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/slab.h>
  19 #include <linux/skbuff.h>
  20 #include <linux/init.h>
  21 #include <linux/kmod.h>
  22 #include <linux/err.h>
  23 #include <net/net_namespace.h>
  24 #include <net/sock.h>
  25 #include <net/sch_generic.h>
  26 #include <net/act_api.h>
  27 #include <net/netlink.h>
  28
  29 void tcf_hash_destroy(struct tcf_common *p, struct tcf_hashinfo *hinfo)
  30 {
  31         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
  32         struct tcf_common **p1p;
  33
  34         for (p1p = &hinfo->htab[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
  35                 if (*p1p == p) {
  36                         write_lock_bh(hinfo->lock);
  37                         *p1p = p->tcfc_next;
  38                         write_unlock_bh(hinfo->lock);
  39                         gen_kill_estimator(&p->tcfc_bstats,
  40                                            &p->tcfc_rate_est);
  41                         kfree(p);
  42                         return;
  43                 }
  44         }
  45         WARN_ON(1);
  46 }
  47 EXPORT_SYMBOL(tcf_hash_destroy);
  48
  49 int tcf_hash_release(struct tcf_common *p, int bind,
  50                      struct tcf_hashinfo *hinfo)
  51 {
  52         int ret = 0;
  53
  54         if (p) {
  55                 if (bind)
  56                         p->tcfc_bindcnt--;
  57
  58                 p->tcfc_refcnt--;
  59                 if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
  60                         tcf_hash_destroy(p, hinfo);
  61                         ret = 1;
  62                 }
  63         }
  64         return ret;
  65 }
  66 EXPORT_SYMBOL(tcf_hash_release);
  67
  68 static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
  69                            struct tc_action *a, struct tcf_hashinfo *hinfo)
  70 {
  71         struct tcf_common *p;
  72         int err = 0, index = -1,i = 0, s_i = 0, n_i = 0;
  73         struct nlattr *nest;
  74
  75         read_lock_bh(hinfo->lock);
  76
  77         s_i = cb->args[0];
  78
  79         for (i = 0; i < (hinfo->hmask + 1); i++) {
  80                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
  81
  82                 for (; p; p = p->tcfc_next) {
  83                         index++;
  84                         if (index < s_i)
  85                                 continue;
  86                         a->priv = p;
  87                         a->order = n_i;
  88
  89                         nest = nla_nest_start(skb, a->order);
  90                         if (nest == NULL)
  91                                 goto nla_put_failure;
  92                         err = tcf_action_dump_1(skb, a, 0, 0);
  93                         if (err < 0) {
  94                                 index--;
  95                                 nlmsg_trim(skb, nest);
  96                                 goto done;
  97                         }
  98                         nla_nest_end(skb, nest);
  99                         n_i++;
 100                         if (n_i >= TCA_ACT_MAX_PRIO)
 101                                 goto done;
 102                 }
 103         }
 104 done:
 105         read_unlock_bh(hinfo->lock);
 106         if (n_i)
 107                 cb->args[0] += n_i;
 108         return n_i;
 109
 110 nla_put_failure:
 111         nla_nest_cancel(skb, nest);
 112         goto done;
 113 }
 114
 115 static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a,
 116                           struct tcf_hashinfo *hinfo)
 117 {
 118         struct tcf_common *p, *s_p;
 119         struct nlattr *nest;
 120         int i= 0, n_i = 0;
 121
 122         nest = nla_nest_start(skb, a->order);
 123         if (nest == NULL)
 124                 goto nla_put_failure;
 125         NLA_PUT_STRING(skb, TCA_KIND, a->ops->kind);
 126         for (i = 0; i < (hinfo->hmask + 1); i++) {
 127                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
 128
 129                 while (p != NULL) {
 130                         s_p = p->tcfc_next;
 131                         if (ACT_P_DELETED == tcf_hash_release(p, 0, hinfo))
 132                                  module_put(a->ops->owner);
 133                         n_i++;
 134                         p = s_p;
 135                 }
 136         }
 137         NLA_PUT_U32(skb, TCA_FCNT, n_i);
 138         nla_nest_end(skb, nest);
 139
 140         return n_i;
 141 nla_put_failure:
 142         nla_nest_cancel(skb, nest);
 143         return -EINVAL;
 144 }
 145
 146 int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
 147                        int type, struct tc_action *a)
 148 {
 149         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 150
 151         if (type == RTM_DELACTION) {
 152                 return tcf_del_walker(skb, a, hinfo);
 153         } else if (type == RTM_GETACTION) {
 154                 return tcf_dump_walker(skb, cb, a, hinfo);
 155         } else {
 156                 printk("tcf_generic_walker: unknown action %d\n", type);
 157                 return -EINVAL;
 158         }
 159 }
 160 EXPORT_SYMBOL(tcf_generic_walker);
 161
 162 struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 163 {
 164         struct tcf_common *p;
 165
 166         read_lock_bh(hinfo->lock);
 167         for (p = hinfo->htab[tcf_hash(index, hinfo->hmask)]; p;
 168              p = p->tcfc_next) {
 169                 if (p->tcfc_index == index)
 170                         break;
 171         }
 172         read_unlock_bh(hinfo->lock);
 173
 174         return p;
 175 }
 176 EXPORT_SYMBOL(tcf_hash_lookup);
 177
 178 u32 tcf_hash_new_index(u32 *idx_gen, struct tcf_hashinfo *hinfo)
 179 {
 180         u32 val = *idx_gen;
 181
 182         do {
 183                 if (++val == 0)
 184                         val = 1;
 185         } while (tcf_hash_lookup(val, hinfo));
 186
 187         return (*idx_gen = val);
 188 }
 189 EXPORT_SYMBOL(tcf_hash_new_index);
 190
 191 int tcf_hash_search(struct tc_action *a, u32 index)
 192 {
 193         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 194         struct tcf_common *p = tcf_hash_lookup(index, hinfo);
 195
 196         if (p) {
 197                 a->priv = p;
 198                 return 1;
 199         }
 200         return 0;
 201 }
 202 EXPORT_SYMBOL(tcf_hash_search);
 203
 204 struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
 205                                   struct tcf_hashinfo *hinfo)
 206 {
 207         struct tcf_common *p = NULL;
 208         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 209                 if (bind)
 210                         p->tcfc_bindcnt++;
 211                 p->tcfc_refcnt++;
 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,
 219                                    struct tc_action *a, int size, int bind,
 220                                    u32 *idx_gen, struct tcf_hashinfo *hinfo)
 221 {
 222         struct tcf_common *p = kzalloc(size, GFP_KERNEL);
 223
 224         if (unlikely(!p))
 225                 return ERR_PTR(-ENOMEM);
 226         p->tcfc_refcnt = 1;
 227         if (bind)
 228                 p->tcfc_bindcnt = 1;
 229
 230         spin_lock_init(&p->tcfc_lock);
 231         p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
 232         p->tcfc_tm.install = jiffies;
 233         p->tcfc_tm.lastuse = jiffies;
 234         if (est) {
 235                 int err = gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
 236                                             &p->tcfc_lock, est);
 237                 if (err) {
 238                         kfree(p);
 239                         return ERR_PTR(err);
 240                 }
 241         }
 242
 243         a->priv = (void *) p;
 244         return p;
 245 }
 246 EXPORT_SYMBOL(tcf_hash_create);
 247
 248 void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
 249 {
 250         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
 251
 252         write_lock_bh(hinfo->lock);
 253         p->tcfc_next = hinfo->htab[h];
 254         hinfo->htab[h] = p;
 255         write_unlock_bh(hinfo->lock);
 256 }
 257 EXPORT_SYMBOL(tcf_hash_insert);
 258
 259 static struct tc_action_ops *act_base = NULL;
 260 static DEFINE_RWLOCK(act_mod_lock);
 261
 262 int tcf_register_action(struct tc_action_ops *act)
 263 {
 264         struct tc_action_ops *a, **ap;
 265
 266         write_lock(&act_mod_lock);
 267         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
 268                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 269                         write_unlock(&act_mod_lock);
 270                         return -EEXIST;
 271                 }
 272         }
 273         act->next = NULL;
 274         *ap = act;
 275         write_unlock(&act_mod_lock);
 276         return 0;
 277 }
 278 EXPORT_SYMBOL(tcf_register_action);
 279
 280 int tcf_unregister_action(struct tc_action_ops *act)
 281 {
 282         struct tc_action_ops *a, **ap;
 283         int err = -ENOENT;
 284
 285         write_lock(&act_mod_lock);
 286         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
 287                 if (a == act)
 288                         break;
 289         if (a) {
 290                 *ap = a->next;
 291                 a->next = NULL;
 292                 err = 0;
 293         }
 294         write_unlock(&act_mod_lock);
 295         return err;
 296 }
 297 EXPORT_SYMBOL(tcf_unregister_action);
 298
 299 /* lookup by name */
 300 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 301 {
 302         struct tc_action_ops *a = NULL;
 303
 304         if (kind) {
 305                 read_lock(&act_mod_lock);
 306                 for (a = act_base; a; a = a->next) {
 307                         if (strcmp(kind, a->kind) == 0) {
 308                                 if (!try_module_get(a->owner)) {
 309                                         read_unlock(&act_mod_lock);
 310                                         return NULL;
 311                                 }
 312                                 break;
 313                         }
 314                 }
 315                 read_unlock(&act_mod_lock);
 316         }
 317         return a;
 318 }
 319
 320 /* lookup by nlattr */
 321 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 322 {
 323         struct tc_action_ops *a = NULL;
 324
 325         if (kind) {
 326                 read_lock(&act_mod_lock);
 327                 for (a = act_base; a; a = a->next) {
 328                         if (nla_strcmp(kind, a->kind) == 0) {
 329                                 if (!try_module_get(a->owner)) {
 330                                         read_unlock(&act_mod_lock);
 331                                         return NULL;
 332                                 }
 333                                 break;
 334                         }
 335                 }
 336                 read_unlock(&act_mod_lock);
 337         }
 338         return a;
 339 }
 340
 341 #if 0
 342 /* lookup by id */
 343 static struct tc_action_ops *tc_lookup_action_id(u32 type)
 344 {
 345         struct tc_action_ops *a = NULL;
 346
 347         if (type) {
 348                 read_lock(&act_mod_lock);
 349                 for (a = act_base; a; a = a->next) {
 350                         if (a->type == type) {
 351                                 if (!try_module_get(a->owner)) {
 352                                         read_unlock(&act_mod_lock);
 353                                         return NULL;
 354                                 }
 355                                 break;
 356                         }
 357                 }
 358                 read_unlock(&act_mod_lock);
 359         }
 360         return a;
 361 }
 362 #endif
 363
 364 int tcf_action_exec(struct sk_buff *skb, struct tc_action *act,
 365                     struct tcf_result *res)
 366 {
 367         struct tc_action *a;
 368         int ret = -1;
 369
 370         if (skb->tc_verd & TC_NCLS) {
 371                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 372                 ret = TC_ACT_OK;
 373                 goto exec_done;
 374         }
 375         while ((a = act) != NULL) {
 376 repeat:
 377                 if (a->ops && a->ops->act) {
 378                         ret = a->ops->act(skb, a, res);
 379                         if (TC_MUNGED & skb->tc_verd) {
 380                                 /* copied already, allow trampling */
 381                                 skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
 382                                 skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
 383                         }
 384                         if (ret == TC_ACT_REPEAT)
 385                                 goto repeat;    /* we need a ttl - JHS */
 386                         if (ret != TC_ACT_PIPE)
 387                                 goto exec_done;
 388                 }
 389                 act = a->next;
 390         }
 391 exec_done:
 392         return ret;
 393 }
 394 EXPORT_SYMBOL(tcf_action_exec);
 395
 396 void tcf_action_destroy(struct tc_action *act, int bind)
 397 {
 398         struct tc_action *a;
 399
 400         for (a = act; a; a = act) {
 401                 if (a->ops && a->ops->cleanup) {
 402                         if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
 403                                 module_put(a->ops->owner);
 404                         act = act->next;
 405                         kfree(a);
 406                 } else { /*FIXME: Remove later - catch insertion bugs*/
 407                         printk("tcf_action_destroy: BUG? destroying NULL ops\n");
 408                         act = act->next;
 409                         kfree(a);
 410                 }
 411         }
 412 }
 413
 414 int
 415 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 416 {
 417         int err = -EINVAL;
 418
 419         if (a->ops == NULL || a->ops->dump == NULL)
 420                 return err;
 421         return a->ops->dump(skb, a, bind, ref);
 422 }
 423
 424 int
 425 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 426 {
 427         int err = -EINVAL;
 428         unsigned char *b = skb_tail_pointer(skb);
 429         struct nlattr *nest;
 430
 431         if (a->ops == NULL || a->ops->dump == NULL)
 432                 return err;
 433
 434         NLA_PUT_STRING(skb, TCA_KIND, a->ops->kind);
 435         if (tcf_action_copy_stats(skb, a, 0))
 436                 goto nla_put_failure;
 437         nest = nla_nest_start(skb, TCA_OPTIONS);
 438         if (nest == NULL)
 439                 goto nla_put_failure;
 440         if ((err = tcf_action_dump_old(skb, a, bind, ref)) > 0) {
 441                 nla_nest_end(skb, nest);
 442                 return err;
 443         }
 444
 445 nla_put_failure:
 446         nlmsg_trim(skb, b);
 447         return -1;
 448 }
 449 EXPORT_SYMBOL(tcf_action_dump_1);
 450
 451 int
 452 tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
 453 {
 454         struct tc_action *a;
 455         int err = -EINVAL;
 456         struct nlattr *nest;
 457
 458         while ((a = act) != NULL) {
 459                 act = a->next;
 460                 nest = nla_nest_start(skb, a->order);
 461                 if (nest == NULL)
 462                         goto nla_put_failure;
 463                 err = tcf_action_dump_1(skb, a, bind, ref);
 464                 if (err < 0)
 465                         goto errout;
 466                 nla_nest_end(skb, nest);
 467         }
 468
 469         return 0;
 470
 471 nla_put_failure:
 472         err = -EINVAL;
 473 errout:
 474         nla_nest_cancel(skb, nest);
 475         return err;
 476 }
 477
 478 struct tc_action *tcf_action_init_1(struct nlattr *nla, struct nlattr *est,
 479                                     char *name, int ovr, int bind)
 480 {
 481         struct tc_action *a;
 482         struct tc_action_ops *a_o;
 483         char act_name[IFNAMSIZ];
 484         struct nlattr *tb[TCA_ACT_MAX+1];
 485         struct nlattr *kind;
 486         int err;
 487
 488         if (name == NULL) {
 489                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 490                 if (err < 0)
 491                         goto err_out;
 492                 err = -EINVAL;
 493                 kind = tb[TCA_ACT_KIND];
 494                 if (kind == NULL)
 495                         goto err_out;
 496                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 497                         goto err_out;
 498         } else {
 499                 err = -EINVAL;
 500                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 501                         goto err_out;
 502         }
 503
 504         a_o = tc_lookup_action_n(act_name);
 505         if (a_o == NULL) {
 506 #ifdef CONFIG_MODULES
 507                 rtnl_unlock();
 508                 request_module("act_%s", act_name);
 509                 rtnl_lock();
 510
 511                 a_o = tc_lookup_action_n(act_name);
 512
 513                 /* We dropped the RTNL semaphore in order to
 514                  * perform the module load.  So, even if we
 515                  * succeeded in loading the module we have to
 516                  * tell the caller to replay the request.  We
 517                  * indicate this using -EAGAIN.
 518                  */
 519                 if (a_o != NULL) {
 520                         err = -EAGAIN;
 521                         goto err_mod;
 522                 }
 523 #endif
 524                 err = -ENOENT;
 525                 goto err_out;
 526         }
 527
 528         err = -ENOMEM;
 529         a = kzalloc(sizeof(*a), GFP_KERNEL);
 530         if (a == NULL)
 531                 goto err_mod;
 532
 533         /* backward compatibility for policer */
 534         if (name == NULL)
 535                 err = a_o->init(tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
 536         else
 537                 err = a_o->init(nla, est, a, ovr, bind);
 538         if (err < 0)
 539                 goto err_free;
 540
 541         /* module count goes up only when brand new policy is created
 542            if it exists and is only bound to in a_o->init() then
 543            ACT_P_CREATED is not returned (a zero is).
 544         */
 545         if (err != ACT_P_CREATED)
 546                 module_put(a_o->owner);
 547         a->ops = a_o;
 548
 549         return a;
 550
 551 err_free:
 552         kfree(a);
 553 err_mod:
 554         module_put(a_o->owner);
 555 err_out:
 556         return ERR_PTR(err);
 557 }
 558
 559 struct tc_action *tcf_action_init(struct nlattr *nla, struct nlattr *est,
 560                                   char *name, int ovr, int bind)
 561 {
 562         struct nlattr *tb[TCA_ACT_MAX_PRIO+1];
 563         struct tc_action *head = NULL, *act, *act_prev = NULL;
 564         int err;
 565         int i;
 566
 567         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 568         if (err < 0)
 569                 return ERR_PTR(err);
 570
 571         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 572                 act = tcf_action_init_1(tb[i], est, name, ovr, bind);
 573                 if (IS_ERR(act))
 574                         goto err;
 575                 act->order = i;
 576
 577                 if (head == NULL)
 578                         head = act;
 579                 else
 580                         act_prev->next = act;
 581                 act_prev = act;
 582         }
 583         return head;
 584
 585 err:
 586         if (head != NULL)
 587                 tcf_action_destroy(head, bind);
 588         return act;
 589 }
 590
 591 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 592                           int compat_mode)
 593 {
 594         int err = 0;
 595         struct gnet_dump d;
 596         struct tcf_act_hdr *h = a->priv;
 597
 598         if (h == NULL)
 599                 goto errout;
 600
 601         /* compat_mode being true specifies a call that is supposed
 602          * to add additional backward compatibility statistic TLVs.
 603          */
 604         if (compat_mode) {
 605                 if (a->type == TCA_OLD_COMPAT)
 606                         err = gnet_stats_start_copy_compat(skb, 0,
 607                                 TCA_STATS, TCA_XSTATS, &h->tcf_lock, &d);
 608                 else
 609                         return 0;
 610         } else
 611                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 612                                             &h->tcf_lock, &d);
 613
 614         if (err < 0)
 615                 goto errout;
 616
 617         if (a->ops != NULL && a->ops->get_stats != NULL)
 618                 if (a->ops->get_stats(skb, a) < 0)
 619                         goto errout;
 620
 621         if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
 622             gnet_stats_copy_rate_est(&d, &h->tcf_bstats,
 623                                      &h->tcf_rate_est) < 0 ||
 624             gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
 625                 goto errout;
 626
 627         if (gnet_stats_finish_copy(&d) < 0)
 628                 goto errout;
 629
 630         return 0;
 631
 632 errout:
 633         return -1;
 634 }
 635
 636 static int
 637 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 pid, u32 seq,
 638              u16 flags, int event, int bind, int ref)
 639 {
 640         struct tcamsg *t;
 641         struct nlmsghdr *nlh;
 642         unsigned char *b = skb_tail_pointer(skb);
 643         struct nlattr *nest;
 644
 645         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 646
 647         t = NLMSG_DATA(nlh);
 648         t->tca_family = AF_UNSPEC;
 649         t->tca__pad1 = 0;
 650         t->tca__pad2 = 0;
 651
 652         nest = nla_nest_start(skb, TCA_ACT_TAB);
 653         if (nest == NULL)
 654                 goto nla_put_failure;
 655
 656         if (tcf_action_dump(skb, a, bind, ref) < 0)
 657                 goto nla_put_failure;
 658
 659         nla_nest_end(skb, nest);
 660
 661         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 662         return skb->len;
 663
 664 nla_put_failure:
 665 nlmsg_failure:
 666         nlmsg_trim(skb, b);
 667         return -1;
 668 }
 669
 670 static int
 671 act_get_notify(u32 pid, struct nlmsghdr *n, struct tc_action *a, int event)
 672 {
 673         struct sk_buff *skb;
 674
 675         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 676         if (!skb)
 677                 return -ENOBUFS;
 678         if (tca_get_fill(skb, a, pid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 679                 kfree_skb(skb);
 680                 return -EINVAL;
 681         }
 682
 683         return rtnl_unicast(skb, &init_net, pid);
 684 }
 685
 686 static struct tc_action *
 687 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 pid)
 688 {
 689         struct nlattr *tb[TCA_ACT_MAX+1];
 690         struct tc_action *a;
 691         int index;
 692         int err;
 693
 694         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 695         if (err < 0)
 696                 goto err_out;
 697
 698         err = -EINVAL;
 699         if (tb[TCA_ACT_INDEX] == NULL ||
 700             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 701                 goto err_out;
 702         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 703
 704         err = -ENOMEM;
 705         a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
 706         if (a == NULL)
 707                 goto err_out;
 708
 709         err = -EINVAL;
 710         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 711         if (a->ops == NULL)
 712                 goto err_free;
 713         if (a->ops->lookup == NULL)
 714                 goto err_mod;
 715         err = -ENOENT;
 716         if (a->ops->lookup(a, index) == 0)
 717                 goto err_mod;
 718
 719         module_put(a->ops->owner);
 720         return a;
 721
 722 err_mod:
 723         module_put(a->ops->owner);
 724 err_free:
 725         kfree(a);
 726 err_out:
 727         return ERR_PTR(err);
 728 }
 729
 730 static void cleanup_a(struct tc_action *act)
 731 {
 732         struct tc_action *a;
 733
 734         for (a = act; a; a = act) {
 735                 act = a->next;
 736                 kfree(a);
 737         }
 738 }
 739
 740 static struct tc_action *create_a(int i)
 741 {
 742         struct tc_action *act;
 743
 744         act = kzalloc(sizeof(*act), GFP_KERNEL);
 745         if (act == NULL) {
 746                 printk("create_a: failed to alloc!\n");
 747                 return NULL;
 748         }
 749         act->order = i;
 750         return act;
 751 }
 752
 753 static int tca_action_flush(struct nlattr *nla, struct nlmsghdr *n, u32 pid)
 754 {
 755         struct sk_buff *skb;
 756         unsigned char *b;
 757         struct nlmsghdr *nlh;
 758         struct tcamsg *t;
 759         struct netlink_callback dcb;
 760         struct nlattr *nest;
 761         struct nlattr *tb[TCA_ACT_MAX+1];
 762         struct nlattr *kind;
 763         struct tc_action *a = create_a(0);
 764         int err = -ENOMEM;
 765
 766         if (a == NULL) {
 767                 printk("tca_action_flush: couldnt create tc_action\n");
 768                 return err;
 769         }
 770
 771         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 772         if (!skb) {
 773                 printk("tca_action_flush: failed skb alloc\n");
 774                 kfree(a);
 775                 return err;
 776         }
 777
 778         b = skb_tail_pointer(skb);
 779
 780         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 781         if (err < 0)
 782                 goto err_out;
 783
 784         err = -EINVAL;
 785         kind = tb[TCA_ACT_KIND];
 786         a->ops = tc_lookup_action(kind);
 787         if (a->ops == NULL)
 788                 goto err_out;
 789
 790         nlh = NLMSG_PUT(skb, pid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t));
 791         t = NLMSG_DATA(nlh);
 792         t->tca_family = AF_UNSPEC;
 793         t->tca__pad1 = 0;
 794         t->tca__pad2 = 0;
 795
 796         nest = nla_nest_start(skb, TCA_ACT_TAB);
 797         if (nest == NULL)
 798                 goto nla_put_failure;
 799
 800         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 801         if (err < 0)
 802                 goto nla_put_failure;
 803         if (err == 0)
 804                 goto noflush_out;
 805
 806         nla_nest_end(skb, nest);
 807
 808         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 809         nlh->nlmsg_flags |= NLM_F_ROOT;
 810         module_put(a->ops->owner);
 811         kfree(a);
 812         err = rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO);
 813         if (err > 0)
 814                 return 0;
 815
 816         return err;
 817
 818 nla_put_failure:
 819 nlmsg_failure:
 820         module_put(a->ops->owner);
 821 err_out:
 822 noflush_out:
 823         kfree_skb(skb);
 824         kfree(a);
 825         return err;
 826 }
 827
 828 static int
 829 tca_action_gd(struct nlattr *nla, struct nlmsghdr *n, u32 pid, int event)
 830 {
 831         int i, ret;
 832         struct nlattr *tb[TCA_ACT_MAX_PRIO+1];
 833         struct tc_action *head = NULL, *act, *act_prev = NULL;
 834
 835         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 836         if (ret < 0)
 837                 return ret;
 838
 839         if (event == RTM_DELACTION && n->nlmsg_flags&NLM_F_ROOT) {
 840                 if (tb[1] != NULL)
 841                         return tca_action_flush(tb[1], n, pid);
 842                 else
 843                         return -EINVAL;
 844         }
 845
 846         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 847                 act = tcf_action_get_1(tb[i], n, pid);
 848                 if (IS_ERR(act)) {
 849                         ret = PTR_ERR(act);
 850                         goto err;
 851                 }
 852                 act->order = i;
 853
 854                 if (head == NULL)
 855                         head = act;
 856                 else
 857                         act_prev->next = act;
 858                 act_prev = act;
 859         }
 860
 861         if (event == RTM_GETACTION)
 862                 ret = act_get_notify(pid, n, head, event);
 863         else { /* delete */
 864                 struct sk_buff *skb;
 865
 866                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 867                 if (!skb) {
 868                         ret = -ENOBUFS;
 869                         goto err;
 870                 }
 871
 872                 if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
 873                                  0, 1) <= 0) {
 874                         kfree_skb(skb);
 875                         ret = -EINVAL;
 876                         goto err;
 877                 }
 878
 879                 /* now do the delete */
 880                 tcf_action_destroy(head, 0);
 881                 ret = rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC,
 882                                      n->nlmsg_flags&NLM_F_ECHO);
 883                 if (ret > 0)
 884                         return 0;
 885                 return ret;
 886         }
 887 err:
 888         cleanup_a(head);
 889         return ret;
 890 }
 891
 892 static int tcf_add_notify(struct tc_action *a, u32 pid, u32 seq, int event,
 893                           u16 flags)
 894 {
 895         struct tcamsg *t;
 896         struct nlmsghdr *nlh;
 897         struct sk_buff *skb;
 898         struct nlattr *nest;
 899         unsigned char *b;
 900         int err = 0;
 901
 902         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 903         if (!skb)
 904                 return -ENOBUFS;
 905
 906         b = skb_tail_pointer(skb);
 907
 908         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 909         t = NLMSG_DATA(nlh);
 910         t->tca_family = AF_UNSPEC;
 911         t->tca__pad1 = 0;
 912         t->tca__pad2 = 0;
 913
 914         nest = nla_nest_start(skb, TCA_ACT_TAB);
 915         if (nest == NULL)
 916                 goto nla_put_failure;
 917
 918         if (tcf_action_dump(skb, a, 0, 0) < 0)
 919                 goto nla_put_failure;
 920
 921         nla_nest_end(skb, nest);
 922
 923         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 924         NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 925
 926         err = rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC, flags&NLM_F_ECHO);
 927         if (err > 0)
 928                 err = 0;
 929         return err;
 930
 931 nla_put_failure:
 932 nlmsg_failure:
 933         kfree_skb(skb);
 934         return -1;
 935 }
 936
 937
 938 static int
 939 tcf_action_add(struct nlattr *nla, struct nlmsghdr *n, u32 pid, int ovr)
 940 {
 941         int ret = 0;
 942         struct tc_action *act;
 943         struct tc_action *a;
 944         u32 seq = n->nlmsg_seq;
 945
 946         act = tcf_action_init(nla, NULL, NULL, ovr, 0);
 947         if (act == NULL)
 948                 goto done;
 949         if (IS_ERR(act)) {
 950                 ret = PTR_ERR(act);
 951                 goto done;
 952         }
 953
 954         /* dump then free all the actions after update; inserted policy
 955          * stays intact
 956          * */
 957         ret = tcf_add_notify(act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
 958         for (a = act; a; a = act) {
 959                 act = a->next;
 960                 kfree(a);
 961         }
 962 done:
 963         return ret;
 964 }
 965
 966 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 967 {
 968         struct net *net = sock_net(skb->sk);
 969         struct nlattr *tca[TCA_ACT_MAX + 1];
 970         u32 pid = skb ? NETLINK_CB(skb).pid : 0;
 971         int ret = 0, ovr = 0;
 972
 973         if (!net_eq(net, &init_net))
 974                 return -EINVAL;
 975
 976         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
 977         if (ret < 0)
 978                 return ret;
 979
 980         if (tca[TCA_ACT_TAB] == NULL) {
 981                 printk("tc_ctl_action: received NO action attribs\n");
 982                 return -EINVAL;
 983         }
 984
 985         /* n->nlmsg_flags&NLM_F_CREATE
 986          * */
 987         switch (n->nlmsg_type) {
 988         case RTM_NEWACTION:
 989                 /* we are going to assume all other flags
 990                  * imply create only if it doesnt exist
 991                  * Note that CREATE | EXCL implies that
 992                  * but since we want avoid ambiguity (eg when flags
 993                  * is zero) then just set this
 994                  */
 995                 if (n->nlmsg_flags&NLM_F_REPLACE)
 996                         ovr = 1;
 997 replay:
 998                 ret = tcf_action_add(tca[TCA_ACT_TAB], n, pid, ovr);
 999                 if (ret == -EAGAIN)
1000                         goto replay;
1001                 break;
1002         case RTM_DELACTION:
1003                 ret = tca_action_gd(tca[TCA_ACT_TAB], n, pid, RTM_DELACTION);
1004                 break;
1005         case RTM_GETACTION:
1006                 ret = tca_action_gd(tca[TCA_ACT_TAB], n, pid, RTM_GETACTION);
1007                 break;
1008         default:
1009                 BUG();
1010         }
1011
1012         return ret;
1013 }
1014
1015 static struct nlattr *
1016 find_dump_kind(const struct nlmsghdr *n)
1017 {
1018         struct nlattr *tb1, *tb2[TCA_ACT_MAX+1];
1019         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1020         struct nlattr *nla[TCAA_MAX + 1];
1021         struct nlattr *kind;
1022
1023         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1024                 return NULL;
1025         tb1 = nla[TCA_ACT_TAB];
1026         if (tb1 == NULL)
1027                 return NULL;
1028
1029         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1030                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1031                 return NULL;
1032
1033         if (tb[1] == NULL)
1034                 return NULL;
1035         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1036                       nla_len(tb[1]), NULL) < 0)
1037                 return NULL;
1038         kind = tb2[TCA_ACT_KIND];
1039
1040         return kind;
1041 }
1042
1043 static int
1044 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1045 {
1046         struct net *net = sock_net(skb->sk);
1047         struct nlmsghdr *nlh;
1048         unsigned char *b = skb_tail_pointer(skb);
1049         struct nlattr *nest;
1050         struct tc_action_ops *a_o;
1051         struct tc_action a;
1052         int ret = 0;
1053         struct tcamsg *t = (struct tcamsg *) NLMSG_DATA(cb->nlh);
1054         struct nlattr *kind = find_dump_kind(cb->nlh);
1055
1056         if (!net_eq(net, &init_net))
1057                 return 0;
1058
1059         if (kind == NULL) {
1060                 printk("tc_dump_action: action bad kind\n");
1061                 return 0;
1062         }
1063
1064         a_o = tc_lookup_action(kind);
1065         if (a_o == NULL) {
1066                 return 0;
1067         }
1068
1069         memset(&a, 0, sizeof(struct tc_action));
1070         a.ops = a_o;
1071
1072         if (a_o->walk == NULL) {
1073                 printk("tc_dump_action: %s !capable of dumping table\n", a_o->kind);
1074                 goto nla_put_failure;
1075         }
1076
1077         nlh = NLMSG_PUT(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
1078                         cb->nlh->nlmsg_type, sizeof(*t));
1079         t = NLMSG_DATA(nlh);
1080         t->tca_family = AF_UNSPEC;
1081         t->tca__pad1 = 0;
1082         t->tca__pad2 = 0;
1083
1084         nest = nla_nest_start(skb, TCA_ACT_TAB);
1085         if (nest == NULL)
1086                 goto nla_put_failure;
1087
1088         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1089         if (ret < 0)
1090                 goto nla_put_failure;
1091
1092         if (ret > 0) {
1093                 nla_nest_end(skb, nest);
1094                 ret = skb->len;
1095         } else
1096                 nla_nest_cancel(skb, nest);
1097
1098         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1099         if (NETLINK_CB(cb->skb).pid && ret)
1100                 nlh->nlmsg_flags |= NLM_F_MULTI;
1101         module_put(a_o->owner);
1102         return skb->len;
1103
1104 nla_put_failure:
1105 nlmsg_failure:
1106         module_put(a_o->owner);
1107         nlmsg_trim(skb, b);
1108         return skb->len;
1109 }
1110
1111 static int __init tc_action_init(void)
1112 {
1113         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL);
1114         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL);
1115         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action);
1116
1117         return 0;
1118 }
1119
1120 subsys_initcall(tc_action_init);