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