net/sched/act_api.c

   1 /*
   2  * net/sched/act_api.c  Packet action API.
   3  *
   4  *              This program is free software; you can redistribute it and/or
   5  *              modify it under the terms of the GNU General Public License
   6  *              as published by the Free Software Foundation; either version
   7  *              2 of the License, or (at your option) any later version.
   8  *
   9  * Author:      Jamal Hadi Salim
  10  *
  11  *
  12  */
  13
  14 #include <linux/types.h>
  15 #include <linux/kernel.h>
  16 #include <linux/string.h>
  17 #include <linux/errno.h>
  18 #include <linux/skbuff.h>
  19 #include <linux/init.h>
  20 #include <linux/kmod.h>
  21 #include <linux/err.h>
  22 #include <net/net_namespace.h>
  23 #include <net/sock.h>
  24 #include <net/sch_generic.h>
  25 #include <net/act_api.h>
  26 #include <net/netlink.h>
  27
  28 void tcf_hash_destroy(struct tcf_common *p, struct tcf_hashinfo *hinfo)
  29 {
  30         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
  31         struct tcf_common **p1p;
  32
  33         for (p1p = &hinfo->htab[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
  34                 if (*p1p == p) {
  35                         write_lock_bh(hinfo->lock);
  36                         *p1p = p->tcfc_next;
  37                         write_unlock_bh(hinfo->lock);
  38                         gen_kill_estimator(&p->tcfc_bstats,
  39                                            &p->tcfc_rate_est);
  40                         kfree(p);
  41                         return;
  42                 }
  43         }
  44         BUG_TRAP(0);
  45 }
  46 EXPORT_SYMBOL(tcf_hash_destroy);
  47
  48 int tcf_hash_release(struct tcf_common *p, int bind,
  49                      struct tcf_hashinfo *hinfo)
  50 {
  51         int ret = 0;
  52
  53         if (p) {
  54                 if (bind)
  55                         p->tcfc_bindcnt--;
  56
  57                 p->tcfc_refcnt--;
  58                 if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
  59                         tcf_hash_destroy(p, hinfo);
  60                         ret = 1;
  61                 }
  62         }
  63         return ret;
  64 }
  65 EXPORT_SYMBOL(tcf_hash_release);
  66
  67 static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
  68                            struct tc_action *a, struct tcf_hashinfo *hinfo)
  69 {
  70         struct tcf_common *p;
  71         int err = 0, index = -1,i = 0, s_i = 0, n_i = 0;
  72         struct nlattr *r ;
  73
  74         read_lock_bh(hinfo->lock);
  75
  76         s_i = cb->args[0];
  77
  78         for (i = 0; i < (hinfo->hmask + 1); i++) {
  79                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
  80
  81                 for (; p; p = p->tcfc_next) {
  82                         index++;
  83                         if (index < s_i)
  84                                 continue;
  85                         a->priv = p;
  86                         a->order = n_i;
  87                         r = (struct nlattr *)skb_tail_pointer(skb);
  88                         NLA_PUT(skb, a->order, 0, NULL);
  89                         err = tcf_action_dump_1(skb, a, 0, 0);
  90                         if (err < 0) {
  91                                 index--;
  92                                 nlmsg_trim(skb, r);
  93                                 goto done;
  94                         }
  95                         r->nla_len = skb_tail_pointer(skb) - (u8 *)r;
  96                         n_i++;
  97                         if (n_i >= TCA_ACT_MAX_PRIO)
  98                                 goto done;
  99                 }
 100         }
 101 done:
 102         read_unlock_bh(hinfo->lock);
 103         if (n_i)
 104                 cb->args[0] += n_i;
 105         return n_i;
 106
 107 nla_put_failure:
 108         nlmsg_trim(skb, r);
 109         goto done;
 110 }
 111
 112 static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a,
 113                           struct tcf_hashinfo *hinfo)
 114 {
 115         struct tcf_common *p, *s_p;
 116         struct nlattr *r ;
 117         int i= 0, n_i = 0;
 118
 119         r = (struct nlattr *)skb_tail_pointer(skb);
 120         NLA_PUT(skb, a->order, 0, NULL);
 121         NLA_PUT(skb, TCA_KIND, IFNAMSIZ, a->ops->kind);
 122         for (i = 0; i < (hinfo->hmask + 1); i++) {
 123                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
 124
 125                 while (p != NULL) {
 126                         s_p = p->tcfc_next;
 127                         if (ACT_P_DELETED == tcf_hash_release(p, 0, hinfo))
 128                                  module_put(a->ops->owner);
 129                         n_i++;
 130                         p = s_p;
 131                 }
 132         }
 133         NLA_PUT(skb, TCA_FCNT, 4, &n_i);
 134         r->nla_len = skb_tail_pointer(skb) - (u8 *)r;
 135
 136         return n_i;
 137 nla_put_failure:
 138         nlmsg_trim(skb, r);
 139         return -EINVAL;
 140 }
 141
 142 int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
 143                        int type, struct tc_action *a)
 144 {
 145         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 146
 147         if (type == RTM_DELACTION) {
 148                 return tcf_del_walker(skb, a, hinfo);
 149         } else if (type == RTM_GETACTION) {
 150                 return tcf_dump_walker(skb, cb, a, hinfo);
 151         } else {
 152                 printk("tcf_generic_walker: unknown action %d\n", type);
 153                 return -EINVAL;
 154         }
 155 }
 156 EXPORT_SYMBOL(tcf_generic_walker);
 157
 158 struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 159 {
 160         struct tcf_common *p;
 161
 162         read_lock_bh(hinfo->lock);
 163         for (p = hinfo->htab[tcf_hash(index, hinfo->hmask)]; p;
 164              p = p->tcfc_next) {
 165                 if (p->tcfc_index == index)
 166                         break;
 167         }
 168         read_unlock_bh(hinfo->lock);
 169
 170         return p;
 171 }
 172 EXPORT_SYMBOL(tcf_hash_lookup);
 173
 174 u32 tcf_hash_new_index(u32 *idx_gen, struct tcf_hashinfo *hinfo)
 175 {
 176         u32 val = *idx_gen;
 177
 178         do {
 179                 if (++val == 0)
 180                         val = 1;
 181         } while (tcf_hash_lookup(val, hinfo));
 182
 183         return (*idx_gen = val);
 184 }
 185 EXPORT_SYMBOL(tcf_hash_new_index);
 186
 187 int tcf_hash_search(struct tc_action *a, u32 index)
 188 {
 189         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 190         struct tcf_common *p = tcf_hash_lookup(index, hinfo);
 191
 192         if (p) {
 193                 a->priv = p;
 194                 return 1;
 195         }
 196         return 0;
 197 }
 198 EXPORT_SYMBOL(tcf_hash_search);
 199
 200 struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
 201                                   struct tcf_hashinfo *hinfo)
 202 {
 203         struct tcf_common *p = NULL;
 204         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 205                 if (bind) {
 206                         p->tcfc_bindcnt++;
 207                         p->tcfc_refcnt++;
 208                 }
 209                 a->priv = p;
 210         }
 211         return p;
 212 }
 213 EXPORT_SYMBOL(tcf_hash_check);
 214
 215 struct tcf_common *tcf_hash_create(u32 index, struct nlattr *est, struct tc_action *a, int size, int bind, u32 *idx_gen, struct tcf_hashinfo *hinfo)
 216 {
 217         struct tcf_common *p = kzalloc(size, GFP_KERNEL);
 218
 219         if (unlikely(!p))
 220                 return p;
 221         p->tcfc_refcnt = 1;
 222         if (bind)
 223                 p->tcfc_bindcnt = 1;
 224
 225         spin_lock_init(&p->tcfc_lock);
 226         p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
 227         p->tcfc_tm.install = jiffies;
 228         p->tcfc_tm.lastuse = jiffies;
 229         if (est)
 230                 gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
 231                                   &p->tcfc_lock, est);
 232         a->priv = (void *) p;
 233         return p;
 234 }
 235 EXPORT_SYMBOL(tcf_hash_create);
 236
 237 void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
 238 {
 239         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
 240
 241         write_lock_bh(hinfo->lock);
 242         p->tcfc_next = hinfo->htab[h];
 243         hinfo->htab[h] = p;
 244         write_unlock_bh(hinfo->lock);
 245 }
 246 EXPORT_SYMBOL(tcf_hash_insert);
 247
 248 static struct tc_action_ops *act_base = NULL;
 249 static DEFINE_RWLOCK(act_mod_lock);
 250
 251 int tcf_register_action(struct tc_action_ops *act)
 252 {
 253         struct tc_action_ops *a, **ap;
 254
 255         write_lock(&act_mod_lock);
 256         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
 257                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 258                         write_unlock(&act_mod_lock);
 259                         return -EEXIST;
 260                 }
 261         }
 262         act->next = NULL;
 263         *ap = act;
 264         write_unlock(&act_mod_lock);
 265         return 0;
 266 }
 267 EXPORT_SYMBOL(tcf_register_action);
 268
 269 int tcf_unregister_action(struct tc_action_ops *act)
 270 {
 271         struct tc_action_ops *a, **ap;
 272         int err = -ENOENT;
 273
 274         write_lock(&act_mod_lock);
 275         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
 276                 if (a == act)
 277                         break;
 278         if (a) {
 279                 *ap = a->next;
 280                 a->next = NULL;
 281                 err = 0;
 282         }
 283         write_unlock(&act_mod_lock);
 284         return err;
 285 }
 286 EXPORT_SYMBOL(tcf_unregister_action);
 287
 288 /* lookup by name */
 289 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 290 {
 291         struct tc_action_ops *a = NULL;
 292
 293         if (kind) {
 294                 read_lock(&act_mod_lock);
 295                 for (a = act_base; a; a = a->next) {
 296                         if (strcmp(kind, a->kind) == 0) {
 297                                 if (!try_module_get(a->owner)) {
 298                                         read_unlock(&act_mod_lock);
 299                                         return NULL;
 300                                 }
 301                                 break;
 302                         }
 303                 }
 304                 read_unlock(&act_mod_lock);
 305         }
 306         return a;
 307 }
 308
 309 /* lookup by nlattr */
 310 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 311 {
 312         struct tc_action_ops *a = NULL;
 313
 314         if (kind) {
 315                 read_lock(&act_mod_lock);
 316                 for (a = act_base; a; a = a->next) {
 317                         if (nla_strcmp(kind, a->kind) == 0) {
 318                                 if (!try_module_get(a->owner)) {
 319                                         read_unlock(&act_mod_lock);
 320                                         return NULL;
 321                                 }
 322                                 break;
 323                         }
 324                 }
 325                 read_unlock(&act_mod_lock);
 326         }
 327         return a;
 328 }
 329
 330 #if 0
 331 /* lookup by id */
 332 static struct tc_action_ops *tc_lookup_action_id(u32 type)
 333 {
 334         struct tc_action_ops *a = NULL;
 335
 336         if (type) {
 337                 read_lock(&act_mod_lock);
 338                 for (a = act_base; a; a = a->next) {
 339                         if (a->type == type) {
 340                                 if (!try_module_get(a->owner)) {
 341                                         read_unlock(&act_mod_lock);
 342                                         return NULL;
 343                                 }
 344                                 break;
 345                         }
 346                 }
 347                 read_unlock(&act_mod_lock);
 348         }
 349         return a;
 350 }
 351 #endif
 352
 353 int tcf_action_exec(struct sk_buff *skb, struct tc_action *act,
 354                     struct tcf_result *res)
 355 {
 356         struct tc_action *a;
 357         int ret = -1;
 358
 359         if (skb->tc_verd & TC_NCLS) {
 360                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 361                 ret = TC_ACT_OK;
 362                 goto exec_done;
 363         }
 364         while ((a = act) != NULL) {
 365 repeat:
 366                 if (a->ops && a->ops->act) {
 367                         ret = a->ops->act(skb, a, res);
 368                         if (TC_MUNGED & skb->tc_verd) {
 369                                 /* copied already, allow trampling */
 370                                 skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
 371                                 skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
 372                         }
 373                         if (ret == TC_ACT_REPEAT)
 374                                 goto repeat;    /* we need a ttl - JHS */
 375                         if (ret != TC_ACT_PIPE)
 376                                 goto exec_done;
 377                 }
 378                 act = a->next;
 379         }
 380 exec_done:
 381         return ret;
 382 }
 383 EXPORT_SYMBOL(tcf_action_exec);
 384
 385 void tcf_action_destroy(struct tc_action *act, int bind)
 386 {
 387         struct tc_action *a;
 388
 389         for (a = act; a; a = act) {
 390                 if (a->ops && a->ops->cleanup) {
 391                         if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
 392                                 module_put(a->ops->owner);
 393                         act = act->next;
 394                         kfree(a);
 395                 } else { /*FIXME: Remove later - catch insertion bugs*/
 396                         printk("tcf_action_destroy: BUG? destroying NULL ops\n");
 397                         act = act->next;
 398                         kfree(a);
 399                 }
 400         }
 401 }
 402
 403 int
 404 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 405 {
 406         int err = -EINVAL;
 407
 408         if (a->ops == NULL || a->ops->dump == NULL)
 409                 return err;
 410         return a->ops->dump(skb, a, bind, ref);
 411 }
 412
 413 int
 414 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 415 {
 416         int err = -EINVAL;
 417         unsigned char *b = skb_tail_pointer(skb);
 418         struct nlattr *r;
 419
 420         if (a->ops == NULL || a->ops->dump == NULL)
 421                 return err;
 422
 423         NLA_PUT(skb, TCA_KIND, IFNAMSIZ, a->ops->kind);
 424         if (tcf_action_copy_stats(skb, a, 0))
 425                 goto nla_put_failure;
 426         r = (struct nlattr *)skb_tail_pointer(skb);
 427         NLA_PUT(skb, TCA_OPTIONS, 0, NULL);
 428         if ((err = tcf_action_dump_old(skb, a, bind, ref)) > 0) {
 429                 r->nla_len = skb_tail_pointer(skb) - (u8 *)r;
 430                 return err;
 431         }
 432
 433 nla_put_failure:
 434         nlmsg_trim(skb, b);
 435         return -1;
 436 }
 437 EXPORT_SYMBOL(tcf_action_dump_1);
 438
 439 int
 440 tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
 441 {
 442         struct tc_action *a;
 443         int err = -EINVAL;
 444         unsigned char *b = skb_tail_pointer(skb);
 445         struct nlattr *r ;
 446
 447         while ((a = act) != NULL) {
 448                 r = (struct nlattr *)skb_tail_pointer(skb);
 449                 act = a->next;
 450                 NLA_PUT(skb, a->order, 0, NULL);
 451                 err = tcf_action_dump_1(skb, a, bind, ref);
 452                 if (err < 0)
 453                         goto errout;
 454                 r->nla_len = skb_tail_pointer(skb) - (u8 *)r;
 455         }
 456
 457         return 0;
 458
 459 nla_put_failure:
 460         err = -EINVAL;
 461 errout:
 462         nlmsg_trim(skb, b);
 463         return err;
 464 }
 465
 466 struct tc_action *tcf_action_init_1(struct nlattr *nla, struct nlattr *est,
 467                                     char *name, int ovr, int bind)
 468 {
 469         struct tc_action *a;
 470         struct tc_action_ops *a_o;
 471         char act_name[IFNAMSIZ];
 472         struct nlattr *tb[TCA_ACT_MAX+1];
 473         struct nlattr *kind;
 474         int err;
 475
 476         err = -EINVAL;
 477
 478         if (name == NULL) {
 479                 if (nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL) < 0)
 480                         goto err_out;
 481                 kind = tb[TCA_ACT_KIND];
 482                 if (kind == NULL)
 483                         goto err_out;
 484                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 485                         goto err_out;
 486         } else {
 487                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 488                         goto err_out;
 489         }
 490
 491         a_o = tc_lookup_action_n(act_name);
 492         if (a_o == NULL) {
 493 #ifdef CONFIG_KMOD
 494                 rtnl_unlock();
 495                 request_module("act_%s", act_name);
 496                 rtnl_lock();
 497
 498                 a_o = tc_lookup_action_n(act_name);
 499
 500                 /* We dropped the RTNL semaphore in order to
 501                  * perform the module load.  So, even if we
 502                  * succeeded in loading the module we have to
 503                  * tell the caller to replay the request.  We
 504                  * indicate this using -EAGAIN.
 505                  */
 506                 if (a_o != NULL) {
 507                         err = -EAGAIN;
 508                         goto err_mod;
 509                 }
 510 #endif
 511                 err = -ENOENT;
 512                 goto err_out;
 513         }
 514
 515         err = -ENOMEM;
 516         a = kzalloc(sizeof(*a), GFP_KERNEL);
 517         if (a == NULL)
 518                 goto err_mod;
 519
 520         /* backward compatibility for policer */
 521         if (name == NULL)
 522                 err = a_o->init(tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
 523         else
 524                 err = a_o->init(nla, est, a, ovr, bind);
 525         if (err < 0)
 526                 goto err_free;
 527
 528         /* module count goes up only when brand new policy is created
 529            if it exists and is only bound to in a_o->init() then
 530            ACT_P_CREATED is not returned (a zero is).
 531         */
 532         if (err != ACT_P_CREATED)
 533                 module_put(a_o->owner);
 534         a->ops = a_o;
 535
 536         return a;
 537
 538 err_free:
 539         kfree(a);
 540 err_mod:
 541         module_put(a_o->owner);
 542 err_out:
 543         return ERR_PTR(err);
 544 }
 545
 546 struct tc_action *tcf_action_init(struct nlattr *nla, struct nlattr *est,
 547                                   char *name, int ovr, int bind)
 548 {
 549         struct nlattr *tb[TCA_ACT_MAX_PRIO+1];
 550         struct tc_action *head = NULL, *act, *act_prev = NULL;
 551         int i;
 552
 553         if (nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL) < 0)
 554                 return ERR_PTR(-EINVAL);
 555
 556         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 557                 act = tcf_action_init_1(tb[i], est, name, ovr, bind);
 558                 if (IS_ERR(act))
 559                         goto err;
 560                 act->order = i;
 561
 562                 if (head == NULL)
 563                         head = act;
 564                 else
 565                         act_prev->next = act;
 566                 act_prev = act;
 567         }
 568         return head;
 569
 570 err:
 571         if (head != NULL)
 572                 tcf_action_destroy(head, bind);
 573         return act;
 574 }
 575
 576 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 577                           int compat_mode)
 578 {
 579         int err = 0;
 580         struct gnet_dump d;
 581         struct tcf_act_hdr *h = a->priv;
 582
 583         if (h == NULL)
 584                 goto errout;
 585
 586         /* compat_mode being true specifies a call that is supposed
 587          * to add additional backward compatiblity statistic TLVs.
 588          */
 589         if (compat_mode) {
 590                 if (a->type == TCA_OLD_COMPAT)
 591                         err = gnet_stats_start_copy_compat(skb, 0,
 592                                 TCA_STATS, TCA_XSTATS, &h->tcf_lock, &d);
 593                 else
 594                         return 0;
 595         } else
 596                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 597                                             &h->tcf_lock, &d);
 598
 599         if (err < 0)
 600                 goto errout;
 601
 602         if (a->ops != NULL && a->ops->get_stats != NULL)
 603                 if (a->ops->get_stats(skb, a) < 0)
 604                         goto errout;
 605
 606         if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
 607             gnet_stats_copy_rate_est(&d, &h->tcf_rate_est) < 0 ||
 608             gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
 609                 goto errout;
 610
 611         if (gnet_stats_finish_copy(&d) < 0)
 612                 goto errout;
 613
 614         return 0;
 615
 616 errout:
 617         return -1;
 618 }
 619
 620 static int
 621 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 pid, u32 seq,
 622              u16 flags, int event, int bind, int ref)
 623 {
 624         struct tcamsg *t;
 625         struct nlmsghdr *nlh;
 626         unsigned char *b = skb_tail_pointer(skb);
 627         struct nlattr *x;
 628
 629         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 630
 631         t = NLMSG_DATA(nlh);
 632         t->tca_family = AF_UNSPEC;
 633         t->tca__pad1 = 0;
 634         t->tca__pad2 = 0;
 635
 636         x = (struct nlattr *)skb_tail_pointer(skb);
 637         NLA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 638
 639         if (tcf_action_dump(skb, a, bind, ref) < 0)
 640                 goto nla_put_failure;
 641
 642         x->nla_len = skb_tail_pointer(skb) - (u8 *)x;
 643
 644         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 645         return skb->len;
 646
 647 nla_put_failure:
 648 nlmsg_failure:
 649         nlmsg_trim(skb, b);
 650         return -1;
 651 }
 652
 653 static int
 654 act_get_notify(u32 pid, struct nlmsghdr *n, struct tc_action *a, int event)
 655 {
 656         struct sk_buff *skb;
 657
 658         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 659         if (!skb)
 660                 return -ENOBUFS;
 661         if (tca_get_fill(skb, a, pid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 662                 kfree_skb(skb);
 663                 return -EINVAL;
 664         }
 665
 666         return rtnl_unicast(skb, &init_net, pid);
 667 }
 668
 669 static struct tc_action *
 670 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 pid)
 671 {
 672         struct nlattr *tb[TCA_ACT_MAX+1];
 673         struct tc_action *a;
 674         int index;
 675         int err;
 676
 677         err = -EINVAL;
 678         if (nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL) < 0)
 679                 goto err_out;
 680
 681         if (tb[TCA_ACT_INDEX] == NULL ||
 682             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 683                 goto err_out;
 684         index = *(int *)nla_data(tb[TCA_ACT_INDEX]);
 685
 686         err = -ENOMEM;
 687         a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
 688         if (a == NULL)
 689                 goto err_out;
 690
 691         err = -EINVAL;
 692         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 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         return a;
 703
 704 err_mod:
 705         module_put(a->ops->owner);
 706 err_free:
 707         kfree(a);
 708 err_out:
 709         return ERR_PTR(err);
 710 }
 711
 712 static void cleanup_a(struct tc_action *act)
 713 {
 714         struct tc_action *a;
 715
 716         for (a = act; a; a = act) {
 717                 act = a->next;
 718                 kfree(a);
 719         }
 720 }
 721
 722 static struct tc_action *create_a(int i)
 723 {
 724         struct tc_action *act;
 725
 726         act = kzalloc(sizeof(*act), GFP_KERNEL);
 727         if (act == NULL) {
 728                 printk("create_a: failed to alloc!\n");
 729                 return NULL;
 730         }
 731         act->order = i;
 732         return act;
 733 }
 734
 735 static int tca_action_flush(struct nlattr *nla, struct nlmsghdr *n, u32 pid)
 736 {
 737         struct sk_buff *skb;
 738         unsigned char *b;
 739         struct nlmsghdr *nlh;
 740         struct tcamsg *t;
 741         struct netlink_callback dcb;
 742         struct nlattr *x;
 743         struct nlattr *tb[TCA_ACT_MAX+1];
 744         struct nlattr *kind;
 745         struct tc_action *a = create_a(0);
 746         int err = -EINVAL;
 747
 748         if (a == NULL) {
 749                 printk("tca_action_flush: couldnt create tc_action\n");
 750                 return err;
 751         }
 752
 753         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 754         if (!skb) {
 755                 printk("tca_action_flush: failed skb alloc\n");
 756                 kfree(a);
 757                 return -ENOBUFS;
 758         }
 759
 760         b = skb_tail_pointer(skb);
 761
 762         if (nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL) < 0)
 763                 goto err_out;
 764
 765         kind = tb[TCA_ACT_KIND];
 766         a->ops = tc_lookup_action(kind);
 767         if (a->ops == NULL)
 768                 goto err_out;
 769
 770         nlh = NLMSG_PUT(skb, pid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t));
 771         t = NLMSG_DATA(nlh);
 772         t->tca_family = AF_UNSPEC;
 773         t->tca__pad1 = 0;
 774         t->tca__pad2 = 0;
 775
 776         x = (struct nlattr *)skb_tail_pointer(skb);
 777         NLA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 778
 779         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 780         if (err < 0)
 781                 goto nla_put_failure;
 782
 783         x->nla_len = skb_tail_pointer(skb) - (u8 *)x;
 784
 785         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 786         nlh->nlmsg_flags |= NLM_F_ROOT;
 787         module_put(a->ops->owner);
 788         kfree(a);
 789         err = rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO);
 790         if (err > 0)
 791                 return 0;
 792
 793         return err;
 794
 795 nla_put_failure:
 796 nlmsg_failure:
 797         module_put(a->ops->owner);
 798 err_out:
 799         kfree_skb(skb);
 800         kfree(a);
 801         return err;
 802 }
 803
 804 static int
 805 tca_action_gd(struct nlattr *nla, struct nlmsghdr *n, u32 pid, int event)
 806 {
 807         int i, ret = 0;
 808         struct nlattr *tb[TCA_ACT_MAX_PRIO+1];
 809         struct tc_action *head = NULL, *act, *act_prev = NULL;
 810
 811         if (nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL) < 0)
 812                 return -EINVAL;
 813
 814         if (event == RTM_DELACTION && n->nlmsg_flags&NLM_F_ROOT) {
 815                 if (tb[0] != NULL && tb[1] == NULL)
 816                         return tca_action_flush(tb[0], n, pid);
 817         }
 818
 819         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 820                 act = tcf_action_get_1(tb[i], n, pid);
 821                 if (IS_ERR(act)) {
 822                         ret = PTR_ERR(act);
 823                         goto err;
 824                 }
 825                 act->order = i;
 826
 827                 if (head == NULL)
 828                         head = act;
 829                 else
 830                         act_prev->next = act;
 831                 act_prev = act;
 832         }
 833
 834         if (event == RTM_GETACTION)
 835                 ret = act_get_notify(pid, n, head, event);
 836         else { /* delete */
 837                 struct sk_buff *skb;
 838
 839                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 840                 if (!skb) {
 841                         ret = -ENOBUFS;
 842                         goto err;
 843                 }
 844
 845                 if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
 846                                  0, 1) <= 0) {
 847                         kfree_skb(skb);
 848                         ret = -EINVAL;
 849                         goto err;
 850                 }
 851
 852                 /* now do the delete */
 853                 tcf_action_destroy(head, 0);
 854                 ret = rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC,
 855                                      n->nlmsg_flags&NLM_F_ECHO);
 856                 if (ret > 0)
 857                         return 0;
 858                 return ret;
 859         }
 860 err:
 861         cleanup_a(head);
 862         return ret;
 863 }
 864
 865 static int tcf_add_notify(struct tc_action *a, u32 pid, u32 seq, int event,
 866                           u16 flags)
 867 {
 868         struct tcamsg *t;
 869         struct nlmsghdr *nlh;
 870         struct sk_buff *skb;
 871         struct nlattr *x;
 872         unsigned char *b;
 873         int err = 0;
 874
 875         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 876         if (!skb)
 877                 return -ENOBUFS;
 878
 879         b = skb_tail_pointer(skb);
 880
 881         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 882         t = NLMSG_DATA(nlh);
 883         t->tca_family = AF_UNSPEC;
 884         t->tca__pad1 = 0;
 885         t->tca__pad2 = 0;
 886
 887         x = (struct nlattr *)skb_tail_pointer(skb);
 888         NLA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 889
 890         if (tcf_action_dump(skb, a, 0, 0) < 0)
 891                 goto nla_put_failure;
 892
 893         x->nla_len = skb_tail_pointer(skb) - (u8 *)x;
 894
 895         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 896         NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 897
 898         err = rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC, flags&NLM_F_ECHO);
 899         if (err > 0)
 900                 err = 0;
 901         return err;
 902
 903 nla_put_failure:
 904 nlmsg_failure:
 905         kfree_skb(skb);
 906         return -1;
 907 }
 908
 909
 910 static int
 911 tcf_action_add(struct nlattr *nla, struct nlmsghdr *n, u32 pid, int ovr)
 912 {
 913         int ret = 0;
 914         struct tc_action *act;
 915         struct tc_action *a;
 916         u32 seq = n->nlmsg_seq;
 917
 918         act = tcf_action_init(nla, NULL, NULL, ovr, 0);
 919         if (act == NULL)
 920                 goto done;
 921         if (IS_ERR(act)) {
 922                 ret = PTR_ERR(act);
 923                 goto done;
 924         }
 925
 926         /* dump then free all the actions after update; inserted policy
 927          * stays intact
 928          * */
 929         ret = tcf_add_notify(act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
 930         for (a = act; a; a = act) {
 931                 act = a->next;
 932                 kfree(a);
 933         }
 934 done:
 935         return ret;
 936 }
 937
 938 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 939 {
 940         struct net *net = skb->sk->sk_net;
 941         struct nlattr *tca[TCA_ACT_MAX + 1];
 942         u32 pid = skb ? NETLINK_CB(skb).pid : 0;
 943         int ret = 0, ovr = 0;
 944
 945         if (net != &init_net)
 946                 return -EINVAL;
 947
 948         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
 949         if (ret < 0)
 950                 return ret;
 951
 952         if (tca[TCA_ACT_TAB] == NULL) {
 953                 printk("tc_ctl_action: received NO action attribs\n");
 954                 return -EINVAL;
 955         }
 956
 957         /* n->nlmsg_flags&NLM_F_CREATE
 958          * */
 959         switch (n->nlmsg_type) {
 960         case RTM_NEWACTION:
 961                 /* we are going to assume all other flags
 962                  * imply create only if it doesnt exist
 963                  * Note that CREATE | EXCL implies that
 964                  * but since we want avoid ambiguity (eg when flags
 965                  * is zero) then just set this
 966                  */
 967                 if (n->nlmsg_flags&NLM_F_REPLACE)
 968                         ovr = 1;
 969 replay:
 970                 ret = tcf_action_add(tca[TCA_ACT_TAB], n, pid, ovr);
 971                 if (ret == -EAGAIN)
 972                         goto replay;
 973                 break;
 974         case RTM_DELACTION:
 975                 ret = tca_action_gd(tca[TCA_ACT_TAB], n, pid, RTM_DELACTION);
 976                 break;
 977         case RTM_GETACTION:
 978                 ret = tca_action_gd(tca[TCA_ACT_TAB], n, pid, RTM_GETACTION);
 979                 break;
 980         default:
 981                 BUG();
 982         }
 983
 984         return ret;
 985 }
 986
 987 static struct nlattr *
 988 find_dump_kind(struct nlmsghdr *n)
 989 {
 990         struct nlattr *tb1, *tb2[TCA_ACT_MAX+1];
 991         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 992         struct nlattr *nla[TCAA_MAX + 1];
 993         struct nlattr *kind;
 994
 995         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
 996                 return NULL;
 997         tb1 = nla[TCA_ACT_TAB];
 998         if (tb1 == NULL)
 999                 return NULL;
1000
1001         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1002                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1003                 return NULL;
1004
1005         if (tb[1] == NULL)
1006                 return NULL;
1007         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1008                       nla_len(tb[1]), NULL) < 0)
1009                 return NULL;
1010         kind = tb2[TCA_ACT_KIND];
1011
1012         return kind;
1013 }
1014
1015 static int
1016 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1017 {
1018         struct net *net = skb->sk->sk_net;
1019         struct nlmsghdr *nlh;
1020         unsigned char *b = skb_tail_pointer(skb);
1021         struct nlattr *x;
1022         struct tc_action_ops *a_o;
1023         struct tc_action a;
1024         int ret = 0;
1025         struct tcamsg *t = (struct tcamsg *) NLMSG_DATA(cb->nlh);
1026         struct nlattr *kind = find_dump_kind(cb->nlh);
1027
1028         if (net != &init_net)
1029                 return 0;
1030
1031         if (kind == NULL) {
1032                 printk("tc_dump_action: action bad kind\n");
1033                 return 0;
1034         }
1035
1036         a_o = tc_lookup_action(kind);
1037         if (a_o == NULL) {
1038                 return 0;
1039         }
1040
1041         memset(&a, 0, sizeof(struct tc_action));
1042         a.ops = a_o;
1043
1044         if (a_o->walk == NULL) {
1045                 printk("tc_dump_action: %s !capable of dumping table\n", a_o->kind);
1046                 goto nla_put_failure;
1047         }
1048
1049         nlh = NLMSG_PUT(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
1050                         cb->nlh->nlmsg_type, sizeof(*t));
1051         t = NLMSG_DATA(nlh);
1052         t->tca_family = AF_UNSPEC;
1053         t->tca__pad1 = 0;
1054         t->tca__pad2 = 0;
1055
1056         x = (struct nlattr *)skb_tail_pointer(skb);
1057         NLA_PUT(skb, TCA_ACT_TAB, 0, NULL);
1058
1059         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1060         if (ret < 0)
1061                 goto nla_put_failure;
1062
1063         if (ret > 0) {
1064                 x->nla_len = skb_tail_pointer(skb) - (u8 *)x;
1065                 ret = skb->len;
1066         } else
1067                 nlmsg_trim(skb, x);
1068
1069         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1070         if (NETLINK_CB(cb->skb).pid && ret)
1071                 nlh->nlmsg_flags |= NLM_F_MULTI;
1072         module_put(a_o->owner);
1073         return skb->len;
1074
1075 nla_put_failure:
1076 nlmsg_failure:
1077         module_put(a_o->owner);
1078         nlmsg_trim(skb, b);
1079         return skb->len;
1080 }
1081
1082 static int __init tc_action_init(void)
1083 {
1084         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL);
1085         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL);
1086         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action);
1087
1088         return 0;
1089 }
1090
1091 subsys_initcall(tc_action_init);