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/skbuff.h>
  19 #include <linux/init.h>
  20 #include <linux/kmod.h>
  21 #include <linux/err.h>
  22 #include <net/net_namespace.h>
  23 #include <net/sock.h>
  24 #include <net/sch_generic.h>
  25 #include <net/act_api.h>
  26 #include <net/netlink.h>
  27
  28 void tcf_hash_destroy(struct tcf_common *p, struct tcf_hashinfo *hinfo)
  29 {
  30         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
  31         struct tcf_common **p1p;
  32
  33         for (p1p = &hinfo->htab[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
  34                 if (*p1p == p) {
  35                         write_lock_bh(hinfo->lock);
  36                         *p1p = p->tcfc_next;
  37                         write_unlock_bh(hinfo->lock);
  38                         gen_kill_estimator(&p->tcfc_bstats,
  39                                            &p->tcfc_rate_est);
  40                         kfree(p);
  41                         return;
  42                 }
  43         }
  44         WARN_ON(1);
  45 }
  46 EXPORT_SYMBOL(tcf_hash_destroy);
  47
  48 int tcf_hash_release(struct tcf_common *p, int bind,
  49                      struct tcf_hashinfo *hinfo)
  50 {
  51         int ret = 0;
  52
  53         if (p) {
  54                 if (bind)
  55                         p->tcfc_bindcnt--;
  56
  57                 p->tcfc_refcnt--;
  58                 if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
  59                         tcf_hash_destroy(p, hinfo);
  60                         ret = 1;
  61                 }
  62         }
  63         return ret;
  64 }
  65 EXPORT_SYMBOL(tcf_hash_release);
  66
  67 static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
  68                            struct tc_action *a, struct tcf_hashinfo *hinfo)
  69 {
  70         struct tcf_common *p;
  71         int err = 0, index = -1,i = 0, s_i = 0, n_i = 0;
  72         struct nlattr *nest;
  73
  74         read_lock_bh(hinfo->lock);
  75
  76         s_i = cb->args[0];
  77
  78         for (i = 0; i < (hinfo->hmask + 1); i++) {
  79                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
  80
  81                 for (; p; p = p->tcfc_next) {
  82                         index++;
  83                         if (index < s_i)
  84                                 continue;
  85                         a->priv = p;
  86                         a->order = n_i;
  87
  88                         nest = nla_nest_start(skb, a->order);
  89                         if (nest == NULL)
  90                                 goto nla_put_failure;
  91                         err = tcf_action_dump_1(skb, a, 0, 0);
  92                         if (err < 0) {
  93                                 index--;
  94                                 nlmsg_trim(skb, nest);
  95                                 goto done;
  96                         }
  97                         nla_nest_end(skb, nest);
  98                         n_i++;
  99                         if (n_i >= TCA_ACT_MAX_PRIO)
 100                                 goto done;
 101                 }
 102         }
 103 done:
 104         read_unlock_bh(hinfo->lock);
 105         if (n_i)
 106                 cb->args[0] += n_i;
 107         return n_i;
 108
 109 nla_put_failure:
 110         nla_nest_cancel(skb, nest);
 111         goto done;
 112 }
 113
 114 static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a,
 115                           struct tcf_hashinfo *hinfo)
 116 {
 117         struct tcf_common *p, *s_p;
 118         struct nlattr *nest;
 119         int i= 0, n_i = 0;
 120
 121         nest = nla_nest_start(skb, a->order);
 122         if (nest == NULL)
 123                 goto nla_put_failure;
 124         NLA_PUT_STRING(skb, TCA_KIND, a->ops->kind);
 125         for (i = 0; i < (hinfo->hmask + 1); i++) {
 126                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
 127
 128                 while (p != NULL) {
 129                         s_p = p->tcfc_next;
 130                         if (ACT_P_DELETED == tcf_hash_release(p, 0, hinfo))
 131                                  module_put(a->ops->owner);
 132                         n_i++;
 133                         p = s_p;
 134                 }
 135         }
 136         NLA_PUT_U32(skb, TCA_FCNT, n_i);
 137         nla_nest_end(skb, nest);
 138
 139         return n_i;
 140 nla_put_failure:
 141         nla_nest_cancel(skb, nest);
 142         return -EINVAL;
 143 }
 144
 145 int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
 146                        int type, struct tc_action *a)
 147 {
 148         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 149
 150         if (type == RTM_DELACTION) {
 151                 return tcf_del_walker(skb, a, hinfo);
 152         } else if (type == RTM_GETACTION) {
 153                 return tcf_dump_walker(skb, cb, a, hinfo);
 154         } else {
 155                 printk("tcf_generic_walker: unknown action %d\n", type);
 156                 return -EINVAL;
 157         }
 158 }
 159 EXPORT_SYMBOL(tcf_generic_walker);
 160
 161 struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 162 {
 163         struct tcf_common *p;
 164
 165         read_lock_bh(hinfo->lock);
 166         for (p = hinfo->htab[tcf_hash(index, hinfo->hmask)]; p;
 167              p = p->tcfc_next) {
 168                 if (p->tcfc_index == index)
 169                         break;
 170         }
 171         read_unlock_bh(hinfo->lock);
 172
 173         return p;
 174 }
 175 EXPORT_SYMBOL(tcf_hash_lookup);
 176
 177 u32 tcf_hash_new_index(u32 *idx_gen, struct tcf_hashinfo *hinfo)
 178 {
 179         u32 val = *idx_gen;
 180
 181         do {
 182                 if (++val == 0)
 183                         val = 1;
 184         } while (tcf_hash_lookup(val, hinfo));
 185
 186         return (*idx_gen = val);
 187 }
 188 EXPORT_SYMBOL(tcf_hash_new_index);
 189
 190 int tcf_hash_search(struct tc_action *a, u32 index)
 191 {
 192         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 193         struct tcf_common *p = tcf_hash_lookup(index, hinfo);
 194
 195         if (p) {
 196                 a->priv = p;
 197                 return 1;
 198         }
 199         return 0;
 200 }
 201 EXPORT_SYMBOL(tcf_hash_search);
 202
 203 struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
 204                                   struct tcf_hashinfo *hinfo)
 205 {
 206         struct tcf_common *p = NULL;
 207         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 208                 if (bind)
 209                         p->tcfc_bindcnt++;
 210                 p->tcfc_refcnt++;
 211                 a->priv = p;
 212         }
 213         return p;
 214 }
 215 EXPORT_SYMBOL(tcf_hash_check);
 216
 217 struct tcf_common *tcf_hash_create(u32 index, struct nlattr *est, struct tc_action *a, int size, int bind, u32 *idx_gen, struct tcf_hashinfo *hinfo)
 218 {
 219         struct tcf_common *p = kzalloc(size, GFP_KERNEL);
 220
 221         if (unlikely(!p))
 222                 return p;
 223         p->tcfc_refcnt = 1;
 224         if (bind)
 225                 p->tcfc_bindcnt = 1;
 226
 227         spin_lock_init(&p->tcfc_lock);
 228         p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
 229         p->tcfc_tm.install = jiffies;
 230         p->tcfc_tm.lastuse = jiffies;
 231         if (est)
 232                 gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
 233                                   &p->tcfc_lock, est);
 234         a->priv = (void *) p;
 235         return p;
 236 }
 237 EXPORT_SYMBOL(tcf_hash_create);
 238
 239 void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
 240 {
 241         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
 242
 243         write_lock_bh(hinfo->lock);
 244         p->tcfc_next = hinfo->htab[h];
 245         hinfo->htab[h] = p;
 246         write_unlock_bh(hinfo->lock);
 247 }
 248 EXPORT_SYMBOL(tcf_hash_insert);
 249
 250 static struct tc_action_ops *act_base = NULL;
 251 static DEFINE_RWLOCK(act_mod_lock);
 252
 253 int tcf_register_action(struct tc_action_ops *act)
 254 {
 255         struct tc_action_ops *a, **ap;
 256
 257         write_lock(&act_mod_lock);
 258         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
 259                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 260                         write_unlock(&act_mod_lock);
 261                         return -EEXIST;
 262                 }
 263         }
 264         act->next = NULL;
 265         *ap = act;
 266         write_unlock(&act_mod_lock);
 267         return 0;
 268 }
 269 EXPORT_SYMBOL(tcf_register_action);
 270
 271 int tcf_unregister_action(struct tc_action_ops *act)
 272 {
 273         struct tc_action_ops *a, **ap;
 274         int err = -ENOENT;
 275
 276         write_lock(&act_mod_lock);
 277         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
 278                 if (a == act)
 279                         break;
 280         if (a) {
 281                 *ap = a->next;
 282                 a->next = NULL;
 283                 err = 0;
 284         }
 285         write_unlock(&act_mod_lock);
 286         return err;
 287 }
 288 EXPORT_SYMBOL(tcf_unregister_action);
 289
 290 /* lookup by name */
 291 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 292 {
 293         struct tc_action_ops *a = NULL;
 294
 295         if (kind) {
 296                 read_lock(&act_mod_lock);
 297                 for (a = act_base; a; a = a->next) {
 298                         if (strcmp(kind, a->kind) == 0) {
 299                                 if (!try_module_get(a->owner)) {
 300                                         read_unlock(&act_mod_lock);
 301                                         return NULL;
 302                                 }
 303                                 break;
 304                         }
 305                 }
 306                 read_unlock(&act_mod_lock);
 307         }
 308         return a;
 309 }
 310
 311 /* lookup by nlattr */
 312 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 313 {
 314         struct tc_action_ops *a = NULL;
 315
 316         if (kind) {
 317                 read_lock(&act_mod_lock);
 318                 for (a = act_base; a; a = a->next) {
 319                         if (nla_strcmp(kind, a->kind) == 0) {
 320                                 if (!try_module_get(a->owner)) {
 321                                         read_unlock(&act_mod_lock);
 322                                         return NULL;
 323                                 }
 324                                 break;
 325                         }
 326                 }
 327                 read_unlock(&act_mod_lock);
 328         }
 329         return a;
 330 }
 331
 332 #if 0
 333 /* lookup by id */
 334 static struct tc_action_ops *tc_lookup_action_id(u32 type)
 335 {
 336         struct tc_action_ops *a = NULL;
 337
 338         if (type) {
 339                 read_lock(&act_mod_lock);
 340                 for (a = act_base; a; a = a->next) {
 341                         if (a->type == type) {
 342                                 if (!try_module_get(a->owner)) {
 343                                         read_unlock(&act_mod_lock);
 344                                         return NULL;
 345                                 }
 346                                 break;
 347                         }
 348                 }
 349                 read_unlock(&act_mod_lock);
 350         }
 351         return a;
 352 }
 353 #endif
 354
 355 int tcf_action_exec(struct sk_buff *skb, struct tc_action *act,
 356                     struct tcf_result *res)
 357 {
 358         struct tc_action *a;
 359         int ret = -1;
 360
 361         if (skb->tc_verd & TC_NCLS) {
 362                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 363                 ret = TC_ACT_OK;
 364                 goto exec_done;
 365         }
 366         while ((a = act) != NULL) {
 367 repeat:
 368                 if (a->ops && a->ops->act) {
 369                         ret = a->ops->act(skb, a, res);
 370                         if (TC_MUNGED & skb->tc_verd) {
 371                                 /* copied already, allow trampling */
 372                                 skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
 373                                 skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
 374                         }
 375                         if (ret == TC_ACT_REPEAT)
 376                                 goto repeat;    /* we need a ttl - JHS */
 377                         if (ret != TC_ACT_PIPE)
 378                                 goto exec_done;
 379                 }
 380                 act = a->next;
 381         }
 382 exec_done:
 383         return ret;
 384 }
 385 EXPORT_SYMBOL(tcf_action_exec);
 386
 387 void tcf_action_destroy(struct tc_action *act, int bind)
 388 {
 389         struct tc_action *a;
 390
 391         for (a = act; a; a = act) {
 392                 if (a->ops && a->ops->cleanup) {
 393                         if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
 394                                 module_put(a->ops->owner);
 395                         act = act->next;
 396                         kfree(a);
 397                 } else { /*FIXME: Remove later - catch insertion bugs*/
 398                         printk("tcf_action_destroy: BUG? destroying NULL ops\n");
 399                         act = act->next;
 400                         kfree(a);
 401                 }
 402         }
 403 }
 404
 405 int
 406 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 407 {
 408         int err = -EINVAL;
 409
 410         if (a->ops == NULL || a->ops->dump == NULL)
 411                 return err;
 412         return a->ops->dump(skb, a, bind, ref);
 413 }
 414
 415 int
 416 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 417 {
 418         int err = -EINVAL;
 419         unsigned char *b = skb_tail_pointer(skb);
 420         struct nlattr *nest;
 421
 422         if (a->ops == NULL || a->ops->dump == NULL)
 423                 return err;
 424
 425         NLA_PUT_STRING(skb, TCA_KIND, a->ops->kind);
 426         if (tcf_action_copy_stats(skb, a, 0))
 427                 goto nla_put_failure;
 428         nest = nla_nest_start(skb, TCA_OPTIONS);
 429         if (nest == NULL)
 430                 goto nla_put_failure;
 431         if ((err = tcf_action_dump_old(skb, a, bind, ref)) > 0) {
 432                 nla_nest_end(skb, nest);
 433                 return err;
 434         }
 435
 436 nla_put_failure:
 437         nlmsg_trim(skb, b);
 438         return -1;
 439 }
 440 EXPORT_SYMBOL(tcf_action_dump_1);
 441
 442 int
 443 tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
 444 {
 445         struct tc_action *a;
 446         int err = -EINVAL;
 447         struct nlattr *nest;
 448
 449         while ((a = act) != NULL) {
 450                 act = a->next;
 451                 nest = nla_nest_start(skb, a->order);
 452                 if (nest == NULL)
 453                         goto nla_put_failure;
 454                 err = tcf_action_dump_1(skb, a, bind, ref);
 455                 if (err < 0)
 456                         goto errout;
 457                 nla_nest_end(skb, nest);
 458         }
 459
 460         return 0;
 461
 462 nla_put_failure:
 463         err = -EINVAL;
 464 errout:
 465         nla_nest_cancel(skb, nest);
 466         return err;
 467 }
 468
 469 struct tc_action *tcf_action_init_1(struct nlattr *nla, struct nlattr *est,
 470                                     char *name, int ovr, int bind)
 471 {
 472         struct tc_action *a;
 473         struct tc_action_ops *a_o;
 474         char act_name[IFNAMSIZ];
 475         struct nlattr *tb[TCA_ACT_MAX+1];
 476         struct nlattr *kind;
 477         int err;
 478
 479         if (name == NULL) {
 480                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 481                 if (err < 0)
 482                         goto err_out;
 483                 err = -EINVAL;
 484                 kind = tb[TCA_ACT_KIND];
 485                 if (kind == NULL)
 486                         goto err_out;
 487                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 488                         goto err_out;
 489         } else {
 490                 err = -EINVAL;
 491                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 492                         goto err_out;
 493         }
 494
 495         a_o = tc_lookup_action_n(act_name);
 496         if (a_o == NULL) {
 497 #ifdef CONFIG_MODULES
 498                 rtnl_unlock();
 499                 request_module("act_%s", act_name);
 500                 rtnl_lock();
 501
 502                 a_o = tc_lookup_action_n(act_name);
 503
 504                 /* We dropped the RTNL semaphore in order to
 505                  * perform the module load.  So, even if we
 506                  * succeeded in loading the module we have to
 507                  * tell the caller to replay the request.  We
 508                  * indicate this using -EAGAIN.
 509                  */
 510                 if (a_o != NULL) {
 511                         err = -EAGAIN;
 512                         goto err_mod;
 513                 }
 514 #endif
 515                 err = -ENOENT;
 516                 goto err_out;
 517         }
 518
 519         err = -ENOMEM;
 520         a = kzalloc(sizeof(*a), GFP_KERNEL);
 521         if (a == NULL)
 522                 goto err_mod;
 523
 524         /* backward compatibility for policer */
 525         if (name == NULL)
 526                 err = a_o->init(tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
 527         else
 528                 err = a_o->init(nla, est, a, ovr, bind);
 529         if (err < 0)
 530                 goto err_free;
 531
 532         /* module count goes up only when brand new policy is created
 533            if it exists and is only bound to in a_o->init() then
 534            ACT_P_CREATED is not returned (a zero is).
 535         */
 536         if (err != ACT_P_CREATED)
 537                 module_put(a_o->owner);
 538         a->ops = a_o;
 539
 540         return a;
 541
 542 err_free:
 543         kfree(a);
 544 err_mod:
 545         module_put(a_o->owner);
 546 err_out:
 547         return ERR_PTR(err);
 548 }
 549
 550 struct tc_action *tcf_action_init(struct nlattr *nla, struct nlattr *est,
 551                                   char *name, int ovr, int bind)
 552 {
 553         struct nlattr *tb[TCA_ACT_MAX_PRIO+1];
 554         struct tc_action *head = NULL, *act, *act_prev = NULL;
 555         int err;
 556         int i;
 557
 558         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 559         if (err < 0)
 560                 return ERR_PTR(err);
 561
 562         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 563                 act = tcf_action_init_1(tb[i], est, name, ovr, bind);
 564                 if (IS_ERR(act))
 565                         goto err;
 566                 act->order = i;
 567
 568                 if (head == NULL)
 569                         head = act;
 570                 else
 571                         act_prev->next = act;
 572                 act_prev = act;
 573         }
 574         return head;
 575
 576 err:
 577         if (head != NULL)
 578                 tcf_action_destroy(head, bind);
 579         return act;
 580 }
 581
 582 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 583                           int compat_mode)
 584 {
 585         int err = 0;
 586         struct gnet_dump d;
 587         struct tcf_act_hdr *h = a->priv;
 588
 589         if (h == NULL)
 590                 goto errout;
 591
 592         /* compat_mode being true specifies a call that is supposed
 593          * to add additional backward compatiblity statistic TLVs.
 594          */
 595         if (compat_mode) {
 596                 if (a->type == TCA_OLD_COMPAT)
 597                         err = gnet_stats_start_copy_compat(skb, 0,
 598                                 TCA_STATS, TCA_XSTATS, &h->tcf_lock, &d);
 599                 else
 600                         return 0;
 601         } else
 602                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 603                                             &h->tcf_lock, &d);
 604
 605         if (err < 0)
 606                 goto errout;
 607
 608         if (a->ops != NULL && a->ops->get_stats != NULL)
 609                 if (a->ops->get_stats(skb, a) < 0)
 610                         goto errout;
 611
 612         if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
 613             gnet_stats_copy_rate_est(&d, &h->tcf_rate_est) < 0 ||
 614             gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
 615                 goto errout;
 616
 617         if (gnet_stats_finish_copy(&d) < 0)
 618                 goto errout;
 619
 620         return 0;
 621
 622 errout:
 623         return -1;
 624 }
 625
 626 static int
 627 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 pid, u32 seq,
 628              u16 flags, int event, int bind, int ref)
 629 {
 630         struct tcamsg *t;
 631         struct nlmsghdr *nlh;
 632         unsigned char *b = skb_tail_pointer(skb);
 633         struct nlattr *nest;
 634
 635         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 636
 637         t = NLMSG_DATA(nlh);
 638         t->tca_family = AF_UNSPEC;
 639         t->tca__pad1 = 0;
 640         t->tca__pad2 = 0;
 641
 642         nest = nla_nest_start(skb, TCA_ACT_TAB);
 643         if (nest == NULL)
 644                 goto nla_put_failure;
 645
 646         if (tcf_action_dump(skb, a, bind, ref) < 0)
 647                 goto nla_put_failure;
 648
 649         nla_nest_end(skb, nest);
 650
 651         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 652         return skb->len;
 653
 654 nla_put_failure:
 655 nlmsg_failure:
 656         nlmsg_trim(skb, b);
 657         return -1;
 658 }
 659
 660 static int
 661 act_get_notify(u32 pid, struct nlmsghdr *n, struct tc_action *a, int event)
 662 {
 663         struct sk_buff *skb;
 664
 665         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 666         if (!skb)
 667                 return -ENOBUFS;
 668         if (tca_get_fill(skb, a, pid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 669                 kfree_skb(skb);
 670                 return -EINVAL;
 671         }
 672
 673         return rtnl_unicast(skb, &init_net, pid);
 674 }
 675
 676 static struct tc_action *
 677 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 pid)
 678 {
 679         struct nlattr *tb[TCA_ACT_MAX+1];
 680         struct tc_action *a;
 681         int index;
 682         int err;
 683
 684         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 685         if (err < 0)
 686                 goto err_out;
 687
 688         err = -EINVAL;
 689         if (tb[TCA_ACT_INDEX] == NULL ||
 690             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 691                 goto err_out;
 692         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 693
 694         err = -ENOMEM;
 695         a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
 696         if (a == NULL)
 697                 goto err_out;
 698
 699         err = -EINVAL;
 700         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 701         if (a->ops == NULL)
 702                 goto err_free;
 703         if (a->ops->lookup == NULL)
 704                 goto err_mod;
 705         err = -ENOENT;
 706         if (a->ops->lookup(a, index) == 0)
 707                 goto err_mod;
 708
 709         module_put(a->ops->owner);
 710         return a;
 711
 712 err_mod:
 713         module_put(a->ops->owner);
 714 err_free:
 715         kfree(a);
 716 err_out:
 717         return ERR_PTR(err);
 718 }
 719
 720 static void cleanup_a(struct tc_action *act)
 721 {
 722         struct tc_action *a;
 723
 724         for (a = act; a; a = act) {
 725                 act = a->next;
 726                 kfree(a);
 727         }
 728 }
 729
 730 static struct tc_action *create_a(int i)
 731 {
 732         struct tc_action *act;
 733
 734         act = kzalloc(sizeof(*act), GFP_KERNEL);
 735         if (act == NULL) {
 736                 printk("create_a: failed to alloc!\n");
 737                 return NULL;
 738         }
 739         act->order = i;
 740         return act;
 741 }
 742
 743 static int tca_action_flush(struct nlattr *nla, struct nlmsghdr *n, u32 pid)
 744 {
 745         struct sk_buff *skb;
 746         unsigned char *b;
 747         struct nlmsghdr *nlh;
 748         struct tcamsg *t;
 749         struct netlink_callback dcb;
 750         struct nlattr *nest;
 751         struct nlattr *tb[TCA_ACT_MAX+1];
 752         struct nlattr *kind;
 753         struct tc_action *a = create_a(0);
 754         int err = -ENOMEM;
 755
 756         if (a == NULL) {
 757                 printk("tca_action_flush: couldnt create tc_action\n");
 758                 return err;
 759         }
 760
 761         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 762         if (!skb) {
 763                 printk("tca_action_flush: failed skb alloc\n");
 764                 kfree(a);
 765                 return err;
 766         }
 767
 768         b = skb_tail_pointer(skb);
 769
 770         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 771         if (err < 0)
 772                 goto err_out;
 773
 774         err = -EINVAL;
 775         kind = tb[TCA_ACT_KIND];
 776         a->ops = tc_lookup_action(kind);
 777         if (a->ops == NULL)
 778                 goto err_out;
 779
 780         nlh = NLMSG_PUT(skb, pid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t));
 781         t = NLMSG_DATA(nlh);
 782         t->tca_family = AF_UNSPEC;
 783         t->tca__pad1 = 0;
 784         t->tca__pad2 = 0;
 785
 786         nest = nla_nest_start(skb, TCA_ACT_TAB);
 787         if (nest == NULL)
 788                 goto nla_put_failure;
 789
 790         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 791         if (err < 0)
 792                 goto nla_put_failure;
 793         if (err == 0)
 794                 goto noflush_out;
 795
 796         nla_nest_end(skb, nest);
 797
 798         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 799         nlh->nlmsg_flags |= NLM_F_ROOT;
 800         module_put(a->ops->owner);
 801         kfree(a);
 802         err = rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO);
 803         if (err > 0)
 804                 return 0;
 805
 806         return err;
 807
 808 nla_put_failure:
 809 nlmsg_failure:
 810         module_put(a->ops->owner);
 811 err_out:
 812 noflush_out:
 813         kfree_skb(skb);
 814         kfree(a);
 815         return err;
 816 }
 817
 818 static int
 819 tca_action_gd(struct nlattr *nla, struct nlmsghdr *n, u32 pid, int event)
 820 {
 821         int i, ret;
 822         struct nlattr *tb[TCA_ACT_MAX_PRIO+1];
 823         struct tc_action *head = NULL, *act, *act_prev = NULL;
 824
 825         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 826         if (ret < 0)
 827                 return ret;
 828
 829         if (event == RTM_DELACTION && n->nlmsg_flags&NLM_F_ROOT) {
 830                 if (tb[1] != NULL)
 831                         return tca_action_flush(tb[1], n, pid);
 832                 else
 833                         return -EINVAL;
 834         }
 835
 836         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 837                 act = tcf_action_get_1(tb[i], n, pid);
 838                 if (IS_ERR(act)) {
 839                         ret = PTR_ERR(act);
 840                         goto err;
 841                 }
 842                 act->order = i;
 843
 844                 if (head == NULL)
 845                         head = act;
 846                 else
 847                         act_prev->next = act;
 848                 act_prev = act;
 849         }
 850
 851         if (event == RTM_GETACTION)
 852                 ret = act_get_notify(pid, n, head, event);
 853         else { /* delete */
 854                 struct sk_buff *skb;
 855
 856                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 857                 if (!skb) {
 858                         ret = -ENOBUFS;
 859                         goto err;
 860                 }
 861
 862                 if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
 863                                  0, 1) <= 0) {
 864                         kfree_skb(skb);
 865                         ret = -EINVAL;
 866                         goto err;
 867                 }
 868
 869                 /* now do the delete */
 870                 tcf_action_destroy(head, 0);
 871                 ret = rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC,
 872                                      n->nlmsg_flags&NLM_F_ECHO);
 873                 if (ret > 0)
 874                         return 0;
 875                 return ret;
 876         }
 877 err:
 878         cleanup_a(head);
 879         return ret;
 880 }
 881
 882 static int tcf_add_notify(struct tc_action *a, u32 pid, u32 seq, int event,
 883                           u16 flags)
 884 {
 885         struct tcamsg *t;
 886         struct nlmsghdr *nlh;
 887         struct sk_buff *skb;
 888         struct nlattr *nest;
 889         unsigned char *b;
 890         int err = 0;
 891
 892         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 893         if (!skb)
 894                 return -ENOBUFS;
 895
 896         b = skb_tail_pointer(skb);
 897
 898         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 899         t = NLMSG_DATA(nlh);
 900         t->tca_family = AF_UNSPEC;
 901         t->tca__pad1 = 0;
 902         t->tca__pad2 = 0;
 903
 904         nest = nla_nest_start(skb, TCA_ACT_TAB);
 905         if (nest == NULL)
 906                 goto nla_put_failure;
 907
 908         if (tcf_action_dump(skb, a, 0, 0) < 0)
 909                 goto nla_put_failure;
 910
 911         nla_nest_end(skb, nest);
 912
 913         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 914         NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 915
 916         err = rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC, flags&NLM_F_ECHO);
 917         if (err > 0)
 918                 err = 0;
 919         return err;
 920
 921 nla_put_failure:
 922 nlmsg_failure:
 923         kfree_skb(skb);
 924         return -1;
 925 }
 926
 927
 928 static int
 929 tcf_action_add(struct nlattr *nla, struct nlmsghdr *n, u32 pid, int ovr)
 930 {
 931         int ret = 0;
 932         struct tc_action *act;
 933         struct tc_action *a;
 934         u32 seq = n->nlmsg_seq;
 935
 936         act = tcf_action_init(nla, NULL, NULL, ovr, 0);
 937         if (act == NULL)
 938                 goto done;
 939         if (IS_ERR(act)) {
 940                 ret = PTR_ERR(act);
 941                 goto done;
 942         }
 943
 944         /* dump then free all the actions after update; inserted policy
 945          * stays intact
 946          * */
 947         ret = tcf_add_notify(act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
 948         for (a = act; a; a = act) {
 949                 act = a->next;
 950                 kfree(a);
 951         }
 952 done:
 953         return ret;
 954 }
 955
 956 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 957 {
 958         struct net *net = sock_net(skb->sk);
 959         struct nlattr *tca[TCA_ACT_MAX + 1];
 960         u32 pid = skb ? NETLINK_CB(skb).pid : 0;
 961         int ret = 0, ovr = 0;
 962
 963         if (net != &init_net)
 964                 return -EINVAL;
 965
 966         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
 967         if (ret < 0)
 968                 return ret;
 969
 970         if (tca[TCA_ACT_TAB] == NULL) {
 971                 printk("tc_ctl_action: received NO action attribs\n");
 972                 return -EINVAL;
 973         }
 974
 975         /* n->nlmsg_flags&NLM_F_CREATE
 976          * */
 977         switch (n->nlmsg_type) {
 978         case RTM_NEWACTION:
 979                 /* we are going to assume all other flags
 980                  * imply create only if it doesnt exist
 981                  * Note that CREATE | EXCL implies that
 982                  * but since we want avoid ambiguity (eg when flags
 983                  * is zero) then just set this
 984                  */
 985                 if (n->nlmsg_flags&NLM_F_REPLACE)
 986                         ovr = 1;
 987 replay:
 988                 ret = tcf_action_add(tca[TCA_ACT_TAB], n, pid, ovr);
 989                 if (ret == -EAGAIN)
 990                         goto replay;
 991                 break;
 992         case RTM_DELACTION:
 993                 ret = tca_action_gd(tca[TCA_ACT_TAB], n, pid, RTM_DELACTION);
 994                 break;
 995         case RTM_GETACTION:
 996                 ret = tca_action_gd(tca[TCA_ACT_TAB], n, pid, RTM_GETACTION);
 997                 break;
 998         default:
 999                 BUG();
1000         }
1001
1002         return ret;
1003 }
1004
1005 static struct nlattr *
1006 find_dump_kind(struct nlmsghdr *n)
1007 {
1008         struct nlattr *tb1, *tb2[TCA_ACT_MAX+1];
1009         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1010         struct nlattr *nla[TCAA_MAX + 1];
1011         struct nlattr *kind;
1012
1013         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1014                 return NULL;
1015         tb1 = nla[TCA_ACT_TAB];
1016         if (tb1 == NULL)
1017                 return NULL;
1018
1019         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1020                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1021                 return NULL;
1022
1023         if (tb[1] == NULL)
1024                 return NULL;
1025         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1026                       nla_len(tb[1]), NULL) < 0)
1027                 return NULL;
1028         kind = tb2[TCA_ACT_KIND];
1029
1030         return kind;
1031 }
1032
1033 static int
1034 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1035 {
1036         struct net *net = sock_net(skb->sk);
1037         struct nlmsghdr *nlh;
1038         unsigned char *b = skb_tail_pointer(skb);
1039         struct nlattr *nest;
1040         struct tc_action_ops *a_o;
1041         struct tc_action a;
1042         int ret = 0;
1043         struct tcamsg *t = (struct tcamsg *) NLMSG_DATA(cb->nlh);
1044         struct nlattr *kind = find_dump_kind(cb->nlh);
1045
1046         if (net != &init_net)
1047                 return 0;
1048
1049         if (kind == NULL) {
1050                 printk("tc_dump_action: action bad kind\n");
1051                 return 0;
1052         }
1053
1054         a_o = tc_lookup_action(kind);
1055         if (a_o == NULL) {
1056                 return 0;
1057         }
1058
1059         memset(&a, 0, sizeof(struct tc_action));
1060         a.ops = a_o;
1061
1062         if (a_o->walk == NULL) {
1063                 printk("tc_dump_action: %s !capable of dumping table\n", a_o->kind);
1064                 goto nla_put_failure;
1065         }
1066
1067         nlh = NLMSG_PUT(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
1068                         cb->nlh->nlmsg_type, sizeof(*t));
1069         t = NLMSG_DATA(nlh);
1070         t->tca_family = AF_UNSPEC;
1071         t->tca__pad1 = 0;
1072         t->tca__pad2 = 0;
1073
1074         nest = nla_nest_start(skb, TCA_ACT_TAB);
1075         if (nest == NULL)
1076                 goto nla_put_failure;
1077
1078         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1079         if (ret < 0)
1080                 goto nla_put_failure;
1081
1082         if (ret > 0) {
1083                 nla_nest_end(skb, nest);
1084                 ret = skb->len;
1085         } else
1086                 nla_nest_cancel(skb, nest);
1087
1088         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1089         if (NETLINK_CB(cb->skb).pid && ret)
1090                 nlh->nlmsg_flags |= NLM_F_MULTI;
1091         module_put(a_o->owner);
1092         return skb->len;
1093
1094 nla_put_failure:
1095 nlmsg_failure:
1096         module_put(a_o->owner);
1097         nlmsg_trim(skb, b);
1098         return skb->len;
1099 }
1100
1101 static int __init tc_action_init(void)
1102 {
1103         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL);
1104         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL);
1105         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action);
1106
1107         return 0;
1108 }
1109
1110 subsys_initcall(tc_action_init);