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