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 <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/sched.h>
  20 #include <linux/string.h>
  21 #include <linux/mm.h>
  22 #include <linux/socket.h>
  23 #include <linux/sockios.h>
  24 #include <linux/in.h>
  25 #include <linux/errno.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/netdevice.h>
  28 #include <linux/skbuff.h>
  29 #include <linux/rtnetlink.h>
  30 #include <linux/init.h>
  31 #include <linux/kmod.h>
  32 #include <net/sock.h>
  33 #include <net/sch_generic.h>
  34 #include <net/act_api.h>
  35
  36 void tcf_hash_destroy(struct tcf_common *p, struct tcf_hashinfo *hinfo)
  37 {
  38         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
  39         struct tcf_common **p1p;
  40
  41         for (p1p = &hinfo->htab[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
  42                 if (*p1p == p) {
  43                         write_lock_bh(hinfo->lock);
  44                         *p1p = p->tcfc_next;
  45                         write_unlock_bh(hinfo->lock);
  46 #ifdef CONFIG_NET_ESTIMATOR
  47                         gen_kill_estimator(&p->tcfc_bstats,
  48                                            &p->tcfc_rate_est);
  49 #endif
  50                         kfree(p);
  51                         return;
  52                 }
  53         }
  54         BUG_TRAP(0);
  55 }
  56 EXPORT_SYMBOL(tcf_hash_destroy);
  57
  58 int tcf_hash_release(struct tcf_common *p, int bind,
  59                      struct tcf_hashinfo *hinfo)
  60 {
  61         int ret = 0;
  62
  63         if (p) {
  64                 if (bind)
  65                         p->tcfc_bindcnt--;
  66
  67                 p->tcfc_refcnt--;
  68                 if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
  69                         tcf_hash_destroy(p, hinfo);
  70                         ret = 1;
  71                 }
  72         }
  73         return ret;
  74 }
  75 EXPORT_SYMBOL(tcf_hash_release);
  76
  77 static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
  78                            struct tc_action *a, struct tcf_hashinfo *hinfo)
  79 {
  80         struct tcf_common *p;
  81         int err = 0, index = -1,i = 0, s_i = 0, n_i = 0;
  82         struct rtattr *r ;
  83
  84         read_lock(hinfo->lock);
  85
  86         s_i = cb->args[0];
  87
  88         for (i = 0; i < (hinfo->hmask + 1); i++) {
  89                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
  90
  91                 for (; p; p = p->tcfc_next) {
  92                         index++;
  93                         if (index < s_i)
  94                                 continue;
  95                         a->priv = p;
  96                         a->order = n_i;
  97                         r = (struct rtattr*) skb->tail;
  98                         RTA_PUT(skb, a->order, 0, NULL);
  99                         err = tcf_action_dump_1(skb, a, 0, 0);
 100                         if (err < 0) {
 101                                 index--;
 102                                 skb_trim(skb, (u8*)r - skb->data);
 103                                 goto done;
 104                         }
 105                         r->rta_len = skb->tail - (u8*)r;
 106                         n_i++;
 107                         if (n_i >= TCA_ACT_MAX_PRIO)
 108                                 goto done;
 109                 }
 110         }
 111 done:
 112         read_unlock(hinfo->lock);
 113         if (n_i)
 114                 cb->args[0] += n_i;
 115         return n_i;
 116
 117 rtattr_failure:
 118         skb_trim(skb, (u8*)r - skb->data);
 119         goto done;
 120 }
 121
 122 static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a,
 123                           struct tcf_hashinfo *hinfo)
 124 {
 125         struct tcf_common *p, *s_p;
 126         struct rtattr *r ;
 127         int i= 0, n_i = 0;
 128
 129         r = (struct rtattr*) skb->tail;
 130         RTA_PUT(skb, a->order, 0, NULL);
 131         RTA_PUT(skb, TCA_KIND, IFNAMSIZ, a->ops->kind);
 132         for (i = 0; i < (hinfo->hmask + 1); i++) {
 133                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
 134
 135                 while (p != NULL) {
 136                         s_p = p->tcfc_next;
 137                         if (ACT_P_DELETED == tcf_hash_release(p, 0, hinfo))
 138                                  module_put(a->ops->owner);
 139                         n_i++;
 140                         p = s_p;
 141                 }
 142         }
 143         RTA_PUT(skb, TCA_FCNT, 4, &n_i);
 144         r->rta_len = skb->tail - (u8*)r;
 145
 146         return n_i;
 147 rtattr_failure:
 148         skb_trim(skb, (u8*)r - skb->data);
 149         return -EINVAL;
 150 }
 151
 152 int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
 153                        int type, struct tc_action *a)
 154 {
 155         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 156
 157         if (type == RTM_DELACTION) {
 158                 return tcf_del_walker(skb, a, hinfo);
 159         } else if (type == RTM_GETACTION) {
 160                 return tcf_dump_walker(skb, cb, a, hinfo);
 161         } else {
 162                 printk("tcf_generic_walker: unknown action %d\n", type);
 163                 return -EINVAL;
 164         }
 165 }
 166 EXPORT_SYMBOL(tcf_generic_walker);
 167
 168 struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 169 {
 170         struct tcf_common *p;
 171
 172         read_lock(hinfo->lock);
 173         for (p = hinfo->htab[tcf_hash(index, hinfo->hmask)]; p;
 174              p = p->tcfc_next) {
 175                 if (p->tcfc_index == index)
 176                         break;
 177         }
 178         read_unlock(hinfo->lock);
 179
 180         return p;
 181 }
 182 EXPORT_SYMBOL(tcf_hash_lookup);
 183
 184 u32 tcf_hash_new_index(u32 *idx_gen, struct tcf_hashinfo *hinfo)
 185 {
 186         u32 val = *idx_gen;
 187
 188         do {
 189                 if (++val == 0)
 190                         val = 1;
 191         } while (tcf_hash_lookup(val, hinfo));
 192
 193         return (*idx_gen = val);
 194 }
 195 EXPORT_SYMBOL(tcf_hash_new_index);
 196
 197 int tcf_hash_search(struct tc_action *a, u32 index)
 198 {
 199         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 200         struct tcf_common *p = tcf_hash_lookup(index, hinfo);
 201
 202         if (p) {
 203                 a->priv = p;
 204                 return 1;
 205         }
 206         return 0;
 207 }
 208 EXPORT_SYMBOL(tcf_hash_search);
 209
 210 struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
 211                                   struct tcf_hashinfo *hinfo)
 212 {
 213         struct tcf_common *p = NULL;
 214         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 215                 if (bind) {
 216                         p->tcfc_bindcnt++;
 217                         p->tcfc_refcnt++;
 218                 }
 219                 a->priv = p;
 220         }
 221         return p;
 222 }
 223 EXPORT_SYMBOL(tcf_hash_check);
 224
 225 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)
 226 {
 227         struct tcf_common *p = kzalloc(size, GFP_KERNEL);
 228
 229         if (unlikely(!p))
 230                 return p;
 231         p->tcfc_refcnt = 1;
 232         if (bind)
 233                 p->tcfc_bindcnt = 1;
 234
 235         spin_lock_init(&p->tcfc_lock);
 236         p->tcfc_stats_lock = &p->tcfc_lock;
 237         p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
 238         p->tcfc_tm.install = jiffies;
 239         p->tcfc_tm.lastuse = jiffies;
 240 #ifdef CONFIG_NET_ESTIMATOR
 241         if (est)
 242                 gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
 243                                   p->tcfc_stats_lock, est);
 244 #endif
 245         a->priv = (void *) p;
 246         return p;
 247 }
 248 EXPORT_SYMBOL(tcf_hash_create);
 249
 250 void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
 251 {
 252         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
 253
 254         write_lock_bh(hinfo->lock);
 255         p->tcfc_next = hinfo->htab[h];
 256         hinfo->htab[h] = p;
 257         write_unlock_bh(hinfo->lock);
 258 }
 259 EXPORT_SYMBOL(tcf_hash_insert);
 260
 261 static struct tc_action_ops *act_base = NULL;
 262 static DEFINE_RWLOCK(act_mod_lock);
 263
 264 int tcf_register_action(struct tc_action_ops *act)
 265 {
 266         struct tc_action_ops *a, **ap;
 267
 268         write_lock(&act_mod_lock);
 269         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
 270                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 271                         write_unlock(&act_mod_lock);
 272                         return -EEXIST;
 273                 }
 274         }
 275         act->next = NULL;
 276         *ap = act;
 277         write_unlock(&act_mod_lock);
 278         return 0;
 279 }
 280
 281 int tcf_unregister_action(struct tc_action_ops *act)
 282 {
 283         struct tc_action_ops *a, **ap;
 284         int err = -ENOENT;
 285
 286         write_lock(&act_mod_lock);
 287         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
 288                 if (a == act)
 289                         break;
 290         if (a) {
 291                 *ap = a->next;
 292                 a->next = NULL;
 293                 err = 0;
 294         }
 295         write_unlock(&act_mod_lock);
 296         return err;
 297 }
 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 rtattr */
 321 static struct tc_action_ops *tc_lookup_action(struct rtattr *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 (rtattr_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
 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;
 428         struct rtattr *r;
 429
 430         if (a->ops == NULL || a->ops->dump == NULL)
 431                 return err;
 432
 433         RTA_PUT(skb, TCA_KIND, IFNAMSIZ, a->ops->kind);
 434         if (tcf_action_copy_stats(skb, a, 0))
 435                 goto rtattr_failure;
 436         r = (struct rtattr*) skb->tail;
 437         RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
 438         if ((err = tcf_action_dump_old(skb, a, bind, ref)) > 0) {
 439                 r->rta_len = skb->tail - (u8*)r;
 440                 return err;
 441         }
 442
 443 rtattr_failure:
 444         skb_trim(skb, b - skb->data);
 445         return -1;
 446 }
 447
 448 int
 449 tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
 450 {
 451         struct tc_action *a;
 452         int err = -EINVAL;
 453         unsigned char *b = skb->tail;
 454         struct rtattr *r ;
 455
 456         while ((a = act) != NULL) {
 457                 r = (struct rtattr*) skb->tail;
 458                 act = a->next;
 459                 RTA_PUT(skb, a->order, 0, NULL);
 460                 err = tcf_action_dump_1(skb, a, bind, ref);
 461                 if (err < 0)
 462                         goto errout;
 463                 r->rta_len = skb->tail - (u8*)r;
 464         }
 465
 466         return 0;
 467
 468 rtattr_failure:
 469         err = -EINVAL;
 470 errout:
 471         skb_trim(skb, b - skb->data);
 472         return err;
 473 }
 474
 475 struct tc_action *tcf_action_init_1(struct rtattr *rta, struct rtattr *est,
 476                                     char *name, int ovr, int bind, int *err)
 477 {
 478         struct tc_action *a;
 479         struct tc_action_ops *a_o;
 480         char act_name[IFNAMSIZ];
 481         struct rtattr *tb[TCA_ACT_MAX+1];
 482         struct rtattr *kind;
 483
 484         *err = -EINVAL;
 485
 486         if (name == NULL) {
 487                 if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
 488                         goto err_out;
 489                 kind = tb[TCA_ACT_KIND-1];
 490                 if (kind == NULL)
 491                         goto err_out;
 492                 if (rtattr_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 493                         goto err_out;
 494         } else {
 495                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 496                         goto err_out;
 497         }
 498
 499         a_o = tc_lookup_action_n(act_name);
 500         if (a_o == NULL) {
 501 #ifdef CONFIG_KMOD
 502                 rtnl_unlock();
 503                 request_module("act_%s", act_name);
 504                 rtnl_lock();
 505
 506                 a_o = tc_lookup_action_n(act_name);
 507
 508                 /* We dropped the RTNL semaphore in order to
 509                  * perform the module load.  So, even if we
 510                  * succeeded in loading the module we have to
 511                  * tell the caller to replay the request.  We
 512                  * indicate this using -EAGAIN.
 513                  */
 514                 if (a_o != NULL) {
 515                         *err = -EAGAIN;
 516                         goto err_mod;
 517                 }
 518 #endif
 519                 *err = -ENOENT;
 520                 goto err_out;
 521         }
 522
 523         *err = -ENOMEM;
 524         a = kzalloc(sizeof(*a), GFP_KERNEL);
 525         if (a == NULL)
 526                 goto err_mod;
 527
 528         /* backward compatibility for policer */
 529         if (name == NULL)
 530                 *err = a_o->init(tb[TCA_ACT_OPTIONS-1], est, a, ovr, bind);
 531         else
 532                 *err = a_o->init(rta, est, a, ovr, bind);
 533         if (*err < 0)
 534                 goto err_free;
 535
 536         /* module count goes up only when brand new policy is created
 537            if it exists and is only bound to in a_o->init() then
 538            ACT_P_CREATED is not returned (a zero is).
 539         */
 540         if (*err != ACT_P_CREATED)
 541                 module_put(a_o->owner);
 542         a->ops = a_o;
 543
 544         *err = 0;
 545         return a;
 546
 547 err_free:
 548         kfree(a);
 549 err_mod:
 550         module_put(a_o->owner);
 551 err_out:
 552         return NULL;
 553 }
 554
 555 struct tc_action *tcf_action_init(struct rtattr *rta, struct rtattr *est,
 556                                   char *name, int ovr, int bind, int *err)
 557 {
 558         struct rtattr *tb[TCA_ACT_MAX_PRIO+1];
 559         struct tc_action *head = NULL, *act, *act_prev = NULL;
 560         int i;
 561
 562         if (rtattr_parse_nested(tb, TCA_ACT_MAX_PRIO, rta) < 0) {
 563                 *err = -EINVAL;
 564                 return head;
 565         }
 566
 567         for (i=0; i < TCA_ACT_MAX_PRIO && tb[i]; i++) {
 568                 act = tcf_action_init_1(tb[i], est, name, ovr, bind, err);
 569                 if (act == NULL)
 570                         goto err;
 571                 act->order = i+1;
 572
 573                 if (head == NULL)
 574                         head = act;
 575                 else
 576                         act_prev->next = act;
 577                 act_prev = act;
 578         }
 579         return head;
 580
 581 err:
 582         if (head != NULL)
 583                 tcf_action_destroy(head, bind);
 584         return NULL;
 585 }
 586
 587 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 588                           int compat_mode)
 589 {
 590         int err = 0;
 591         struct gnet_dump d;
 592         struct tcf_act_hdr *h = a->priv;
 593
 594         if (h == NULL)
 595                 goto errout;
 596
 597         /* compat_mode being true specifies a call that is supposed
 598          * to add additional backward compatiblity statistic TLVs.
 599          */
 600         if (compat_mode) {
 601                 if (a->type == TCA_OLD_COMPAT)
 602                         err = gnet_stats_start_copy_compat(skb, 0,
 603                                 TCA_STATS, TCA_XSTATS, h->tcf_stats_lock, &d);
 604                 else
 605                         return 0;
 606         } else
 607                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 608                         h->tcf_stats_lock, &d);
 609
 610         if (err < 0)
 611                 goto errout;
 612
 613         if (a->ops != NULL && a->ops->get_stats != NULL)
 614                 if (a->ops->get_stats(skb, a) < 0)
 615                         goto errout;
 616
 617         if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
 618 #ifdef CONFIG_NET_ESTIMATOR
 619             gnet_stats_copy_rate_est(&d, &h->tcf_rate_est) < 0 ||
 620 #endif
 621             gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
 622                 goto errout;
 623
 624         if (gnet_stats_finish_copy(&d) < 0)
 625                 goto errout;
 626
 627         return 0;
 628
 629 errout:
 630         return -1;
 631 }
 632
 633 static int
 634 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 pid, u32 seq,
 635              u16 flags, int event, int bind, int ref)
 636 {
 637         struct tcamsg *t;
 638         struct nlmsghdr *nlh;
 639         unsigned char *b = skb->tail;
 640         struct rtattr *x;
 641
 642         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 643
 644         t = NLMSG_DATA(nlh);
 645         t->tca_family = AF_UNSPEC;
 646         t->tca__pad1 = 0;
 647         t->tca__pad2 = 0;
 648
 649         x = (struct rtattr*) skb->tail;
 650         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 651
 652         if (tcf_action_dump(skb, a, bind, ref) < 0)
 653                 goto rtattr_failure;
 654
 655         x->rta_len = skb->tail - (u8*)x;
 656
 657         nlh->nlmsg_len = skb->tail - b;
 658         return skb->len;
 659
 660 rtattr_failure:
 661 nlmsg_failure:
 662         skb_trim(skb, b - skb->data);
 663         return -1;
 664 }
 665
 666 static int
 667 act_get_notify(u32 pid, struct nlmsghdr *n, struct tc_action *a, int event)
 668 {
 669         struct sk_buff *skb;
 670
 671         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 672         if (!skb)
 673                 return -ENOBUFS;
 674         if (tca_get_fill(skb, a, pid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 675                 kfree_skb(skb);
 676                 return -EINVAL;
 677         }
 678
 679         return rtnl_unicast(skb, pid);
 680 }
 681
 682 static struct tc_action *
 683 tcf_action_get_1(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int *err)
 684 {
 685         struct rtattr *tb[TCA_ACT_MAX+1];
 686         struct tc_action *a;
 687         int index;
 688
 689         *err = -EINVAL;
 690         if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
 691                 return NULL;
 692
 693         if (tb[TCA_ACT_INDEX - 1] == NULL ||
 694             RTA_PAYLOAD(tb[TCA_ACT_INDEX - 1]) < sizeof(index))
 695                 return NULL;
 696         index = *(int *)RTA_DATA(tb[TCA_ACT_INDEX - 1]);
 697
 698         *err = -ENOMEM;
 699         a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
 700         if (a == NULL)
 701                 return NULL;
 702
 703         *err = -EINVAL;
 704         a->ops = tc_lookup_action(tb[TCA_ACT_KIND - 1]);
 705         if (a->ops == NULL)
 706                 goto err_free;
 707         if (a->ops->lookup == NULL)
 708                 goto err_mod;
 709         *err = -ENOENT;
 710         if (a->ops->lookup(a, index) == 0)
 711                 goto err_mod;
 712
 713         module_put(a->ops->owner);
 714         *err = 0;
 715         return a;
 716 err_mod:
 717         module_put(a->ops->owner);
 718 err_free:
 719         kfree(a);
 720         return NULL;
 721 }
 722
 723 static void cleanup_a(struct tc_action *act)
 724 {
 725         struct tc_action *a;
 726
 727         for (a = act; a; a = act) {
 728                 act = a->next;
 729                 kfree(a);
 730         }
 731 }
 732
 733 static struct tc_action *create_a(int i)
 734 {
 735         struct tc_action *act;
 736
 737         act = kzalloc(sizeof(*act), GFP_KERNEL);
 738         if (act == NULL) {
 739                 printk("create_a: failed to alloc!\n");
 740                 return NULL;
 741         }
 742         act->order = i;
 743         return act;
 744 }
 745
 746 static int tca_action_flush(struct rtattr *rta, struct nlmsghdr *n, u32 pid)
 747 {
 748         struct sk_buff *skb;
 749         unsigned char *b;
 750         struct nlmsghdr *nlh;
 751         struct tcamsg *t;
 752         struct netlink_callback dcb;
 753         struct rtattr *x;
 754         struct rtattr *tb[TCA_ACT_MAX+1];
 755         struct rtattr *kind;
 756         struct tc_action *a = create_a(0);
 757         int err = -EINVAL;
 758
 759         if (a == NULL) {
 760                 printk("tca_action_flush: couldnt create tc_action\n");
 761                 return err;
 762         }
 763
 764         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 765         if (!skb) {
 766                 printk("tca_action_flush: failed skb alloc\n");
 767                 kfree(a);
 768                 return -ENOBUFS;
 769         }
 770
 771         b = (unsigned char *)skb->tail;
 772
 773         if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
 774                 goto err_out;
 775
 776         kind = tb[TCA_ACT_KIND-1];
 777         a->ops = tc_lookup_action(kind);
 778         if (a->ops == NULL)
 779                 goto err_out;
 780
 781         nlh = NLMSG_PUT(skb, pid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t));
 782         t = NLMSG_DATA(nlh);
 783         t->tca_family = AF_UNSPEC;
 784         t->tca__pad1 = 0;
 785         t->tca__pad2 = 0;
 786
 787         x = (struct rtattr *) skb->tail;
 788         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 789
 790         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 791         if (err < 0)
 792                 goto rtattr_failure;
 793
 794         x->rta_len = skb->tail - (u8 *) x;
 795
 796         nlh->nlmsg_len = skb->tail - b;
 797         nlh->nlmsg_flags |= NLM_F_ROOT;
 798         module_put(a->ops->owner);
 799         kfree(a);
 800         err = rtnetlink_send(skb, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO);
 801         if (err > 0)
 802                 return 0;
 803
 804         return err;
 805
 806 rtattr_failure:
 807 nlmsg_failure:
 808         module_put(a->ops->owner);
 809 err_out:
 810         kfree_skb(skb);
 811         kfree(a);
 812         return err;
 813 }
 814
 815 static int
 816 tca_action_gd(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int event)
 817 {
 818         int i, ret = 0;
 819         struct rtattr *tb[TCA_ACT_MAX_PRIO+1];
 820         struct tc_action *head = NULL, *act, *act_prev = NULL;
 821
 822         if (rtattr_parse_nested(tb, TCA_ACT_MAX_PRIO, rta) < 0)
 823                 return -EINVAL;
 824
 825         if (event == RTM_DELACTION && n->nlmsg_flags&NLM_F_ROOT) {
 826                 if (tb[0] != NULL && tb[1] == NULL)
 827                         return tca_action_flush(tb[0], n, pid);
 828         }
 829
 830         for (i=0; i < TCA_ACT_MAX_PRIO && tb[i]; i++) {
 831                 act = tcf_action_get_1(tb[i], n, pid, &ret);
 832                 if (act == NULL)
 833                         goto err;
 834                 act->order = i+1;
 835
 836                 if (head == NULL)
 837                         head = act;
 838                 else
 839                         act_prev->next = act;
 840                 act_prev = act;
 841         }
 842
 843         if (event == RTM_GETACTION)
 844                 ret = act_get_notify(pid, n, head, event);
 845         else { /* delete */
 846                 struct sk_buff *skb;
 847
 848                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 849                 if (!skb) {
 850                         ret = -ENOBUFS;
 851                         goto err;
 852                 }
 853
 854                 if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
 855                                  0, 1) <= 0) {
 856                         kfree_skb(skb);
 857                         ret = -EINVAL;
 858                         goto err;
 859                 }
 860
 861                 /* now do the delete */
 862                 tcf_action_destroy(head, 0);
 863                 ret = rtnetlink_send(skb, pid, RTNLGRP_TC,
 864                                      n->nlmsg_flags&NLM_F_ECHO);
 865                 if (ret > 0)
 866                         return 0;
 867                 return ret;
 868         }
 869 err:
 870         cleanup_a(head);
 871         return ret;
 872 }
 873
 874 static int tcf_add_notify(struct tc_action *a, u32 pid, u32 seq, int event,
 875                           u16 flags)
 876 {
 877         struct tcamsg *t;
 878         struct nlmsghdr *nlh;
 879         struct sk_buff *skb;
 880         struct rtattr *x;
 881         unsigned char *b;
 882         int err = 0;
 883
 884         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 885         if (!skb)
 886                 return -ENOBUFS;
 887
 888         b = (unsigned char *)skb->tail;
 889
 890         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 891         t = NLMSG_DATA(nlh);
 892         t->tca_family = AF_UNSPEC;
 893         t->tca__pad1 = 0;
 894         t->tca__pad2 = 0;
 895
 896         x = (struct rtattr*) skb->tail;
 897         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 898
 899         if (tcf_action_dump(skb, a, 0, 0) < 0)
 900                 goto rtattr_failure;
 901
 902         x->rta_len = skb->tail - (u8*)x;
 903
 904         nlh->nlmsg_len = skb->tail - b;
 905         NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 906
 907         err = rtnetlink_send(skb, pid, RTNLGRP_TC, flags&NLM_F_ECHO);
 908         if (err > 0)
 909                 err = 0;
 910         return err;
 911
 912 rtattr_failure:
 913 nlmsg_failure:
 914         kfree_skb(skb);
 915         return -1;
 916 }
 917
 918
 919 static int
 920 tcf_action_add(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int ovr)
 921 {
 922         int ret = 0;
 923         struct tc_action *act;
 924         struct tc_action *a;
 925         u32 seq = n->nlmsg_seq;
 926
 927         act = tcf_action_init(rta, NULL, NULL, ovr, 0, &ret);
 928         if (act == NULL)
 929                 goto done;
 930
 931         /* dump then free all the actions after update; inserted policy
 932          * stays intact
 933          * */
 934         ret = tcf_add_notify(act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
 935         for (a = act; a; a = act) {
 936                 act = a->next;
 937                 kfree(a);
 938         }
 939 done:
 940         return ret;
 941 }
 942
 943 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 944 {
 945         struct rtattr **tca = arg;
 946         u32 pid = skb ? NETLINK_CB(skb).pid : 0;
 947         int ret = 0, ovr = 0;
 948
 949         if (tca[TCA_ACT_TAB-1] == NULL) {
 950                 printk("tc_ctl_action: received NO action attribs\n");
 951                 return -EINVAL;
 952         }
 953
 954         /* n->nlmsg_flags&NLM_F_CREATE
 955          * */
 956         switch (n->nlmsg_type) {
 957         case RTM_NEWACTION:
 958                 /* we are going to assume all other flags
 959                  * imply create only if it doesnt exist
 960                  * Note that CREATE | EXCL implies that
 961                  * but since we want avoid ambiguity (eg when flags
 962                  * is zero) then just set this
 963                  */
 964                 if (n->nlmsg_flags&NLM_F_REPLACE)
 965                         ovr = 1;
 966 replay:
 967                 ret = tcf_action_add(tca[TCA_ACT_TAB-1], n, pid, ovr);
 968                 if (ret == -EAGAIN)
 969                         goto replay;
 970                 break;
 971         case RTM_DELACTION:
 972                 ret = tca_action_gd(tca[TCA_ACT_TAB-1], n, pid, RTM_DELACTION);
 973                 break;
 974         case RTM_GETACTION:
 975                 ret = tca_action_gd(tca[TCA_ACT_TAB-1], n, pid, RTM_GETACTION);
 976                 break;
 977         default:
 978                 BUG();
 979         }
 980
 981         return ret;
 982 }
 983
 984 static struct rtattr *
 985 find_dump_kind(struct nlmsghdr *n)
 986 {
 987         struct rtattr *tb1, *tb2[TCA_ACT_MAX+1];
 988         struct rtattr *tb[TCA_ACT_MAX_PRIO + 1];
 989         struct rtattr *rta[TCAA_MAX + 1];
 990         struct rtattr *kind;
 991         int min_len = NLMSG_LENGTH(sizeof(struct tcamsg));
 992         int attrlen = n->nlmsg_len - NLMSG_ALIGN(min_len);
 993         struct rtattr *attr = (void *) n + NLMSG_ALIGN(min_len);
 994
 995         if (rtattr_parse(rta, TCAA_MAX, attr, attrlen) < 0)
 996                 return NULL;
 997         tb1 = rta[TCA_ACT_TAB - 1];
 998         if (tb1 == NULL)
 999                 return NULL;
1000
1001         if (rtattr_parse(tb, TCA_ACT_MAX_PRIO, RTA_DATA(tb1),
1002                          NLMSG_ALIGN(RTA_PAYLOAD(tb1))) < 0)
1003                 return NULL;
1004         if (tb[0] == NULL)
1005                 return NULL;
1006
1007         if (rtattr_parse(tb2, TCA_ACT_MAX, RTA_DATA(tb[0]),
1008                          RTA_PAYLOAD(tb[0])) < 0)
1009                 return NULL;
1010         kind = tb2[TCA_ACT_KIND-1];
1011
1012         return kind;
1013 }
1014
1015 static int
1016 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1017 {
1018         struct nlmsghdr *nlh;
1019         unsigned char *b = skb->tail;
1020         struct rtattr *x;
1021         struct tc_action_ops *a_o;
1022         struct tc_action a;
1023         int ret = 0;
1024         struct tcamsg *t = (struct tcamsg *) NLMSG_DATA(cb->nlh);
1025         struct rtattr *kind = find_dump_kind(cb->nlh);
1026
1027         if (kind == NULL) {
1028                 printk("tc_dump_action: action bad kind\n");
1029                 return 0;
1030         }
1031
1032         a_o = tc_lookup_action(kind);
1033         if (a_o == NULL) {
1034                 return 0;
1035         }
1036
1037         memset(&a, 0, sizeof(struct tc_action));
1038         a.ops = a_o;
1039
1040         if (a_o->walk == NULL) {
1041                 printk("tc_dump_action: %s !capable of dumping table\n", a_o->kind);
1042                 goto rtattr_failure;
1043         }
1044
1045         nlh = NLMSG_PUT(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
1046                         cb->nlh->nlmsg_type, sizeof(*t));
1047         t = NLMSG_DATA(nlh);
1048         t->tca_family = AF_UNSPEC;
1049         t->tca__pad1 = 0;
1050         t->tca__pad2 = 0;
1051
1052         x = (struct rtattr *) skb->tail;
1053         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
1054
1055         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1056         if (ret < 0)
1057                 goto rtattr_failure;
1058
1059         if (ret > 0) {
1060                 x->rta_len = skb->tail - (u8 *) x;
1061                 ret = skb->len;
1062         } else
1063                 skb_trim(skb, (u8*)x - skb->data);
1064
1065         nlh->nlmsg_len = skb->tail - b;
1066         if (NETLINK_CB(cb->skb).pid && ret)
1067                 nlh->nlmsg_flags |= NLM_F_MULTI;
1068         module_put(a_o->owner);
1069         return skb->len;
1070
1071 rtattr_failure:
1072 nlmsg_failure:
1073         module_put(a_o->owner);
1074         skb_trim(skb, b - skb->data);
1075         return skb->len;
1076 }
1077
1078 static int __init tc_action_init(void)
1079 {
1080         struct rtnetlink_link *link_p = rtnetlink_links[PF_UNSPEC];
1081
1082         if (link_p) {
1083                 link_p[RTM_NEWACTION-RTM_BASE].doit = tc_ctl_action;
1084                 link_p[RTM_DELACTION-RTM_BASE].doit = tc_ctl_action;
1085                 link_p[RTM_GETACTION-RTM_BASE].doit = tc_ctl_action;
1086                 link_p[RTM_GETACTION-RTM_BASE].dumpit = tc_dump_action;
1087         }
1088
1089         return 0;
1090 }
1091
1092 subsys_initcall(tc_action_init);
1093
1094 EXPORT_SYMBOL(tcf_register_action);
1095 EXPORT_SYMBOL(tcf_unregister_action);
1096 EXPORT_SYMBOL(tcf_action_exec);
1097 EXPORT_SYMBOL(tcf_action_dump_1);