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/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 #ifdef CONFIG_NET_ESTIMATOR
  46                         gen_kill_estimator(&p->tcfc_bstats,
  47                                            &p->tcfc_rate_est);
  48 #endif
  49                         kfree(p);
  50                         return;
  51                 }
  52         }
  53         BUG_TRAP(0);
  54 }
  55 EXPORT_SYMBOL(tcf_hash_destroy);
  56
  57 int tcf_hash_release(struct tcf_common *p, int bind,
  58                      struct tcf_hashinfo *hinfo)
  59 {
  60         int ret = 0;
  61
  62         if (p) {
  63                 if (bind)
  64                         p->tcfc_bindcnt--;
  65
  66                 p->tcfc_refcnt--;
  67                 if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
  68                         tcf_hash_destroy(p, hinfo);
  69                         ret = 1;
  70                 }
  71         }
  72         return ret;
  73 }
  74 EXPORT_SYMBOL(tcf_hash_release);
  75
  76 static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
  77                            struct tc_action *a, struct tcf_hashinfo *hinfo)
  78 {
  79         struct tcf_common *p;
  80         int err = 0, index = -1,i = 0, s_i = 0, n_i = 0;
  81         struct rtattr *r ;
  82
  83         read_lock(hinfo->lock);
  84
  85         s_i = cb->args[0];
  86
  87         for (i = 0; i < (hinfo->hmask + 1); i++) {
  88                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
  89
  90                 for (; p; p = p->tcfc_next) {
  91                         index++;
  92                         if (index < s_i)
  93                                 continue;
  94                         a->priv = p;
  95                         a->order = n_i;
  96                         r = (struct rtattr *)skb_tail_pointer(skb);
  97                         RTA_PUT(skb, a->order, 0, NULL);
  98                         err = tcf_action_dump_1(skb, a, 0, 0);
  99                         if (err < 0) {
 100                                 index--;
 101                                 nlmsg_trim(skb, r);
 102                                 goto done;
 103                         }
 104                         r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
 105                         n_i++;
 106                         if (n_i >= TCA_ACT_MAX_PRIO)
 107                                 goto done;
 108                 }
 109         }
 110 done:
 111         read_unlock(hinfo->lock);
 112         if (n_i)
 113                 cb->args[0] += n_i;
 114         return n_i;
 115
 116 rtattr_failure:
 117         nlmsg_trim(skb, r);
 118         goto done;
 119 }
 120
 121 static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a,
 122                           struct tcf_hashinfo *hinfo)
 123 {
 124         struct tcf_common *p, *s_p;
 125         struct rtattr *r ;
 126         int i= 0, n_i = 0;
 127
 128         r = (struct rtattr *)skb_tail_pointer(skb);
 129         RTA_PUT(skb, a->order, 0, NULL);
 130         RTA_PUT(skb, TCA_KIND, IFNAMSIZ, a->ops->kind);
 131         for (i = 0; i < (hinfo->hmask + 1); i++) {
 132                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
 133
 134                 while (p != NULL) {
 135                         s_p = p->tcfc_next;
 136                         if (ACT_P_DELETED == tcf_hash_release(p, 0, hinfo))
 137                                  module_put(a->ops->owner);
 138                         n_i++;
 139                         p = s_p;
 140                 }
 141         }
 142         RTA_PUT(skb, TCA_FCNT, 4, &n_i);
 143         r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
 144
 145         return n_i;
 146 rtattr_failure:
 147         nlmsg_trim(skb, r);
 148         return -EINVAL;
 149 }
 150
 151 int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
 152                        int type, struct tc_action *a)
 153 {
 154         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 155
 156         if (type == RTM_DELACTION) {
 157                 return tcf_del_walker(skb, a, hinfo);
 158         } else if (type == RTM_GETACTION) {
 159                 return tcf_dump_walker(skb, cb, a, hinfo);
 160         } else {
 161                 printk("tcf_generic_walker: unknown action %d\n", type);
 162                 return -EINVAL;
 163         }
 164 }
 165 EXPORT_SYMBOL(tcf_generic_walker);
 166
 167 struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 168 {
 169         struct tcf_common *p;
 170
 171         read_lock(hinfo->lock);
 172         for (p = hinfo->htab[tcf_hash(index, hinfo->hmask)]; p;
 173              p = p->tcfc_next) {
 174                 if (p->tcfc_index == index)
 175                         break;
 176         }
 177         read_unlock(hinfo->lock);
 178
 179         return p;
 180 }
 181 EXPORT_SYMBOL(tcf_hash_lookup);
 182
 183 u32 tcf_hash_new_index(u32 *idx_gen, struct tcf_hashinfo *hinfo)
 184 {
 185         u32 val = *idx_gen;
 186
 187         do {
 188                 if (++val == 0)
 189                         val = 1;
 190         } while (tcf_hash_lookup(val, hinfo));
 191
 192         return (*idx_gen = val);
 193 }
 194 EXPORT_SYMBOL(tcf_hash_new_index);
 195
 196 int tcf_hash_search(struct tc_action *a, u32 index)
 197 {
 198         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 199         struct tcf_common *p = tcf_hash_lookup(index, hinfo);
 200
 201         if (p) {
 202                 a->priv = p;
 203                 return 1;
 204         }
 205         return 0;
 206 }
 207 EXPORT_SYMBOL(tcf_hash_search);
 208
 209 struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
 210                                   struct tcf_hashinfo *hinfo)
 211 {
 212         struct tcf_common *p = NULL;
 213         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 214                 if (bind) {
 215                         p->tcfc_bindcnt++;
 216                         p->tcfc_refcnt++;
 217                 }
 218                 a->priv = p;
 219         }
 220         return p;
 221 }
 222 EXPORT_SYMBOL(tcf_hash_check);
 223
 224 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)
 225 {
 226         struct tcf_common *p = kzalloc(size, GFP_KERNEL);
 227
 228         if (unlikely(!p))
 229                 return p;
 230         p->tcfc_refcnt = 1;
 231         if (bind)
 232                 p->tcfc_bindcnt = 1;
 233
 234         spin_lock_init(&p->tcfc_lock);
 235         p->tcfc_stats_lock = &p->tcfc_lock;
 236         p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
 237         p->tcfc_tm.install = jiffies;
 238         p->tcfc_tm.lastuse = jiffies;
 239 #ifdef CONFIG_NET_ESTIMATOR
 240         if (est)
 241                 gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
 242                                   p->tcfc_stats_lock, est);
 243 #endif
 244         a->priv = (void *) p;
 245         return p;
 246 }
 247 EXPORT_SYMBOL(tcf_hash_create);
 248
 249 void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
 250 {
 251         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
 252
 253         write_lock_bh(hinfo->lock);
 254         p->tcfc_next = hinfo->htab[h];
 255         hinfo->htab[h] = p;
 256         write_unlock_bh(hinfo->lock);
 257 }
 258 EXPORT_SYMBOL(tcf_hash_insert);
 259
 260 static struct tc_action_ops *act_base = NULL;
 261 static DEFINE_RWLOCK(act_mod_lock);
 262
 263 int tcf_register_action(struct tc_action_ops *act)
 264 {
 265         struct tc_action_ops *a, **ap;
 266
 267         write_lock(&act_mod_lock);
 268         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
 269                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 270                         write_unlock(&act_mod_lock);
 271                         return -EEXIST;
 272                 }
 273         }
 274         act->next = NULL;
 275         *ap = act;
 276         write_unlock(&act_mod_lock);
 277         return 0;
 278 }
 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
 298 /* lookup by name */
 299 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 300 {
 301         struct tc_action_ops *a = NULL;
 302
 303         if (kind) {
 304                 read_lock(&act_mod_lock);
 305                 for (a = act_base; a; a = a->next) {
 306                         if (strcmp(kind, a->kind) == 0) {
 307                                 if (!try_module_get(a->owner)) {
 308                                         read_unlock(&act_mod_lock);
 309                                         return NULL;
 310                                 }
 311                                 break;
 312                         }
 313                 }
 314                 read_unlock(&act_mod_lock);
 315         }
 316         return a;
 317 }
 318
 319 /* lookup by rtattr */
 320 static struct tc_action_ops *tc_lookup_action(struct rtattr *kind)
 321 {
 322         struct tc_action_ops *a = NULL;
 323
 324         if (kind) {
 325                 read_lock(&act_mod_lock);
 326                 for (a = act_base; a; a = a->next) {
 327                         if (rtattr_strcmp(kind, a->kind) == 0) {
 328                                 if (!try_module_get(a->owner)) {
 329                                         read_unlock(&act_mod_lock);
 330                                         return NULL;
 331                                 }
 332                                 break;
 333                         }
 334                 }
 335                 read_unlock(&act_mod_lock);
 336         }
 337         return a;
 338 }
 339
 340 #if 0
 341 /* lookup by id */
 342 static struct tc_action_ops *tc_lookup_action_id(u32 type)
 343 {
 344         struct tc_action_ops *a = NULL;
 345
 346         if (type) {
 347                 read_lock(&act_mod_lock);
 348                 for (a = act_base; a; a = a->next) {
 349                         if (a->type == type) {
 350                                 if (!try_module_get(a->owner)) {
 351                                         read_unlock(&act_mod_lock);
 352                                         return NULL;
 353                                 }
 354                                 break;
 355                         }
 356                 }
 357                 read_unlock(&act_mod_lock);
 358         }
 359         return a;
 360 }
 361 #endif
 362
 363 int tcf_action_exec(struct sk_buff *skb, struct tc_action *act,
 364                     struct tcf_result *res)
 365 {
 366         struct tc_action *a;
 367         int ret = -1;
 368
 369         if (skb->tc_verd & TC_NCLS) {
 370                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 371                 ret = TC_ACT_OK;
 372                 goto exec_done;
 373         }
 374         while ((a = act) != NULL) {
 375 repeat:
 376                 if (a->ops && a->ops->act) {
 377                         ret = a->ops->act(skb, a, res);
 378                         if (TC_MUNGED & skb->tc_verd) {
 379                                 /* copied already, allow trampling */
 380                                 skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
 381                                 skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
 382                         }
 383                         if (ret == TC_ACT_REPEAT)
 384                                 goto repeat;    /* we need a ttl - JHS */
 385                         if (ret != TC_ACT_PIPE)
 386                                 goto exec_done;
 387                 }
 388                 act = a->next;
 389         }
 390 exec_done:
 391         return ret;
 392 }
 393
 394 void tcf_action_destroy(struct tc_action *act, int bind)
 395 {
 396         struct tc_action *a;
 397
 398         for (a = act; a; a = act) {
 399                 if (a->ops && a->ops->cleanup) {
 400                         if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
 401                                 module_put(a->ops->owner);
 402                         act = act->next;
 403                         kfree(a);
 404                 } else { /*FIXME: Remove later - catch insertion bugs*/
 405                         printk("tcf_action_destroy: BUG? destroying NULL ops\n");
 406                         act = act->next;
 407                         kfree(a);
 408                 }
 409         }
 410 }
 411
 412 int
 413 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 414 {
 415         int err = -EINVAL;
 416
 417         if (a->ops == NULL || a->ops->dump == NULL)
 418                 return err;
 419         return a->ops->dump(skb, a, bind, ref);
 420 }
 421
 422 int
 423 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 424 {
 425         int err = -EINVAL;
 426         unsigned char *b = skb_tail_pointer(skb);
 427         struct rtattr *r;
 428
 429         if (a->ops == NULL || a->ops->dump == NULL)
 430                 return err;
 431
 432         RTA_PUT(skb, TCA_KIND, IFNAMSIZ, a->ops->kind);
 433         if (tcf_action_copy_stats(skb, a, 0))
 434                 goto rtattr_failure;
 435         r = (struct rtattr *)skb_tail_pointer(skb);
 436         RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
 437         if ((err = tcf_action_dump_old(skb, a, bind, ref)) > 0) {
 438                 r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
 439                 return err;
 440         }
 441
 442 rtattr_failure:
 443         nlmsg_trim(skb, b);
 444         return -1;
 445 }
 446
 447 int
 448 tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
 449 {
 450         struct tc_action *a;
 451         int err = -EINVAL;
 452         unsigned char *b = skb_tail_pointer(skb);
 453         struct rtattr *r ;
 454
 455         while ((a = act) != NULL) {
 456                 r = (struct rtattr *)skb_tail_pointer(skb);
 457                 act = a->next;
 458                 RTA_PUT(skb, a->order, 0, NULL);
 459                 err = tcf_action_dump_1(skb, a, bind, ref);
 460                 if (err < 0)
 461                         goto errout;
 462                 r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
 463         }
 464
 465         return 0;
 466
 467 rtattr_failure:
 468         err = -EINVAL;
 469 errout:
 470         nlmsg_trim(skb, b);
 471         return err;
 472 }
 473
 474 struct tc_action *tcf_action_init_1(struct rtattr *rta, struct rtattr *est,
 475                                     char *name, int ovr, int bind, int *err)
 476 {
 477         struct tc_action *a;
 478         struct tc_action_ops *a_o;
 479         char act_name[IFNAMSIZ];
 480         struct rtattr *tb[TCA_ACT_MAX+1];
 481         struct rtattr *kind;
 482
 483         *err = -EINVAL;
 484
 485         if (name == NULL) {
 486                 if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
 487                         goto err_out;
 488                 kind = tb[TCA_ACT_KIND-1];
 489                 if (kind == NULL)
 490                         goto err_out;
 491                 if (rtattr_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 492                         goto err_out;
 493         } else {
 494                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 495                         goto err_out;
 496         }
 497
 498         a_o = tc_lookup_action_n(act_name);
 499         if (a_o == NULL) {
 500 #ifdef CONFIG_KMOD
 501                 rtnl_unlock();
 502                 request_module("act_%s", act_name);
 503                 rtnl_lock();
 504
 505                 a_o = tc_lookup_action_n(act_name);
 506
 507                 /* We dropped the RTNL semaphore in order to
 508                  * perform the module load.  So, even if we
 509                  * succeeded in loading the module we have to
 510                  * tell the caller to replay the request.  We
 511                  * indicate this using -EAGAIN.
 512                  */
 513                 if (a_o != NULL) {
 514                         *err = -EAGAIN;
 515                         goto err_mod;
 516                 }
 517 #endif
 518                 *err = -ENOENT;
 519                 goto err_out;
 520         }
 521
 522         *err = -ENOMEM;
 523         a = kzalloc(sizeof(*a), GFP_KERNEL);
 524         if (a == NULL)
 525                 goto err_mod;
 526
 527         /* backward compatibility for policer */
 528         if (name == NULL)
 529                 *err = a_o->init(tb[TCA_ACT_OPTIONS-1], est, a, ovr, bind);
 530         else
 531                 *err = a_o->init(rta, est, a, ovr, bind);
 532         if (*err < 0)
 533                 goto err_free;
 534
 535         /* module count goes up only when brand new policy is created
 536            if it exists and is only bound to in a_o->init() then
 537            ACT_P_CREATED is not returned (a zero is).
 538         */
 539         if (*err != ACT_P_CREATED)
 540                 module_put(a_o->owner);
 541         a->ops = a_o;
 542
 543         *err = 0;
 544         return a;
 545
 546 err_free:
 547         kfree(a);
 548 err_mod:
 549         module_put(a_o->owner);
 550 err_out:
 551         return NULL;
 552 }
 553
 554 struct tc_action *tcf_action_init(struct rtattr *rta, struct rtattr *est,
 555                                   char *name, int ovr, int bind, int *err)
 556 {
 557         struct rtattr *tb[TCA_ACT_MAX_PRIO+1];
 558         struct tc_action *head = NULL, *act, *act_prev = NULL;
 559         int i;
 560
 561         if (rtattr_parse_nested(tb, TCA_ACT_MAX_PRIO, rta) < 0) {
 562                 *err = -EINVAL;
 563                 return head;
 564         }
 565
 566         for (i=0; i < TCA_ACT_MAX_PRIO && tb[i]; i++) {
 567                 act = tcf_action_init_1(tb[i], est, name, ovr, bind, err);
 568                 if (act == NULL)
 569                         goto err;
 570                 act->order = i+1;
 571
 572                 if (head == NULL)
 573                         head = act;
 574                 else
 575                         act_prev->next = act;
 576                 act_prev = act;
 577         }
 578         return head;
 579
 580 err:
 581         if (head != NULL)
 582                 tcf_action_destroy(head, bind);
 583         return NULL;
 584 }
 585
 586 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 587                           int compat_mode)
 588 {
 589         int err = 0;
 590         struct gnet_dump d;
 591         struct tcf_act_hdr *h = a->priv;
 592
 593         if (h == NULL)
 594                 goto errout;
 595
 596         /* compat_mode being true specifies a call that is supposed
 597          * to add additional backward compatiblity statistic TLVs.
 598          */
 599         if (compat_mode) {
 600                 if (a->type == TCA_OLD_COMPAT)
 601                         err = gnet_stats_start_copy_compat(skb, 0,
 602                                 TCA_STATS, TCA_XSTATS, h->tcf_stats_lock, &d);
 603                 else
 604                         return 0;
 605         } else
 606                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 607                         h->tcf_stats_lock, &d);
 608
 609         if (err < 0)
 610                 goto errout;
 611
 612         if (a->ops != NULL && a->ops->get_stats != NULL)
 613                 if (a->ops->get_stats(skb, a) < 0)
 614                         goto errout;
 615
 616         if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
 617 #ifdef CONFIG_NET_ESTIMATOR
 618             gnet_stats_copy_rate_est(&d, &h->tcf_rate_est) < 0 ||
 619 #endif
 620             gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
 621                 goto errout;
 622
 623         if (gnet_stats_finish_copy(&d) < 0)
 624                 goto errout;
 625
 626         return 0;
 627
 628 errout:
 629         return -1;
 630 }
 631
 632 static int
 633 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 pid, u32 seq,
 634              u16 flags, int event, int bind, int ref)
 635 {
 636         struct tcamsg *t;
 637         struct nlmsghdr *nlh;
 638         unsigned char *b = skb_tail_pointer(skb);
 639         struct rtattr *x;
 640
 641         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 642
 643         t = NLMSG_DATA(nlh);
 644         t->tca_family = AF_UNSPEC;
 645         t->tca__pad1 = 0;
 646         t->tca__pad2 = 0;
 647
 648         x = (struct rtattr *)skb_tail_pointer(skb);
 649         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 650
 651         if (tcf_action_dump(skb, a, bind, ref) < 0)
 652                 goto rtattr_failure;
 653
 654         x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
 655
 656         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 657         return skb->len;
 658
 659 rtattr_failure:
 660 nlmsg_failure:
 661         nlmsg_trim(skb, b);
 662         return -1;
 663 }
 664
 665 static int
 666 act_get_notify(u32 pid, struct nlmsghdr *n, struct tc_action *a, int event)
 667 {
 668         struct sk_buff *skb;
 669
 670         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 671         if (!skb)
 672                 return -ENOBUFS;
 673         if (tca_get_fill(skb, a, pid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 674                 kfree_skb(skb);
 675                 return -EINVAL;
 676         }
 677
 678         return rtnl_unicast(skb, pid);
 679 }
 680
 681 static struct tc_action *
 682 tcf_action_get_1(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int *err)
 683 {
 684         struct rtattr *tb[TCA_ACT_MAX+1];
 685         struct tc_action *a;
 686         int index;
 687
 688         *err = -EINVAL;
 689         if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
 690                 return NULL;
 691
 692         if (tb[TCA_ACT_INDEX - 1] == NULL ||
 693             RTA_PAYLOAD(tb[TCA_ACT_INDEX - 1]) < sizeof(index))
 694                 return NULL;
 695         index = *(int *)RTA_DATA(tb[TCA_ACT_INDEX - 1]);
 696
 697         *err = -ENOMEM;
 698         a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
 699         if (a == NULL)
 700                 return NULL;
 701
 702         *err = -EINVAL;
 703         a->ops = tc_lookup_action(tb[TCA_ACT_KIND - 1]);
 704         if (a->ops == NULL)
 705                 goto err_free;
 706         if (a->ops->lookup == NULL)
 707                 goto err_mod;
 708         *err = -ENOENT;
 709         if (a->ops->lookup(a, index) == 0)
 710                 goto err_mod;
 711
 712         module_put(a->ops->owner);
 713         *err = 0;
 714         return a;
 715 err_mod:
 716         module_put(a->ops->owner);
 717 err_free:
 718         kfree(a);
 719         return NULL;
 720 }
 721
 722 static void cleanup_a(struct tc_action *act)
 723 {
 724         struct tc_action *a;
 725
 726         for (a = act; a; a = act) {
 727                 act = a->next;
 728                 kfree(a);
 729         }
 730 }
 731
 732 static struct tc_action *create_a(int i)
 733 {
 734         struct tc_action *act;
 735
 736         act = kzalloc(sizeof(*act), GFP_KERNEL);
 737         if (act == NULL) {
 738                 printk("create_a: failed to alloc!\n");
 739                 return NULL;
 740         }
 741         act->order = i;
 742         return act;
 743 }
 744
 745 static int tca_action_flush(struct rtattr *rta, struct nlmsghdr *n, u32 pid)
 746 {
 747         struct sk_buff *skb;
 748         unsigned char *b;
 749         struct nlmsghdr *nlh;
 750         struct tcamsg *t;
 751         struct netlink_callback dcb;
 752         struct rtattr *x;
 753         struct rtattr *tb[TCA_ACT_MAX+1];
 754         struct rtattr *kind;
 755         struct tc_action *a = create_a(0);
 756         int err = -EINVAL;
 757
 758         if (a == NULL) {
 759                 printk("tca_action_flush: couldnt create tc_action\n");
 760                 return err;
 761         }
 762
 763         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 764         if (!skb) {
 765                 printk("tca_action_flush: failed skb alloc\n");
 766                 kfree(a);
 767                 return -ENOBUFS;
 768         }
 769
 770         b = skb_tail_pointer(skb);
 771
 772         if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
 773                 goto err_out;
 774
 775         kind = tb[TCA_ACT_KIND-1];
 776         a->ops = tc_lookup_action(kind);
 777         if (a->ops == NULL)
 778                 goto err_out;
 779
 780         nlh = NLMSG_PUT(skb, pid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t));
 781         t = NLMSG_DATA(nlh);
 782         t->tca_family = AF_UNSPEC;
 783         t->tca__pad1 = 0;
 784         t->tca__pad2 = 0;
 785
 786         x = (struct rtattr *)skb_tail_pointer(skb);
 787         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 788
 789         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 790         if (err < 0)
 791                 goto rtattr_failure;
 792
 793         x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
 794
 795         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 796         nlh->nlmsg_flags |= NLM_F_ROOT;
 797         module_put(a->ops->owner);
 798         kfree(a);
 799         err = rtnetlink_send(skb, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO);
 800         if (err > 0)
 801                 return 0;
 802
 803         return err;
 804
 805 rtattr_failure:
 806 nlmsg_failure:
 807         module_put(a->ops->owner);
 808 err_out:
 809         kfree_skb(skb);
 810         kfree(a);
 811         return err;
 812 }
 813
 814 static int
 815 tca_action_gd(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int event)
 816 {
 817         int i, ret = 0;
 818         struct rtattr *tb[TCA_ACT_MAX_PRIO+1];
 819         struct tc_action *head = NULL, *act, *act_prev = NULL;
 820
 821         if (rtattr_parse_nested(tb, TCA_ACT_MAX_PRIO, rta) < 0)
 822                 return -EINVAL;
 823
 824         if (event == RTM_DELACTION && n->nlmsg_flags&NLM_F_ROOT) {
 825                 if (tb[0] != NULL && tb[1] == NULL)
 826                         return tca_action_flush(tb[0], n, pid);
 827         }
 828
 829         for (i=0; i < TCA_ACT_MAX_PRIO && tb[i]; i++) {
 830                 act = tcf_action_get_1(tb[i], n, pid, &ret);
 831                 if (act == NULL)
 832                         goto err;
 833                 act->order = i+1;
 834
 835                 if (head == NULL)
 836                         head = act;
 837                 else
 838                         act_prev->next = act;
 839                 act_prev = act;
 840         }
 841
 842         if (event == RTM_GETACTION)
 843                 ret = act_get_notify(pid, n, head, event);
 844         else { /* delete */
 845                 struct sk_buff *skb;
 846
 847                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 848                 if (!skb) {
 849                         ret = -ENOBUFS;
 850                         goto err;
 851                 }
 852
 853                 if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
 854                                  0, 1) <= 0) {
 855                         kfree_skb(skb);
 856                         ret = -EINVAL;
 857                         goto err;
 858                 }
 859
 860                 /* now do the delete */
 861                 tcf_action_destroy(head, 0);
 862                 ret = rtnetlink_send(skb, pid, RTNLGRP_TC,
 863                                      n->nlmsg_flags&NLM_F_ECHO);
 864                 if (ret > 0)
 865                         return 0;
 866                 return ret;
 867         }
 868 err:
 869         cleanup_a(head);
 870         return ret;
 871 }
 872
 873 static int tcf_add_notify(struct tc_action *a, u32 pid, u32 seq, int event,
 874                           u16 flags)
 875 {
 876         struct tcamsg *t;
 877         struct nlmsghdr *nlh;
 878         struct sk_buff *skb;
 879         struct rtattr *x;
 880         unsigned char *b;
 881         int err = 0;
 882
 883         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 884         if (!skb)
 885                 return -ENOBUFS;
 886
 887         b = skb_tail_pointer(skb);
 888
 889         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 890         t = NLMSG_DATA(nlh);
 891         t->tca_family = AF_UNSPEC;
 892         t->tca__pad1 = 0;
 893         t->tca__pad2 = 0;
 894
 895         x = (struct rtattr *)skb_tail_pointer(skb);
 896         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 897
 898         if (tcf_action_dump(skb, a, 0, 0) < 0)
 899                 goto rtattr_failure;
 900
 901         x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
 902
 903         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 904         NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 905
 906         err = rtnetlink_send(skb, pid, RTNLGRP_TC, flags&NLM_F_ECHO);
 907         if (err > 0)
 908                 err = 0;
 909         return err;
 910
 911 rtattr_failure:
 912 nlmsg_failure:
 913         kfree_skb(skb);
 914         return -1;
 915 }
 916
 917
 918 static int
 919 tcf_action_add(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int ovr)
 920 {
 921         int ret = 0;
 922         struct tc_action *act;
 923         struct tc_action *a;
 924         u32 seq = n->nlmsg_seq;
 925
 926         act = tcf_action_init(rta, NULL, NULL, ovr, 0, &ret);
 927         if (act == NULL)
 928                 goto done;
 929
 930         /* dump then free all the actions after update; inserted policy
 931          * stays intact
 932          * */
 933         ret = tcf_add_notify(act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
 934         for (a = act; a; a = act) {
 935                 act = a->next;
 936                 kfree(a);
 937         }
 938 done:
 939         return ret;
 940 }
 941
 942 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 943 {
 944         struct rtattr **tca = arg;
 945         u32 pid = skb ? NETLINK_CB(skb).pid : 0;
 946         int ret = 0, ovr = 0;
 947
 948         if (tca[TCA_ACT_TAB-1] == NULL) {
 949                 printk("tc_ctl_action: received NO action attribs\n");
 950                 return -EINVAL;
 951         }
 952
 953         /* n->nlmsg_flags&NLM_F_CREATE
 954          * */
 955         switch (n->nlmsg_type) {
 956         case RTM_NEWACTION:
 957                 /* we are going to assume all other flags
 958                  * imply create only if it doesnt exist
 959                  * Note that CREATE | EXCL implies that
 960                  * but since we want avoid ambiguity (eg when flags
 961                  * is zero) then just set this
 962                  */
 963                 if (n->nlmsg_flags&NLM_F_REPLACE)
 964                         ovr = 1;
 965 replay:
 966                 ret = tcf_action_add(tca[TCA_ACT_TAB-1], n, pid, ovr);
 967                 if (ret == -EAGAIN)
 968                         goto replay;
 969                 break;
 970         case RTM_DELACTION:
 971                 ret = tca_action_gd(tca[TCA_ACT_TAB-1], n, pid, RTM_DELACTION);
 972                 break;
 973         case RTM_GETACTION:
 974                 ret = tca_action_gd(tca[TCA_ACT_TAB-1], n, pid, RTM_GETACTION);
 975                 break;
 976         default:
 977                 BUG();
 978         }
 979
 980         return ret;
 981 }
 982
 983 static struct rtattr *
 984 find_dump_kind(struct nlmsghdr *n)
 985 {
 986         struct rtattr *tb1, *tb2[TCA_ACT_MAX+1];
 987         struct rtattr *tb[TCA_ACT_MAX_PRIO + 1];
 988         struct rtattr *rta[TCAA_MAX + 1];
 989         struct rtattr *kind;
 990         int min_len = NLMSG_LENGTH(sizeof(struct tcamsg));
 991         int attrlen = n->nlmsg_len - NLMSG_ALIGN(min_len);
 992         struct rtattr *attr = (void *) n + NLMSG_ALIGN(min_len);
 993
 994         if (rtattr_parse(rta, TCAA_MAX, attr, attrlen) < 0)
 995                 return NULL;
 996         tb1 = rta[TCA_ACT_TAB - 1];
 997         if (tb1 == NULL)
 998                 return NULL;
 999
1000         if (rtattr_parse(tb, TCA_ACT_MAX_PRIO, RTA_DATA(tb1),
1001                          NLMSG_ALIGN(RTA_PAYLOAD(tb1))) < 0)
1002                 return NULL;
1003         if (tb[0] == NULL)
1004                 return NULL;
1005
1006         if (rtattr_parse(tb2, TCA_ACT_MAX, RTA_DATA(tb[0]),
1007                          RTA_PAYLOAD(tb[0])) < 0)
1008                 return NULL;
1009         kind = tb2[TCA_ACT_KIND-1];
1010
1011         return kind;
1012 }
1013
1014 static int
1015 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1016 {
1017         struct nlmsghdr *nlh;
1018         unsigned char *b = skb_tail_pointer(skb);
1019         struct rtattr *x;
1020         struct tc_action_ops *a_o;
1021         struct tc_action a;
1022         int ret = 0;
1023         struct tcamsg *t = (struct tcamsg *) NLMSG_DATA(cb->nlh);
1024         struct rtattr *kind = find_dump_kind(cb->nlh);
1025
1026         if (kind == NULL) {
1027                 printk("tc_dump_action: action bad kind\n");
1028                 return 0;
1029         }
1030
1031         a_o = tc_lookup_action(kind);
1032         if (a_o == NULL) {
1033                 return 0;
1034         }
1035
1036         memset(&a, 0, sizeof(struct tc_action));
1037         a.ops = a_o;
1038
1039         if (a_o->walk == NULL) {
1040                 printk("tc_dump_action: %s !capable of dumping table\n", a_o->kind);
1041                 goto rtattr_failure;
1042         }
1043
1044         nlh = NLMSG_PUT(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
1045                         cb->nlh->nlmsg_type, sizeof(*t));
1046         t = NLMSG_DATA(nlh);
1047         t->tca_family = AF_UNSPEC;
1048         t->tca__pad1 = 0;
1049         t->tca__pad2 = 0;
1050
1051         x = (struct rtattr *)skb_tail_pointer(skb);
1052         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
1053
1054         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1055         if (ret < 0)
1056                 goto rtattr_failure;
1057
1058         if (ret > 0) {
1059                 x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
1060                 ret = skb->len;
1061         } else
1062                 nlmsg_trim(skb, x);
1063
1064         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1065         if (NETLINK_CB(cb->skb).pid && ret)
1066                 nlh->nlmsg_flags |= NLM_F_MULTI;
1067         module_put(a_o->owner);
1068         return skb->len;
1069
1070 rtattr_failure:
1071 nlmsg_failure:
1072         module_put(a_o->owner);
1073         nlmsg_trim(skb, b);
1074         return skb->len;
1075 }
1076
1077 static int __init tc_action_init(void)
1078 {
1079         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL);
1080         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL);
1081         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action);
1082
1083         return 0;
1084 }
1085
1086 subsys_initcall(tc_action_init);
1087
1088 EXPORT_SYMBOL(tcf_register_action);
1089 EXPORT_SYMBOL(tcf_unregister_action);
1090 EXPORT_SYMBOL(tcf_action_exec);
1091 EXPORT_SYMBOL(tcf_action_dump_1);