 {
 991         struct net *net = sock_net(skb->sk);
 992         struct nlattr *tca[TCA_ACT_MAX + 1];
 993         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
 994         int ret = 0, ovr = 0;
 995
 996         if ((n->nlmsg_type != RTM_GETACTION) && !capable(CAP_NET_ADMIN))
 997                 return -EPERM;
 998
 999         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
1000         if (ret < 0)
1001                 return ret;
1002
1003         if (tca[TCA_ACT_TAB] == NULL) {
1004                 pr_notice("tc_ctl_action: received NO action attribs\n");
1005                 return -EINVAL;
1006         }
1007
1008         /* n->nlmsg_flags & NLM_F_CREATE */
1009         switch (n->nlmsg_type) {
1010         case RTM_NEWACTION:
1011                 /* we are going to assume all other flags
1012                  * imply create only if it doesn't exist
1013                  * Note that CREATE | EXCL implies that
1014                  * but since we want avoid ambiguity (eg when flags
1015                  * is zero) then just set this
1016                  */
1017                 if (n->nlmsg_flags & NLM_F_REPLACE)
1018                         ovr = 1;
1019 replay:
1020                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr);
1021                 if (ret == -EAGAIN)
1022                         goto replay;
1023                 break;
1024         case RTM_DELACTION:
1025                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1026                                     portid, RTM_DELACTION);
1027                 break;
1028         case RTM_GETACTION:
1029                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1030                                     portid, RTM_GETACTION);
1031                 break;
1032         default:
1033                 BUG();
1034         }
1035
1036         return ret;
1037 }
1038
1039 static struct nlattr *
1040 find_dump_kind(const struct nlmsghdr *n)
1041 {
1042         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1043         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1044         struct nlattr *nla[TCAA_MAX + 1];
1045         struct nlattr *kind;
1046
1047         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1048                 return NULL;
1049         tb1 = nla[TCA_ACT_TAB];
1050         if (tb1 == NULL)
1051                 return NULL;
1052
1053         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1054                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1055                 return NULL;
1056
1057         if (tb[1] == NULL)
1058                 return NULL;
1059         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1060                       nla_len(tb[1]), NULL) < 0)
1061                 return NULL;
1062         kind = tb2[TCA_ACT_KIND];
1063
1064         return kind;
1065 }
1066
1067 static int
1068 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1069 {
1070         struct nlmsghdr *nlh;
1071         unsigned char *b = skb_tail_pointer(skb);
1072         struct nlattr *nest;
1073         struct tc_action_ops *a_o;
1074         struct tc_action a;
1075         int ret = 0;
1076         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1077         struct nlattr *kind = find_dump_kind(cb->nlh);
1078
1079         if (kind == NULL) {
1080                 pr_info("tc_dump_action: action bad kind\n");
1081                 return 0;
1082         }
1083
1084         a_o = tc_lookup_action(kind);
1085         if (a_o == NULL)
1086                 return 0;
1087
1088         memset(&a, 0, sizeof(struct tc_action));
1089         a.ops = a_o;
1090
1091         if (a_o->walk == NULL) {
1092                 WARN(1, "tc_dump_action: %s !capable of dumping table\n",
1093                      a_o->kind);
1094                 goto out_module_put;
1095         }
1096
1097         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1098                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1099         if (!nlh)
1100                 goto out_module_put;
1101         t = nlmsg_data(nlh);
1102         t->tca_family = AF_UNSPEC;
1103         t->tca__pad1 = 0;
1104         t->tca__pad2 = 0;
1105
1106         nest = nla_nest_start(skb, TCA_ACT_TAB);
1107         if (nest == NULL)
1108                 goto out_module_put;
1109
1110         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1111         if (ret < 0)
1112                 goto out_module_put;
1113
1114         if (ret > 0) {
1115                 nla_nest_end(skb, nest);
1116                 ret = skb->len;
1117         } else
1118                 nla_nest_cancel(skb, nest);
1119
1120         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1121         if (NETLINK_CB(cb->skb).portid && ret)
1122                 nlh->nlmsg_flags |= NLM_F_MULTI;
1123         module_put(a_o->owner);
1124         return skb->len;
1125
1126 out_module_put:
1127         module_put(a_o->owner);
1128         nlmsg_trim(skb, b);
1129         return skb->len;
1130 }
1131
1132 static int __init tc_action_init(void)
1133 {
1134         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
1135         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
1136         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1137                       NULL);
1138
1139         return 0;
1140 }
1141
1142 subsys_initcall(tc_action_init);