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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 <asm/uaccess.h>
  15 #include <asm/system.h>
  16 #include <linux/bitops.h>
  17 #include <linux/types.h>
  18 #include <linux/kernel.h>
  19 #include <linux/string.h>
  20 #include <linux/mm.h>
  21 #include <linux/socket.h>
  22 #include <linux/sockios.h>
  23 #include <linux/in.h>
  24 #include <linux/errno.h>
  25 #include <linux/interrupt.h>
  26 #include <linux/netdevice.h>
  27 #include <linux/skbuff.h>
  28 #include <linux/init.h>
  29 #include <linux/kmod.h>
  30 #include <net/sock.h>
  31 #include <net/sch_generic.h>
  32 #include <net/act_api.h>
  33 #include <net/netlink.h>
  34
  35 void tcf_hash_destroy(struct tcf_common *p, struct tcf_hashinfo *hinfo)
  36 {
  37         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
  38         struct tcf_common **p1p;
  39
  40         for (p1p = &hinfo->htab[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
  41                 if (*p1p == p) {
  42                         write_lock_bh(hinfo->lock);
  43                         *p1p = p->tcfc_next;
  44                         write_unlock_bh(hinfo->lock);
  45                         gen_kill_estimator(&p->tcfc_bstats,
  46                                            &p->tcfc_rate_est);
  47                         kfree(p);
  48                         return;
  49                 }
  50         }
  51         BUG_TRAP(0);
  52 }
  53 EXPORT_SYMBOL(tcf_hash_destroy);
  54
  55 int tcf_hash_release(struct tcf_common *p, int bind,
  56                      struct tcf_hashinfo *hinfo)
  57 {
  58         int ret = 0;
  59
  60         if (p) {
  61                 if (bind)
  62                         p->tcfc_bindcnt--;
  63
  64                 p->tcfc_refcnt--;
  65                 if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
  66                         tcf_hash_destroy(p, hinfo);
  67                         ret = 1;
  68                 }
  69         }
  70         return ret;
  71 }
  72 EXPORT_SYMBOL(tcf_hash_release);
  73
  74 static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
  75                            struct tc_action *a, struct tcf_hashinfo *hinfo)
  76 {
  77         struct tcf_common *p;
  78         int err = 0, index = -1,i = 0, s_i = 0, n_i = 0;
  79         struct rtattr *r ;
  80
  81         read_lock(hinfo->lock);
  82
  83         s_i = cb->args[0];
  84
  85         for (i = 0; i < (hinfo->hmask + 1); i++) {
  86                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
  87
  88                 for (; p; p = p->tcfc_next) {
  89                         index++;
  90                         if (index < s_i)
  91                                 continue;
  92                         a->priv = p;
  93                         a->order = n_i;
  94                         r = (struct rtattr *)skb_tail_pointer(skb);
  95                         RTA_PUT(skb, a->order, 0, NULL);
  96                         err = tcf_action_dump_1(skb, a, 0, 0);
  97                         if (err < 0) {
  98                                 index--;
  99                                 nlmsg_trim(skb, r);
 100                                 goto done;
 101                         }
 102                         r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
 103                         n_i++;
 104                         if (n_i >= TCA_ACT_MAX_PRIO)
 105                                 goto done;
 106                 }
 107         }
 108 done:
 109         read_unlock(hinfo->lock);
 110         if (n_i)
 111                 cb->args[0] += n_i;
 112         return n_i;
 113
 114 rtattr_failure:
 115         nlmsg_trim(skb, r);
 116         goto done;
 117 }
 118
 119 static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a,
 120                           struct tcf_hashinfo *hinfo)
 121 {
 122         struct tcf_common *p, *s_p;
 123         struct rtattr *r ;
 124         int i= 0, n_i = 0;
 125
 126         r = (struct rtattr *)skb_tail_pointer(skb);
 127         RTA_PUT(skb, a->order, 0, NULL);
 128         RTA_PUT(skb, TCA_KIND, IFNAMSIZ, a->ops->kind);
 129         for (i = 0; i < (hinfo->hmask + 1); i++) {
 130                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
 131
 132                 while (p != NULL) {
 133                         s_p = p->tcfc_next;
 134                         if (ACT_P_DELETED == tcf_hash_release(p, 0, hinfo))
 135                                  module_put(a->ops->owner);
 136                         n_i++;
 137                         p = s_p;
 138                 }
 139         }
 140         RTA_PUT(skb, TCA_FCNT, 4, &n_i);
 141         r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
 142
 143         return n_i;
 144 rtattr_failure:
 145         nlmsg_trim(skb, r);
 146         return -EINVAL;
 147 }
 148
 149 int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
 150                        int type, struct tc_action *a)
 151 {
 152         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 153
 154         if (type == RTM_DELACTION) {
 155                 return tcf_del_walker(skb, a, hinfo);
 156         } else if (type == RTM_GETACTION) {
 157                 return tcf_dump_walker(skb, cb, a, hinfo);
 158         } else {
 159                 printk("tcf_generic_walker: unknown action %d\n", type);
 160                 return -EINVAL;
 161         }
 162 }
 163 EXPORT_SYMBOL(tcf_generic_walker);
 164
 165 struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 166 {
 167         struct tcf_common *p;
 168
 169         read_lock(hinfo->lock);
 170         for (p = hinfo->htab[tcf_hash(index, hinfo->hmask)]; p;
 171              p = p->tcfc_next) {
 172                 if (p->tcfc_index == index)
 173                         break;
 174         }
 175         read_unlock(hinfo->lock);
 176
 177         return p;
 178 }
 179 EXPORT_SYMBOL(tcf_hash_lookup);
 180
 181 u32 tcf_hash_new_index(u32 *idx_gen, struct tcf_hashinfo *hinfo)
 182 {
 183         u32 val = *idx_gen;
 184
 185         do {
 186                 if (++val == 0)
 187                         val = 1;
 188         } while (tcf_hash_lookup(val, hinfo));
 189
 190         return (*idx_gen = val);
 191 }
 192 EXPORT_SYMBOL(tcf_hash_new_index);
 193
 194 int tcf_hash_search(struct tc_action *a, u32 index)
 195 {
 196         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 197         struct tcf_common *p = tcf_hash_lookup(index, hinfo);
 198
 199         if (p) {
 200                 a->priv = p;
 201                 return 1;
 202         }
 203         return 0;
 204 }
 205 EXPORT_SYMBOL(tcf_hash_search);
 206
 207 struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
 208                                   struct tcf_hashinfo *hinfo)
 209 {
 210         struct tcf_common *p = NULL;
 211         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 212                 if (bind) {
 213                         p->tcfc_bindcnt++;
 214                         p->tcfc_refcnt++;
 215                 }
 216                 a->priv = p;
 217         }
 218         return p;
 219 }
 220 EXPORT_SYMBOL(tcf_hash_check);
 221
 222 struct tcf_common *tcf_hash_create(u32 index, struct rtattr *est, struct tc_action *a, int size, int bind, u32 *idx_gen, struct tcf_hashinfo *hinfo)
 223 {
 224         struct tcf_common *p = kzalloc(size, GFP_KERNEL);
 225
 226         if (unlikely(!p))
 227                 return p;
 228         p->tcfc_refcnt = 1;
 229         if (bind)
 230                 p->tcfc_bindcnt = 1;
 231
 232         spin_lock_init(&p->tcfc_lock);
 233         p->tcfc_stats_lock = &p->tcfc_lock;
 234         p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
 235         p->tcfc_tm.install = jiffies;
 236         p->tcfc_tm.lastuse = jiffies;
 237         if (est)
 238                 gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
 239                                   p->tcfc_stats_lock, est);
 240         a->priv = (void *) p;
 241         return p;
 242 }
 243 EXPORT_SYMBOL(tcf_hash_create);
 244
 245 void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
 246 {
 247         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
 248
 249         write_lock_bh(hinfo->lock);
 250         p->tcfc_next = hinfo->htab[h];
 251         hinfo->htab[h] = p;
 252         write_unlock_bh(hinfo->lock);
 253 }
 254 EXPORT_SYMBOL(tcf_hash_insert);
 255
 256 static struct tc_action_ops *act_base = NULL;
 257 static DEFINE_RWLOCK(act_mod_lock);
 258
 259 int tcf_register_action(struct tc_action_ops *act)
 260 {
 261         struct tc_action_ops *a, **ap;
 262
 263         write_lock(&act_mod_lock);
 264         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
 265                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 266                         write_unlock(&act_mod_lock);
 267                         return -EEXIST;
 268                 }
 269         }
 270         act->next = NULL;
 271         *ap = act;
 272         write_unlock(&act_mod_lock);
 273         return 0;
 274 }
 275
 276 int tcf_unregister_action(struct tc_action_ops *act)
 277 {
 278         struct tc_action_ops *a, **ap;
 279         int err = -ENOENT;
 280
 281         write_lock(&act_mod_lock);
 282         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
 283                 if (a == act)
 284                         break;
 285         if (a) {
 286                 *ap = a->next;
 287                 a->next = NULL;
 288                 err = 0;
 289         }
 290         write_unlock(&act_mod_lock);
 291         return err;
 292 }
 293
 294 /* lookup by name */
 295 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 296 {
 297         struct tc_action_ops *a = NULL;
 298
 299         if (kind) {
 300                 read_lock(&act_mod_lock);
 301                 for (a = act_base; a; a = a->next) {
 302                         if (strcmp(kind, a->kind) == 0) {
 303                                 if (!try_module_get(a->owner)) {
 304                                         read_unlock(&act_mod_lock);
 305                                         return NULL;
 306                                 }
 307                                 break;
 308                         }
 309                 }
 310                 read_unlock(&act_mod_lock);
 311         }
 312         return a;
 313 }
 314
 315 /* lookup by rtattr */
 316 static struct tc_action_ops *tc_lookup_action(struct rtattr *kind)
 317 {
 318         struct tc_action_ops *a = NULL;
 319
 320         if (kind) {
 321                 read_lock(&act_mod_lock);
 322                 for (a = act_base; a; a = a->next) {
 323                         if (rtattr_strcmp(kind, a->kind) == 0) {
 324                                 if (!try_module_get(a->owner)) {
 325                                         read_unlock(&act_mod_lock);
 326                                         return NULL;
 327                                 }
 328                                 break;
 329                         }
 330                 }
 331                 read_unlock(&act_mod_lock);
 332         }
 333         return a;
 334 }
 335
 336 #if 0
 337 /* lookup by id */
 338 static struct tc_action_ops *tc_lookup_action_id(u32 type)
 339 {
 340         struct tc_action_ops *a = NULL;
 341
 342         if (type) {
 343                 read_lock(&act_mod_lock);
 344                 for (a = act_base; a; a = a->next) {
 345                         if (a->type == type) {
 346                                 if (!try_module_get(a->owner)) {
 347                                         read_unlock(&act_mod_lock);
 348                                         return NULL;
 349                                 }
 350                                 break;
 351                         }
 352                 }
 353                 read_unlock(&act_mod_lock);
 354         }
 355         return a;
 356 }
 357 #endif
 358
 359 int tcf_action_exec(struct sk_buff *skb, struct tc_action *act,
 360                     struct tcf_result *res)
 361 {
 362         struct tc_action *a;
 363         int ret = -1;
 364
 365         if (skb->tc_verd & TC_NCLS) {
 366                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 367                 ret = TC_ACT_OK;
 368                 goto exec_done;
 369         }
 370         while ((a = act) != NULL) {
 371 repeat:
 372                 if (a->ops && a->ops->act) {
 373                         ret = a->ops->act(skb, a, res);
 374                         if (TC_MUNGED & skb->tc_verd) {
 375                                 /* copied already, allow trampling */
 376                                 skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
 377                                 skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
 378                         }
 379                         if (ret == TC_ACT_REPEAT)
 380                                 goto repeat;    /* we need a ttl - JHS */
 381                         if (ret != TC_ACT_PIPE)
 382                                 goto exec_done;
 383                 }
 384                 act = a->next;
 385         }
 386 exec_done:
 387         return ret;
 388 }
 389
 390 void tcf_action_destroy(struct tc_action *act, int bind)
 391 {
 392         struct tc_action *a;
 393
 394         for (a = act; a; a = act) {
 395                 if (a->ops && a->ops->cleanup) {
 396                         if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
 397                                 module_put(a->ops->owner);
 398                         act = act->next;
 399                         kfree(a);
 400                 } else { /*FIXME: Remove later - catch insertion bugs*/
 401                         printk("tcf_action_destroy: BUG? destroying NULL ops\n");
 402                         act = act->next;
 403                         kfree(a);
 404                 }
 405         }
 406 }
 407
 408 int
 409 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 410 {
 411         int err = -EINVAL;
 412
 413         if (a->ops == NULL || a->ops->dump == NULL)
 414                 return err;
 415         return a->ops->dump(skb, a, bind, ref);
 416 }
 417
 418 int
 419 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 420 {
 421         int err = -EINVAL;
 422         unsigned char *b = skb_tail_pointer(skb);
 423         struct rtattr *r;
 424
 425         if (a->ops == NULL || a->ops->dump == NULL)
 426                 return err;
 427
 428         RTA_PUT(skb, TCA_KIND, IFNAMSIZ, a->ops->kind);
 429         if (tcf_action_copy_stats(skb, a, 0))
 430                 goto rtattr_failure;
 431         r = (struct rtattr *)skb_tail_pointer(skb);
 432         RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
 433         if ((err = tcf_action_dump_old(skb, a, bind, ref)) > 0) {
 434                 r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
 435                 return err;
 436         }
 437
 438 rtattr_failure:
 439         nlmsg_trim(skb, b);
 440         return -1;
 441 }
 442
 443 int
 444 tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
 445 {
 446         struct tc_action *a;
 447         int err = -EINVAL;
 448         unsigned char *b = skb_tail_pointer(skb);
 449         struct rtattr *r ;
 450
 451         while ((a = act) != NULL) {
 452                 r = (struct rtattr *)skb_tail_pointer(skb);
 453                 act = a->next;
 454                 RTA_PUT(skb, a->order, 0, NULL);
 455                 err = tcf_action_dump_1(skb, a, bind, ref);
 456                 if (err < 0)
 457                         goto errout;
 458                 r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
 459         }
 460
 461         return 0;
 462
 463 rtattr_failure:
 464         err = -EINVAL;
 465 errout:
 466         nlmsg_trim(skb, b);
 467         return err;
 468 }
 469
 470 struct tc_action *tcf_action_init_1(struct rtattr *rta, struct rtattr *est,
 471                                     char *name, int ovr, int bind, int *err)
 472 {
 473         struct tc_action *a;
 474         struct tc_action_ops *a_o;
 475         char act_name[IFNAMSIZ];
 476         struct rtattr *tb[TCA_ACT_MAX+1];
 477         struct rtattr *kind;
 478
 479         *err = -EINVAL;
 480
 481         if (name == NULL) {
 482                 if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
 483                         goto err_out;
 484                 kind = tb[TCA_ACT_KIND-1];
 485                 if (kind == NULL)
 486                         goto err_out;
 487                 if (rtattr_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 488                         goto err_out;
 489         } else {
 490                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 491                         goto err_out;
 492         }
 493
 494         a_o = tc_lookup_action_n(act_name);
 495         if (a_o == NULL) {
 496 #ifdef CONFIG_KMOD
 497                 rtnl_unlock();
 498                 request_module("act_%s", act_name);
 499                 rtnl_lock();
 500
 501                 a_o = tc_lookup_action_n(act_name);
 502
 503                 /* We dropped the RTNL semaphore in order to
 504                  * perform the module load.  So, even if we
 505                  * succeeded in loading the module we have to
 506                  * tell the caller to replay the request.  We
 507                  * indicate this using -EAGAIN.
 508                  */
 509                 if (a_o != NULL) {
 510                         *err = -EAGAIN;
 511                         goto err_mod;
 512                 }
 513 #endif
 514                 *err = -ENOENT;
 515                 goto err_out;
 516         }
 517
 518         *err = -ENOMEM;
 519         a = kzalloc(sizeof(*a), GFP_KERNEL);
 520         if (a == NULL)
 521                 goto err_mod;
 522
 523         /* backward compatibility for policer */
 524         if (name == NULL)
 525                 *err = a_o->init(tb[TCA_ACT_OPTIONS-1], est, a, ovr, bind);
 526         else
 527                 *err = a_o->init(rta, est, a, ovr, bind);
 528         if (*err < 0)
 529                 goto err_free;
 530
 531         /* module count goes up only when brand new policy is created
 532            if it exists and is only bound to in a_o->init() then
 533            ACT_P_CREATED is not returned (a zero is).
 534         */
 535         if (*err != ACT_P_CREATED)
 536                 module_put(a_o->owner);
 537         a->ops = a_o;
 538
 539         *err = 0;
 540         return a;
 541
 542 err_free:
 543         kfree(a);
 544 err_mod:
 545         module_put(a_o->owner);
 546 err_out:
 547         return NULL;
 548 }
 549
 550 struct tc_action *tcf_action_init(struct rtattr *rta, struct rtattr *est,
 551                                   char *name, int ovr, int bind, int *err)
 552 {
 553         struct rtattr *tb[TCA_ACT_MAX_PRIO+1];
 554         struct tc_action *head = NULL, *act, *act_prev = NULL;
 555         int i;
 556
 557         if (rtattr_parse_nested(tb, TCA_ACT_MAX_PRIO, rta) < 0) {
 558                 *err = -EINVAL;
 559                 return head;
 560         }
 561
 562         for (i=0; i < TCA_ACT_MAX_PRIO && tb[i]; i++) {
 563                 act = tcf_action_init_1(tb[i], est, name, ovr, bind, err);
 564                 if (act == NULL)
 565                         goto err;
 566                 act->order = i+1;
 567
 568                 if (head == NULL)
 569                         head = act;
 570                 else
 571                         act_prev->next = act;
 572                 act_prev = act;
 573         }
 574         return head;
 575
 576 err:
 577         if (head != NULL)
 578                 tcf_action_destroy(head, bind);
 579         return NULL;
 580 }
 581
 582 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 583                           int compat_mode)
 584 {
 585         int err = 0;
 586         struct gnet_dump d;
 587         struct tcf_act_hdr *h = a->priv;
 588
 589         if (h == NULL)
 590                 goto errout;
 591
 592         /* compat_mode being true specifies a call that is supposed
 593          * to add additional backward compatiblity statistic TLVs.
 594          */
 595         if (compat_mode) {
 596                 if (a->type == TCA_OLD_COMPAT)
 597                         err = gnet_stats_start_copy_compat(skb, 0,
 598                                 TCA_STATS, TCA_XSTATS, h->tcf_stats_lock, &d);
 599                 else
 600                         return 0;
 601         } else
 602                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 603                         h->tcf_stats_lock, &d);
 604
 605         if (err < 0)
 606                 goto errout;
 607
 608         if (a->ops != NULL && a->ops->get_stats != NULL)
 609                 if (a->ops->get_stats(skb, a) < 0)
 610                         goto errout;
 611
 612         if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
 613             gnet_stats_copy_rate_est(&d, &h->tcf_rate_est) < 0 ||
 614             gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
 615                 goto errout;
 616
 617         if (gnet_stats_finish_copy(&d) < 0)
 618                 goto errout;
 619
 620         return 0;
 621
 622 errout:
 623         return -1;
 624 }
 625
 626 static int
 627 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 pid, u32 seq,
 628              u16 flags, int event, int bind, int ref)
 629 {
 630         struct tcamsg *t;
 631         struct nlmsghdr *nlh;
 632         unsigned char *b = skb_tail_pointer(skb);
 633         struct rtattr *x;
 634
 635         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 636
 637         t = NLMSG_DATA(nlh);
 638         t->tca_family = AF_UNSPEC;
 639         t->tca__pad1 = 0;
 640         t->tca__pad2 = 0;
 641
 642         x = (struct rtattr *)skb_tail_pointer(skb);
 643         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 644
 645         if (tcf_action_dump(skb, a, bind, ref) < 0)
 646                 goto rtattr_failure;
 647
 648         x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
 649
 650         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 651         return skb->len;
 652
 653 rtattr_failure:
 654 nlmsg_failure:
 655         nlmsg_trim(skb, b);
 656         return -1;
 657 }
 658
 659 static int
 660 act_get_notify(u32 pid, struct nlmsghdr *n, struct tc_action *a, int event)
 661 {
 662         struct sk_buff *skb;
 663
 664         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 665         if (!skb)
 666                 return -ENOBUFS;
 667         if (tca_get_fill(skb, a, pid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 668                 kfree_skb(skb);
 669                 return -EINVAL;
 670         }
 671
 672         return rtnl_unicast(skb, pid);
 673 }
 674
 675 static struct tc_action *
 676 tcf_action_get_1(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int *err)
 677 {
 678         struct rtattr *tb[TCA_ACT_MAX+1];
 679         struct tc_action *a;
 680         int index;
 681
 682         *err = -EINVAL;
 683         if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
 684                 return NULL;
 685
 686         if (tb[TCA_ACT_INDEX - 1] == NULL ||
 687             RTA_PAYLOAD(tb[TCA_ACT_INDEX - 1]) < sizeof(index))
 688                 return NULL;
 689         index = *(int *)RTA_DATA(tb[TCA_ACT_INDEX - 1]);
 690
 691         *err = -ENOMEM;
 692         a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
 693         if (a == NULL)
 694                 return NULL;
 695
 696         *err = -EINVAL;
 697         a->ops = tc_lookup_action(tb[TCA_ACT_KIND - 1]);
 698         if (a->ops == NULL)
 699                 goto err_free;
 700         if (a->ops->lookup == NULL)
 701                 goto err_mod;
 702         *err = -ENOENT;
 703         if (a->ops->lookup(a, index) == 0)
 704                 goto err_mod;
 705
 706         module_put(a->ops->owner);
 707         *err = 0;
 708         return a;
 709 err_mod:
 710         module_put(a->ops->owner);
 711 err_free:
 712         kfree(a);
 713         return NULL;
 714 }
 715
 716 static void cleanup_a(struct tc_action *act)
 717 {
 718         struct tc_action *a;
 719
 720         for (a = act; a; a = act) {
 721                 act = a->next;
 722                 kfree(a);
 723         }
 724 }
 725
 726 static struct tc_action *create_a(int i)
 727 {
 728         struct tc_action *act;
 729
 730         act = kzalloc(sizeof(*act), GFP_KERNEL);
 731         if (act == NULL) {
 732                 printk("create_a: failed to alloc!\n");
 733                 return NULL;
 734         }
 735         act->order = i;
 736         return act;
 737 }
 738
 739 static int tca_action_flush(struct rtattr *rta, struct nlmsghdr *n, u32 pid)
 740 {
 741         struct sk_buff *skb;
 742         unsigned char *b;
 743         struct nlmsghdr *nlh;
 744         struct tcamsg *t;
 745         struct netlink_callback dcb;
 746         struct rtattr *x;
 747         struct rtattr *tb[TCA_ACT_MAX+1];
 748         struct rtattr *kind;
 749         struct tc_action *a = create_a(0);
 750         int err = -EINVAL;
 751
 752         if (a == NULL) {
 753                 printk("tca_action_flush: couldnt create tc_action\n");
 754                 return err;
 755         }
 756
 757         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 758         if (!skb) {
 759                 printk("tca_action_flush: failed skb alloc\n");
 760                 kfree(a);
 761                 return -ENOBUFS;
 762         }
 763
 764         b = skb_tail_pointer(skb);
 765
 766         if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
 767                 goto err_out;
 768
 769         kind = tb[TCA_ACT_KIND-1];
 770         a->ops = tc_lookup_action(kind);
 771         if (a->ops == NULL)
 772                 goto err_out;
 773
 774         nlh = NLMSG_PUT(skb, pid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t));
 775         t = NLMSG_DATA(nlh);
 776         t->tca_family = AF_UNSPEC;
 777         t->tca__pad1 = 0;
 778         t->tca__pad2 = 0;
 779
 780         x = (struct rtattr *)skb_tail_pointer(skb);
 781         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 782
 783         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 784         if (err < 0)
 785                 goto rtattr_failure;
 786
 787         x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
 788
 789         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 790         nlh->nlmsg_flags |= NLM_F_ROOT;
 791         module_put(a->ops->owner);
 792         kfree(a);
 793         err = rtnetlink_send(skb, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO);
 794         if (err > 0)
 795                 return 0;
 796
 797         return err;
 798
 799 rtattr_failure:
 800 nlmsg_failure:
 801         module_put(a->ops->owner);
 802 err_out:
 803         kfree_skb(skb);
 804         kfree(a);
 805         return err;
 806 }
 807
 808 static int
 809 tca_action_gd(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int event)
 810 {
 811         int i, ret = 0;
 812         struct rtattr *tb[TCA_ACT_MAX_PRIO+1];
 813         struct tc_action *head = NULL, *act, *act_prev = NULL;
 814
 815         if (rtattr_parse_nested(tb, TCA_ACT_MAX_PRIO, rta) < 0)
 816                 return -EINVAL;
 817
 818         if (event == RTM_DELACTION && n->nlmsg_flags&NLM_F_ROOT) {
 819                 if (tb[0] != NULL && tb[1] == NULL)
 820                         return tca_action_flush(tb[0], n, pid);
 821         }
 822
 823         for (i=0; i < TCA_ACT_MAX_PRIO && tb[i]; i++) {
 824                 act = tcf_action_get_1(tb[i], n, pid, &ret);
 825                 if (act == NULL)
 826                         goto err;
 827                 act->order = i+1;
 828
 829                 if (head == NULL)
 830                         head = act;
 831                 else
 832                         act_prev->next = act;
 833                 act_prev = act;
 834         }
 835
 836         if (event == RTM_GETACTION)
 837                 ret = act_get_notify(pid, n, head, event);
 838         else { /* delete */
 839                 struct sk_buff *skb;
 840
 841                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 842                 if (!skb) {
 843                         ret = -ENOBUFS;
 844                         goto err;
 845                 }
 846
 847                 if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
 848                                  0, 1) <= 0) {
 849                         kfree_skb(skb);
 850                         ret = -EINVAL;
 851                         goto err;
 852                 }
 853
 854                 /* now do the delete */
 855                 tcf_action_destroy(head, 0);
 856                 ret = rtnetlink_send(skb, pid, RTNLGRP_TC,
 857                                      n->nlmsg_flags&NLM_F_ECHO);
 858                 if (ret > 0)
 859                         return 0;
 860                 return ret;
 861         }
 862 err:
 863         cleanup_a(head);
 864         return ret;
 865 }
 866
 867 static int tcf_add_notify(struct tc_action *a, u32 pid, u32 seq, int event,
 868                           u16 flags)
 869 {
 870         struct tcamsg *t;
 871         struct nlmsghdr *nlh;
 872         struct sk_buff *skb;
 873         struct rtattr *x;
 874         unsigned char *b;
 875         int err = 0;
 876
 877         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 878         if (!skb)
 879                 return -ENOBUFS;
 880
 881         b = skb_tail_pointer(skb);
 882
 883         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 884         t = NLMSG_DATA(nlh);
 885         t->tca_family = AF_UNSPEC;
 886         t->tca__pad1 = 0;
 887         t->tca__pad2 = 0;
 888
 889         x = (struct rtattr *)skb_tail_pointer(skb);
 890         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 891
 892         if (tcf_action_dump(skb, a, 0, 0) < 0)
 893                 goto rtattr_failure;
 894
 895         x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
 896
 897         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 898         NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 899
 900         err = rtnetlink_send(skb, pid, RTNLGRP_TC, flags&NLM_F_ECHO);
 901         if (err > 0)
 902                 err = 0;
 903         return err;
 904
 905 rtattr_failure:
 906 nlmsg_failure:
 907         kfree_skb(skb);
 908         return -1;
 909 }
 910
 911
 912 static int
 913 tcf_action_add(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int ovr)
 914 {
 915         int ret = 0;
 916         struct tc_action *act;
 917         struct tc_action *a;
 918         u32 seq = n->nlmsg_seq;
 919
 920         act = tcf_action_init(rta, NULL, NULL, ovr, 0, &ret);
 921         if (act == NULL)
 922                 goto done;
 923
 924         /* dump then free all the actions after update; inserted policy
 925          * stays intact
 926          * */
 927         ret = tcf_add_notify(act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
 928         for (a = act; a; a = act) {
 929                 act = a->next;
 930                 kfree(a);
 931         }
 932 done:
 933         return ret;
 934 }
 935
 936 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 937 {
 938         struct rtattr **tca = arg;
 939         u32 pid = skb ? NETLINK_CB(skb).pid : 0;
 940         int ret = 0, ovr = 0;
 941
 942         if (tca[TCA_ACT_TAB-1] == NULL) {
 943                 printk("tc_ctl_action: received NO action attribs\n");
 944                 return -EINVAL;
 945         }
 946
 947         /* n->nlmsg_flags&NLM_F_CREATE
 948          * */
 949         switch (n->nlmsg_type) {
 950         case RTM_NEWACTION:
 951                 /* we are going to assume all other flags
 952                  * imply create only if it doesnt exist
 953                  * Note that CREATE | EXCL implies that
 954                  * but since we want avoid ambiguity (eg when flags
 955                  * is zero) then just set this
 956                  */
 957                 if (n->nlmsg_flags&NLM_F_REPLACE)
 958                         ovr = 1;
 959 replay:
 960                 ret = tcf_action_add(tca[TCA_ACT_TAB-1], n, pid, ovr);
 961                 if (ret == -EAGAIN)
 962                         goto replay;
 963                 break;
 964         case RTM_DELACTION:
 965                 ret = tca_action_gd(tca[TCA_ACT_TAB-1], n, pid, RTM_DELACTION);
 966                 break;
 967         case RTM_GETACTION:
 968                 ret = tca_action_gd(tca[TCA_ACT_TAB-1], n, pid, RTM_GETACTION);
 969                 break;
 970         default:
 971                 BUG();
 972         }
 973
 974         return ret;
 975 }
 976
 977 static struct rtattr *
 978 find_dump_kind(struct nlmsghdr *n)
 979 {
 980         struct rtattr *tb1, *tb2[TCA_ACT_MAX+1];
 981         struct rtattr *tb[TCA_ACT_MAX_PRIO + 1];
 982         struct rtattr *rta[TCAA_MAX + 1];
 983         struct rtattr *kind;
 984         int min_len = NLMSG_LENGTH(sizeof(struct tcamsg));
 985         int attrlen = n->nlmsg_len - NLMSG_ALIGN(min_len);
 986         struct rtattr *attr = (void *) n + NLMSG_ALIGN(min_len);
 987
 988         if (rtattr_parse(rta, TCAA_MAX, attr, attrlen) < 0)
 989                 return NULL;
 990         tb1 = rta[TCA_ACT_TAB - 1];
 991         if (tb1 == NULL)
 992                 return NULL;
 993
 994         if (rtattr_parse(tb, TCA_ACT_MAX_PRIO, RTA_DATA(tb1),
 995                          NLMSG_ALIGN(RTA_PAYLOAD(tb1))) < 0)
 996                 return NULL;
 997         if (tb[0] == NULL)
 998                 return NULL;
 999
1000         if (rtattr_parse(tb2, TCA_ACT_MAX, RTA_DATA(tb[0]),
1001                          RTA_PAYLOAD(tb[0])) < 0)
1002                 return NULL;
1003         kind = tb2[TCA_ACT_KIND-1];
1004
1005         return kind;
1006 }
1007
1008 static int
1009 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1010 {
1011         struct nlmsghdr *nlh;
1012         unsigned char *b = skb_tail_pointer(skb);
1013         struct rtattr *x;
1014         struct tc_action_ops *a_o;
1015         struct tc_action a;
1016         int ret = 0;
1017         struct tcamsg *t = (struct tcamsg *) NLMSG_DATA(cb->nlh);
1018         struct rtattr *kind = find_dump_kind(cb->nlh);
1019
1020         if (kind == NULL) {
1021                 printk("tc_dump_action: action bad kind\n");
1022                 return 0;
1023         }
1024
1025         a_o = tc_lookup_action(kind);
1026         if (a_o == NULL) {
1027                 return 0;
1028         }
1029
1030         memset(&a, 0, sizeof(struct tc_action));
1031         a.ops = a_o;
1032
1033         if (a_o->walk == NULL) {
1034                 printk("tc_dump_action: %s !capable of dumping table\n", a_o->kind);
1035                 goto rtattr_failure;
1036         }
1037
1038         nlh = NLMSG_PUT(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
1039                         cb->nlh->nlmsg_type, sizeof(*t));
1040         t = NLMSG_DATA(nlh);
1041         t->tca_family = AF_UNSPEC;
1042         t->tca__pad1 = 0;
1043         t->tca__pad2 = 0;
1044
1045         x = (struct rtattr *)skb_tail_pointer(skb);
1046         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
1047
1048         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1049         if (ret < 0)
1050                 goto rtattr_failure;
1051
1052         if (ret > 0) {
1053                 x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
1054                 ret = skb->len;
1055         } else
1056                 nlmsg_trim(skb, x);
1057
1058         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1059         if (NETLINK_CB(cb->skb).pid && ret)
1060                 nlh->nlmsg_flags |= NLM_F_MULTI;
1061         module_put(a_o->owner);
1062         return skb->len;
1063
1064 rtattr_failure:
1065 nlmsg_failure:
1066         module_put(a_o->owner);
1067         nlmsg_trim(skb, b);
1068         return skb->len;
1069 }
1070
1071 static int __init tc_action_init(void)
1072 {
1073         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL);
1074         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL);
1075         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action);
1076
1077         return 0;
1078 }
1079
1080 subsys_initcall(tc_action_init);
1081
1082 EXPORT_SYMBOL(tcf_register_action);
1083 EXPORT_SYMBOL(tcf_unregister_action);
1084 EXPORT_SYMBOL(tcf_action_exec);
1085 EXPORT_SYMBOL(tcf_action_dump_1);