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