net/sched/act_api.c

   1 /*
   2  * net/sched/act_api.c  Packet action API.
   3  *
   4  *              This program is free software; you can redistribute it and/or
   5  *              modify it under the terms of the GNU General Public License
   6  *              as published by the Free Software Foundation; either version
   7  *              2 of the License, or (at your option) any later version.
   8  *
   9  * Author:      Jamal Hadi Salim
  10  *
  11  *
  12  */
  13
  14 #include <linux/types.h>
  15 #include <linux/kernel.h>
  16 #include <linux/string.h>
  17 #include <linux/errno.h>
  18 #include <linux/slab.h>
  19 #include <linux/skbuff.h>
  20 #include <linux/init.h>
  21 #include <linux/kmod.h>
  22 #include <linux/err.h>
  23 #include <net/net_namespace.h>
  24 #include <net/sock.h>
  25 #include <net/sch_generic.h>
  26 #include <net/act_api.h>
  27 #include <net/netlink.h>
  28
  29 void tcf_hash_destroy(struct tcf_common *p, struct tcf_hashinfo *hinfo)
  30 {
  31         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
  32         struct tcf_common **p1p;
  33
  34         for (p1p = &hinfo->htab[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
  35                 if (*p1p == p) {
  36                         write_lock_bh(hinfo->lock);
  37                         *p1p = p->tcfc_next;
  38                         write_unlock_bh(hinfo->lock);
  39                         gen_kill_estimator(&p->tcfc_bstats,
  40                                            &p->tcfc_rate_est);
  41                         /*
  42                          * gen_estimator est_timer() might access p->tcfc_lock
  43                          * or bstats, wait a RCU grace period before freeing p
  44                          */
  45                         kfree_rcu(p, tcfc_rcu);
  46                         return;
  47                 }
  48         }
  49         WARN_ON(1);
  50 }
  51 EXPORT_SYMBOL(tcf_hash_destroy);
  52
  53 int tcf_hash_release(struct tcf_common *p, int bind,
  54                      struct tcf_hashinfo *hinfo)
  55 {
  56         int ret = 0;
  57
  58         if (p) {
  59                 if (bind)
  60                         p->tcfc_bindcnt--;
  61
  62                 p->tcfc_refcnt--;
  63                 if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
  64                         tcf_hash_destroy(p, hinfo);
  65                         ret = 1;
  66                 }
  67         }
  68         return ret;
  69 }
  70 EXPORT_SYMBOL(tcf_hash_release);
  71
  72 static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
  73                            struct tc_action *a, struct tcf_hashinfo *hinfo)
  74 {
  75         struct tcf_common *p;
  76         int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
  77         struct nlattr *nest;
  78
  79         read_lock_bh(hinfo->lock);
  80
  81         s_i = cb->args[0];
  82
  83         for (i = 0; i < (hinfo->hmask + 1); i++) {
  84                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
  85
  86                 for (; p; p = p->tcfc_next) {
  87                         index++;
  88                         if (index < s_i)
  89                                 continue;
  90                         a->priv = p;
  91                         a->order = n_i;
  92
  93                         nest = nla_nest_start(skb, a->order);
  94                         if (nest == NULL)
  95                                 goto nla_put_failure;
  96                         err = tcf_action_dump_1(skb, a, 0, 0);
  97                         if (err < 0) {
  98                                 index--;
  99                                 nlmsg_trim(skb, nest);
 100                                 goto done;
 101                         }
 102                         nla_nest_end(skb, nest);
 103                         n_i++;
 104                         if (n_i >= TCA_ACT_MAX_PRIO)
 105                                 goto done;
 106                 }
 107         }
 108 done:
 109         read_unlock_bh(hinfo->lock);
 110         if (n_i)
 111                 cb->args[0] += n_i;
 112         return n_i;
 113
 114 nla_put_failure:
 115         nla_nest_cancel(skb, nest);
 116         goto done;
 117 }
 118
 119 static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a,
 120                           struct tcf_hashinfo *hinfo)
 121 {
 122         struct tcf_common *p, *s_p;
 123         struct nlattr *nest;
 124         int i = 0, n_i = 0;
 125
 126         nest = nla_nest_start(skb, a->order);
 127         if (nest == NULL)
 128                 goto nla_put_failure;
 129         NLA_PUT_STRING(skb, TCA_KIND, a->ops->kind);
 130         for (i = 0; i < (hinfo->hmask + 1); i++) {
 131                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
 132
 133                 while (p != NULL) {
 134                         s_p = p->tcfc_next;
 135                         if (ACT_P_DELETED == tcf_hash_release(p, 0, hinfo))
 136                                 module_put(a->ops->owner);
 137                         n_i++;
 138                         p = s_p;
 139                 }
 140         }
 141         NLA_PUT_U32(skb, TCA_FCNT, n_i);
 142         nla_nest_end(skb, nest);
 143
 144         return n_i;
 145 nla_put_failure:
 146         nla_nest_cancel(skb, nest);
 147         return -EINVAL;
 148 }
 149
 150 int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
 151                        int type, struct tc_action *a)
 152 {
 153         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 154
 155         if (type == RTM_DELACTION) {
 156                 return tcf_del_walker(skb, a, hinfo);
 157         } else if (type == RTM_GETACTION) {
 158                 return tcf_dump_walker(skb, cb, a, hinfo);
 159         } else {
 160                 WARN(1, "tcf_generic_walker: unknown action %d\n", type);
 161                 return -EINVAL;
 162         }
 163 }
 164 EXPORT_SYMBOL(tcf_generic_walker);
 165
 166 struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 167 {
 168         struct tcf_common *p;
 169
 170         read_lock_bh(hinfo->lock);
 171         for (p = hinfo->htab[tcf_hash(index, hinfo->hmask)]; p;
 172              p = p->tcfc_next) {
 173                 if (p->tcfc_index == index)
 174                         break;
 175         }
 176         read_unlock_bh(hinfo->lock);
 177
 178         return p;
 179 }
 180 EXPORT_SYMBOL(tcf_hash_lookup);
 181
 182 u32 tcf_hash_new_index(u32 *idx_gen, struct tcf_hashinfo *hinfo)
 183 {
 184         u32 val = *idx_gen;
 185
 186         do {
 187                 if (++val == 0)
 188                         val = 1;
 189         } while (tcf_hash_lookup(val, hinfo));
 190
 191         return (*idx_gen = val);
 192 }
 193 EXPORT_SYMBOL(tcf_hash_new_index);
 194
 195 int tcf_hash_search(struct tc_action *a, u32 index)
 196 {
 197         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 198         struct tcf_common *p = tcf_hash_lookup(index, hinfo);
 199
 200         if (p) {
 201                 a->priv = p;
 202                 return 1;
 203         }
 204         return 0;
 205 }
 206 EXPORT_SYMBOL(tcf_hash_search);
 207
 208 struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
 209                                   struct tcf_hashinfo *hinfo)
 210 {
 211         struct tcf_common *p = NULL;
 212         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 213                 if (bind)
 214                         p->tcfc_bindcnt++;
 215                 p->tcfc_refcnt++;
 216                 a->priv = p;
 217         }
 218         return p;
 219 }
 220 EXPORT_SYMBOL(tcf_hash_check);
 221
 222 struct tcf_common *tcf_hash_create(u32 index, struct nlattr *est,
 223                                    struct tc_action *a, int size, int bind,
 224                                    u32 *idx_gen, struct tcf_hashinfo *hinfo)
 225 {
 226         struct tcf_common *p = kzalloc(size, GFP_KERNEL);
 227
 228         if (unlikely(!p))
 229                 return ERR_PTR(-ENOMEM);
 230         p->tcfc_refcnt = 1;
 231         if (bind)
 232                 p->tcfc_bindcnt = 1;
 233
 234         spin_lock_init(&p->tcfc_lock);
 235         p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
 236         p->tcfc_tm.install = jiffies;
 237         p->tcfc_tm.lastuse = jiffies;
 238         if (est) {
 239                 int err = gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
 240                                             &p->tcfc_lock, est);
 241                 if (err) {
 242                         kfree(p);
 243                         return ERR_PTR(err);
 244                 }
 245         }
 246
 247         a->priv = (void *) p;
 248         return p;
 249 }
 250 EXPORT_SYMBOL(tcf_hash_create);
 251
 252 void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
 253 {
 254         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
 255
 256         write_lock_bh(hinfo->lock);
 257         p->tcfc_next = hinfo->htab[h];
 258         hinfo->htab[h] = p;
 259         write_unlock_bh(hinfo->lock);
 260 }
 261 EXPORT_SYMBOL(tcf_hash_insert);
 262
 263 static struct tc_action_ops *act_base = NULL;
 264 static DEFINE_RWLOCK(act_mod_lock);
 265
 266 int tcf_register_action(struct tc_action_ops *act)
 267 {
 268         struct tc_action_ops *a, **ap;
 269
 270         write_lock(&act_mod_lock);
 271         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
 272                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 273                         write_unlock(&act_mod_lock);
 274                         return -EEXIST;
 275                 }
 276         }
 277         act->next = NULL;
 278         *ap = act;
 279         write_unlock(&act_mod_lock);
 280         return 0;
 281 }
 282 EXPORT_SYMBOL(tcf_register_action);
 283
 284 int tcf_unregister_action(struct tc_action_ops *act)
 285 {
 286         struct tc_action_ops *a, **ap;
 287         int err = -ENOENT;
 288
 289         write_lock(&act_mod_lock);
 290         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
 291                 if (a == act)
 292                         break;
 293         if (a) {
 294                 *ap = a->next;
 295                 a->next = NULL;
 296                 err = 0;
 297         }
 298         write_unlock(&act_mod_lock);
 299         return err;
 300 }
 301 EXPORT_SYMBOL(tcf_unregister_action);
 302
 303 /* lookup by name */
 304 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 305 {
 306         struct tc_action_ops *a = NULL;
 307
 308         if (kind) {
 309                 read_lock(&act_mod_lock);
 310                 for (a = act_base; a; a = a->next) {
 311                         if (strcmp(kind, a->kind) == 0) {
 312                                 if (!try_module_get(a->owner)) {
 313                                         read_unlock(&act_mod_lock);
 314                                         return NULL;
 315                                 }
 316                                 break;
 317                         }
 318                 }
 319                 read_unlock(&act_mod_lock);
 320         }
 321         return a;
 322 }
 323
 324 /* lookup by nlattr */
 325 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 326 {
 327         struct tc_action_ops *a = NULL;
 328
 329         if (kind) {
 330                 read_lock(&act_mod_lock);
 331                 for (a = act_base; a; a = a->next) {
 332                         if (nla_strcmp(kind, a->kind) == 0) {
 333                                 if (!try_module_get(a->owner)) {
 334                                         read_unlock(&act_mod_lock);
 335                                         return NULL;
 336                                 }
 337                                 break;
 338                         }
 339                 }
 340                 read_unlock(&act_mod_lock);
 341         }
 342         return a;
 343 }
 344
 345 #if 0
 346 /* lookup by id */
 347 static struct tc_action_ops *tc_lookup_action_id(u32 type)
 348 {
 349         struct tc_action_ops *a = NULL;
 350
 351         if (type) {
 352                 read_lock(&act_mod_lock);
 353                 for (a = act_base; a; a = a->next) {
 354                         if (a->type == type) {
 355                                 if (!try_module_get(a->owner)) {
 356                                         read_unlock(&act_mod_lock);
 357                                         return NULL;
 358                                 }
 359                                 break;
 360                         }
 361                 }
 362                 read_unlock(&act_mod_lock);
 363         }
 364         return a;
 365 }
 366 #endif
 367
 368 int tcf_action_exec(struct sk_buff *skb, const struct tc_action *act,
 369                     struct tcf_result *res)
 370 {
 371         const struct tc_action *a;
 372         int ret = -1;
 373
 374         if (skb->tc_verd & TC_NCLS) {
 375                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 376                 ret = TC_ACT_OK;
 377                 goto exec_done;
 378         }
 379         while ((a = act) != NULL) {
 380 repeat:
 381                 if (a->ops && a->ops->act) {
 382                         ret = a->ops->act(skb, a, res);
 383                         if (TC_MUNGED & skb->tc_verd) {
 384                                 /* copied already, allow trampling */
 385                                 skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
 386                                 skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
 387                         }
 388                         if (ret == TC_ACT_REPEAT)
 389                                 goto repeat;    /* we need a ttl - JHS */
 390                         if (ret != TC_ACT_PIPE)
 391                                 goto exec_done;
 392                 }
 393                 act = a->next;
 394         }
 395 exec_done:
 396         return ret;
 397 }
 398 EXPORT_SYMBOL(tcf_action_exec);
 399
 400 void tcf_action_destroy(struct tc_action *act, int bind)
 401 {
 402         struct tc_action *a;
 403
 404         for (a = act; a; a = act) {
 405                 if (a->ops && a->ops->cleanup) {
 406                         if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
 407                                 module_put(a->ops->owner);
 408                         act = act->next;
 409                         kfree(a);
 410                 } else {
 411                         /*FIXME: Remove later - catch insertion bugs*/
 412                         WARN(1, "tcf_action_destroy: BUG? destroying NULL ops\n");
 413                         act = act->next;
 414                         kfree(a);
 415                 }
 416         }
 417 }
 418
 419 int
 420 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 421 {
 422         int err = -EINVAL;
 423
 424         if (a->ops == NULL || a->ops->dump == NULL)
 425                 return err;
 426         return a->ops->dump(skb, a, bind, ref);
 427 }
 428
 429 int
 430 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 431 {
 432         int err = -EINVAL;
 433         unsigned char *b = skb_tail_pointer(skb);
 434         struct nlattr *nest;
 435
 436         if (a->ops == NULL || a->ops->dump == NULL)
 437                 return err;
 438
 439         NLA_PUT_STRING(skb, TCA_KIND, a->ops->kind);
 440         if (tcf_action_copy_stats(skb, a, 0))
 441                 goto nla_put_failure;
 442         nest = nla_nest_start(skb, TCA_OPTIONS);
 443         if (nest == NULL)
 444                 goto nla_put_failure;
 445         err = tcf_action_dump_old(skb, a, bind, ref);
 446         if (err > 0) {
 447                 nla_nest_end(skb, nest);
 448                 return err;
 449         }
 450
 451 nla_put_failure:
 452         nlmsg_trim(skb, b);
 453         return -1;
 454 }
 455 EXPORT_SYMBOL(tcf_action_dump_1);
 456
 457 int
 458 tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
 459 {
 460         struct tc_action *a;
 461         int err = -EINVAL;
 462         struct nlattr *nest;
 463
 464         while ((a = act) != NULL) {
 465                 act = a->next;
 466                 nest = nla_nest_start(skb, a->order);
 467                 if (nest == NULL)
 468                         goto nla_put_failure;
 469                 err = tcf_action_dump_1(skb, a, bind, ref);
 470                 if (err < 0)
 471                         goto errout;
 472                 nla_nest_end(skb, nest);
 473         }
 474
 475         return 0;
 476
 477 nla_put_failure:
 478         err = -EINVAL;
 479 errout:
 480         nla_nest_cancel(skb, nest);
 481         return err;
 482 }
 483
 484 struct tc_action *tcf_action_init_1(struct nlattr *nla, struct nlattr *est,
 485                                     char *name, int ovr, int bind)
 486 {
 487         struct tc_action *a;
 488         struct tc_action_ops *a_o;
 489         char act_name[IFNAMSIZ];
 490         struct nlattr *tb[TCA_ACT_MAX + 1];
 491         struct nlattr *kind;
 492         int err;
 493
 494         if (name == NULL) {
 495                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 496                 if (err < 0)
 497                         goto err_out;
 498                 err = -EINVAL;
 499                 kind = tb[TCA_ACT_KIND];
 500                 if (kind == NULL)
 501                         goto err_out;
 502                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 503                         goto err_out;
 504         } else {
 505                 err = -EINVAL;
 506                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 507                         goto err_out;
 508         }
 509
 510         a_o = tc_lookup_action_n(act_name);
 511         if (a_o == NULL) {
 512 #ifdef CONFIG_MODULES
 513                 rtnl_unlock();
 514                 request_module("act_%s", act_name);
 515                 rtnl_lock();
 516
 517                 a_o = tc_lookup_action_n(act_name);
 518
 519                 /* We dropped the RTNL semaphore in order to
 520                  * perform the module load.  So, even if we
 521                  * succeeded in loading the module we have to
 522                  * tell the caller to replay the request.  We
 523                  * indicate this using -EAGAIN.
 524                  */
 525                 if (a_o != NULL) {
 526                         err = -EAGAIN;
 527                         goto err_mod;
 528                 }
 529 #endif
 530                 err = -ENOENT;
 531                 goto err_out;
 532         }
 533
 534         err = -ENOMEM;
 535         a = kzalloc(sizeof(*a), GFP_KERNEL);
 536         if (a == NULL)
 537                 goto err_mod;
 538
 539         /* backward compatibility for policer */
 540         if (name == NULL)
 541                 err = a_o->init(tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
 542         else
 543                 err = a_o->init(nla, est, a, ovr, bind);
 544         if (err < 0)
 545                 goto err_free;
 546
 547         /* module count goes up only when brand new policy is created
 548          * if it exists and is only bound to in a_o->init() then
 549          * ACT_P_CREATED is not returned (a zero is).
 550          */
 551         if (err != ACT_P_CREATED)
 552                 module_put(a_o->owner);
 553         a->ops = a_o;
 554
 555         return a;
 556
 557 err_free:
 558         kfree(a);
 559 err_mod:
 560         module_put(a_o->owner);
 561 err_out:
 562         return ERR_PTR(err);
 563 }
 564
 565 struct tc_action *tcf_action_init(struct nlattr *nla, struct nlattr *est,
 566                                   char *name, int ovr, int bind)
 567 {
 568         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 569         struct tc_action *head = NULL, *act, *act_prev = NULL;
 570         int err;
 571         int i;
 572
 573         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 574         if (err < 0)
 575                 return ERR_PTR(err);
 576
 577         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 578                 act = tcf_action_init_1(tb[i], est, name, ovr, bind);
 579                 if (IS_ERR(act))
 580                         goto err;
 581                 act->order = i;
 582
 583                 if (head == NULL)
 584                         head = act;
 585                 else
 586                         act_prev->next = act;
 587                 act_prev = act;
 588         }
 589         return head;
 590
 591 err:
 592         if (head != NULL)
 593                 tcf_action_destroy(head, bind);
 594         return act;
 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_act_hdr *h = a->priv;
 603
 604         if (h == 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, &h->tcf_lock, &d);
 614                 else
 615                         return 0;
 616         } else
 617                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 618                                             &h->tcf_lock, &d);
 619
 620         if (err < 0)
 621                 goto errout;
 622
 623         if (a->ops != NULL && a->ops->get_stats != NULL)
 624                 if (a->ops->get_stats(skb, a) < 0)
 625                         goto errout;
 626
 627         if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
 628             gnet_stats_copy_rate_est(&d, &h->tcf_bstats,
 629                                      &h->tcf_rate_est) < 0 ||
 630             gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
 631                 goto errout;
 632
 633         if (gnet_stats_finish_copy(&d) < 0)
 634                 goto errout;
 635
 636         return 0;
 637
 638 errout:
 639         return -1;
 640 }
 641
 642 static int
 643 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 pid, u32 seq,
 644              u16 flags, int event, int bind, int ref)
 645 {
 646         struct tcamsg *t;
 647         struct nlmsghdr *nlh;
 648         unsigned char *b = skb_tail_pointer(skb);
 649         struct nlattr *nest;
 650
 651         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 652
 653         t = NLMSG_DATA(nlh);
 654         t->tca_family = AF_UNSPEC;
 655         t->tca__pad1 = 0;
 656         t->tca__pad2 = 0;
 657
 658         nest = nla_nest_start(skb, TCA_ACT_TAB);
 659         if (nest == NULL)
 660                 goto nla_put_failure;
 661
 662         if (tcf_action_dump(skb, a, bind, ref) < 0)
 663                 goto nla_put_failure;
 664
 665         nla_nest_end(skb, nest);
 666
 667         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 668         return skb->len;
 669
 670 nla_put_failure:
 671 nlmsg_failure:
 672         nlmsg_trim(skb, b);
 673         return -1;
 674 }
 675
 676 static int
 677 act_get_notify(struct net *net, u32 pid, struct nlmsghdr *n,
 678                struct tc_action *a, int event)
 679 {
 680         struct sk_buff *skb;
 681
 682         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 683         if (!skb)
 684                 return -ENOBUFS;
 685         if (tca_get_fill(skb, a, pid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 686                 kfree_skb(skb);
 687                 return -EINVAL;
 688         }
 689
 690         return rtnl_unicast(skb, net, pid);
 691 }
 692
 693 static struct tc_action *
 694 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 pid)
 695 {
 696         struct nlattr *tb[TCA_ACT_MAX + 1];
 697         struct tc_action *a;
 698         int index;
 699         int err;
 700
 701         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 702         if (err < 0)
 703                 goto err_out;
 704
 705         err = -EINVAL;
 706         if (tb[TCA_ACT_INDEX] == NULL ||
 707             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 708                 goto err_out;
 709         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 710
 711         err = -ENOMEM;
 712         a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
 713         if (a == NULL)
 714                 goto err_out;
 715
 716         err = -EINVAL;
 717         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 718         if (a->ops == NULL)
 719                 goto err_free;
 720         if (a->ops->lookup == NULL)
 721                 goto err_mod;
 722         err = -ENOENT;
 723         if (a->ops->lookup(a, index) == 0)
 724                 goto err_mod;
 725
 726         module_put(a->ops->owner);
 727         return a;
 728
 729 err_mod:
 730         module_put(a->ops->owner);
 731 err_free:
 732         kfree(a);
 733 err_out:
 734         return ERR_PTR(err);
 735 }
 736
 737 static void cleanup_a(struct tc_action *act)
 738 {
 739         struct tc_action *a;
 740
 741         for (a = act; a; a = act) {
 742                 act = a->next;
 743                 kfree(a);
 744         }
 745 }
 746
 747 static struct tc_action *create_a(int i)
 748 {
 749         struct tc_action *act;
 750
 751         act = kzalloc(sizeof(*act), GFP_KERNEL);
 752         if (act == NULL) {
 753                 pr_debug("create_a: failed to alloc!\n");
 754                 return NULL;
 755         }
 756         act->order = i;
 757         return act;
 758 }
 759
 760 static int tca_action_flush(struct net *net, struct nlattr *nla,
 761                             struct nlmsghdr *n, u32 pid)
 762 {
 763         struct sk_buff *skb;
 764         unsigned char *b;
 765         struct nlmsghdr *nlh;
 766         struct tcamsg *t;
 767         struct netlink_callback dcb;
 768         struct nlattr *nest;
 769         struct nlattr *tb[TCA_ACT_MAX + 1];
 770         struct nlattr *kind;
 771         struct tc_action *a = create_a(0);
 772         int err = -ENOMEM;
 773
 774         if (a == NULL) {
 775                 pr_debug("tca_action_flush: couldnt create tc_action\n");
 776                 return err;
 777         }
 778
 779         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 780         if (!skb) {
 781                 pr_debug("tca_action_flush: failed skb alloc\n");
 782                 kfree(a);
 783                 return err;
 784         }
 785
 786         b = skb_tail_pointer(skb);
 787
 788         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 789         if (err < 0)
 790                 goto err_out;
 791
 792         err = -EINVAL;
 793         kind = tb[TCA_ACT_KIND];
 794         a->ops = tc_lookup_action(kind);
 795         if (a->ops == NULL)
 796                 goto err_out;
 797
 798         nlh = NLMSG_PUT(skb, pid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t));
 799         t = NLMSG_DATA(nlh);
 800         t->tca_family = AF_UNSPEC;
 801         t->tca__pad1 = 0;
 802         t->tca__pad2 = 0;
 803
 804         nest = nla_nest_start(skb, TCA_ACT_TAB);
 805         if (nest == NULL)
 806                 goto nla_put_failure;
 807
 808         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 809         if (err < 0)
 810                 goto nla_put_failure;
 811         if (err == 0)
 812                 goto noflush_out;
 813
 814         nla_nest_end(skb, nest);
 815
 816         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 817         nlh->nlmsg_flags |= NLM_F_ROOT;
 818         module_put(a->ops->owner);
 819         kfree(a);
 820         err = rtnetlink_send(skb, net, pid, RTNLGRP_TC,
 821                              n->nlmsg_flags & NLM_F_ECHO);
 822         if (err > 0)
 823                 return 0;
 824
 825         return err;
 826
 827 nla_put_failure:
 828 nlmsg_failure:
 829         module_put(a->ops->owner);
 830 err_out:
 831 noflush_out:
 832         kfree_skb(skb);
 833         kfree(a);
 834         return err;
 835 }
 836
 837 static int
 838 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 839               u32 pid, int event)
 840 {
 841         int i, ret;
 842         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 843         struct tc_action *head = NULL, *act, *act_prev = NULL;
 844
 845         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 846         if (ret < 0)
 847                 return ret;
 848
 849         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
 850                 if (tb[1] != NULL)
 851                         return tca_action_flush(net, tb[1], n, pid);
 852                 else
 853                         return -EINVAL;
 854         }
 855
 856         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 857                 act = tcf_action_get_1(tb[i], n, pid);
 858                 if (IS_ERR(act)) {
 859                         ret = PTR_ERR(act);
 860                         goto err;
 861                 }
 862                 act->order = i;
 863
 864                 if (head == NULL)
 865                         head = act;
 866                 else
 867                         act_prev->next = act;
 868                 act_prev = act;
 869         }
 870
 871         if (event == RTM_GETACTION)
 872                 ret = act_get_notify(net, pid, n, head, event);
 873         else { /* delete */
 874                 struct sk_buff *skb;
 875
 876                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 877                 if (!skb) {
 878                         ret = -ENOBUFS;
 879                         goto err;
 880                 }
 881
 882                 if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
 883                                  0, 1) <= 0) {
 884                         kfree_skb(skb);
 885                         ret = -EINVAL;
 886                         goto err;
 887                 }
 888
 889                 /* now do the delete */
 890                 tcf_action_destroy(head, 0);
 891                 ret = rtnetlink_send(skb, net, pid, RTNLGRP_TC,
 892                                      n->nlmsg_flags & NLM_F_ECHO);
 893                 if (ret > 0)
 894                         return 0;
 895                 return ret;
 896         }
 897 err:
 898         cleanup_a(head);
 899         return ret;
 900 }
 901
 902 static int tcf_add_notify(struct net *net, struct tc_action *a,
 903                           u32 pid, u32 seq, int event, u16 flags)
 904 {
 905         struct tcamsg *t;
 906         struct nlmsghdr *nlh;
 907         struct sk_buff *skb;
 908         struct nlattr *nest;
 909         unsigned char *b;
 910         int err = 0;
 911
 912         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 913         if (!skb)
 914                 return -ENOBUFS;
 915
 916         b = skb_tail_pointer(skb);
 917
 918         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 919         t = NLMSG_DATA(nlh);
 920         t->tca_family = AF_UNSPEC;
 921         t->tca__pad1 = 0;
 922         t->tca__pad2 = 0;
 923
 924         nest = nla_nest_start(skb, TCA_ACT_TAB);
 925         if (nest == NULL)
 926                 goto nla_put_failure;
 927
 928         if (tcf_action_dump(skb, a, 0, 0) < 0)
 929                 goto nla_put_failure;
 930
 931         nla_nest_end(skb, nest);
 932
 933         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 934         NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 935
 936         err = rtnetlink_send(skb, net, pid, RTNLGRP_TC, flags & NLM_F_ECHO);
 937         if (err > 0)
 938                 err = 0;
 939         return err;
 940
 941 nla_put_failure:
 942 nlmsg_failure:
 943         kfree_skb(skb);
 944         return -1;
 945 }
 946
 947
 948 static int
 949 tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 950                u32 pid, int ovr)
 951 {
 952         int ret = 0;
 953         struct tc_action *act;
 954         struct tc_action *a;
 955         u32 seq = n->nlmsg_seq;
 956
 957         act = tcf_action_init(nla, NULL, NULL, ovr, 0);
 958         if (act == NULL)
 959                 goto done;
 960         if (IS_ERR(act)) {
 961                 ret = PTR_ERR(act);
 962                 goto done;
 963         }
 964
 965         /* dump then free all the actions after update; inserted policy
 966          * stays intact
 967          */
 968         ret = tcf_add_notify(net, act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
 969         for (a = act; a; a = act) {
 970                 act = a->next;
 971                 kfree(a);
 972         }
 973 done:
 974         return ret;
 975 }
 976
 977 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 978 {
 979         struct net *net = sock_net(skb->sk);
 980         struct nlattr *tca[TCA_ACT_MAX + 1];
 981         u32 pid = skb ? NETLINK_CB(skb).pid : 0;
 982         int ret = 0, ovr = 0;
 983
 984         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
 985         if (ret < 0)
 986                 return ret;
 987
 988         if (tca[TCA_ACT_TAB] == NULL) {
 989                 pr_notice("tc_ctl_action: received NO action attribs\n");
 990                 return -EINVAL;
 991         }
 992
 993         /* n->nlmsg_flags & NLM_F_CREATE */
 994         switch (n->nlmsg_type) {
 995         case RTM_NEWACTION:
 996                 /* we are going to assume all other flags
 997                  * imply create only if it doesn't exist
 998                  * Note that CREATE | EXCL implies that
 999                  * but since we want avoid ambiguity (eg when flags
1000                  * is zero) then just set this
1001                  */
1002                 if (n->nlmsg_flags & NLM_F_REPLACE)
1003                         ovr = 1;
1004 replay:
1005                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, pid, ovr);
1006                 if (ret == -EAGAIN)
1007                         goto replay;
1008                 break;
1009         case RTM_DELACTION:
1010                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1011                                     pid, RTM_DELACTION);
1012                 break;
1013         case RTM_GETACTION:
1014                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1015                                     pid, RTM_GETACTION);
1016                 break;
1017         default:
1018                 BUG();
1019         }
1020
1021         return ret;
1022 }
1023
1024 static struct nlattr *
1025 find_dump_kind(const struct nlmsghdr *n)
1026 {
1027         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1028         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1029         struct nlattr *nla[TCAA_MAX + 1];
1030         struct nlattr *kind;
1031
1032         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1033                 return NULL;
1034         tb1 = nla[TCA_ACT_TAB];
1035         if (tb1 == NULL)
1036                 return NULL;
1037
1038         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1039                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1040                 return NULL;
1041
1042         if (tb[1] == NULL)
1043                 return NULL;
1044         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1045                       nla_len(tb[1]), NULL) < 0)
1046                 return NULL;
1047         kind = tb2[TCA_ACT_KIND];
1048
1049         return kind;
1050 }
1051
1052 static int
1053 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1054 {
1055         struct nlmsghdr *nlh;
1056         unsigned char *b = skb_tail_pointer(skb);
1057         struct nlattr *nest;
1058         struct tc_action_ops *a_o;
1059         struct tc_action a;
1060         int ret = 0;
1061         struct tcamsg *t = (struct tcamsg *) NLMSG_DATA(cb->nlh);
1062         struct nlattr *kind = find_dump_kind(cb->nlh);
1063
1064         if (kind == NULL) {
1065                 pr_info("tc_dump_action: action bad kind\n");
1066                 return 0;
1067         }
1068
1069         a_o = tc_lookup_action(kind);
1070         if (a_o == NULL)
1071                 return 0;
1072
1073         memset(&a, 0, sizeof(struct tc_action));
1074         a.ops = a_o;
1075
1076         if (a_o->walk == NULL) {
1077                 WARN(1, "tc_dump_action: %s !capable of dumping table\n",
1078                      a_o->kind);
1079                 goto nla_put_failure;
1080         }
1081
1082         nlh = NLMSG_PUT(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
1083                         cb->nlh->nlmsg_type, sizeof(*t));
1084         t = NLMSG_DATA(nlh);
1085         t->tca_family = AF_UNSPEC;
1086         t->tca__pad1 = 0;
1087         t->tca__pad2 = 0;
1088
1089         nest = nla_nest_start(skb, TCA_ACT_TAB);
1090         if (nest == NULL)
1091                 goto nla_put_failure;
1092
1093         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1094         if (ret < 0)
1095                 goto nla_put_failure;
1096
1097         if (ret > 0) {
1098                 nla_nest_end(skb, nest);
1099                 ret = skb->len;
1100         } else
1101                 nla_nest_cancel(skb, nest);
1102
1103         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1104         if (NETLINK_CB(cb->skb).pid && ret)
1105                 nlh->nlmsg_flags |= NLM_F_MULTI;
1106         module_put(a_o->owner);
1107         return skb->len;
1108
1109 nla_put_failure:
1110 nlmsg_failure:
1111         module_put(a_o->owner);
1112         nlmsg_trim(skb, b);
1113         return skb->len;
1114 }
1115
1116 static int __init tc_action_init(void)
1117 {
1118         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
1119         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
1120         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1121                       NULL);
1122
1123         return 0;
1124 }
1125
1126 subsys_initcall(tc_action_init);