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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 compatibility 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_bstats,
 622                                      &h->tcf_rate_est) < 0 ||
 623             gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
 624                 goto errout;
 625
 626         if (gnet_stats_finish_copy(&d) < 0)
 627                 goto errout;
 628
 629         return 0;
 630
 631 errout:
 632         return -1;
 633 }
 634
 635 static int
 636 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 pid, u32 seq,
 637              u16 flags, int event, int bind, int ref)
 638 {
 639         struct tcamsg *t;
 640         struct nlmsghdr *nlh;
 641         unsigned char *b = skb_tail_pointer(skb);
 642         struct nlattr *nest;
 643
 644         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 645
 646         t = NLMSG_DATA(nlh);
 647         t->tca_family = AF_UNSPEC;
 648         t->tca__pad1 = 0;
 649         t->tca__pad2 = 0;
 650
 651         nest = nla_nest_start(skb, TCA_ACT_TAB);
 652         if (nest == NULL)
 653                 goto nla_put_failure;
 654
 655         if (tcf_action_dump(skb, a, bind, ref) < 0)
 656                 goto nla_put_failure;
 657
 658         nla_nest_end(skb, nest);
 659
 660         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 661         return skb->len;
 662
 663 nla_put_failure:
 664 nlmsg_failure:
 665         nlmsg_trim(skb, b);
 666         return -1;
 667 }
 668
 669 static int
 670 act_get_notify(u32 pid, struct nlmsghdr *n, struct tc_action *a, int event)
 671 {
 672         struct sk_buff *skb;
 673
 674         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 675         if (!skb)
 676                 return -ENOBUFS;
 677         if (tca_get_fill(skb, a, pid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 678                 kfree_skb(skb);
 679                 return -EINVAL;
 680         }
 681
 682         return rtnl_unicast(skb, &init_net, pid);
 683 }
 684
 685 static struct tc_action *
 686 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 pid)
 687 {
 688         struct nlattr *tb[TCA_ACT_MAX+1];
 689         struct tc_action *a;
 690         int index;
 691         int err;
 692
 693         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 694         if (err < 0)
 695                 goto err_out;
 696
 697         err = -EINVAL;
 698         if (tb[TCA_ACT_INDEX] == NULL ||
 699             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 700                 goto err_out;
 701         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 702
 703         err = -ENOMEM;
 704         a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
 705         if (a == NULL)
 706                 goto err_out;
 707
 708         err = -EINVAL;
 709         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 710         if (a->ops == NULL)
 711                 goto err_free;
 712         if (a->ops->lookup == NULL)
 713                 goto err_mod;
 714         err = -ENOENT;
 715         if (a->ops->lookup(a, index) == 0)
 716                 goto err_mod;
 717
 718         module_put(a->ops->owner);
 719         return a;
 720
 721 err_mod:
 722         module_put(a->ops->owner);
 723 err_free:
 724         kfree(a);
 725 err_out:
 726         return ERR_PTR(err);
 727 }
 728
 729 static void cleanup_a(struct tc_action *act)
 730 {
 731         struct tc_action *a;
 732
 733         for (a = act; a; a = act) {
 734                 act = a->next;
 735                 kfree(a);
 736         }
 737 }
 738
 739 static struct tc_action *create_a(int i)
 740 {
 741         struct tc_action *act;
 742
 743         act = kzalloc(sizeof(*act), GFP_KERNEL);
 744         if (act == NULL) {
 745                 printk("create_a: failed to alloc!\n");
 746                 return NULL;
 747         }
 748         act->order = i;
 749         return act;
 750 }
 751
 752 static int tca_action_flush(struct nlattr *nla, struct nlmsghdr *n, u32 pid)
 753 {
 754         struct sk_buff *skb;
 755         unsigned char *b;
 756         struct nlmsghdr *nlh;
 757         struct tcamsg *t;
 758         struct netlink_callback dcb;
 759         struct nlattr *nest;
 760         struct nlattr *tb[TCA_ACT_MAX+1];
 761         struct nlattr *kind;
 762         struct tc_action *a = create_a(0);
 763         int err = -ENOMEM;
 764
 765         if (a == NULL) {
 766                 printk("tca_action_flush: couldnt create tc_action\n");
 767                 return err;
 768         }
 769
 770         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 771         if (!skb) {
 772                 printk("tca_action_flush: failed skb alloc\n");
 773                 kfree(a);
 774                 return err;
 775         }
 776
 777         b = skb_tail_pointer(skb);
 778
 779         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 780         if (err < 0)
 781                 goto err_out;
 782
 783         err = -EINVAL;
 784         kind = tb[TCA_ACT_KIND];
 785         a->ops = tc_lookup_action(kind);
 786         if (a->ops == NULL)
 787                 goto err_out;
 788
 789         nlh = NLMSG_PUT(skb, pid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t));
 790         t = NLMSG_DATA(nlh);
 791         t->tca_family = AF_UNSPEC;
 792         t->tca__pad1 = 0;
 793         t->tca__pad2 = 0;
 794
 795         nest = nla_nest_start(skb, TCA_ACT_TAB);
 796         if (nest == NULL)
 797                 goto nla_put_failure;
 798
 799         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 800         if (err < 0)
 801                 goto nla_put_failure;
 802         if (err == 0)
 803                 goto noflush_out;
 804
 805         nla_nest_end(skb, nest);
 806
 807         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 808         nlh->nlmsg_flags |= NLM_F_ROOT;
 809         module_put(a->ops->owner);
 810         kfree(a);
 811         err = rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO);
 812         if (err > 0)
 813                 return 0;
 814
 815         return err;
 816
 817 nla_put_failure:
 818 nlmsg_failure:
 819         module_put(a->ops->owner);
 820 err_out:
 821 noflush_out:
 822         kfree_skb(skb);
 823         kfree(a);
 824         return err;
 825 }
 826
 827 static int
 828 tca_action_gd(struct nlattr *nla, struct nlmsghdr *n, u32 pid, int event)
 829 {
 830         int i, ret;
 831         struct nlattr *tb[TCA_ACT_MAX_PRIO+1];
 832         struct tc_action *head = NULL, *act, *act_prev = NULL;
 833
 834         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 835         if (ret < 0)
 836                 return ret;
 837
 838         if (event == RTM_DELACTION && n->nlmsg_flags&NLM_F_ROOT) {
 839                 if (tb[1] != NULL)
 840                         return tca_action_flush(tb[1], n, pid);
 841                 else
 842                         return -EINVAL;
 843         }
 844
 845         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 846                 act = tcf_action_get_1(tb[i], n, pid);
 847                 if (IS_ERR(act)) {
 848                         ret = PTR_ERR(act);
 849                         goto err;
 850                 }
 851                 act->order = i;
 852
 853                 if (head == NULL)
 854                         head = act;
 855                 else
 856                         act_prev->next = act;
 857                 act_prev = act;
 858         }
 859
 860         if (event == RTM_GETACTION)
 861                 ret = act_get_notify(pid, n, head, event);
 862         else { /* delete */
 863                 struct sk_buff *skb;
 864
 865                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 866                 if (!skb) {
 867                         ret = -ENOBUFS;
 868                         goto err;
 869                 }
 870
 871                 if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
 872                                  0, 1) <= 0) {
 873                         kfree_skb(skb);
 874                         ret = -EINVAL;
 875                         goto err;
 876                 }
 877
 878                 /* now do the delete */
 879                 tcf_action_destroy(head, 0);
 880                 ret = rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC,
 881                                      n->nlmsg_flags&NLM_F_ECHO);
 882                 if (ret > 0)
 883                         return 0;
 884                 return ret;
 885         }
 886 err:
 887         cleanup_a(head);
 888         return ret;
 889 }
 890
 891 static int tcf_add_notify(struct tc_action *a, u32 pid, u32 seq, int event,
 892                           u16 flags)
 893 {
 894         struct tcamsg *t;
 895         struct nlmsghdr *nlh;
 896         struct sk_buff *skb;
 897         struct nlattr *nest;
 898         unsigned char *b;
 899         int err = 0;
 900
 901         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 902         if (!skb)
 903                 return -ENOBUFS;
 904
 905         b = skb_tail_pointer(skb);
 906
 907         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 908         t = NLMSG_DATA(nlh);
 909         t->tca_family = AF_UNSPEC;
 910         t->tca__pad1 = 0;
 911         t->tca__pad2 = 0;
 912
 913         nest = nla_nest_start(skb, TCA_ACT_TAB);
 914         if (nest == NULL)
 915                 goto nla_put_failure;
 916
 917         if (tcf_action_dump(skb, a, 0, 0) < 0)
 918                 goto nla_put_failure;
 919
 920         nla_nest_end(skb, nest);
 921
 922         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 923         NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 924
 925         err = rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC, flags&NLM_F_ECHO);
 926         if (err > 0)
 927                 err = 0;
 928         return err;
 929
 930 nla_put_failure:
 931 nlmsg_failure:
 932         kfree_skb(skb);
 933         return -1;
 934 }
 935
 936
 937 static int
 938 tcf_action_add(struct nlattr *nla, struct nlmsghdr *n, u32 pid, int ovr)
 939 {
 940         int ret = 0;
 941         struct tc_action *act;
 942         struct tc_action *a;
 943         u32 seq = n->nlmsg_seq;
 944
 945         act = tcf_action_init(nla, NULL, NULL, ovr, 0);
 946         if (act == NULL)
 947                 goto done;
 948         if (IS_ERR(act)) {
 949                 ret = PTR_ERR(act);
 950                 goto done;
 951         }
 952
 953         /* dump then free all the actions after update; inserted policy
 954          * stays intact
 955          * */
 956         ret = tcf_add_notify(act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
 957         for (a = act; a; a = act) {
 958                 act = a->next;
 959                 kfree(a);
 960         }
 961 done:
 962         return ret;
 963 }
 964
 965 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 966 {
 967         struct net *net = sock_net(skb->sk);
 968         struct nlattr *tca[TCA_ACT_MAX + 1];
 969         u32 pid = skb ? NETLINK_CB(skb).pid : 0;
 970         int ret = 0, ovr = 0;
 971
 972         if (!net_eq(net, &init_net))
 973                 return -EINVAL;
 974
 975         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
 976         if (ret < 0)
 977                 return ret;
 978
 979         if (tca[TCA_ACT_TAB] == NULL) {
 980                 printk("tc_ctl_action: received NO action attribs\n");
 981                 return -EINVAL;
 982         }
 983
 984         /* n->nlmsg_flags&NLM_F_CREATE
 985          * */
 986         switch (n->nlmsg_type) {
 987         case RTM_NEWACTION:
 988                 /* we are going to assume all other flags
 989                  * imply create only if it doesnt exist
 990                  * Note that CREATE | EXCL implies that
 991                  * but since we want avoid ambiguity (eg when flags
 992                  * is zero) then just set this
 993                  */
 994                 if (n->nlmsg_flags&NLM_F_REPLACE)
 995                         ovr = 1;
 996 replay:
 997                 ret = tcf_action_add(tca[TCA_ACT_TAB], n, pid, ovr);
 998                 if (ret == -EAGAIN)
 999                         goto replay;
1000                 break;
1001         case RTM_DELACTION:
1002                 ret = tca_action_gd(tca[TCA_ACT_TAB], n, pid, RTM_DELACTION);
1003                 break;
1004         case RTM_GETACTION:
1005                 ret = tca_action_gd(tca[TCA_ACT_TAB], n, pid, RTM_GETACTION);
1006                 break;
1007         default:
1008                 BUG();
1009         }
1010
1011         return ret;
1012 }
1013
1014 static struct nlattr *
1015 find_dump_kind(const struct nlmsghdr *n)
1016 {
1017         struct nlattr *tb1, *tb2[TCA_ACT_MAX+1];
1018         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1019         struct nlattr *nla[TCAA_MAX + 1];
1020         struct nlattr *kind;
1021
1022         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1023                 return NULL;
1024         tb1 = nla[TCA_ACT_TAB];
1025         if (tb1 == NULL)
1026                 return NULL;
1027
1028         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1029                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1030                 return NULL;
1031
1032         if (tb[1] == NULL)
1033                 return NULL;
1034         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1035                       nla_len(tb[1]), NULL) < 0)
1036                 return NULL;
1037         kind = tb2[TCA_ACT_KIND];
1038
1039         return kind;
1040 }
1041
1042 static int
1043 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1044 {
1045         struct net *net = sock_net(skb->sk);
1046         struct nlmsghdr *nlh;
1047         unsigned char *b = skb_tail_pointer(skb);
1048         struct nlattr *nest;
1049         struct tc_action_ops *a_o;
1050         struct tc_action a;
1051         int ret = 0;
1052         struct tcamsg *t = (struct tcamsg *) NLMSG_DATA(cb->nlh);
1053         struct nlattr *kind = find_dump_kind(cb->nlh);
1054
1055         if (!net_eq(net, &init_net))
1056                 return 0;
1057
1058         if (kind == NULL) {
1059                 printk("tc_dump_action: action bad kind\n");
1060                 return 0;
1061         }
1062
1063         a_o = tc_lookup_action(kind);
1064         if (a_o == NULL) {
1065                 return 0;
1066         }
1067
1068         memset(&a, 0, sizeof(struct tc_action));
1069         a.ops = a_o;
1070
1071         if (a_o->walk == NULL) {
1072                 printk("tc_dump_action: %s !capable of dumping table\n", a_o->kind);
1073                 goto nla_put_failure;
1074         }
1075
1076         nlh = NLMSG_PUT(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
1077                         cb->nlh->nlmsg_type, sizeof(*t));
1078         t = NLMSG_DATA(nlh);
1079         t->tca_family = AF_UNSPEC;
1080         t->tca__pad1 = 0;
1081         t->tca__pad2 = 0;
1082
1083         nest = nla_nest_start(skb, TCA_ACT_TAB);
1084         if (nest == NULL)
1085                 goto nla_put_failure;
1086
1087         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1088         if (ret < 0)
1089                 goto nla_put_failure;
1090
1091         if (ret > 0) {
1092                 nla_nest_end(skb, nest);
1093                 ret = skb->len;
1094         } else
1095                 nla_nest_cancel(skb, nest);
1096
1097         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1098         if (NETLINK_CB(cb->skb).pid && ret)
1099                 nlh->nlmsg_flags |= NLM_F_MULTI;
1100         module_put(a_o->owner);
1101         return skb->len;
1102
1103 nla_put_failure:
1104 nlmsg_failure:
1105         module_put(a_o->owner);
1106         nlmsg_trim(skb, b);
1107         return skb->len;
1108 }
1109
1110 static int __init tc_action_init(void)
1111 {
1112         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL);
1113         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL);
1114         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action);
1115
1116         return 0;
1117 }
1118
1119 subsys_initcall(tc_action_init);