net/sched/cls_u32.c

   1 /*
   2  * net/sched/cls_u32.c  Ugly (or Universal) 32bit key Packet Classifier.
   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  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  10  *
  11  *      The filters are packed to hash tables of key nodes
  12  *      with a set of 32bit key/mask pairs at every node.
  13  *      Nodes reference next level hash tables etc.
  14  *
  15  *      This scheme is the best universal classifier I managed to
  16  *      invent; it is not super-fast, but it is not slow (provided you
  17  *      program it correctly), and general enough.  And its relative
  18  *      speed grows as the number of rules becomes larger.
  19  *
  20  *      It seems that it represents the best middle point between
  21  *      speed and manageability both by human and by machine.
  22  *
  23  *      It is especially useful for link sharing combined with QoS;
  24  *      pure RSVP doesn't need such a general approach and can use
  25  *      much simpler (and faster) schemes, sort of cls_rsvp.c.
  26  */
  27
  28 #include <asm/uaccess.h>
  29 #include <asm/system.h>
  30 #include <asm/bitops.h>
  31 #include <linux/config.h>
  32 #include <linux/module.h>
  33 #include <linux/types.h>
  34 #include <linux/kernel.h>
  35 #include <linux/sched.h>
  36 #include <linux/string.h>
  37 #include <linux/mm.h>
  38 #include <linux/socket.h>
  39 #include <linux/sockios.h>
  40 #include <linux/in.h>
  41 #include <linux/errno.h>
  42 #include <linux/interrupt.h>
  43 #include <linux/if_ether.h>
  44 #include <linux/inet.h>
  45 #include <linux/netdevice.h>
  46 #include <linux/etherdevice.h>
  47 #include <linux/notifier.h>
  48 #include <linux/rtnetlink.h>
  49 #include <net/ip.h>
  50 #include <net/route.h>
  51 #include <linux/skbuff.h>
  52 #include <net/sock.h>
  53 #include <net/pkt_sched.h>
  54
  55
  56 struct tc_u_knode
  57 {
  58         struct tc_u_knode       *next;
  59         u32                     handle;
  60         struct tc_u_hnode       *ht_up;
  61 #ifdef CONFIG_NET_CLS_POLICE
  62         struct tcf_police       *police;
  63 #endif
  64         struct tcf_result       res;
  65         struct tc_u_hnode       *ht_down;
  66         struct tc_u32_sel       sel;
  67 };
  68
  69 struct tc_u_hnode
  70 {
  71         struct tc_u_hnode       *next;
  72         u32                     handle;
  73         u32                     prio;
  74         struct tc_u_common      *tp_c;
  75         int                     refcnt;
  76         unsigned                divisor;
  77         struct tc_u_knode       *ht[1];
  78 };
  79
  80 struct tc_u_common
  81 {
  82         struct tc_u_common      *next;
  83         struct tc_u_hnode       *hlist;
  84         struct Qdisc            *q;
  85         int                     refcnt;
  86         u32                     hgenerator;
  87 };
  88
  89 static struct tc_u_common *u32_list;
  90
  91 static __inline__ unsigned u32_hash_fold(u32 key, struct tc_u32_sel *sel)
  92 {
  93         unsigned h = key & sel->hmask;
  94
  95         h ^= h>>16;
  96         h ^= h>>8;
  97         return h;
  98 }
  99
 100 static int u32_classify(struct sk_buff *skb, struct tcf_proto *tp, struct tcf_result *res)
 101 {
 102         struct {
 103                 struct tc_u_knode *knode;
 104                 u8                *ptr;
 105         } stack[TC_U32_MAXDEPTH];
 106
 107         struct tc_u_hnode *ht = (struct tc_u_hnode*)tp->root;
 108         u8 *ptr = skb->nh.raw;
 109         struct tc_u_knode *n;
 110         int sdepth = 0;
 111         int off2 = 0;
 112         int sel = 0;
 113         int i;
 114
 115 next_ht:
 116         n = ht->ht[sel];
 117
 118 next_knode:
 119         if (n) {
 120                 struct tc_u32_key *key = n->sel.keys;
 121
 122                 for (i = n->sel.nkeys; i>0; i--, key++) {
 123                         if ((*(u32*)(ptr+key->off+(off2&key->offmask))^key->val)&key->mask) {
 124                                 n = n->next;
 125                                 goto next_knode;
 126                         }
 127                 }
 128                 if (n->ht_down == NULL) {
 129 check_terminal:
 130                         if (n->sel.flags&TC_U32_TERMINAL) {
 131                                 *res = n->res;
 132 #ifdef CONFIG_NET_CLS_POLICE
 133                                 if (n->police) {
 134                                         int pol_res = tcf_police(skb, n->police);
 135                                         if (pol_res >= 0)
 136                                                 return pol_res;
 137                                 } else
 138 #endif
 139                                         return 0;
 140                         }
 141                         n = n->next;
 142                         goto next_knode;
 143                 }
 144
 145                 /* PUSH */
 146                 if (sdepth >= TC_U32_MAXDEPTH)
 147                         goto deadloop;
 148                 stack[sdepth].knode = n;
 149                 stack[sdepth].ptr = ptr;
 150                 sdepth++;
 151
 152                 ht = n->ht_down;
 153                 sel = 0;
 154                 if (ht->divisor)
 155                         sel = ht->divisor&u32_hash_fold(*(u32*)(ptr+n->sel.hoff), &n->sel);
 156
 157                 if (!(n->sel.flags&(TC_U32_VAROFFSET|TC_U32_OFFSET|TC_U32_EAT)))
 158                         goto next_ht;
 159
 160                 if (n->sel.flags&(TC_U32_OFFSET|TC_U32_VAROFFSET)) {
 161                         off2 = n->sel.off + 3;
 162                         if (n->sel.flags&TC_U32_VAROFFSET)
 163                                 off2 += ntohs(n->sel.offmask & *(u16*)(ptr+n->sel.offoff)) >>n->sel.offshift;
 164                         off2 &= ~3;
 165                 }
 166                 if (n->sel.flags&TC_U32_EAT) {
 167                         ptr += off2;
 168                         off2 = 0;
 169                 }
 170
 171                 if (ptr < skb->tail)
 172                         goto next_ht;
 173         }
 174
 175         /* POP */
 176         if (sdepth--) {
 177                 n = stack[sdepth].knode;
 178                 ht = n->ht_up;
 179                 ptr = stack[sdepth].ptr;
 180                 goto check_terminal;
 181         }
 182         return -1;
 183
 184 deadloop:
 185         if (net_ratelimit())
 186                 printk("cls_u32: dead loop\n");
 187         return -1;
 188 }
 189
 190 static __inline__ struct tc_u_hnode *
 191 u32_lookup_ht(struct tc_u_common *tp_c, u32 handle)
 192 {
 193         struct tc_u_hnode *ht;
 194
 195         for (ht = tp_c->hlist; ht; ht = ht->next)
 196                 if (ht->handle == handle)
 197                         break;
 198
 199         return ht;
 200 }
 201
 202 static __inline__ struct tc_u_knode *
 203 u32_lookup_key(struct tc_u_hnode *ht, u32 handle)
 204 {
 205         unsigned sel;
 206         struct tc_u_knode *n;
 207
 208         sel = TC_U32_HASH(handle);
 209         if (sel > ht->divisor)
 210                 return 0;
 211
 212         for (n = ht->ht[sel]; n; n = n->next)
 213                 if (n->handle == handle)
 214                         return n;
 215
 216         return NULL;
 217 }
 218
 219
 220 static unsigned long u32_get(struct tcf_proto *tp, u32 handle)
 221 {
 222         struct tc_u_hnode *ht;
 223         struct tc_u_common *tp_c = tp->data;
 224
 225         if (TC_U32_HTID(handle) == TC_U32_ROOT)
 226                 ht = tp->root;
 227         else
 228                 ht = u32_lookup_ht(tp_c, TC_U32_HTID(handle));
 229
 230         if (!ht)
 231                 return 0;
 232
 233         if (TC_U32_KEY(handle) == 0)
 234                 return (unsigned long)ht;
 235
 236         return (unsigned long)u32_lookup_key(ht, handle);
 237 }
 238
 239 static void u32_put(struct tcf_proto *tp, unsigned long f)
 240 {
 241 }
 242
 243 static u32 gen_new_htid(struct tc_u_common *tp_c)
 244 {
 245         int i = 0x800;
 246
 247         do {
 248                 if (++tp_c->hgenerator == 0x7FF)
 249                         tp_c->hgenerator = 1;
 250         } while (--i>0 && u32_lookup_ht(tp_c, (tp_c->hgenerator|0x800)<<20));
 251
 252         return i > 0 ? (tp_c->hgenerator|0x800)<<20 : 0;
 253 }
 254
 255 static int u32_init(struct tcf_proto *tp)
 256 {
 257         struct tc_u_hnode *root_ht;
 258         struct tc_u_common *tp_c;
 259
 260         MOD_INC_USE_COUNT;
 261
 262         for (tp_c = u32_list; tp_c; tp_c = tp_c->next)
 263                 if (tp_c->q == tp->q)
 264                         break;
 265
 266         root_ht = kmalloc(sizeof(*root_ht), GFP_KERNEL);
 267         if (root_ht == NULL) {
 268                 MOD_DEC_USE_COUNT;
 269                 return -ENOBUFS;
 270         }
 271         memset(root_ht, 0, sizeof(*root_ht));
 272         root_ht->divisor = 0;
 273         root_ht->refcnt++;
 274         root_ht->handle = tp_c ? gen_new_htid(tp_c) : 0x80000000;
 275         root_ht->prio = tp->prio;
 276
 277         if (tp_c == NULL) {
 278                 tp_c = kmalloc(sizeof(*tp_c), GFP_KERNEL);
 279                 if (tp_c == NULL) {
 280                         kfree(root_ht);
 281                         MOD_DEC_USE_COUNT;
 282                         return -ENOBUFS;
 283                 }
 284                 memset(tp_c, 0, sizeof(*tp_c));
 285                 tp_c->q = tp->q;
 286                 tp_c->next = u32_list;
 287                 u32_list = tp_c;
 288         }
 289
 290         tp_c->refcnt++;
 291         root_ht->next = tp_c->hlist;
 292         tp_c->hlist = root_ht;
 293         root_ht->tp_c = tp_c;
 294
 295         tp->root = root_ht;
 296         tp->data = tp_c;
 297         return 0;
 298 }
 299
 300 static int u32_destroy_key(struct tcf_proto *tp, struct tc_u_knode *n)
 301 {
 302         unsigned long cl;
 303
 304         if ((cl = __cls_set_class(&n->res.class, 0)) != 0)
 305                 tp->q->ops->cl_ops->unbind_tcf(tp->q, cl);
 306 #ifdef CONFIG_NET_CLS_POLICE
 307         tcf_police_release(n->police);
 308 #endif
 309         if (n->ht_down)
 310                 n->ht_down->refcnt--;
 311         kfree(n);
 312         return 0;
 313 }
 314
 315 static int u32_delete_key(struct tcf_proto *tp, struct tc_u_knode* key)
 316 {
 317         struct tc_u_knode **kp;
 318         struct tc_u_hnode *ht = key->ht_up;
 319
 320         if (ht) {
 321                 for (kp = &ht->ht[TC_U32_HASH(key->handle)]; *kp; kp = &(*kp)->next) {
 322                         if (*kp == key) {
 323                                 tcf_tree_lock(tp);
 324                                 *kp = key->next;
 325                                 tcf_tree_unlock(tp);
 326
 327                                 u32_destroy_key(tp, key);
 328                                 return 0;
 329                         }
 330                 }
 331         }
 332         BUG_TRAP(0);
 333         return 0;
 334 }
 335
 336 static void u32_clear_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
 337 {
 338         struct tc_u_knode *n;
 339         unsigned h;
 340
 341         for (h=0; h<=ht->divisor; h++) {
 342                 while ((n = ht->ht[h]) != NULL) {
 343                         ht->ht[h] = n->next;
 344
 345                         u32_destroy_key(tp, n);
 346                 }
 347         }
 348 }
 349
 350 static int u32_destroy_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
 351 {
 352         struct tc_u_common *tp_c = tp->data;
 353         struct tc_u_hnode **hn;
 354
 355         BUG_TRAP(!ht->refcnt);
 356
 357         u32_clear_hnode(tp, ht);
 358
 359         for (hn = &tp_c->hlist; *hn; hn = &(*hn)->next) {
 360                 if (*hn == ht) {
 361                         *hn = ht->next;
 362                         kfree(ht);
 363                         return 0;
 364                 }
 365         }
 366
 367         BUG_TRAP(0);
 368         return -ENOENT;
 369 }
 370
 371 static void u32_destroy(struct tcf_proto *tp)
 372 {
 373         struct tc_u_common *tp_c = tp->data;
 374         struct tc_u_hnode *root_ht = xchg(&tp->root, NULL);
 375
 376         BUG_TRAP(root_ht != NULL);
 377
 378         if (root_ht && --root_ht->refcnt == 0)
 379                 u32_destroy_hnode(tp, root_ht);
 380
 381         if (--tp_c->refcnt == 0) {
 382                 struct tc_u_hnode *ht;
 383                 struct tc_u_common **tp_cp;
 384
 385                 for (tp_cp = &u32_list; *tp_cp; tp_cp = &(*tp_cp)->next) {
 386                         if (*tp_cp == tp_c) {
 387                                 *tp_cp = tp_c->next;
 388                                 break;
 389                         }
 390                 }
 391
 392                 for (ht=tp_c->hlist; ht; ht = ht->next)
 393                         u32_clear_hnode(tp, ht);
 394
 395                 while ((ht = tp_c->hlist) != NULL) {
 396                         tp_c->hlist = ht->next;
 397
 398                         BUG_TRAP(ht->refcnt == 0);
 399
 400                         kfree(ht);
 401                 };
 402
 403                 kfree(tp_c);
 404         }
 405
 406         MOD_DEC_USE_COUNT;
 407         tp->data = NULL;
 408 }
 409
 410 static int u32_delete(struct tcf_proto *tp, unsigned long arg)
 411 {
 412         struct tc_u_hnode *ht = (struct tc_u_hnode*)arg;
 413
 414         if (ht == NULL)
 415                 return 0;
 416
 417         if (TC_U32_KEY(ht->handle))
 418                 return u32_delete_key(tp, (struct tc_u_knode*)ht);
 419
 420         if (tp->root == ht)
 421                 return -EINVAL;
 422
 423         if (--ht->refcnt == 0)
 424                 u32_destroy_hnode(tp, ht);
 425
 426         return 0;
 427 }
 428
 429 static u32 gen_new_kid(struct tc_u_hnode *ht, u32 handle)
 430 {
 431         struct tc_u_knode *n;
 432         unsigned i = 0x7FF;
 433
 434         for (n=ht->ht[TC_U32_HASH(handle)]; n; n = n->next)
 435                 if (i < TC_U32_NODE(n->handle))
 436                         i = TC_U32_NODE(n->handle);
 437         i++;
 438
 439         return handle|(i>0xFFF ? 0xFFF : i);
 440 }
 441
 442 static int u32_set_parms(struct Qdisc *q, unsigned long base,
 443                          struct tc_u_hnode *ht,
 444                          struct tc_u_knode *n, struct rtattr **tb,
 445                          struct rtattr *est)
 446 {
 447         if (tb[TCA_U32_LINK-1]) {
 448                 u32 handle = *(u32*)RTA_DATA(tb[TCA_U32_LINK-1]);
 449                 struct tc_u_hnode *ht_down = NULL;
 450
 451                 if (TC_U32_KEY(handle))
 452                         return -EINVAL;
 453
 454                 if (handle) {
 455                         ht_down = u32_lookup_ht(ht->tp_c, handle);
 456
 457                         if (ht_down == NULL)
 458                                 return -EINVAL;
 459                         ht_down->refcnt++;
 460                 }
 461
 462                 sch_tree_lock(q);
 463                 ht_down = xchg(&n->ht_down, ht_down);
 464                 sch_tree_unlock(q);
 465
 466                 if (ht_down)
 467                         ht_down->refcnt--;
 468         }
 469         if (tb[TCA_U32_CLASSID-1]) {
 470                 unsigned long cl;
 471
 472                 n->res.classid = *(u32*)RTA_DATA(tb[TCA_U32_CLASSID-1]);
 473                 sch_tree_lock(q);
 474                 cl = __cls_set_class(&n->res.class, q->ops->cl_ops->bind_tcf(q, base, n->res.classid));
 475                 sch_tree_unlock(q);
 476                 if (cl)
 477                         q->ops->cl_ops->unbind_tcf(q, cl);
 478         }
 479 #ifdef CONFIG_NET_CLS_POLICE
 480         if (tb[TCA_U32_POLICE-1]) {
 481                 struct tcf_police *police = tcf_police_locate(tb[TCA_U32_POLICE-1], est);
 482
 483                 sch_tree_lock(q);
 484                 police = xchg(&n->police, police);
 485                 sch_tree_unlock(q);
 486
 487                 tcf_police_release(police);
 488         }
 489 #endif
 490         return 0;
 491 }
 492
 493 static int u32_change(struct tcf_proto *tp, unsigned long base, u32 handle,
 494                       struct rtattr **tca,
 495                       unsigned long *arg)
 496 {
 497         struct tc_u_common *tp_c = tp->data;
 498         struct tc_u_hnode *ht;
 499         struct tc_u_knode *n;
 500         struct tc_u32_sel *s;
 501         struct rtattr *opt = tca[TCA_OPTIONS-1];
 502         struct rtattr *tb[TCA_U32_MAX];
 503         u32 htid;
 504         int err;
 505
 506         if (opt == NULL)
 507                 return handle ? -EINVAL : 0;
 508
 509         if (rtattr_parse(tb, TCA_U32_MAX, RTA_DATA(opt), RTA_PAYLOAD(opt)) < 0)
 510                 return -EINVAL;
 511
 512         if ((n = (struct tc_u_knode*)*arg) != NULL) {
 513                 if (TC_U32_KEY(n->handle) == 0)
 514                         return -EINVAL;
 515
 516                 return u32_set_parms(tp->q, base, n->ht_up, n, tb, tca[TCA_RATE-1]);
 517         }
 518
 519         if (tb[TCA_U32_DIVISOR-1]) {
 520                 unsigned divisor = *(unsigned*)RTA_DATA(tb[TCA_U32_DIVISOR-1]);
 521
 522                 if (--divisor > 0x100)
 523                         return -EINVAL;
 524                 if (TC_U32_KEY(handle))
 525                         return -EINVAL;
 526                 if (handle == 0) {
 527                         handle = gen_new_htid(tp->data);
 528                         if (handle == 0)
 529                                 return -ENOMEM;
 530                 }
 531                 ht = kmalloc(sizeof(*ht) + divisor*sizeof(void*), GFP_KERNEL);
 532                 if (ht == NULL)
 533                         return -ENOBUFS;
 534                 memset(ht, 0, sizeof(*ht) + divisor*sizeof(void*));
 535                 ht->tp_c = tp_c;
 536                 ht->refcnt = 0;
 537                 ht->divisor = divisor;
 538                 ht->handle = handle;
 539                 ht->prio = tp->prio;
 540                 ht->next = tp_c->hlist;
 541                 tp_c->hlist = ht;
 542                 *arg = (unsigned long)ht;
 543                 return 0;
 544         }
 545
 546         if (tb[TCA_U32_HASH-1]) {
 547                 htid = *(unsigned*)RTA_DATA(tb[TCA_U32_HASH-1]);
 548                 if (TC_U32_HTID(htid) == TC_U32_ROOT) {
 549                         ht = tp->root;
 550                         htid = ht->handle;
 551                 } else {
 552                         ht = u32_lookup_ht(tp->data, TC_U32_HTID(htid));
 553                         if (ht == NULL)
 554                                 return -EINVAL;
 555                 }
 556         } else {
 557                 ht = tp->root;
 558                 htid = ht->handle;
 559         }
 560
 561         if (ht->divisor < TC_U32_HASH(htid))
 562                 return -EINVAL;
 563
 564         if (handle) {
 565                 if (TC_U32_HTID(handle) && TC_U32_HTID(handle^htid))
 566                         return -EINVAL;
 567                 handle = htid | TC_U32_NODE(handle);
 568         } else
 569                 handle = gen_new_kid(ht, htid);
 570
 571         if (tb[TCA_U32_SEL-1] == 0 ||
 572             RTA_PAYLOAD(tb[TCA_U32_SEL-1]) < sizeof(struct tc_u32_sel))
 573                 return -EINVAL;
 574
 575         s = RTA_DATA(tb[TCA_U32_SEL-1]);
 576         n = kmalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key), GFP_KERNEL);
 577         if (n == NULL)
 578                 return -ENOBUFS;
 579         memset(n, 0, sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key));
 580         memcpy(&n->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
 581         n->ht_up = ht;
 582         n->handle = handle;
 583         err = u32_set_parms(tp->q, base, ht, n, tb, tca[TCA_RATE-1]);
 584         if (err == 0) {
 585                 struct tc_u_knode **ins;
 586                 for (ins = &ht->ht[TC_U32_HASH(handle)]; *ins; ins = &(*ins)->next)
 587                         if (TC_U32_NODE(handle) < TC_U32_NODE((*ins)->handle))
 588                                 break;
 589
 590                 n->next = *ins;
 591                 wmb();
 592                 *ins = n;
 593
 594                 *arg = (unsigned long)n;
 595                 return 0;
 596         }
 597         kfree(n);
 598         return err;
 599 }
 600
 601 static void u32_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 602 {
 603         struct tc_u_common *tp_c = tp->data;
 604         struct tc_u_hnode *ht;
 605         struct tc_u_knode *n;
 606         unsigned h;
 607
 608         if (arg->stop)
 609                 return;
 610
 611         for (ht = tp_c->hlist; ht; ht = ht->next) {
 612                 if (ht->prio != tp->prio)
 613                         continue;
 614                 if (arg->count >= arg->skip) {
 615                         if (arg->fn(tp, (unsigned long)ht, arg) < 0) {
 616                                 arg->stop = 1;
 617                                 return;
 618                         }
 619                 }
 620                 arg->count++;
 621                 for (h = 0; h <= ht->divisor; h++) {
 622                         for (n = ht->ht[h]; n; n = n->next) {
 623                                 if (arg->count < arg->skip) {
 624                                         arg->count++;
 625                                         continue;
 626                                 }
 627                                 if (arg->fn(tp, (unsigned long)n, arg) < 0) {
 628                                         arg->stop = 1;
 629                                         return;
 630                                 }
 631                                 arg->count++;
 632                         }
 633                 }
 634         }
 635 }
 636
 637 static int u32_dump(struct tcf_proto *tp, unsigned long fh,
 638                      struct sk_buff *skb, struct tcmsg *t)
 639 {
 640         struct tc_u_knode *n = (struct tc_u_knode*)fh;
 641         unsigned char    *b = skb->tail;
 642         struct rtattr *rta;
 643
 644         if (n == NULL)
 645                 return skb->len;
 646
 647         t->tcm_handle = n->handle;
 648
 649         rta = (struct rtattr*)b;
 650         RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
 651
 652         if (TC_U32_KEY(n->handle) == 0) {
 653                 struct tc_u_hnode *ht = (struct tc_u_hnode*)fh;
 654                 u32 divisor = ht->divisor+1;
 655                 RTA_PUT(skb, TCA_U32_DIVISOR, 4, &divisor);
 656         } else {
 657                 RTA_PUT(skb, TCA_U32_SEL,
 658                         sizeof(n->sel) + n->sel.nkeys*sizeof(struct tc_u32_key),
 659                         &n->sel);
 660                 if (n->ht_up) {
 661                         u32 htid = n->handle & 0xFFFFF000;
 662                         RTA_PUT(skb, TCA_U32_HASH, 4, &htid);
 663                 }
 664                 if (n->res.classid)
 665                         RTA_PUT(skb, TCA_U32_CLASSID, 4, &n->res.classid);
 666                 if (n->ht_down)
 667                         RTA_PUT(skb, TCA_U32_LINK, 4, &n->ht_down->handle);
 668 #ifdef CONFIG_NET_CLS_POLICE
 669                 if (n->police) {
 670                         struct rtattr * p_rta = (struct rtattr*)skb->tail;
 671
 672                         RTA_PUT(skb, TCA_U32_POLICE, 0, NULL);
 673
 674                         if (tcf_police_dump(skb, n->police) < 0)
 675                                 goto rtattr_failure;
 676
 677                         p_rta->rta_len = skb->tail - (u8*)p_rta;
 678                 }
 679 #endif
 680         }
 681
 682         rta->rta_len = skb->tail - b;
 683 #ifdef CONFIG_NET_CLS_POLICE
 684         if (TC_U32_KEY(n->handle) && n->police) {
 685                 if (qdisc_copy_stats(skb, &n->police->stats))
 686                         goto rtattr_failure;
 687         }
 688 #endif
 689         return skb->len;
 690
 691 rtattr_failure:
 692         skb_trim(skb, b - skb->data);
 693         return -1;
 694 }
 695
 696 struct tcf_proto_ops cls_u32_ops = {
 697         NULL,
 698         "u32",
 699         u32_classify,
 700         u32_init,
 701         u32_destroy,
 702
 703         u32_get,
 704         u32_put,
 705         u32_change,
 706         u32_delete,
 707         u32_walk,
 708         u32_dump
 709 };
 710
 711 #ifdef MODULE
 712 int init_module(void)
 713 {
 714         return register_tcf_proto_ops(&cls_u32_ops);
 715 }
 716
 717 void cleanup_module(void)
 718 {
 719         unregister_tcf_proto_ops(&cls_u32_ops);
 720 }
 721 #endif
 722 MODULE_LICENSE("GPL");