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 static void free_tcf(struct rcu_head *head)
  31 {
  32         struct tcf_common *p = container_of(head, struct tcf_common, tcfc_rcu);
  33
  34         free_percpu(p->cpu_bstats);
  35         free_percpu(p->cpu_qstats);
  36         kfree(p);
  37 }
  38
  39 static void tcf_hash_destroy(struct tc_action *a)
  40 {
  41         struct tcf_common *p = a->priv;
  42         struct tcf_hashinfo *hinfo = a->ops->hinfo;
  43
  44         spin_lock_bh(&hinfo->lock);
  45         hlist_del(&p->tcfc_head);
  46         spin_unlock_bh(&hinfo->lock);
  47         gen_kill_estimator(&p->tcfc_bstats,
  48                            &p->tcfc_rate_est);
  49         /*
  50          * gen_estimator est_timer() might access p->tcfc_lock
  51          * or bstats, wait a RCU grace period before freeing p
  52          */
  53         call_rcu(&p->tcfc_rcu, free_tcf);
  54 }
  55
  56 int __tcf_hash_release(struct tc_action *a, bool bind, bool strict)
  57 {
  58         struct tcf_common *p = a->priv;
  59         int ret = 0;
  60
  61         if (p) {
  62                 if (bind)
  63                         p->tcfc_bindcnt--;
  64                 else if (strict && p->tcfc_bindcnt > 0)
  65                         return -EPERM;
  66
  67                 p->tcfc_refcnt--;
  68                 if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
  69                         if (a->ops->cleanup)
  70                                 a->ops->cleanup(a, bind);
  71                         tcf_hash_destroy(a);
  72                         ret = 1;
  73                 }
  74         }
  75
  76         return ret;
  77 }
  78 EXPORT_SYMBOL(__tcf_hash_release);
  79
  80 static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
  81                            struct tc_action *a)
  82 {
  83         struct tcf_hashinfo *hinfo = a->ops->hinfo;
  84         struct hlist_head *head;
  85         struct tcf_common *p;
  86         int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
  87         struct nlattr *nest;
  88
  89         spin_lock_bh(&hinfo->lock);
  90
  91         s_i = cb->args[0];
  92
  93         for (i = 0; i < (hinfo->hmask + 1); i++) {
  94                 head = &hinfo->htab[tcf_hash(i, hinfo->hmask)];
  95
  96                 hlist_for_each_entry_rcu(p, head, tcfc_head) {
  97                         index++;
  98                         if (index < s_i)
  99                                 continue;
 100                         a->priv = p;
 101                         a->order = n_i;
 102
 103                         nest = nla_nest_start(skb, a->order);
 104                         if (nest == NULL) {
 105                                 index--;
 106                                 goto nla_put_failure;
 107                         }
 108                         err = tcf_action_dump_1(skb, a, 0, 0);
 109                         if (err < 0) {
 110                                 index--;
 111                                 nlmsg_trim(skb, nest);
 112                                 goto done;
 113                         }
 114                         nla_nest_end(skb, nest);
 115                         n_i++;
 116                         if (n_i >= TCA_ACT_MAX_PRIO)
 117                                 goto done;
 118                 }
 119         }
 120 done:
 121         spin_unlock_bh(&hinfo->lock);
 122         if (n_i)
 123                 cb->args[0] += n_i;
 124         return n_i;
 125
 126 nla_put_failure:
 127         nla_nest_cancel(skb, nest);
 128         goto done;
 129 }
 130
 131 static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a)
 132 {
 133         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 134         struct hlist_head *head;
 135         struct hlist_node *n;
 136         struct tcf_common *p;
 137         struct nlattr *nest;
 138         int i = 0, n_i = 0;
 139         int ret = -EINVAL;
 140
 141         nest = nla_nest_start(skb, a->order);
 142         if (nest == NULL)
 143                 goto nla_put_failure;
 144         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 145                 goto nla_put_failure;
 146         for (i = 0; i < (hinfo->hmask + 1); i++) {
 147                 head = &hinfo->htab[tcf_hash(i, hinfo->hmask)];
 148                 hlist_for_each_entry_safe(p, n, head, tcfc_head) {
 149                         a->priv = p;
 150                         ret = __tcf_hash_release(a, false, true);
 151                         if (ret == ACT_P_DELETED) {
 152                                 module_put(a->ops->owner);
 153                                 n_i++;
 154                         } else if (ret < 0)
 155                                 goto nla_put_failure;
 156                 }
 157         }
 158         if (nla_put_u32(skb, TCA_FCNT, n_i))
 159                 goto nla_put_failure;
 160         nla_nest_end(skb, nest);
 161
 162         return n_i;
 163 nla_put_failure:
 164         nla_nest_cancel(skb, nest);
 165         return ret;
 166 }
 167
 168 static int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
 169                               int type, struct tc_action *a)
 170 {
 171         if (type == RTM_DELACTION) {
 172                 return tcf_del_walker(skb, a);
 173         } else if (type == RTM_GETACTION) {
 174                 return tcf_dump_walker(skb, cb, a);
 175         } else {
 176                 WARN(1, "tcf_generic_walker: unknown action %d\n", type);
 177                 return -EINVAL;
 178         }
 179 }
 180
 181 static struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 182 {
 183         struct tcf_common *p = NULL;
 184         struct hlist_head *head;
 185
 186         spin_lock_bh(&hinfo->lock);
 187         head = &hinfo->htab[tcf_hash(index, hinfo->hmask)];
 188         hlist_for_each_entry_rcu(p, head, tcfc_head)
 189                 if (p->tcfc_index == index)
 190                         break;
 191         spin_unlock_bh(&hinfo->lock);
 192
 193         return p;
 194 }
 195
 196 u32 tcf_hash_new_index(struct tcf_hashinfo *hinfo)
 197 {
 198         u32 val = hinfo->index;
 199
 200         do {
 201                 if (++val == 0)
 202                         val = 1;
 203         } while (tcf_hash_lookup(val, hinfo));
 204
 205         hinfo->index = val;
 206         return val;
 207 }
 208 EXPORT_SYMBOL(tcf_hash_new_index);
 209
 210 int tcf_hash_search(struct tc_action *a, u32 index)
 211 {
 212         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 213         struct tcf_common *p = tcf_hash_lookup(index, hinfo);
 214
 215         if (p) {
 216                 a->priv = p;
 217                 return 1;
 218         }
 219         return 0;
 220 }
 221 EXPORT_SYMBOL(tcf_hash_search);
 222
 223 int tcf_hash_check(u32 index, struct tc_action *a, int bind)
 224 {
 225         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 226         struct tcf_common *p = NULL;
 227         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 228                 if (bind)
 229                         p->tcfc_bindcnt++;
 230                 p->tcfc_refcnt++;
 231                 a->priv = p;
 232                 return 1;
 233         }
 234         return 0;
 235 }
 236 EXPORT_SYMBOL(tcf_hash_check);
 237
 238 void tcf_hash_cleanup(struct tc_action *a, struct nlattr *est)
 239 {
 240         struct tcf_common *pc = a->priv;
 241         if (est)
 242                 gen_kill_estimator(&pc->tcfc_bstats,
 243                                    &pc->tcfc_rate_est);
 244         call_rcu(&pc->tcfc_rcu, free_tcf);
 245 }
 246 EXPORT_SYMBOL(tcf_hash_cleanup);
 247
 248 int tcf_hash_create(u32 index, struct nlattr *est, struct tc_action *a,
 249                     int size, int bind, bool cpustats)
 250 {
 251         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 252         struct tcf_common *p = kzalloc(size, GFP_KERNEL);
 253         int err = -ENOMEM;
 254
 255         if (unlikely(!p))
 256                 return -ENOMEM;
 257         p->tcfc_refcnt = 1;
 258         if (bind)
 259                 p->tcfc_bindcnt = 1;
 260
 261         if (cpustats) {
 262                 p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
 263                 if (!p->cpu_bstats) {
 264 err1:
 265                         kfree(p);
 266                         return err;
 267                 }
 268                 p->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
 269                 if (!p->cpu_qstats) {
 270 err2:
 271                         free_percpu(p->cpu_bstats);
 272                         goto err1;
 273                 }
 274         }
 275         spin_lock_init(&p->tcfc_lock);
 276         INIT_HLIST_NODE(&p->tcfc_head);
 277         p->tcfc_index = index ? index : tcf_hash_new_index(hinfo);
 278         p->tcfc_tm.install = jiffies;
 279         p->tcfc_tm.lastuse = jiffies;
 280         if (est) {
 281                 err = gen_new_estimator(&p->tcfc_bstats, p->cpu_bstats,
 282                                         &p->tcfc_rate_est,
 283                                         &p->tcfc_lock, est);
 284                 if (err) {
 285                         free_percpu(p->cpu_qstats);
 286                         goto err2;
 287                 }
 288         }
 289
 290         a->priv = (void *) p;
 291         return 0;
 292 }
 293 EXPORT_SYMBOL(tcf_hash_create);
 294
 295 void tcf_hash_insert(struct tc_action *a)
 296 {
 297         struct tcf_common *p = a->priv;
 298         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 299         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
 300
 301         spin_lock_bh(&hinfo->lock);
 302         hlist_add_head(&p->tcfc_head, &hinfo->htab[h]);
 303         spin_unlock_bh(&hinfo->lock);
 304 }
 305 EXPORT_SYMBOL(tcf_hash_insert);
 306
 307 static LIST_HEAD(act_base);
 308 static DEFINE_RWLOCK(act_mod_lock);
 309
 310 int tcf_register_action(struct tc_action_ops *act, unsigned int mask)
 311 {
 312         struct tc_action_ops *a;
 313         int err;
 314
 315         /* Must supply act, dump and init */
 316         if (!act->act || !act->dump || !act->init)
 317                 return -EINVAL;
 318
 319         /* Supply defaults */
 320         if (!act->lookup)
 321                 act->lookup = tcf_hash_search;
 322         if (!act->walk)
 323                 act->walk = tcf_generic_walker;
 324
 325         act->hinfo = kmalloc(sizeof(struct tcf_hashinfo), GFP_KERNEL);
 326         if (!act->hinfo)
 327                 return -ENOMEM;
 328         err = tcf_hashinfo_init(act->hinfo, mask);
 329         if (err) {
 330                 kfree(act->hinfo);
 331                 return err;
 332         }
 333
 334         write_lock(&act_mod_lock);
 335         list_for_each_entry(a, &act_base, head) {
 336                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 337                         write_unlock(&act_mod_lock);
 338                         tcf_hashinfo_destroy(act->hinfo);
 339                         kfree(act->hinfo);
 340                         return -EEXIST;
 341                 }
 342         }
 343         list_add_tail(&act->head, &act_base);
 344         write_unlock(&act_mod_lock);
 345         return 0;
 346 }
 347 EXPORT_SYMBOL(tcf_register_action);
 348
 349 int tcf_unregister_action(struct tc_action_ops *act)
 350 {
 351         struct tc_action_ops *a;
 352         int err = -ENOENT;
 353
 354         write_lock(&act_mod_lock);
 355         list_for_each_entry(a, &act_base, head) {
 356                 if (a == act) {
 357                         list_del(&act->head);
 358                         tcf_hashinfo_destroy(act->hinfo);
 359                         kfree(act->hinfo);
 360                         err = 0;
 361                         break;
 362                 }
 363         }
 364         write_unlock(&act_mod_lock);
 365         return err;
 366 }
 367 EXPORT_SYMBOL(tcf_unregister_action);
 368
 369 /* lookup by name */
 370 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 371 {
 372         struct tc_action_ops *a, *res = NULL;
 373
 374         if (kind) {
 375                 read_lock(&act_mod_lock);
 376                 list_for_each_entry(a, &act_base, head) {
 377                         if (strcmp(kind, a->kind) == 0) {
 378                                 if (try_module_get(a->owner))
 379                                         res = a;
 380                                 break;
 381                         }
 382                 }
 383                 read_unlock(&act_mod_lock);
 384         }
 385         return res;
 386 }
 387
 388 /* lookup by nlattr */
 389 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 390 {
 391         struct tc_action_ops *a, *res = NULL;
 392
 393         if (kind) {
 394                 read_lock(&act_mod_lock);
 395                 list_for_each_entry(a, &act_base, head) {
 396                         if (nla_strcmp(kind, a->kind) == 0) {
 397                                 if (try_module_get(a->owner))
 398                                         res = a;
 399                                 break;
 400                         }
 401                 }
 402                 read_unlock(&act_mod_lock);
 403         }
 404         return res;
 405 }
 406
 407 int tcf_action_exec(struct sk_buff *skb, const struct list_head *actions,
 408                     struct tcf_result *res)
 409 {
 410         const struct tc_action *a;
 411         int ret = -1;
 412
 413         if (skb->tc_verd & TC_NCLS) {
 414                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 415                 ret = TC_ACT_OK;
 416                 goto exec_done;
 417         }
 418         list_for_each_entry(a, actions, list) {
 419 repeat:
 420                 ret = a->ops->act(skb, a, res);
 421                 if (ret == TC_ACT_REPEAT)
 422                         goto repeat;    /* we need a ttl - JHS */
 423                 if (ret != TC_ACT_PIPE)
 424                         goto exec_done;
 425         }
 426 exec_done:
 427         return ret;
 428 }
 429 EXPORT_SYMBOL(tcf_action_exec);
 430
 431 int tcf_action_destroy(struct list_head *actions, int bind)
 432 {
 433         struct tc_action *a, *tmp;
 434         int ret = 0;
 435
 436         list_for_each_entry_safe(a, tmp, actions, list) {
 437                 ret = __tcf_hash_release(a, bind, true);
 438                 if (ret == ACT_P_DELETED)
 439                         module_put(a->ops->owner);
 440                 else if (ret < 0)
 441                         return ret;
 442                 list_del(&a->list);
 443                 kfree(a);
 444         }
 445         return ret;
 446 }
 447
 448 int
 449 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 450 {
 451         return a->ops->dump(skb, a, bind, ref);
 452 }
 453
 454 int
 455 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 456 {
 457         int err = -EINVAL;
 458         unsigned char *b = skb_tail_pointer(skb);
 459         struct nlattr *nest;
 460
 461         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 462                 goto nla_put_failure;
 463         if (tcf_action_copy_stats(skb, a, 0))
 464                 goto nla_put_failure;
 465         nest = nla_nest_start(skb, TCA_OPTIONS);
 466         if (nest == NULL)
 467                 goto nla_put_failure;
 468         err = tcf_action_dump_old(skb, a, bind, ref);
 469         if (err > 0) {
 470                 nla_nest_end(skb, nest);
 471                 return err;
 472         }
 473
 474 nla_put_failure:
 475         nlmsg_trim(skb, b);
 476         return -1;
 477 }
 478 EXPORT_SYMBOL(tcf_action_dump_1);
 479
 480 int
 481 tcf_action_dump(struct sk_buff *skb, struct list_head *actions, int bind, int ref)
 482 {
 483         struct tc_action *a;
 484         int err = -EINVAL;
 485         struct nlattr *nest;
 486
 487         list_for_each_entry(a, actions, list) {
 488                 nest = nla_nest_start(skb, a->order);
 489                 if (nest == NULL)
 490                         goto nla_put_failure;
 491                 err = tcf_action_dump_1(skb, a, bind, ref);
 492                 if (err < 0)
 493                         goto errout;
 494                 nla_nest_end(skb, nest);
 495         }
 496
 497         return 0;
 498
 499 nla_put_failure:
 500         err = -EINVAL;
 501 errout:
 502         nla_nest_cancel(skb, nest);
 503         return err;
 504 }
 505
 506 struct tc_action *tcf_action_init_1(struct net *net, struct nlattr *nla,
 507                                     struct nlattr *est, char *name, int ovr,
 508                                     int bind)
 509 {
 510         struct tc_action *a;
 511         struct tc_action_ops *a_o;
 512         char act_name[IFNAMSIZ];
 513         struct nlattr *tb[TCA_ACT_MAX + 1];
 514         struct nlattr *kind;
 515         int err;
 516
 517         if (name == NULL) {
 518                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 519                 if (err < 0)
 520                         goto err_out;
 521                 err = -EINVAL;
 522                 kind = tb[TCA_ACT_KIND];
 523                 if (kind == NULL)
 524                         goto err_out;
 525                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 526                         goto err_out;
 527         } else {
 528                 err = -EINVAL;
 529                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 530                         goto err_out;
 531         }
 532
 533         a_o = tc_lookup_action_n(act_name);
 534         if (a_o == NULL) {
 535 #ifdef CONFIG_MODULES
 536                 rtnl_unlock();
 537                 request_module("act_%s", act_name);
 538                 rtnl_lock();
 539
 540                 a_o = tc_lookup_action_n(act_name);
 541
 542                 /* We dropped the RTNL semaphore in order to
 543                  * perform the module load.  So, even if we
 544                  * succeeded in loading the module we have to
 545                  * tell the caller to replay the request.  We
 546                  * indicate this using -EAGAIN.
 547                  */
 548                 if (a_o != NULL) {
 549                         err = -EAGAIN;
 550                         goto err_mod;
 551                 }
 552 #endif
 553                 err = -ENOENT;
 554                 goto err_out;
 555         }
 556
 557         err = -ENOMEM;
 558         a = kzalloc(sizeof(*a), GFP_KERNEL);
 559         if (a == NULL)
 560                 goto err_mod;
 561
 562         a->ops = a_o;
 563         INIT_LIST_HEAD(&a->list);
 564         /* backward compatibility for policer */
 565         if (name == NULL)
 566                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
 567         else
 568                 err = a_o->init(net, nla, est, a, ovr, bind);
 569         if (err < 0)
 570                 goto err_free;
 571
 572         /* module count goes up only when brand new policy is created
 573          * if it exists and is only bound to in a_o->init() then
 574          * ACT_P_CREATED is not returned (a zero is).
 575          */
 576         if (err != ACT_P_CREATED)
 577                 module_put(a_o->owner);
 578
 579         return a;
 580
 581 err_free:
 582         kfree(a);
 583 err_mod:
 584         module_put(a_o->owner);
 585 err_out:
 586         return ERR_PTR(err);
 587 }
 588
 589 int tcf_action_init(struct net *net, struct nlattr *nla,
 590                                   struct nlattr *est, char *name, int ovr,
 591                                   int bind, struct list_head *actions)
 592 {
 593         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 594         struct tc_action *act;
 595         int err;
 596         int i;
 597
 598         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 599         if (err < 0)
 600                 return err;
 601
 602         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 603                 act = tcf_action_init_1(net, tb[i], est, name, ovr, bind);
 604                 if (IS_ERR(act)) {
 605                         err = PTR_ERR(act);
 606                         goto err;
 607                 }
 608                 act->order = i;
 609                 list_add_tail(&act->list, actions);
 610         }
 611         return 0;
 612
 613 err:
 614         tcf_action_destroy(actions, bind);
 615         return err;
 616 }
 617
 618 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 619                           int compat_mode)
 620 {
 621         int err = 0;
 622         struct gnet_dump d;
 623         struct tcf_common *p = a->priv;
 624
 625         if (p == NULL)
 626                 goto errout;
 627
 628         /* compat_mode being true specifies a call that is supposed
 629          * to add additional backward compatibility statistic TLVs.
 630          */
 631         if (compat_mode) {
 632                 if (a->type == TCA_OLD_COMPAT)
 633                         err = gnet_stats_start_copy_compat(skb, 0,
 634                                 TCA_STATS, TCA_XSTATS, &p->tcfc_lock, &d);
 635                 else
 636                         return 0;
 637         } else
 638                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 639                                             &p->tcfc_lock, &d);
 640
 641         if (err < 0)
 642                 goto errout;
 643
 644         if (gnet_stats_copy_basic(&d, p->cpu_bstats, &p->tcfc_bstats) < 0 ||
 645             gnet_stats_copy_rate_est(&d, &p->tcfc_bstats,
 646                                      &p->tcfc_rate_est) < 0 ||
 647             gnet_stats_copy_queue(&d, p->cpu_qstats,
 648                                   &p->tcfc_qstats,
 649                                   p->tcfc_qstats.qlen) < 0)
 650                 goto errout;
 651
 652         if (gnet_stats_finish_copy(&d) < 0)
 653                 goto errout;
 654
 655         return 0;
 656
 657 errout:
 658         return -1;
 659 }
 660
 661 static int
 662 tca_get_fill(struct sk_buff *skb, struct list_head *actions, u32 portid, u32 seq,
 663              u16 flags, int event, int bind, int ref)
 664 {
 665         struct tcamsg *t;
 666         struct nlmsghdr *nlh;
 667         unsigned char *b = skb_tail_pointer(skb);
 668         struct nlattr *nest;
 669
 670         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
 671         if (!nlh)
 672                 goto out_nlmsg_trim;
 673         t = nlmsg_data(nlh);
 674         t->tca_family = AF_UNSPEC;
 675         t->tca__pad1 = 0;
 676         t->tca__pad2 = 0;
 677
 678         nest = nla_nest_start(skb, TCA_ACT_TAB);
 679         if (nest == NULL)
 680                 goto out_nlmsg_trim;
 681
 682         if (tcf_action_dump(skb, actions, bind, ref) < 0)
 683                 goto out_nlmsg_trim;
 684
 685         nla_nest_end(skb, nest);
 686
 687         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 688         return skb->len;
 689
 690 out_nlmsg_trim:
 691         nlmsg_trim(skb, b);
 692         return -1;
 693 }
 694
 695 static int
 696 act_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
 697                struct list_head *actions, int event)
 698 {
 699         struct sk_buff *skb;
 700
 701         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 702         if (!skb)
 703                 return -ENOBUFS;
 704         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 705                 kfree_skb(skb);
 706                 return -EINVAL;
 707         }
 708
 709         return rtnl_unicast(skb, net, portid);
 710 }
 711
 712 static struct tc_action *create_a(int i)
 713 {
 714         struct tc_action *act;
 715
 716         act = kzalloc(sizeof(*act), GFP_KERNEL);
 717         if (act == NULL) {
 718                 pr_debug("create_a: failed to alloc!\n");
 719                 return NULL;
 720         }
 721         act->order = i;
 722         INIT_LIST_HEAD(&act->list);
 723         return act;
 724 }
 725
 726 static struct tc_action *
 727 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 portid)
 728 {
 729         struct nlattr *tb[TCA_ACT_MAX + 1];
 730         struct tc_action *a;
 731         int index;
 732         int err;
 733
 734         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 735         if (err < 0)
 736                 goto err_out;
 737
 738         err = -EINVAL;
 739         if (tb[TCA_ACT_INDEX] == NULL ||
 740             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 741                 goto err_out;
 742         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 743
 744         err = -ENOMEM;
 745         a = create_a(0);
 746         if (a == NULL)
 747                 goto err_out;
 748
 749         err = -EINVAL;
 750         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 751         if (a->ops == NULL) /* could happen in batch of actions */
 752                 goto err_free;
 753         err = -ENOENT;
 754         if (a->ops->lookup(a, index) == 0)
 755                 goto err_mod;
 756
 757         module_put(a->ops->owner);
 758         return a;
 759
 760 err_mod:
 761         module_put(a->ops->owner);
 762 err_free:
 763         kfree(a);
 764 err_out:
 765         return ERR_PTR(err);
 766 }
 767
 768 static void cleanup_a(struct list_head *actions)
 769 {
 770         struct tc_action *a, *tmp;
 771
 772         list_for_each_entry_safe(a, tmp, actions, list) {
 773                 list_del(&a->list);
 774                 kfree(a);
 775         }
 776 }
 777
 778 static int tca_action_flush(struct net *net, struct nlattr *nla,
 779                             struct nlmsghdr *n, u32 portid)
 780 {
 781         struct sk_buff *skb;
 782         unsigned char *b;
 783         struct nlmsghdr *nlh;
 784         struct tcamsg *t;
 785         struct netlink_callback dcb;
 786         struct nlattr *nest;
 787         struct nlattr *tb[TCA_ACT_MAX + 1];
 788         struct nlattr *kind;
 789         struct tc_action a;
 790         int err = -ENOMEM;
 791
 792         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 793         if (!skb) {
 794                 pr_debug("tca_action_flush: failed skb alloc\n");
 795                 return err;
 796         }
 797
 798         b = skb_tail_pointer(skb);
 799
 800         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 801         if (err < 0)
 802                 goto err_out;
 803
 804         err = -EINVAL;
 805         kind = tb[TCA_ACT_KIND];
 806         memset(&a, 0, sizeof(struct tc_action));
 807         INIT_LIST_HEAD(&a.list);
 808         a.ops = tc_lookup_action(kind);
 809         if (a.ops == NULL) /*some idjot trying to flush unknown action */
 810                 goto err_out;
 811
 812         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t), 0);
 813         if (!nlh)
 814                 goto out_module_put;
 815         t = nlmsg_data(nlh);
 816         t->tca_family = AF_UNSPEC;
 817         t->tca__pad1 = 0;
 818         t->tca__pad2 = 0;
 819
 820         nest = nla_nest_start(skb, TCA_ACT_TAB);
 821         if (nest == NULL)
 822                 goto out_module_put;
 823
 824         err = a.ops->walk(skb, &dcb, RTM_DELACTION, &a);
 825         if (err <= 0)
 826                 goto out_module_put;
 827
 828         nla_nest_end(skb, nest);
 829
 830         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 831         nlh->nlmsg_flags |= NLM_F_ROOT;
 832         module_put(a.ops->owner);
 833         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 834                              n->nlmsg_flags & NLM_F_ECHO);
 835         if (err > 0)
 836                 return 0;
 837
 838         return err;
 839
 840 out_module_put:
 841         module_put(a.ops->owner);
 842 err_out:
 843         kfree_skb(skb);
 844         return err;
 845 }
 846
 847 static int
 848 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
 849                u32 portid)
 850 {
 851         int ret;
 852         struct sk_buff *skb;
 853
 854         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 855         if (!skb)
 856                 return -ENOBUFS;
 857
 858         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
 859                          0, 1) <= 0) {
 860                 kfree_skb(skb);
 861                 return -EINVAL;
 862         }
 863
 864         /* now do the delete */
 865         ret = tcf_action_destroy(actions, 0);
 866         if (ret < 0) {
 867                 kfree_skb(skb);
 868                 return ret;
 869         }
 870
 871         ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 872                              n->nlmsg_flags & NLM_F_ECHO);
 873         if (ret > 0)
 874                 return 0;
 875         return ret;
 876 }
 877
 878 static int
 879 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 880               u32 portid, int event)
 881 {
 882         int i, ret;
 883         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 884         struct tc_action *act;
 885         LIST_HEAD(actions);
 886
 887         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 888         if (ret < 0)
 889                 return ret;
 890
 891         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
 892                 if (tb[1] != NULL)
 893                         return tca_action_flush(net, tb[1], n, portid);
 894                 else
 895                         return -EINVAL;
 896         }
 897
 898         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 899                 act = tcf_action_get_1(tb[i], n, portid);
 900                 if (IS_ERR(act)) {
 901                         ret = PTR_ERR(act);
 902                         goto err;
 903                 }
 904                 act->order = i;
 905                 list_add_tail(&act->list, &actions);
 906         }
 907
 908         if (event == RTM_GETACTION)
 909                 ret = act_get_notify(net, portid, n, &actions, event);
 910         else { /* delete */
 911                 ret = tcf_del_notify(net, n, &actions, portid);
 912                 if (ret)
 913                         goto err;
 914                 return ret;
 915         }
 916 err:
 917         cleanup_a(&actions);
 918         return ret;
 919 }
 920
 921 static int
 922 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
 923                u32 portid)
 924 {
 925         struct sk_buff *skb;
 926         int err = 0;
 927
 928         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 929         if (!skb)
 930                 return -ENOBUFS;
 931
 932         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
 933                          RTM_NEWACTION, 0, 0) <= 0) {
 934                 kfree_skb(skb);
 935                 return -EINVAL;
 936         }
 937
 938         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 939                              n->nlmsg_flags & NLM_F_ECHO);
 940         if (err > 0)
 941                 err = 0;
 942         return err;
 943 }
 944
 945 static int
 946 tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 947                u32 portid, int ovr)
 948 {
 949         int ret = 0;
 950         LIST_HEAD(actions);
 951
 952         ret = tcf_action_init(net, nla, NULL, NULL, ovr, 0, &actions);
 953         if (ret)
 954                 goto done;
 955
 956         /* dump then free all the actions after update; inserted policy
 957          * stays intact
 958          */
 959         ret = tcf_add_notify(net, n, &actions, portid);
 960         cleanup_a(&actions);
 961 done:
 962         return ret;
 963 }
 964
 965 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n)
 966 {
 967         struct net *net = sock_net(skb->sk);
 968         struct nlattr *tca[TCA_ACT_MAX + 1];
 969         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
 970         int ret = 0, ovr = 0;
 971
 972         if ((n->nlmsg_type != RTM_GETACTION) && !netlink_capable(skb, CAP_NET_ADMIN))
 973                 return -EPERM;
 974
 975         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
 976         if (ret < 0)
 977                 return ret;
 978
 979         if (tca[TCA_ACT_TAB] == NULL) {
 980                 pr_notice("tc_ctl_action: received NO action attribs\n");
 981                 return -EINVAL;
 982         }
 983
 984         /* n->nlmsg_flags & NLM_F_CREATE */
 985         switch (n->nlmsg_type) {
 986         case RTM_NEWACTION:
 987                 /* we are going to assume all other flags
 988                  * imply create only if it doesn't exist
 989                  * Note that CREATE | EXCL implies that
 990                  * but since we want avoid ambiguity (eg when flags
 991                  * is zero) then just set this
 992                  */
 993                 if (n->nlmsg_flags & NLM_F_REPLACE)
 994                         ovr = 1;
 995 replay:
 996                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr);
 997                 if (ret == -EAGAIN)
 998                         goto replay;
 999                 break;
1000         case RTM_DELACTION:
1001                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1002                                     portid, RTM_DELACTION);
1003                 break;
1004         case RTM_GETACTION:
1005                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1006                                     portid, RTM_GETACTION);
1007                 break;
1008         default:
1009                 BUG();
1010         }
1011
1012         return ret;
1013 }
1014
1015 static struct nlattr *
1016 find_dump_kind(const struct nlmsghdr *n)
1017 {
1018         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1019         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1020         struct nlattr *nla[TCAA_MAX + 1];
1021         struct nlattr *kind;
1022
1023         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1024                 return NULL;
1025         tb1 = nla[TCA_ACT_TAB];
1026         if (tb1 == NULL)
1027                 return NULL;
1028
1029         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1030                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1031                 return NULL;
1032
1033         if (tb[1] == NULL)
1034                 return NULL;
1035         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1036                       nla_len(tb[1]), NULL) < 0)
1037                 return NULL;
1038         kind = tb2[TCA_ACT_KIND];
1039
1040         return kind;
1041 }
1042
1043 static int
1044 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1045 {
1046         struct nlmsghdr *nlh;
1047         unsigned char *b = skb_tail_pointer(skb);
1048         struct nlattr *nest;
1049         struct tc_action_ops *a_o;
1050         struct tc_action a;
1051         int ret = 0;
1052         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1053         struct nlattr *kind = find_dump_kind(cb->nlh);
1054
1055         if (kind == NULL) {
1056                 pr_info("tc_dump_action: action bad kind\n");
1057                 return 0;
1058         }
1059
1060         a_o = tc_lookup_action(kind);
1061         if (a_o == NULL)
1062                 return 0;
1063
1064         memset(&a, 0, sizeof(struct tc_action));
1065         a.ops = a_o;
1066
1067         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1068                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1069         if (!nlh)
1070                 goto out_module_put;
1071         t = nlmsg_data(nlh);
1072         t->tca_family = AF_UNSPEC;
1073         t->tca__pad1 = 0;
1074         t->tca__pad2 = 0;
1075
1076         nest = nla_nest_start(skb, TCA_ACT_TAB);
1077         if (nest == NULL)
1078                 goto out_module_put;
1079
1080         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1081         if (ret < 0)
1082                 goto out_module_put;
1083
1084         if (ret > 0) {
1085                 nla_nest_end(skb, nest);
1086                 ret = skb->len;
1087         } else
1088                 nla_nest_cancel(skb, nest);
1089
1090         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1091         if (NETLINK_CB(cb->skb).portid && ret)
1092                 nlh->nlmsg_flags |= NLM_F_MULTI;
1093         module_put(a_o->owner);
1094         return skb->len;
1095
1096 out_module_put:
1097         module_put(a_o->owner);
1098         nlmsg_trim(skb, b);
1099         return skb->len;
1100 }
1101
1102 static int __init tc_action_init(void)
1103 {
1104         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
1105         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
1106         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1107                       NULL);
1108
1109         return 0;
1110 }
1111
1112 subsys_initcall(tc_action_init);