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