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 <net/net_namespace.h>
  22 #include <net/sock.h>
  23 #include <net/sch_generic.h>
  24 #include <net/act_api.h>
  25 #include <net/netlink.h>
  26
  27 void tcf_hash_destroy(struct tcf_common *p, struct tcf_hashinfo *hinfo)
  28 {
  29         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
  30         struct tcf_common **p1p;
  31
  32         for (p1p = &hinfo->htab[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
  33                 if (*p1p == p) {
  34                         write_lock_bh(hinfo->lock);
  35                         *p1p = p->tcfc_next;
  36                         write_unlock_bh(hinfo->lock);
  37                         gen_kill_estimator(&p->tcfc_bstats,
  38                                            &p->tcfc_rate_est);
  39                         kfree(p);
  40                         return;
  41                 }
  42         }
  43         BUG_TRAP(0);
  44 }
  45 EXPORT_SYMBOL(tcf_hash_destroy);
  46
  47 int tcf_hash_release(struct tcf_common *p, int bind,
  48                      struct tcf_hashinfo *hinfo)
  49 {
  50         int ret = 0;
  51
  52         if (p) {
  53                 if (bind)
  54                         p->tcfc_bindcnt--;
  55
  56                 p->tcfc_refcnt--;
  57                 if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
  58                         tcf_hash_destroy(p, hinfo);
  59                         ret = 1;
  60                 }
  61         }
  62         return ret;
  63 }
  64 EXPORT_SYMBOL(tcf_hash_release);
  65
  66 static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
  67                            struct tc_action *a, struct tcf_hashinfo *hinfo)
  68 {
  69         struct tcf_common *p;
  70         int err = 0, index = -1,i = 0, s_i = 0, n_i = 0;
  71         struct rtattr *r ;
  72
  73         read_lock_bh(hinfo->lock);
  74
  75         s_i = cb->args[0];
  76
  77         for (i = 0; i < (hinfo->hmask + 1); i++) {
  78                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
  79
  80                 for (; p; p = p->tcfc_next) {
  81                         index++;
  82                         if (index < s_i)
  83                                 continue;
  84                         a->priv = p;
  85                         a->order = n_i;
  86                         r = (struct rtattr *)skb_tail_pointer(skb);
  87                         RTA_PUT(skb, a->order, 0, NULL);
  88                         err = tcf_action_dump_1(skb, a, 0, 0);
  89                         if (err < 0) {
  90                                 index--;
  91                                 nlmsg_trim(skb, r);
  92                                 goto done;
  93                         }
  94                         r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
  95                         n_i++;
  96                         if (n_i >= TCA_ACT_MAX_PRIO)
  97                                 goto done;
  98                 }
  99         }
 100 done:
 101         read_unlock_bh(hinfo->lock);
 102         if (n_i)
 103                 cb->args[0] += n_i;
 104         return n_i;
 105
 106 rtattr_failure:
 107         nlmsg_trim(skb, r);
 108         goto done;
 109 }
 110
 111 static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a,
 112                           struct tcf_hashinfo *hinfo)
 113 {
 114         struct tcf_common *p, *s_p;
 115         struct rtattr *r ;
 116         int i= 0, n_i = 0;
 117
 118         r = (struct rtattr *)skb_tail_pointer(skb);
 119         RTA_PUT(skb, a->order, 0, NULL);
 120         RTA_PUT(skb, TCA_KIND, IFNAMSIZ, a->ops->kind);
 121         for (i = 0; i < (hinfo->hmask + 1); i++) {
 122                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
 123
 124                 while (p != NULL) {
 125                         s_p = p->tcfc_next;
 126                         if (ACT_P_DELETED == tcf_hash_release(p, 0, hinfo))
 127                                  module_put(a->ops->owner);
 128                         n_i++;
 129                         p = s_p;
 130                 }
 131         }
 132         RTA_PUT(skb, TCA_FCNT, 4, &n_i);
 133         r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
 134
 135         return n_i;
 136 rtattr_failure:
 137         nlmsg_trim(skb, r);
 138         return -EINVAL;
 139 }
 140
 141 int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
 142                        int type, struct tc_action *a)
 143 {
 144         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 145
 146         if (type == RTM_DELACTION) {
 147                 return tcf_del_walker(skb, a, hinfo);
 148         } else if (type == RTM_GETACTION) {
 149                 return tcf_dump_walker(skb, cb, a, hinfo);
 150         } else {
 151                 printk("tcf_generic_walker: unknown action %d\n", type);
 152                 return -EINVAL;
 153         }
 154 }
 155 EXPORT_SYMBOL(tcf_generic_walker);
 156
 157 struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 158 {
 159         struct tcf_common *p;
 160
 161         read_lock_bh(hinfo->lock);
 162         for (p = hinfo->htab[tcf_hash(index, hinfo->hmask)]; p;
 163              p = p->tcfc_next) {
 164                 if (p->tcfc_index == index)
 165                         break;
 166         }
 167         read_unlock_bh(hinfo->lock);
 168
 169         return p;
 170 }
 171 EXPORT_SYMBOL(tcf_hash_lookup);
 172
 173 u32 tcf_hash_new_index(u32 *idx_gen, struct tcf_hashinfo *hinfo)
 174 {
 175         u32 val = *idx_gen;
 176
 177         do {
 178                 if (++val == 0)
 179                         val = 1;
 180         } while (tcf_hash_lookup(val, hinfo));
 181
 182         return (*idx_gen = val);
 183 }
 184 EXPORT_SYMBOL(tcf_hash_new_index);
 185
 186 int tcf_hash_search(struct tc_action *a, u32 index)
 187 {
 188         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 189         struct tcf_common *p = tcf_hash_lookup(index, hinfo);
 190
 191         if (p) {
 192                 a->priv = p;
 193                 return 1;
 194         }
 195         return 0;
 196 }
 197 EXPORT_SYMBOL(tcf_hash_search);
 198
 199 struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
 200                                   struct tcf_hashinfo *hinfo)
 201 {
 202         struct tcf_common *p = NULL;
 203         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 204                 if (bind) {
 205                         p->tcfc_bindcnt++;
 206                         p->tcfc_refcnt++;
 207                 }
 208                 a->priv = p;
 209         }
 210         return p;
 211 }
 212 EXPORT_SYMBOL(tcf_hash_check);
 213
 214 struct tcf_common *tcf_hash_create(u32 index, struct rtattr *est, struct tc_action *a, int size, int bind, u32 *idx_gen, struct tcf_hashinfo *hinfo)
 215 {
 216         struct tcf_common *p = kzalloc(size, GFP_KERNEL);
 217
 218         if (unlikely(!p))
 219                 return p;
 220         p->tcfc_refcnt = 1;
 221         if (bind)
 222                 p->tcfc_bindcnt = 1;
 223
 224         spin_lock_init(&p->tcfc_lock);
 225         p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
 226         p->tcfc_tm.install = jiffies;
 227         p->tcfc_tm.lastuse = jiffies;
 228         if (est)
 229                 gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
 230                                   &p->tcfc_lock, est);
 231         a->priv = (void *) p;
 232         return p;
 233 }
 234 EXPORT_SYMBOL(tcf_hash_create);
 235
 236 void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
 237 {
 238         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
 239
 240         write_lock_bh(hinfo->lock);
 241         p->tcfc_next = hinfo->htab[h];
 242         hinfo->htab[h] = p;
 243         write_unlock_bh(hinfo->lock);
 244 }
 245 EXPORT_SYMBOL(tcf_hash_insert);
 246
 247 static struct tc_action_ops *act_base = NULL;
 248 static DEFINE_RWLOCK(act_mod_lock);
 249
 250 int tcf_register_action(struct tc_action_ops *act)
 251 {
 252         struct tc_action_ops *a, **ap;
 253
 254         write_lock(&act_mod_lock);
 255         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
 256                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 257                         write_unlock(&act_mod_lock);
 258                         return -EEXIST;
 259                 }
 260         }
 261         act->next = NULL;
 262         *ap = act;
 263         write_unlock(&act_mod_lock);
 264         return 0;
 265 }
 266
 267 int tcf_unregister_action(struct tc_action_ops *act)
 268 {
 269         struct tc_action_ops *a, **ap;
 270         int err = -ENOENT;
 271
 272         write_lock(&act_mod_lock);
 273         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
 274                 if (a == act)
 275                         break;
 276         if (a) {
 277                 *ap = a->next;
 278                 a->next = NULL;
 279                 err = 0;
 280         }
 281         write_unlock(&act_mod_lock);
 282         return err;
 283 }
 284
 285 /* lookup by name */
 286 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 287 {
 288         struct tc_action_ops *a = NULL;
 289
 290         if (kind) {
 291                 read_lock(&act_mod_lock);
 292                 for (a = act_base; a; a = a->next) {
 293                         if (strcmp(kind, a->kind) == 0) {
 294                                 if (!try_module_get(a->owner)) {
 295                                         read_unlock(&act_mod_lock);
 296                                         return NULL;
 297                                 }
 298                                 break;
 299                         }
 300                 }
 301                 read_unlock(&act_mod_lock);
 302         }
 303         return a;
 304 }
 305
 306 /* lookup by rtattr */
 307 static struct tc_action_ops *tc_lookup_action(struct rtattr *kind)
 308 {
 309         struct tc_action_ops *a = NULL;
 310
 311         if (kind) {
 312                 read_lock(&act_mod_lock);
 313                 for (a = act_base; a; a = a->next) {
 314                         if (rtattr_strcmp(kind, a->kind) == 0) {
 315                                 if (!try_module_get(a->owner)) {
 316                                         read_unlock(&act_mod_lock);
 317                                         return NULL;
 318                                 }
 319                                 break;
 320                         }
 321                 }
 322                 read_unlock(&act_mod_lock);
 323         }
 324         return a;
 325 }
 326
 327 #if 0
 328 /* lookup by id */
 329 static struct tc_action_ops *tc_lookup_action_id(u32 type)
 330 {
 331         struct tc_action_ops *a = NULL;
 332
 333         if (type) {
 334                 read_lock(&act_mod_lock);
 335                 for (a = act_base; a; a = a->next) {
 336                         if (a->type == type) {
 337                                 if (!try_module_get(a->owner)) {
 338                                         read_unlock(&act_mod_lock);
 339                                         return NULL;
 340                                 }
 341                                 break;
 342                         }
 343                 }
 344                 read_unlock(&act_mod_lock);
 345         }
 346         return a;
 347 }
 348 #endif
 349
 350 int tcf_action_exec(struct sk_buff *skb, struct tc_action *act,
 351                     struct tcf_result *res)
 352 {
 353         struct tc_action *a;
 354         int ret = -1;
 355
 356         if (skb->tc_verd & TC_NCLS) {
 357                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 358                 ret = TC_ACT_OK;
 359                 goto exec_done;
 360         }
 361         while ((a = act) != NULL) {
 362 repeat:
 363                 if (a->ops && a->ops->act) {
 364                         ret = a->ops->act(skb, a, res);
 365                         if (TC_MUNGED & skb->tc_verd) {
 366                                 /* copied already, allow trampling */
 367                                 skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
 368                                 skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
 369                         }
 370                         if (ret == TC_ACT_REPEAT)
 371                                 goto repeat;    /* we need a ttl - JHS */
 372                         if (ret != TC_ACT_PIPE)
 373                                 goto exec_done;
 374                 }
 375                 act = a->next;
 376         }
 377 exec_done:
 378         return ret;
 379 }
 380
 381 void tcf_action_destroy(struct tc_action *act, int bind)
 382 {
 383         struct tc_action *a;
 384
 385         for (a = act; a; a = act) {
 386                 if (a->ops && a->ops->cleanup) {
 387                         if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
 388                                 module_put(a->ops->owner);
 389                         act = act->next;
 390                         kfree(a);
 391                 } else { /*FIXME: Remove later - catch insertion bugs*/
 392                         printk("tcf_action_destroy: BUG? destroying NULL ops\n");
 393                         act = act->next;
 394                         kfree(a);
 395                 }
 396         }
 397 }
 398
 399 int
 400 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 401 {
 402         int err = -EINVAL;
 403
 404         if (a->ops == NULL || a->ops->dump == NULL)
 405                 return err;
 406         return a->ops->dump(skb, a, bind, ref);
 407 }
 408
 409 int
 410 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 411 {
 412         int err = -EINVAL;
 413         unsigned char *b = skb_tail_pointer(skb);
 414         struct rtattr *r;
 415
 416         if (a->ops == NULL || a->ops->dump == NULL)
 417                 return err;
 418
 419         RTA_PUT(skb, TCA_KIND, IFNAMSIZ, a->ops->kind);
 420         if (tcf_action_copy_stats(skb, a, 0))
 421                 goto rtattr_failure;
 422         r = (struct rtattr *)skb_tail_pointer(skb);
 423         RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
 424         if ((err = tcf_action_dump_old(skb, a, bind, ref)) > 0) {
 425                 r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
 426                 return err;
 427         }
 428
 429 rtattr_failure:
 430         nlmsg_trim(skb, b);
 431         return -1;
 432 }
 433
 434 int
 435 tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
 436 {
 437         struct tc_action *a;
 438         int err = -EINVAL;
 439         unsigned char *b = skb_tail_pointer(skb);
 440         struct rtattr *r ;
 441
 442         while ((a = act) != NULL) {
 443                 r = (struct rtattr *)skb_tail_pointer(skb);
 444                 act = a->next;
 445                 RTA_PUT(skb, a->order, 0, NULL);
 446                 err = tcf_action_dump_1(skb, a, bind, ref);
 447                 if (err < 0)
 448                         goto errout;
 449                 r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
 450         }
 451
 452         return 0;
 453
 454 rtattr_failure:
 455         err = -EINVAL;
 456 errout:
 457         nlmsg_trim(skb, b);
 458         return err;
 459 }
 460
 461 struct tc_action *tcf_action_init_1(struct rtattr *rta, struct rtattr *est,
 462                                     char *name, int ovr, int bind, int *err)
 463 {
 464         struct tc_action *a;
 465         struct tc_action_ops *a_o;
 466         char act_name[IFNAMSIZ];
 467         struct rtattr *tb[TCA_ACT_MAX+1];
 468         struct rtattr *kind;
 469
 470         *err = -EINVAL;
 471
 472         if (name == NULL) {
 473                 if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
 474                         goto err_out;
 475                 kind = tb[TCA_ACT_KIND-1];
 476                 if (kind == NULL)
 477                         goto err_out;
 478                 if (rtattr_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 479                         goto err_out;
 480         } else {
 481                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 482                         goto err_out;
 483         }
 484
 485         a_o = tc_lookup_action_n(act_name);
 486         if (a_o == NULL) {
 487 #ifdef CONFIG_KMOD
 488                 rtnl_unlock();
 489                 request_module("act_%s", act_name);
 490                 rtnl_lock();
 491
 492                 a_o = tc_lookup_action_n(act_name);
 493
 494                 /* We dropped the RTNL semaphore in order to
 495                  * perform the module load.  So, even if we
 496                  * succeeded in loading the module we have to
 497                  * tell the caller to replay the request.  We
 498                  * indicate this using -EAGAIN.
 499                  */
 500                 if (a_o != NULL) {
 501                         *err = -EAGAIN;
 502                         goto err_mod;
 503                 }
 504 #endif
 505                 *err = -ENOENT;
 506                 goto err_out;
 507         }
 508
 509         *err = -ENOMEM;
 510         a = kzalloc(sizeof(*a), GFP_KERNEL);
 511         if (a == NULL)
 512                 goto err_mod;
 513
 514         /* backward compatibility for policer */
 515         if (name == NULL)
 516                 *err = a_o->init(tb[TCA_ACT_OPTIONS-1], est, a, ovr, bind);
 517         else
 518                 *err = a_o->init(rta, est, a, ovr, bind);
 519         if (*err < 0)
 520                 goto err_free;
 521
 522         /* module count goes up only when brand new policy is created
 523            if it exists and is only bound to in a_o->init() then
 524            ACT_P_CREATED is not returned (a zero is).
 525         */
 526         if (*err != ACT_P_CREATED)
 527                 module_put(a_o->owner);
 528         a->ops = a_o;
 529
 530         *err = 0;
 531         return a;
 532
 533 err_free:
 534         kfree(a);
 535 err_mod:
 536         module_put(a_o->owner);
 537 err_out:
 538         return NULL;
 539 }
 540
 541 struct tc_action *tcf_action_init(struct rtattr *rta, struct rtattr *est,
 542                                   char *name, int ovr, int bind, int *err)
 543 {
 544         struct rtattr *tb[TCA_ACT_MAX_PRIO+1];
 545         struct tc_action *head = NULL, *act, *act_prev = NULL;
 546         int i;
 547
 548         if (rtattr_parse_nested(tb, TCA_ACT_MAX_PRIO, rta) < 0) {
 549                 *err = -EINVAL;
 550                 return head;
 551         }
 552
 553         for (i=0; i < TCA_ACT_MAX_PRIO && tb[i]; i++) {
 554                 act = tcf_action_init_1(tb[i], est, name, ovr, bind, err);
 555                 if (act == NULL)
 556                         goto err;
 557                 act->order = i+1;
 558
 559                 if (head == NULL)
 560                         head = act;
 561                 else
 562                         act_prev->next = act;
 563                 act_prev = act;
 564         }
 565         return head;
 566
 567 err:
 568         if (head != NULL)
 569                 tcf_action_destroy(head, bind);
 570         return NULL;
 571 }
 572
 573 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 574                           int compat_mode)
 575 {
 576         int err = 0;
 577         struct gnet_dump d;
 578         struct tcf_act_hdr *h = a->priv;
 579
 580         if (h == NULL)
 581                 goto errout;
 582
 583         /* compat_mode being true specifies a call that is supposed
 584          * to add additional backward compatiblity statistic TLVs.
 585          */
 586         if (compat_mode) {
 587                 if (a->type == TCA_OLD_COMPAT)
 588                         err = gnet_stats_start_copy_compat(skb, 0,
 589                                 TCA_STATS, TCA_XSTATS, &h->tcf_lock, &d);
 590                 else
 591                         return 0;
 592         } else
 593                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 594                                             &h->tcf_lock, &d);
 595
 596         if (err < 0)
 597                 goto errout;
 598
 599         if (a->ops != NULL && a->ops->get_stats != NULL)
 600                 if (a->ops->get_stats(skb, a) < 0)
 601                         goto errout;
 602
 603         if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
 604             gnet_stats_copy_rate_est(&d, &h->tcf_rate_est) < 0 ||
 605             gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
 606                 goto errout;
 607
 608         if (gnet_stats_finish_copy(&d) < 0)
 609                 goto errout;
 610
 611         return 0;
 612
 613 errout:
 614         return -1;
 615 }
 616
 617 static int
 618 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 pid, u32 seq,
 619              u16 flags, int event, int bind, int ref)
 620 {
 621         struct tcamsg *t;
 622         struct nlmsghdr *nlh;
 623         unsigned char *b = skb_tail_pointer(skb);
 624         struct rtattr *x;
 625
 626         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 627
 628         t = NLMSG_DATA(nlh);
 629         t->tca_family = AF_UNSPEC;
 630         t->tca__pad1 = 0;
 631         t->tca__pad2 = 0;
 632
 633         x = (struct rtattr *)skb_tail_pointer(skb);
 634         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 635
 636         if (tcf_action_dump(skb, a, bind, ref) < 0)
 637                 goto rtattr_failure;
 638
 639         x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
 640
 641         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 642         return skb->len;
 643
 644 rtattr_failure:
 645 nlmsg_failure:
 646         nlmsg_trim(skb, b);
 647         return -1;
 648 }
 649
 650 static int
 651 act_get_notify(u32 pid, struct nlmsghdr *n, struct tc_action *a, int event)
 652 {
 653         struct sk_buff *skb;
 654
 655         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 656         if (!skb)
 657                 return -ENOBUFS;
 658         if (tca_get_fill(skb, a, pid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 659                 kfree_skb(skb);
 660                 return -EINVAL;
 661         }
 662
 663         return rtnl_unicast(skb, &init_net, pid);
 664 }
 665
 666 static struct tc_action *
 667 tcf_action_get_1(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int *err)
 668 {
 669         struct rtattr *tb[TCA_ACT_MAX+1];
 670         struct tc_action *a;
 671         int index;
 672
 673         *err = -EINVAL;
 674         if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
 675                 return NULL;
 676
 677         if (tb[TCA_ACT_INDEX - 1] == NULL ||
 678             RTA_PAYLOAD(tb[TCA_ACT_INDEX - 1]) < sizeof(index))
 679                 return NULL;
 680         index = *(int *)RTA_DATA(tb[TCA_ACT_INDEX - 1]);
 681
 682         *err = -ENOMEM;
 683         a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
 684         if (a == NULL)
 685                 return NULL;
 686
 687         *err = -EINVAL;
 688         a->ops = tc_lookup_action(tb[TCA_ACT_KIND - 1]);
 689         if (a->ops == NULL)
 690                 goto err_free;
 691         if (a->ops->lookup == NULL)
 692                 goto err_mod;
 693         *err = -ENOENT;
 694         if (a->ops->lookup(a, index) == 0)
 695                 goto err_mod;
 696
 697         module_put(a->ops->owner);
 698         *err = 0;
 699         return a;
 700 err_mod:
 701         module_put(a->ops->owner);
 702 err_free:
 703         kfree(a);
 704         return NULL;
 705 }
 706
 707 static void cleanup_a(struct tc_action *act)
 708 {
 709         struct tc_action *a;
 710
 711         for (a = act; a; a = act) {
 712                 act = a->next;
 713                 kfree(a);
 714         }
 715 }
 716
 717 static struct tc_action *create_a(int i)
 718 {
 719         struct tc_action *act;
 720
 721         act = kzalloc(sizeof(*act), GFP_KERNEL);
 722         if (act == NULL) {
 723                 printk("create_a: failed to alloc!\n");
 724                 return NULL;
 725         }
 726         act->order = i;
 727         return act;
 728 }
 729
 730 static int tca_action_flush(struct rtattr *rta, struct nlmsghdr *n, u32 pid)
 731 {
 732         struct sk_buff *skb;
 733         unsigned char *b;
 734         struct nlmsghdr *nlh;
 735         struct tcamsg *t;
 736         struct netlink_callback dcb;
 737         struct rtattr *x;
 738         struct rtattr *tb[TCA_ACT_MAX+1];
 739         struct rtattr *kind;
 740         struct tc_action *a = create_a(0);
 741         int err = -EINVAL;
 742
 743         if (a == NULL) {
 744                 printk("tca_action_flush: couldnt create tc_action\n");
 745                 return err;
 746         }
 747
 748         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 749         if (!skb) {
 750                 printk("tca_action_flush: failed skb alloc\n");
 751                 kfree(a);
 752                 return -ENOBUFS;
 753         }
 754
 755         b = skb_tail_pointer(skb);
 756
 757         if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
 758                 goto err_out;
 759
 760         kind = tb[TCA_ACT_KIND-1];
 761         a->ops = tc_lookup_action(kind);
 762         if (a->ops == NULL)
 763                 goto err_out;
 764
 765         nlh = NLMSG_PUT(skb, pid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t));
 766         t = NLMSG_DATA(nlh);
 767         t->tca_family = AF_UNSPEC;
 768         t->tca__pad1 = 0;
 769         t->tca__pad2 = 0;
 770
 771         x = (struct rtattr *)skb_tail_pointer(skb);
 772         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 773
 774         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 775         if (err < 0)
 776                 goto rtattr_failure;
 777
 778         x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
 779
 780         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 781         nlh->nlmsg_flags |= NLM_F_ROOT;
 782         module_put(a->ops->owner);
 783         kfree(a);
 784         err = rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO);
 785         if (err > 0)
 786                 return 0;
 787
 788         return err;
 789
 790 rtattr_failure:
 791 nlmsg_failure:
 792         module_put(a->ops->owner);
 793 err_out:
 794         kfree_skb(skb);
 795         kfree(a);
 796         return err;
 797 }
 798
 799 static int
 800 tca_action_gd(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int event)
 801 {
 802         int i, ret = 0;
 803         struct rtattr *tb[TCA_ACT_MAX_PRIO+1];
 804         struct tc_action *head = NULL, *act, *act_prev = NULL;
 805
 806         if (rtattr_parse_nested(tb, TCA_ACT_MAX_PRIO, rta) < 0)
 807                 return -EINVAL;
 808
 809         if (event == RTM_DELACTION && n->nlmsg_flags&NLM_F_ROOT) {
 810                 if (tb[0] != NULL && tb[1] == NULL)
 811                         return tca_action_flush(tb[0], n, pid);
 812         }
 813
 814         for (i=0; i < TCA_ACT_MAX_PRIO && tb[i]; i++) {
 815                 act = tcf_action_get_1(tb[i], n, pid, &ret);
 816                 if (act == NULL)
 817                         goto err;
 818                 act->order = i+1;
 819
 820                 if (head == NULL)
 821                         head = act;
 822                 else
 823                         act_prev->next = act;
 824                 act_prev = act;
 825         }
 826
 827         if (event == RTM_GETACTION)
 828                 ret = act_get_notify(pid, n, head, event);
 829         else { /* delete */
 830                 struct sk_buff *skb;
 831
 832                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 833                 if (!skb) {
 834                         ret = -ENOBUFS;
 835                         goto err;
 836                 }
 837
 838                 if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
 839                                  0, 1) <= 0) {
 840                         kfree_skb(skb);
 841                         ret = -EINVAL;
 842                         goto err;
 843                 }
 844
 845                 /* now do the delete */
 846                 tcf_action_destroy(head, 0);
 847                 ret = rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC,
 848                                      n->nlmsg_flags&NLM_F_ECHO);
 849                 if (ret > 0)
 850                         return 0;
 851                 return ret;
 852         }
 853 err:
 854         cleanup_a(head);
 855         return ret;
 856 }
 857
 858 static int tcf_add_notify(struct tc_action *a, u32 pid, u32 seq, int event,
 859                           u16 flags)
 860 {
 861         struct tcamsg *t;
 862         struct nlmsghdr *nlh;
 863         struct sk_buff *skb;
 864         struct rtattr *x;
 865         unsigned char *b;
 866         int err = 0;
 867
 868         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 869         if (!skb)
 870                 return -ENOBUFS;
 871
 872         b = skb_tail_pointer(skb);
 873
 874         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 875         t = NLMSG_DATA(nlh);
 876         t->tca_family = AF_UNSPEC;
 877         t->tca__pad1 = 0;
 878         t->tca__pad2 = 0;
 879
 880         x = (struct rtattr *)skb_tail_pointer(skb);
 881         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 882
 883         if (tcf_action_dump(skb, a, 0, 0) < 0)
 884                 goto rtattr_failure;
 885
 886         x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
 887
 888         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 889         NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 890
 891         err = rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC, flags&NLM_F_ECHO);
 892         if (err > 0)
 893                 err = 0;
 894         return err;
 895
 896 rtattr_failure:
 897 nlmsg_failure:
 898         kfree_skb(skb);
 899         return -1;
 900 }
 901
 902
 903 static int
 904 tcf_action_add(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int ovr)
 905 {
 906         int ret = 0;
 907         struct tc_action *act;
 908         struct tc_action *a;
 909         u32 seq = n->nlmsg_seq;
 910
 911         act = tcf_action_init(rta, NULL, NULL, ovr, 0, &ret);
 912         if (act == NULL)
 913                 goto done;
 914
 915         /* dump then free all the actions after update; inserted policy
 916          * stays intact
 917          * */
 918         ret = tcf_add_notify(act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
 919         for (a = act; a; a = act) {
 920                 act = a->next;
 921                 kfree(a);
 922         }
 923 done:
 924         return ret;
 925 }
 926
 927 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 928 {
 929         struct net *net = skb->sk->sk_net;
 930         struct rtattr **tca = arg;
 931         u32 pid = skb ? NETLINK_CB(skb).pid : 0;
 932         int ret = 0, ovr = 0;
 933
 934         if (net != &init_net)
 935                 return -EINVAL;
 936
 937         if (tca[TCA_ACT_TAB-1] == NULL) {
 938                 printk("tc_ctl_action: received NO action attribs\n");
 939                 return -EINVAL;
 940         }
 941
 942         /* n->nlmsg_flags&NLM_F_CREATE
 943          * */
 944         switch (n->nlmsg_type) {
 945         case RTM_NEWACTION:
 946                 /* we are going to assume all other flags
 947                  * imply create only if it doesnt exist
 948                  * Note that CREATE | EXCL implies that
 949                  * but since we want avoid ambiguity (eg when flags
 950                  * is zero) then just set this
 951                  */
 952                 if (n->nlmsg_flags&NLM_F_REPLACE)
 953                         ovr = 1;
 954 replay:
 955                 ret = tcf_action_add(tca[TCA_ACT_TAB-1], n, pid, ovr);
 956                 if (ret == -EAGAIN)
 957                         goto replay;
 958                 break;
 959         case RTM_DELACTION:
 960                 ret = tca_action_gd(tca[TCA_ACT_TAB-1], n, pid, RTM_DELACTION);
 961                 break;
 962         case RTM_GETACTION:
 963                 ret = tca_action_gd(tca[TCA_ACT_TAB-1], n, pid, RTM_GETACTION);
 964                 break;
 965         default:
 966                 BUG();
 967         }
 968
 969         return ret;
 970 }
 971
 972 static struct rtattr *
 973 find_dump_kind(struct nlmsghdr *n)
 974 {
 975         struct rtattr *tb1, *tb2[TCA_ACT_MAX+1];
 976         struct rtattr *tb[TCA_ACT_MAX_PRIO + 1];
 977         struct rtattr *rta[TCAA_MAX + 1];
 978         struct rtattr *kind;
 979         int min_len = NLMSG_LENGTH(sizeof(struct tcamsg));
 980         int attrlen = n->nlmsg_len - NLMSG_ALIGN(min_len);
 981         struct rtattr *attr = (void *) n + NLMSG_ALIGN(min_len);
 982
 983         if (rtattr_parse(rta, TCAA_MAX, attr, attrlen) < 0)
 984                 return NULL;
 985         tb1 = rta[TCA_ACT_TAB - 1];
 986         if (tb1 == NULL)
 987                 return NULL;
 988
 989         if (rtattr_parse(tb, TCA_ACT_MAX_PRIO, RTA_DATA(tb1),
 990                          NLMSG_ALIGN(RTA_PAYLOAD(tb1))) < 0)
 991                 return NULL;
 992         if (tb[0] == NULL)
 993                 return NULL;
 994
 995         if (rtattr_parse(tb2, TCA_ACT_MAX, RTA_DATA(tb[0]),
 996                          RTA_PAYLOAD(tb[0])) < 0)
 997                 return NULL;
 998         kind = tb2[TCA_ACT_KIND-1];
 999
1000         return kind;
1001 }
1002
1003 static int
1004 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1005 {
1006         struct net *net = skb->sk->sk_net;
1007         struct nlmsghdr *nlh;
1008         unsigned char *b = skb_tail_pointer(skb);
1009         struct rtattr *x;
1010         struct tc_action_ops *a_o;
1011         struct tc_action a;
1012         int ret = 0;
1013         struct tcamsg *t = (struct tcamsg *) NLMSG_DATA(cb->nlh);
1014         struct rtattr *kind = find_dump_kind(cb->nlh);
1015
1016         if (net != &init_net)
1017                 return 0;
1018
1019         if (kind == NULL) {
1020                 printk("tc_dump_action: action bad kind\n");
1021                 return 0;
1022         }
1023
1024         a_o = tc_lookup_action(kind);
1025         if (a_o == NULL) {
1026                 return 0;
1027         }
1028
1029         memset(&a, 0, sizeof(struct tc_action));
1030         a.ops = a_o;
1031
1032         if (a_o->walk == NULL) {
1033                 printk("tc_dump_action: %s !capable of dumping table\n", a_o->kind);
1034                 goto rtattr_failure;
1035         }
1036
1037         nlh = NLMSG_PUT(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
1038                         cb->nlh->nlmsg_type, sizeof(*t));
1039         t = NLMSG_DATA(nlh);
1040         t->tca_family = AF_UNSPEC;
1041         t->tca__pad1 = 0;
1042         t->tca__pad2 = 0;
1043
1044         x = (struct rtattr *)skb_tail_pointer(skb);
1045         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
1046
1047         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1048         if (ret < 0)
1049                 goto rtattr_failure;
1050
1051         if (ret > 0) {
1052                 x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
1053                 ret = skb->len;
1054         } else
1055                 nlmsg_trim(skb, x);
1056
1057         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1058         if (NETLINK_CB(cb->skb).pid && ret)
1059                 nlh->nlmsg_flags |= NLM_F_MULTI;
1060         module_put(a_o->owner);
1061         return skb->len;
1062
1063 rtattr_failure:
1064 nlmsg_failure:
1065         module_put(a_o->owner);
1066         nlmsg_trim(skb, b);
1067         return skb->len;
1068 }
1069
1070 static int __init tc_action_init(void)
1071 {
1072         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL);
1073         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL);
1074         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action);
1075
1076         return 0;
1077 }
1078
1079 subsys_initcall(tc_action_init);
1080
1081 EXPORT_SYMBOL(tcf_register_action);
1082 EXPORT_SYMBOL(tcf_unregister_action);
1083 EXPORT_SYMBOL(tcf_action_exec);
1084 EXPORT_SYMBOL(tcf_action_dump_1);