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