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 EXPORT_SYMBOL(tcf_register_action);
 267
 268 int tcf_unregister_action(struct tc_action_ops *act)
 269 {
 270         struct tc_action_ops *a, **ap;
 271         int err = -ENOENT;
 272
 273         write_lock(&act_mod_lock);
 274         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
 275                 if (a == act)
 276                         break;
 277         if (a) {
 278                 *ap = a->next;
 279                 a->next = NULL;
 280                 err = 0;
 281         }
 282         write_unlock(&act_mod_lock);
 283         return err;
 284 }
 285 EXPORT_SYMBOL(tcf_unregister_action);
 286
 287 /* lookup by name */
 288 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 289 {
 290         struct tc_action_ops *a = NULL;
 291
 292         if (kind) {
 293                 read_lock(&act_mod_lock);
 294                 for (a = act_base; a; a = a->next) {
 295                         if (strcmp(kind, a->kind) == 0) {
 296                                 if (!try_module_get(a->owner)) {
 297                                         read_unlock(&act_mod_lock);
 298                                         return NULL;
 299                                 }
 300                                 break;
 301                         }
 302                 }
 303                 read_unlock(&act_mod_lock);
 304         }
 305         return a;
 306 }
 307
 308 /* lookup by rtattr */
 309 static struct tc_action_ops *tc_lookup_action(struct rtattr *kind)
 310 {
 311         struct tc_action_ops *a = NULL;
 312
 313         if (kind) {
 314                 read_lock(&act_mod_lock);
 315                 for (a = act_base; a; a = a->next) {
 316                         if (rtattr_strcmp(kind, a->kind) == 0) {
 317                                 if (!try_module_get(a->owner)) {
 318                                         read_unlock(&act_mod_lock);
 319                                         return NULL;
 320                                 }
 321                                 break;
 322                         }
 323                 }
 324                 read_unlock(&act_mod_lock);
 325         }
 326         return a;
 327 }
 328
 329 #if 0
 330 /* lookup by id */
 331 static struct tc_action_ops *tc_lookup_action_id(u32 type)
 332 {
 333         struct tc_action_ops *a = NULL;
 334
 335         if (type) {
 336                 read_lock(&act_mod_lock);
 337                 for (a = act_base; a; a = a->next) {
 338                         if (a->type == type) {
 339                                 if (!try_module_get(a->owner)) {
 340                                         read_unlock(&act_mod_lock);
 341                                         return NULL;
 342                                 }
 343                                 break;
 344                         }
 345                 }
 346                 read_unlock(&act_mod_lock);
 347         }
 348         return a;
 349 }
 350 #endif
 351
 352 int tcf_action_exec(struct sk_buff *skb, struct tc_action *act,
 353                     struct tcf_result *res)
 354 {
 355         struct tc_action *a;
 356         int ret = -1;
 357
 358         if (skb->tc_verd & TC_NCLS) {
 359                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 360                 ret = TC_ACT_OK;
 361                 goto exec_done;
 362         }
 363         while ((a = act) != NULL) {
 364 repeat:
 365                 if (a->ops && a->ops->act) {
 366                         ret = a->ops->act(skb, a, res);
 367                         if (TC_MUNGED & skb->tc_verd) {
 368                                 /* copied already, allow trampling */
 369                                 skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
 370                                 skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
 371                         }
 372                         if (ret == TC_ACT_REPEAT)
 373                                 goto repeat;    /* we need a ttl - JHS */
 374                         if (ret != TC_ACT_PIPE)
 375                                 goto exec_done;
 376                 }
 377                 act = a->next;
 378         }
 379 exec_done:
 380         return ret;
 381 }
 382 EXPORT_SYMBOL(tcf_action_exec);
 383
 384 void tcf_action_destroy(struct tc_action *act, int bind)
 385 {
 386         struct tc_action *a;
 387
 388         for (a = act; a; a = act) {
 389                 if (a->ops && a->ops->cleanup) {
 390                         if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
 391                                 module_put(a->ops->owner);
 392                         act = act->next;
 393                         kfree(a);
 394                 } else { /*FIXME: Remove later - catch insertion bugs*/
 395                         printk("tcf_action_destroy: BUG? destroying NULL ops\n");
 396                         act = act->next;
 397                         kfree(a);
 398                 }
 399         }
 400 }
 401
 402 int
 403 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 404 {
 405         int err = -EINVAL;
 406
 407         if (a->ops == NULL || a->ops->dump == NULL)
 408                 return err;
 409         return a->ops->dump(skb, a, bind, ref);
 410 }
 411
 412 int
 413 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 414 {
 415         int err = -EINVAL;
 416         unsigned char *b = skb_tail_pointer(skb);
 417         struct rtattr *r;
 418
 419         if (a->ops == NULL || a->ops->dump == NULL)
 420                 return err;
 421
 422         RTA_PUT(skb, TCA_KIND, IFNAMSIZ, a->ops->kind);
 423         if (tcf_action_copy_stats(skb, a, 0))
 424                 goto rtattr_failure;
 425         r = (struct rtattr *)skb_tail_pointer(skb);
 426         RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
 427         if ((err = tcf_action_dump_old(skb, a, bind, ref)) > 0) {
 428                 r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
 429                 return err;
 430         }
 431
 432 rtattr_failure:
 433         nlmsg_trim(skb, b);
 434         return -1;
 435 }
 436 EXPORT_SYMBOL(tcf_action_dump_1);
 437
 438 int
 439 tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
 440 {
 441         struct tc_action *a;
 442         int err = -EINVAL;
 443         unsigned char *b = skb_tail_pointer(skb);
 444         struct rtattr *r ;
 445
 446         while ((a = act) != NULL) {
 447                 r = (struct rtattr *)skb_tail_pointer(skb);
 448                 act = a->next;
 449                 RTA_PUT(skb, a->order, 0, NULL);
 450                 err = tcf_action_dump_1(skb, a, bind, ref);
 451                 if (err < 0)
 452                         goto errout;
 453                 r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
 454         }
 455
 456         return 0;
 457
 458 rtattr_failure:
 459         err = -EINVAL;
 460 errout:
 461         nlmsg_trim(skb, b);
 462         return err;
 463 }
 464
 465 struct tc_action *tcf_action_init_1(struct rtattr *rta, struct rtattr *est,
 466                                     char *name, int ovr, int bind, int *err)
 467 {
 468         struct tc_action *a;
 469         struct tc_action_ops *a_o;
 470         char act_name[IFNAMSIZ];
 471         struct rtattr *tb[TCA_ACT_MAX+1];
 472         struct rtattr *kind;
 473
 474         *err = -EINVAL;
 475
 476         if (name == NULL) {
 477                 if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
 478                         goto err_out;
 479                 kind = tb[TCA_ACT_KIND-1];
 480                 if (kind == NULL)
 481                         goto err_out;
 482                 if (rtattr_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 483                         goto err_out;
 484         } else {
 485                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 486                         goto err_out;
 487         }
 488
 489         a_o = tc_lookup_action_n(act_name);
 490         if (a_o == NULL) {
 491 #ifdef CONFIG_KMOD
 492                 rtnl_unlock();
 493                 request_module("act_%s", act_name);
 494                 rtnl_lock();
 495
 496                 a_o = tc_lookup_action_n(act_name);
 497
 498                 /* We dropped the RTNL semaphore in order to
 499                  * perform the module load.  So, even if we
 500                  * succeeded in loading the module we have to
 501                  * tell the caller to replay the request.  We
 502                  * indicate this using -EAGAIN.
 503                  */
 504                 if (a_o != NULL) {
 505                         *err = -EAGAIN;
 506                         goto err_mod;
 507                 }
 508 #endif
 509                 *err = -ENOENT;
 510                 goto err_out;
 511         }
 512
 513         *err = -ENOMEM;
 514         a = kzalloc(sizeof(*a), GFP_KERNEL);
 515         if (a == NULL)
 516                 goto err_mod;
 517
 518         /* backward compatibility for policer */
 519         if (name == NULL)
 520                 *err = a_o->init(tb[TCA_ACT_OPTIONS-1], est, a, ovr, bind);
 521         else
 522                 *err = a_o->init(rta, est, a, ovr, bind);
 523         if (*err < 0)
 524                 goto err_free;
 525
 526         /* module count goes up only when brand new policy is created
 527            if it exists and is only bound to in a_o->init() then
 528            ACT_P_CREATED is not returned (a zero is).
 529         */
 530         if (*err != ACT_P_CREATED)
 531                 module_put(a_o->owner);
 532         a->ops = a_o;
 533
 534         *err = 0;
 535         return a;
 536
 537 err_free:
 538         kfree(a);
 539 err_mod:
 540         module_put(a_o->owner);
 541 err_out:
 542         return NULL;
 543 }
 544
 545 struct tc_action *tcf_action_init(struct rtattr *rta, struct rtattr *est,
 546                                   char *name, int ovr, int bind, int *err)
 547 {
 548         struct rtattr *tb[TCA_ACT_MAX_PRIO+1];
 549         struct tc_action *head = NULL, *act, *act_prev = NULL;
 550         int i;
 551
 552         if (rtattr_parse_nested(tb, TCA_ACT_MAX_PRIO, rta) < 0) {
 553                 *err = -EINVAL;
 554                 return head;
 555         }
 556
 557         for (i=0; i < TCA_ACT_MAX_PRIO && tb[i]; i++) {
 558                 act = tcf_action_init_1(tb[i], est, name, ovr, bind, err);
 559                 if (act == NULL)
 560                         goto err;
 561                 act->order = i+1;
 562
 563                 if (head == NULL)
 564                         head = act;
 565                 else
 566                         act_prev->next = act;
 567                 act_prev = act;
 568         }
 569         return head;
 570
 571 err:
 572         if (head != NULL)
 573                 tcf_action_destroy(head, bind);
 574         return NULL;
 575 }
 576
 577 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 578                           int compat_mode)
 579 {
 580         int err = 0;
 581         struct gnet_dump d;
 582         struct tcf_act_hdr *h = a->priv;
 583
 584         if (h == NULL)
 585                 goto errout;
 586
 587         /* compat_mode being true specifies a call that is supposed
 588          * to add additional backward compatiblity statistic TLVs.
 589          */
 590         if (compat_mode) {
 591                 if (a->type == TCA_OLD_COMPAT)
 592                         err = gnet_stats_start_copy_compat(skb, 0,
 593                                 TCA_STATS, TCA_XSTATS, &h->tcf_lock, &d);
 594                 else
 595                         return 0;
 596         } else
 597                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 598                                             &h->tcf_lock, &d);
 599
 600         if (err < 0)
 601                 goto errout;
 602
 603         if (a->ops != NULL && a->ops->get_stats != NULL)
 604                 if (a->ops->get_stats(skb, a) < 0)
 605                         goto errout;
 606
 607         if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
 608             gnet_stats_copy_rate_est(&d, &h->tcf_rate_est) < 0 ||
 609             gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
 610                 goto errout;
 611
 612         if (gnet_stats_finish_copy(&d) < 0)
 613                 goto errout;
 614
 615         return 0;
 616
 617 errout:
 618         return -1;
 619 }
 620
 621 static int
 622 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 pid, u32 seq,
 623              u16 flags, int event, int bind, int ref)
 624 {
 625         struct tcamsg *t;
 626         struct nlmsghdr *nlh;
 627         unsigned char *b = skb_tail_pointer(skb);
 628         struct rtattr *x;
 629
 630         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 631
 632         t = NLMSG_DATA(nlh);
 633         t->tca_family = AF_UNSPEC;
 634         t->tca__pad1 = 0;
 635         t->tca__pad2 = 0;
 636
 637         x = (struct rtattr *)skb_tail_pointer(skb);
 638         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 639
 640         if (tcf_action_dump(skb, a, bind, ref) < 0)
 641                 goto rtattr_failure;
 642
 643         x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
 644
 645         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 646         return skb->len;
 647
 648 rtattr_failure:
 649 nlmsg_failure:
 650         nlmsg_trim(skb, b);
 651         return -1;
 652 }
 653
 654 static int
 655 act_get_notify(u32 pid, struct nlmsghdr *n, struct tc_action *a, int event)
 656 {
 657         struct sk_buff *skb;
 658
 659         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 660         if (!skb)
 661                 return -ENOBUFS;
 662         if (tca_get_fill(skb, a, pid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 663                 kfree_skb(skb);
 664                 return -EINVAL;
 665         }
 666
 667         return rtnl_unicast(skb, &init_net, pid);
 668 }
 669
 670 static struct tc_action *
 671 tcf_action_get_1(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int *err)
 672 {
 673         struct rtattr *tb[TCA_ACT_MAX+1];
 674         struct tc_action *a;
 675         int index;
 676
 677         *err = -EINVAL;
 678         if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
 679                 return NULL;
 680
 681         if (tb[TCA_ACT_INDEX - 1] == NULL ||
 682             RTA_PAYLOAD(tb[TCA_ACT_INDEX - 1]) < sizeof(index))
 683                 return NULL;
 684         index = *(int *)RTA_DATA(tb[TCA_ACT_INDEX - 1]);
 685
 686         *err = -ENOMEM;
 687         a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
 688         if (a == NULL)
 689                 return NULL;
 690
 691         *err = -EINVAL;
 692         a->ops = tc_lookup_action(tb[TCA_ACT_KIND - 1]);
 693         if (a->ops == NULL)
 694                 goto err_free;
 695         if (a->ops->lookup == NULL)
 696                 goto err_mod;
 697         *err = -ENOENT;
 698         if (a->ops->lookup(a, index) == 0)
 699                 goto err_mod;
 700
 701         module_put(a->ops->owner);
 702         *err = 0;
 703         return a;
 704 err_mod:
 705         module_put(a->ops->owner);
 706 err_free:
 707         kfree(a);
 708         return NULL;
 709 }
 710
 711 static void cleanup_a(struct tc_action *act)
 712 {
 713         struct tc_action *a;
 714
 715         for (a = act; a; a = act) {
 716                 act = a->next;
 717                 kfree(a);
 718         }
 719 }
 720
 721 static struct tc_action *create_a(int i)
 722 {
 723         struct tc_action *act;
 724
 725         act = kzalloc(sizeof(*act), GFP_KERNEL);
 726         if (act == NULL) {
 727                 printk("create_a: failed to alloc!\n");
 728                 return NULL;
 729         }
 730         act->order = i;
 731         return act;
 732 }
 733
 734 static int tca_action_flush(struct rtattr *rta, struct nlmsghdr *n, u32 pid)
 735 {
 736         struct sk_buff *skb;
 737         unsigned char *b;
 738         struct nlmsghdr *nlh;
 739         struct tcamsg *t;
 740         struct netlink_callback dcb;
 741         struct rtattr *x;
 742         struct rtattr *tb[TCA_ACT_MAX+1];
 743         struct rtattr *kind;
 744         struct tc_action *a = create_a(0);
 745         int err = -EINVAL;
 746
 747         if (a == NULL) {
 748                 printk("tca_action_flush: couldnt create tc_action\n");
 749                 return err;
 750         }
 751
 752         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 753         if (!skb) {
 754                 printk("tca_action_flush: failed skb alloc\n");
 755                 kfree(a);
 756                 return -ENOBUFS;
 757         }
 758
 759         b = skb_tail_pointer(skb);
 760
 761         if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
 762                 goto err_out;
 763
 764         kind = tb[TCA_ACT_KIND-1];
 765         a->ops = tc_lookup_action(kind);
 766         if (a->ops == NULL)
 767                 goto err_out;
 768
 769         nlh = NLMSG_PUT(skb, pid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t));
 770         t = NLMSG_DATA(nlh);
 771         t->tca_family = AF_UNSPEC;
 772         t->tca__pad1 = 0;
 773         t->tca__pad2 = 0;
 774
 775         x = (struct rtattr *)skb_tail_pointer(skb);
 776         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 777
 778         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 779         if (err < 0)
 780                 goto rtattr_failure;
 781
 782         x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
 783
 784         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 785         nlh->nlmsg_flags |= NLM_F_ROOT;
 786         module_put(a->ops->owner);
 787         kfree(a);
 788         err = rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO);
 789         if (err > 0)
 790                 return 0;
 791
 792         return err;
 793
 794 rtattr_failure:
 795 nlmsg_failure:
 796         module_put(a->ops->owner);
 797 err_out:
 798         kfree_skb(skb);
 799         kfree(a);
 800         return err;
 801 }
 802
 803 static int
 804 tca_action_gd(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int event)
 805 {
 806         int i, ret = 0;
 807         struct rtattr *tb[TCA_ACT_MAX_PRIO+1];
 808         struct tc_action *head = NULL, *act, *act_prev = NULL;
 809
 810         if (rtattr_parse_nested(tb, TCA_ACT_MAX_PRIO, rta) < 0)
 811                 return -EINVAL;
 812
 813         if (event == RTM_DELACTION && n->nlmsg_flags&NLM_F_ROOT) {
 814                 if (tb[0] != NULL && tb[1] == NULL)
 815                         return tca_action_flush(tb[0], n, pid);
 816         }
 817
 818         for (i=0; i < TCA_ACT_MAX_PRIO && tb[i]; i++) {
 819                 act = tcf_action_get_1(tb[i], n, pid, &ret);
 820                 if (act == NULL)
 821                         goto err;
 822                 act->order = i+1;
 823
 824                 if (head == NULL)
 825                         head = act;
 826                 else
 827                         act_prev->next = act;
 828                 act_prev = act;
 829         }
 830
 831         if (event == RTM_GETACTION)
 832                 ret = act_get_notify(pid, n, head, event);
 833         else { /* delete */
 834                 struct sk_buff *skb;
 835
 836                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 837                 if (!skb) {
 838                         ret = -ENOBUFS;
 839                         goto err;
 840                 }
 841
 842                 if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
 843                                  0, 1) <= 0) {
 844                         kfree_skb(skb);
 845                         ret = -EINVAL;
 846                         goto err;
 847                 }
 848
 849                 /* now do the delete */
 850                 tcf_action_destroy(head, 0);
 851                 ret = rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC,
 852                                      n->nlmsg_flags&NLM_F_ECHO);
 853                 if (ret > 0)
 854                         return 0;
 855                 return ret;
 856         }
 857 err:
 858         cleanup_a(head);
 859         return ret;
 860 }
 861
 862 static int tcf_add_notify(struct tc_action *a, u32 pid, u32 seq, int event,
 863                           u16 flags)
 864 {
 865         struct tcamsg *t;
 866         struct nlmsghdr *nlh;
 867         struct sk_buff *skb;
 868         struct rtattr *x;
 869         unsigned char *b;
 870         int err = 0;
 871
 872         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 873         if (!skb)
 874                 return -ENOBUFS;
 875
 876         b = skb_tail_pointer(skb);
 877
 878         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 879         t = NLMSG_DATA(nlh);
 880         t->tca_family = AF_UNSPEC;
 881         t->tca__pad1 = 0;
 882         t->tca__pad2 = 0;
 883
 884         x = (struct rtattr *)skb_tail_pointer(skb);
 885         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 886
 887         if (tcf_action_dump(skb, a, 0, 0) < 0)
 888                 goto rtattr_failure;
 889
 890         x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
 891
 892         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 893         NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 894
 895         err = rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC, flags&NLM_F_ECHO);
 896         if (err > 0)
 897                 err = 0;
 898         return err;
 899
 900 rtattr_failure:
 901 nlmsg_failure:
 902         kfree_skb(skb);
 903         return -1;
 904 }
 905
 906
 907 static int
 908 tcf_action_add(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int ovr)
 909 {
 910         int ret = 0;
 911         struct tc_action *act;
 912         struct tc_action *a;
 913         u32 seq = n->nlmsg_seq;
 914
 915         act = tcf_action_init(rta, NULL, NULL, ovr, 0, &ret);
 916         if (act == NULL)
 917                 goto done;
 918
 919         /* dump then free all the actions after update; inserted policy
 920          * stays intact
 921          * */
 922         ret = tcf_add_notify(act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
 923         for (a = act; a; a = act) {
 924                 act = a->next;
 925                 kfree(a);
 926         }
 927 done:
 928         return ret;
 929 }
 930
 931 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 932 {
 933         struct net *net = skb->sk->sk_net;
 934         struct rtattr **tca = arg;
 935         u32 pid = skb ? NETLINK_CB(skb).pid : 0;
 936         int ret = 0, ovr = 0;
 937
 938         if (net != &init_net)
 939                 return -EINVAL;
 940
 941         if (tca[TCA_ACT_TAB-1] == NULL) {
 942                 printk("tc_ctl_action: received NO action attribs\n");
 943                 return -EINVAL;
 944         }
 945
 946         /* n->nlmsg_flags&NLM_F_CREATE
 947          * */
 948         switch (n->nlmsg_type) {
 949         case RTM_NEWACTION:
 950                 /* we are going to assume all other flags
 951                  * imply create only if it doesnt exist
 952                  * Note that CREATE | EXCL implies that
 953                  * but since we want avoid ambiguity (eg when flags
 954                  * is zero) then just set this
 955                  */
 956                 if (n->nlmsg_flags&NLM_F_REPLACE)
 957                         ovr = 1;
 958 replay:
 959                 ret = tcf_action_add(tca[TCA_ACT_TAB-1], n, pid, ovr);
 960                 if (ret == -EAGAIN)
 961                         goto replay;
 962                 break;
 963         case RTM_DELACTION:
 964                 ret = tca_action_gd(tca[TCA_ACT_TAB-1], n, pid, RTM_DELACTION);
 965                 break;
 966         case RTM_GETACTION:
 967                 ret = tca_action_gd(tca[TCA_ACT_TAB-1], n, pid, RTM_GETACTION);
 968                 break;
 969         default:
 970                 BUG();
 971         }
 972
 973         return ret;
 974 }
 975
 976 static struct rtattr *
 977 find_dump_kind(struct nlmsghdr *n)
 978 {
 979         struct rtattr *tb1, *tb2[TCA_ACT_MAX+1];
 980         struct rtattr *tb[TCA_ACT_MAX_PRIO + 1];
 981         struct rtattr *rta[TCAA_MAX + 1];
 982         struct rtattr *kind;
 983         int min_len = NLMSG_LENGTH(sizeof(struct tcamsg));
 984         int attrlen = n->nlmsg_len - NLMSG_ALIGN(min_len);
 985         struct rtattr *attr = (void *) n + NLMSG_ALIGN(min_len);
 986
 987         if (rtattr_parse(rta, TCAA_MAX, attr, attrlen) < 0)
 988                 return NULL;
 989         tb1 = rta[TCA_ACT_TAB - 1];
 990         if (tb1 == NULL)
 991                 return NULL;
 992
 993         if (rtattr_parse(tb, TCA_ACT_MAX_PRIO, RTA_DATA(tb1),
 994                          NLMSG_ALIGN(RTA_PAYLOAD(tb1))) < 0)
 995                 return NULL;
 996         if (tb[0] == NULL)
 997                 return NULL;
 998
 999         if (rtattr_parse(tb2, TCA_ACT_MAX, RTA_DATA(tb[0]),
1000                          RTA_PAYLOAD(tb[0])) < 0)
1001                 return NULL;
1002         kind = tb2[TCA_ACT_KIND-1];
1003
1004         return kind;
1005 }
1006
1007 static int
1008 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1009 {
1010         struct net *net = skb->sk->sk_net;
1011         struct nlmsghdr *nlh;
1012         unsigned char *b = skb_tail_pointer(skb);
1013         struct rtattr *x;
1014         struct tc_action_ops *a_o;
1015         struct tc_action a;
1016         int ret = 0;
1017         struct tcamsg *t = (struct tcamsg *) NLMSG_DATA(cb->nlh);
1018         struct rtattr *kind = find_dump_kind(cb->nlh);
1019
1020         if (net != &init_net)
1021                 return 0;
1022
1023         if (kind == NULL) {
1024                 printk("tc_dump_action: action bad kind\n");
1025                 return 0;
1026         }
1027
1028         a_o = tc_lookup_action(kind);
1029         if (a_o == NULL) {
1030                 return 0;
1031         }
1032
1033         memset(&a, 0, sizeof(struct tc_action));
1034         a.ops = a_o;
1035
1036         if (a_o->walk == NULL) {
1037                 printk("tc_dump_action: %s !capable of dumping table\n", a_o->kind);
1038                 goto rtattr_failure;
1039         }
1040
1041         nlh = NLMSG_PUT(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
1042                         cb->nlh->nlmsg_type, sizeof(*t));
1043         t = NLMSG_DATA(nlh);
1044         t->tca_family = AF_UNSPEC;
1045         t->tca__pad1 = 0;
1046         t->tca__pad2 = 0;
1047
1048         x = (struct rtattr *)skb_tail_pointer(skb);
1049         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
1050
1051         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1052         if (ret < 0)
1053                 goto rtattr_failure;
1054
1055         if (ret > 0) {
1056                 x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
1057                 ret = skb->len;
1058         } else
1059                 nlmsg_trim(skb, x);
1060
1061         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1062         if (NETLINK_CB(cb->skb).pid && ret)
1063                 nlh->nlmsg_flags |= NLM_F_MULTI;
1064         module_put(a_o->owner);
1065         return skb->len;
1066
1067 rtattr_failure:
1068 nlmsg_failure:
1069         module_put(a_o->owner);
1070         nlmsg_trim(skb, b);
1071         return skb->len;
1072 }
1073
1074 static int __init tc_action_init(void)
1075 {
1076         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL);
1077         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL);
1078         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action);
1079
1080         return 0;
1081 }
1082
1083 subsys_initcall(tc_action_init);