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   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         WARN_ON(1);
  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                 a->priv = p;
 212         }
 213         return p;
 214 }
 215 EXPORT_SYMBOL(tcf_hash_check);
 216
 217 struct tcf_common *tcf_hash_create(u32 index, struct nlattr *est,
 218                                    struct tc_action *a, int size, int bind,
 219                                    u32 *idx_gen, struct tcf_hashinfo *hinfo)
 220 {
 221         struct tcf_common *p = kzalloc(size, GFP_KERNEL);
 222
 223         if (unlikely(!p))
 224                 return ERR_PTR(-ENOMEM);
 225         p->tcfc_refcnt = 1;
 226         if (bind)
 227                 p->tcfc_bindcnt = 1;
 228
 229         spin_lock_init(&p->tcfc_lock);
 230         p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
 231         p->tcfc_tm.install = jiffies;
 232         p->tcfc_tm.lastuse = jiffies;
 233         if (est) {
 234                 int err = gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
 235                                             &p->tcfc_lock, est);
 236                 if (err) {
 237                         kfree(p);
 238                         return ERR_PTR(err);
 239                 }
 240         }
 241
 242         a->priv = (void *) p;
 243         return p;
 244 }
 245 EXPORT_SYMBOL(tcf_hash_create);
 246
 247 void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
 248 {
 249         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
 250
 251         write_lock_bh(hinfo->lock);
 252         p->tcfc_next = hinfo->htab[h];
 253         hinfo->htab[h] = p;
 254         write_unlock_bh(hinfo->lock);
 255 }
 256 EXPORT_SYMBOL(tcf_hash_insert);
 257
 258 static struct tc_action_ops *act_base = NULL;
 259 static DEFINE_RWLOCK(act_mod_lock);
 260
 261 int tcf_register_action(struct tc_action_ops *act)
 262 {
 263         struct tc_action_ops *a, **ap;
 264
 265         write_lock(&act_mod_lock);
 266         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
 267                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 268                         write_unlock(&act_mod_lock);
 269                         return -EEXIST;
 270                 }
 271         }
 272         act->next = NULL;
 273         *ap = act;
 274         write_unlock(&act_mod_lock);
 275         return 0;
 276 }
 277 EXPORT_SYMBOL(tcf_register_action);
 278
 279 int tcf_unregister_action(struct tc_action_ops *act)
 280 {
 281         struct tc_action_ops *a, **ap;
 282         int err = -ENOENT;
 283
 284         write_lock(&act_mod_lock);
 285         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
 286                 if (a == act)
 287                         break;
 288         if (a) {
 289                 *ap = a->next;
 290                 a->next = NULL;
 291                 err = 0;
 292         }
 293         write_unlock(&act_mod_lock);
 294         return err;
 295 }
 296 EXPORT_SYMBOL(tcf_unregister_action);
 297
 298 /* lookup by name */
 299 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 300 {
 301         struct tc_action_ops *a = NULL;
 302
 303         if (kind) {
 304                 read_lock(&act_mod_lock);
 305                 for (a = act_base; a; a = a->next) {
 306                         if (strcmp(kind, a->kind) == 0) {
 307                                 if (!try_module_get(a->owner)) {
 308                                         read_unlock(&act_mod_lock);
 309                                         return NULL;
 310                                 }
 311                                 break;
 312                         }
 313                 }
 314                 read_unlock(&act_mod_lock);
 315         }
 316         return a;
 317 }
 318
 319 /* lookup by nlattr */
 320 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 321 {
 322         struct tc_action_ops *a = NULL;
 323
 324         if (kind) {
 325                 read_lock(&act_mod_lock);
 326                 for (a = act_base; a; a = a->next) {
 327                         if (nla_strcmp(kind, a->kind) == 0) {
 328                                 if (!try_module_get(a->owner)) {
 329                                         read_unlock(&act_mod_lock);
 330                                         return NULL;
 331                                 }
 332                                 break;
 333                         }
 334                 }
 335                 read_unlock(&act_mod_lock);
 336         }
 337         return a;
 338 }
 339
 340 #if 0
 341 /* lookup by id */
 342 static struct tc_action_ops *tc_lookup_action_id(u32 type)
 343 {
 344         struct tc_action_ops *a = NULL;
 345
 346         if (type) {
 347                 read_lock(&act_mod_lock);
 348                 for (a = act_base; a; a = a->next) {
 349                         if (a->type == type) {
 350                                 if (!try_module_get(a->owner)) {
 351                                         read_unlock(&act_mod_lock);
 352                                         return NULL;
 353                                 }
 354                                 break;
 355                         }
 356                 }
 357                 read_unlock(&act_mod_lock);
 358         }
 359         return a;
 360 }
 361 #endif
 362
 363 int tcf_action_exec(struct sk_buff *skb, struct tc_action *act,
 364                     struct tcf_result *res)
 365 {
 366         struct tc_action *a;
 367         int ret = -1;
 368
 369         if (skb->tc_verd & TC_NCLS) {
 370                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 371                 ret = TC_ACT_OK;
 372                 goto exec_done;
 373         }
 374         while ((a = act) != NULL) {
 375 repeat:
 376                 if (a->ops && a->ops->act) {
 377                         ret = a->ops->act(skb, a, res);
 378                         if (TC_MUNGED & skb->tc_verd) {
 379                                 /* copied already, allow trampling */
 380                                 skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
 381                                 skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
 382                         }
 383                         if (ret == TC_ACT_REPEAT)
 384                                 goto repeat;    /* we need a ttl - JHS */
 385                         if (ret != TC_ACT_PIPE)
 386                                 goto exec_done;
 387                 }
 388                 act = a->next;
 389         }
 390 exec_done:
 391         return ret;
 392 }
 393 EXPORT_SYMBOL(tcf_action_exec);
 394
 395 void tcf_action_destroy(struct tc_action *act, int bind)
 396 {
 397         struct tc_action *a;
 398
 399         for (a = act; a; a = act) {
 400                 if (a->ops && a->ops->cleanup) {
 401                         if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
 402                                 module_put(a->ops->owner);
 403                         act = act->next;
 404                         kfree(a);
 405                 } else { /*FIXME: Remove later - catch insertion bugs*/
 406                         printk("tcf_action_destroy: BUG? destroying NULL ops\n");
 407                         act = act->next;
 408                         kfree(a);
 409                 }
 410         }
 411 }
 412
 413 int
 414 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 415 {
 416         int err = -EINVAL;
 417
 418         if (a->ops == NULL || a->ops->dump == NULL)
 419                 return err;
 420         return a->ops->dump(skb, a, bind, ref);
 421 }
 422
 423 int
 424 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 425 {
 426         int err = -EINVAL;
 427         unsigned char *b = skb_tail_pointer(skb);
 428         struct nlattr *nest;
 429
 430         if (a->ops == NULL || a->ops->dump == NULL)
 431                 return err;
 432
 433         NLA_PUT_STRING(skb, TCA_KIND, a->ops->kind);
 434         if (tcf_action_copy_stats(skb, a, 0))
 435                 goto nla_put_failure;
 436         nest = nla_nest_start(skb, TCA_OPTIONS);
 437         if (nest == NULL)
 438                 goto nla_put_failure;
 439         if ((err = tcf_action_dump_old(skb, a, bind, ref)) > 0) {
 440                 nla_nest_end(skb, nest);
 441                 return err;
 442         }
 443
 444 nla_put_failure:
 445         nlmsg_trim(skb, b);
 446         return -1;
 447 }
 448 EXPORT_SYMBOL(tcf_action_dump_1);
 449
 450 int
 451 tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
 452 {
 453         struct tc_action *a;
 454         int err = -EINVAL;
 455         struct nlattr *nest;
 456
 457         while ((a = act) != NULL) {
 458                 act = a->next;
 459                 nest = nla_nest_start(skb, a->order);
 460                 if (nest == NULL)
 461                         goto nla_put_failure;
 462                 err = tcf_action_dump_1(skb, a, bind, ref);
 463                 if (err < 0)
 464                         goto errout;
 465                 nla_nest_end(skb, nest);
 466         }
 467
 468         return 0;
 469
 470 nla_put_failure:
 471         err = -EINVAL;
 472 errout:
 473         nla_nest_cancel(skb, nest);
 474         return err;
 475 }
 476
 477 struct tc_action *tcf_action_init_1(struct nlattr *nla, struct nlattr *est,
 478                                     char *name, int ovr, int bind)
 479 {
 480         struct tc_action *a;
 481         struct tc_action_ops *a_o;
 482         char act_name[IFNAMSIZ];
 483         struct nlattr *tb[TCA_ACT_MAX+1];
 484         struct nlattr *kind;
 485         int err;
 486
 487         if (name == NULL) {
 488                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 489                 if (err < 0)
 490                         goto err_out;
 491                 err = -EINVAL;
 492                 kind = tb[TCA_ACT_KIND];
 493                 if (kind == NULL)
 494                         goto err_out;
 495                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 496                         goto err_out;
 497         } else {
 498                 err = -EINVAL;
 499                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 500                         goto err_out;
 501         }
 502
 503         a_o = tc_lookup_action_n(act_name);
 504         if (a_o == NULL) {
 505 #ifdef CONFIG_MODULES
 506                 rtnl_unlock();
 507                 request_module("act_%s", act_name);
 508                 rtnl_lock();
 509
 510                 a_o = tc_lookup_action_n(act_name);
 511
 512                 /* We dropped the RTNL semaphore in order to
 513                  * perform the module load.  So, even if we
 514                  * succeeded in loading the module we have to
 515                  * tell the caller to replay the request.  We
 516                  * indicate this using -EAGAIN.
 517                  */
 518                 if (a_o != NULL) {
 519                         err = -EAGAIN;
 520                         goto err_mod;
 521                 }
 522 #endif
 523                 err = -ENOENT;
 524                 goto err_out;
 525         }
 526
 527         err = -ENOMEM;
 528         a = kzalloc(sizeof(*a), GFP_KERNEL);
 529         if (a == NULL)
 530                 goto err_mod;
 531
 532         /* backward compatibility for policer */
 533         if (name == NULL)
 534                 err = a_o->init(tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
 535         else
 536                 err = a_o->init(nla, est, a, ovr, bind);
 537         if (err < 0)
 538                 goto err_free;
 539
 540         /* module count goes up only when brand new policy is created
 541            if it exists and is only bound to in a_o->init() then
 542            ACT_P_CREATED is not returned (a zero is).
 543         */
 544         if (err != ACT_P_CREATED)
 545                 module_put(a_o->owner);
 546         a->ops = a_o;
 547
 548         return a;
 549
 550 err_free:
 551         kfree(a);
 552 err_mod:
 553         module_put(a_o->owner);
 554 err_out:
 555         return ERR_PTR(err);
 556 }
 557
 558 struct tc_action *tcf_action_init(struct nlattr *nla, struct nlattr *est,
 559                                   char *name, int ovr, int bind)
 560 {
 561         struct nlattr *tb[TCA_ACT_MAX_PRIO+1];
 562         struct tc_action *head = NULL, *act, *act_prev = NULL;
 563         int err;
 564         int i;
 565
 566         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 567         if (err < 0)
 568                 return ERR_PTR(err);
 569
 570         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 571                 act = tcf_action_init_1(tb[i], est, name, ovr, bind);
 572                 if (IS_ERR(act))
 573                         goto err;
 574                 act->order = i;
 575
 576                 if (head == NULL)
 577                         head = act;
 578                 else
 579                         act_prev->next = act;
 580                 act_prev = act;
 581         }
 582         return head;
 583
 584 err:
 585         if (head != NULL)
 586                 tcf_action_destroy(head, bind);
 587         return act;
 588 }
 589
 590 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 591                           int compat_mode)
 592 {
 593         int err = 0;
 594         struct gnet_dump d;
 595         struct tcf_act_hdr *h = a->priv;
 596
 597         if (h == NULL)
 598                 goto errout;
 599
 600         /* compat_mode being true specifies a call that is supposed
 601          * to add additional backward compatiblity statistic TLVs.
 602          */
 603         if (compat_mode) {
 604                 if (a->type == TCA_OLD_COMPAT)
 605                         err = gnet_stats_start_copy_compat(skb, 0,
 606                                 TCA_STATS, TCA_XSTATS, &h->tcf_lock, &d);
 607                 else
 608                         return 0;
 609         } else
 610                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 611                                             &h->tcf_lock, &d);
 612
 613         if (err < 0)
 614                 goto errout;
 615
 616         if (a->ops != NULL && a->ops->get_stats != NULL)
 617                 if (a->ops->get_stats(skb, a) < 0)
 618                         goto errout;
 619
 620         if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
 621             gnet_stats_copy_rate_est(&d, &h->tcf_rate_est) < 0 ||
 622             gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
 623                 goto errout;
 624
 625         if (gnet_stats_finish_copy(&d) < 0)
 626                 goto errout;
 627
 628         return 0;
 629
 630 errout:
 631         return -1;
 632 }
 633
 634 static int
 635 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 pid, u32 seq,
 636              u16 flags, int event, int bind, int ref)
 637 {
 638         struct tcamsg *t;
 639         struct nlmsghdr *nlh;
 640         unsigned char *b = skb_tail_pointer(skb);
 641         struct nlattr *nest;
 642
 643         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 644
 645         t = NLMSG_DATA(nlh);
 646         t->tca_family = AF_UNSPEC;
 647         t->tca__pad1 = 0;
 648         t->tca__pad2 = 0;
 649
 650         nest = nla_nest_start(skb, TCA_ACT_TAB);
 651         if (nest == NULL)
 652                 goto nla_put_failure;
 653
 654         if (tcf_action_dump(skb, a, bind, ref) < 0)
 655                 goto nla_put_failure;
 656
 657         nla_nest_end(skb, nest);
 658
 659         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 660         return skb->len;
 661
 662 nla_put_failure:
 663 nlmsg_failure:
 664         nlmsg_trim(skb, b);
 665         return -1;
 666 }
 667
 668 static int
 669 act_get_notify(u32 pid, struct nlmsghdr *n, struct tc_action *a, int event)
 670 {
 671         struct sk_buff *skb;
 672
 673         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 674         if (!skb)
 675                 return -ENOBUFS;
 676         if (tca_get_fill(skb, a, pid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 677                 kfree_skb(skb);
 678                 return -EINVAL;
 679         }
 680
 681         return rtnl_unicast(skb, &init_net, pid);
 682 }
 683
 684 static struct tc_action *
 685 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 pid)
 686 {
 687         struct nlattr *tb[TCA_ACT_MAX+1];
 688         struct tc_action *a;
 689         int index;
 690         int err;
 691
 692         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 693         if (err < 0)
 694                 goto err_out;
 695
 696         err = -EINVAL;
 697         if (tb[TCA_ACT_INDEX] == NULL ||
 698             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 699                 goto err_out;
 700         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 701
 702         err = -ENOMEM;
 703         a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
 704         if (a == NULL)
 705                 goto err_out;
 706
 707         err = -EINVAL;
 708         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 709         if (a->ops == NULL)
 710                 goto err_free;
 711         if (a->ops->lookup == NULL)
 712                 goto err_mod;
 713         err = -ENOENT;
 714         if (a->ops->lookup(a, index) == 0)
 715                 goto err_mod;
 716
 717         module_put(a->ops->owner);
 718         return a;
 719
 720 err_mod:
 721         module_put(a->ops->owner);
 722 err_free:
 723         kfree(a);
 724 err_out:
 725         return ERR_PTR(err);
 726 }
 727
 728 static void cleanup_a(struct tc_action *act)
 729 {
 730         struct tc_action *a;
 731
 732         for (a = act; a; a = act) {
 733                 act = a->next;
 734                 kfree(a);
 735         }
 736 }
 737
 738 static struct tc_action *create_a(int i)
 739 {
 740         struct tc_action *act;
 741
 742         act = kzalloc(sizeof(*act), GFP_KERNEL);
 743         if (act == NULL) {
 744                 printk("create_a: failed to alloc!\n");
 745                 return NULL;
 746         }
 747         act->order = i;
 748         return act;
 749 }
 750
 751 static int tca_action_flush(struct nlattr *nla, struct nlmsghdr *n, u32 pid)
 752 {
 753         struct sk_buff *skb;
 754         unsigned char *b;
 755         struct nlmsghdr *nlh;
 756         struct tcamsg *t;
 757         struct netlink_callback dcb;
 758         struct nlattr *nest;
 759         struct nlattr *tb[TCA_ACT_MAX+1];
 760         struct nlattr *kind;
 761         struct tc_action *a = create_a(0);
 762         int err = -ENOMEM;
 763
 764         if (a == NULL) {
 765                 printk("tca_action_flush: couldnt create tc_action\n");
 766                 return err;
 767         }
 768
 769         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 770         if (!skb) {
 771                 printk("tca_action_flush: failed skb alloc\n");
 772                 kfree(a);
 773                 return err;
 774         }
 775
 776         b = skb_tail_pointer(skb);
 777
 778         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 779         if (err < 0)
 780                 goto err_out;
 781
 782         err = -EINVAL;
 783         kind = tb[TCA_ACT_KIND];
 784         a->ops = tc_lookup_action(kind);
 785         if (a->ops == NULL)
 786                 goto err_out;
 787
 788         nlh = NLMSG_PUT(skb, pid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t));
 789         t = NLMSG_DATA(nlh);
 790         t->tca_family = AF_UNSPEC;
 791         t->tca__pad1 = 0;
 792         t->tca__pad2 = 0;
 793
 794         nest = nla_nest_start(skb, TCA_ACT_TAB);
 795         if (nest == NULL)
 796                 goto nla_put_failure;
 797
 798         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 799         if (err < 0)
 800                 goto nla_put_failure;
 801         if (err == 0)
 802                 goto noflush_out;
 803
 804         nla_nest_end(skb, nest);
 805
 806         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 807         nlh->nlmsg_flags |= NLM_F_ROOT;
 808         module_put(a->ops->owner);
 809         kfree(a);
 810         err = rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO);
 811         if (err > 0)
 812                 return 0;
 813
 814         return err;
 815
 816 nla_put_failure:
 817 nlmsg_failure:
 818         module_put(a->ops->owner);
 819 err_out:
 820 noflush_out:
 821         kfree_skb(skb);
 822         kfree(a);
 823         return err;
 824 }
 825
 826 static int
 827 tca_action_gd(struct nlattr *nla, struct nlmsghdr *n, u32 pid, int event)
 828 {
 829         int i, ret;
 830         struct nlattr *tb[TCA_ACT_MAX_PRIO+1];
 831         struct tc_action *head = NULL, *act, *act_prev = NULL;
 832
 833         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 834         if (ret < 0)
 835                 return ret;
 836
 837         if (event == RTM_DELACTION && n->nlmsg_flags&NLM_F_ROOT) {
 838                 if (tb[1] != NULL)
 839                         return tca_action_flush(tb[1], n, pid);
 840                 else
 841                         return -EINVAL;
 842         }
 843
 844         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 845                 act = tcf_action_get_1(tb[i], n, pid);
 846                 if (IS_ERR(act)) {
 847                         ret = PTR_ERR(act);
 848                         goto err;
 849                 }
 850                 act->order = i;
 851
 852                 if (head == NULL)
 853                         head = act;
 854                 else
 855                         act_prev->next = act;
 856                 act_prev = act;
 857         }
 858
 859         if (event == RTM_GETACTION)
 860                 ret = act_get_notify(pid, n, head, event);
 861         else { /* delete */
 862                 struct sk_buff *skb;
 863
 864                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 865                 if (!skb) {
 866                         ret = -ENOBUFS;
 867                         goto err;
 868                 }
 869
 870                 if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
 871                                  0, 1) <= 0) {
 872                         kfree_skb(skb);
 873                         ret = -EINVAL;
 874                         goto err;
 875                 }
 876
 877                 /* now do the delete */
 878                 tcf_action_destroy(head, 0);
 879                 ret = rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC,
 880                                      n->nlmsg_flags&NLM_F_ECHO);
 881                 if (ret > 0)
 882                         return 0;
 883                 return ret;
 884         }
 885 err:
 886         cleanup_a(head);
 887         return ret;
 888 }
 889
 890 static int tcf_add_notify(struct tc_action *a, u32 pid, u32 seq, int event,
 891                           u16 flags)
 892 {
 893         struct tcamsg *t;
 894         struct nlmsghdr *nlh;
 895         struct sk_buff *skb;
 896         struct nlattr *nest;
 897         unsigned char *b;
 898         int err = 0;
 899
 900         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 901         if (!skb)
 902                 return -ENOBUFS;
 903
 904         b = skb_tail_pointer(skb);
 905
 906         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 907         t = NLMSG_DATA(nlh);
 908         t->tca_family = AF_UNSPEC;
 909         t->tca__pad1 = 0;
 910         t->tca__pad2 = 0;
 911
 912         nest = nla_nest_start(skb, TCA_ACT_TAB);
 913         if (nest == NULL)
 914                 goto nla_put_failure;
 915
 916         if (tcf_action_dump(skb, a, 0, 0) < 0)
 917                 goto nla_put_failure;
 918
 919         nla_nest_end(skb, nest);
 920
 921         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 922         NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 923
 924         err = rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC, flags&NLM_F_ECHO);
 925         if (err > 0)
 926                 err = 0;
 927         return err;
 928
 929 nla_put_failure:
 930 nlmsg_failure:
 931         kfree_skb(skb);
 932         return -1;
 933 }
 934
 935
 936 static int
 937 tcf_action_add(struct nlattr *nla, struct nlmsghdr *n, u32 pid, int ovr)
 938 {
 939         int ret = 0;
 940         struct tc_action *act;
 941         struct tc_action *a;
 942         u32 seq = n->nlmsg_seq;
 943
 944         act = tcf_action_init(nla, NULL, NULL, ovr, 0);
 945         if (act == NULL)
 946                 goto done;
 947         if (IS_ERR(act)) {
 948                 ret = PTR_ERR(act);
 949                 goto done;
 950         }
 951
 952         /* dump then free all the actions after update; inserted policy
 953          * stays intact
 954          * */
 955         ret = tcf_add_notify(act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
 956         for (a = act; a; a = act) {
 957                 act = a->next;
 958                 kfree(a);
 959         }
 960 done:
 961         return ret;
 962 }
 963
 964 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 965 {
 966         struct net *net = sock_net(skb->sk);
 967         struct nlattr *tca[TCA_ACT_MAX + 1];
 968         u32 pid = skb ? NETLINK_CB(skb).pid : 0;
 969         int ret = 0, ovr = 0;
 970
 971         if (net != &init_net)
 972                 return -EINVAL;
 973
 974         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
 975         if (ret < 0)
 976                 return ret;
 977
 978         if (tca[TCA_ACT_TAB] == NULL) {
 979                 printk("tc_ctl_action: received NO action attribs\n");
 980                 return -EINVAL;
 981         }
 982
 983         /* n->nlmsg_flags&NLM_F_CREATE
 984          * */
 985         switch (n->nlmsg_type) {
 986         case RTM_NEWACTION:
 987                 /* we are going to assume all other flags
 988                  * imply create only if it doesnt exist
 989                  * Note that CREATE | EXCL implies that
 990                  * but since we want avoid ambiguity (eg when flags
 991                  * is zero) then just set this
 992                  */
 993                 if (n->nlmsg_flags&NLM_F_REPLACE)
 994                         ovr = 1;
 995 replay:
 996                 ret = tcf_action_add(tca[TCA_ACT_TAB], n, pid, ovr);
 997                 if (ret == -EAGAIN)
 998                         goto replay;
 999                 break;
1000         case RTM_DELACTION:
1001                 ret = tca_action_gd(tca[TCA_ACT_TAB], n, pid, RTM_DELACTION);
1002                 break;
1003         case RTM_GETACTION:
1004                 ret = tca_action_gd(tca[TCA_ACT_TAB], n, pid, RTM_GETACTION);
1005                 break;
1006         default:
1007                 BUG();
1008         }
1009
1010         return ret;
1011 }
1012
1013 static struct nlattr *
1014 find_dump_kind(struct nlmsghdr *n)
1015 {
1016         struct nlattr *tb1, *tb2[TCA_ACT_MAX+1];
1017         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1018         struct nlattr *nla[TCAA_MAX + 1];
1019         struct nlattr *kind;
1020
1021         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1022                 return NULL;
1023         tb1 = nla[TCA_ACT_TAB];
1024         if (tb1 == NULL)
1025                 return NULL;
1026
1027         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1028                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1029                 return NULL;
1030
1031         if (tb[1] == NULL)
1032                 return NULL;
1033         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1034                       nla_len(tb[1]), NULL) < 0)
1035                 return NULL;
1036         kind = tb2[TCA_ACT_KIND];
1037
1038         return kind;
1039 }
1040
1041 static int
1042 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1043 {
1044         struct net *net = sock_net(skb->sk);
1045         struct nlmsghdr *nlh;
1046         unsigned char *b = skb_tail_pointer(skb);
1047         struct nlattr *nest;
1048         struct tc_action_ops *a_o;
1049         struct tc_action a;
1050         int ret = 0;
1051         struct tcamsg *t = (struct tcamsg *) NLMSG_DATA(cb->nlh);
1052         struct nlattr *kind = find_dump_kind(cb->nlh);
1053
1054         if (net != &init_net)
1055                 return 0;
1056
1057         if (kind == NULL) {
1058                 printk("tc_dump_action: action bad kind\n");
1059                 return 0;
1060         }
1061
1062         a_o = tc_lookup_action(kind);
1063         if (a_o == NULL) {
1064                 return 0;
1065         }
1066
1067         memset(&a, 0, sizeof(struct tc_action));
1068         a.ops = a_o;
1069
1070         if (a_o->walk == NULL) {
1071                 printk("tc_dump_action: %s !capable of dumping table\n", a_o->kind);
1072                 goto nla_put_failure;
1073         }
1074
1075         nlh = NLMSG_PUT(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
1076                         cb->nlh->nlmsg_type, sizeof(*t));
1077         t = NLMSG_DATA(nlh);
1078         t->tca_family = AF_UNSPEC;
1079         t->tca__pad1 = 0;
1080         t->tca__pad2 = 0;
1081
1082         nest = nla_nest_start(skb, TCA_ACT_TAB);
1083         if (nest == NULL)
1084                 goto nla_put_failure;
1085
1086         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1087         if (ret < 0)
1088                 goto nla_put_failure;
1089
1090         if (ret > 0) {
1091                 nla_nest_end(skb, nest);
1092                 ret = skb->len;
1093         } else
1094                 nla_nest_cancel(skb, nest);
1095
1096         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1097         if (NETLINK_CB(cb->skb).pid && ret)
1098                 nlh->nlmsg_flags |= NLM_F_MULTI;
1099         module_put(a_o->owner);
1100         return skb->len;
1101
1102 nla_put_failure:
1103 nlmsg_failure:
1104         module_put(a_o->owner);
1105         nlmsg_trim(skb, b);
1106         return skb->len;
1107 }
1108
1109 static int __init tc_action_init(void)
1110 {
1111         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL);
1112         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL);
1113         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action);
1114
1115         return 0;
1116 }
1117
1118 subsys_initcall(tc_action_init);