net/sched/cls_tcindex.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * net/sched/cls_tcindex.c      Packet classifier for skb->tc_index
   4  *
   5  * Written 1998,1999 by Werner Almesberger, EPFL ICA
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/types.h>
  10 #include <linux/kernel.h>
  11 #include <linux/skbuff.h>
  12 #include <linux/errno.h>
  13 #include <linux/slab.h>
  14 #include <linux/refcount.h>
  15 #include <net/act_api.h>
  16 #include <net/netlink.h>
  17 #include <net/pkt_cls.h>
  18 #include <net/sch_generic.h>
  19 #include <net/tc_wrapper.h>
  20
  21 /*
  22  * Passing parameters to the root seems to be done more awkwardly than really
  23  * necessary. At least, u32 doesn't seem to use such dirty hacks. To be
  24  * verified. FIXME.
  25  */
  26
  27 #define PERFECT_HASH_THRESHOLD  64      /* use perfect hash if not bigger */
  28 #define DEFAULT_HASH_SIZE       64      /* optimized for diffserv */
  29
  30
  31 struct tcindex_data;
  32
  33 struct tcindex_filter_result {
  34         struct tcf_exts         exts;
  35         struct tcf_result       res;
  36         struct tcindex_data     *p;
  37         struct rcu_work         rwork;
  38 };
  39
  40 struct tcindex_filter {
  41         u16 key;
  42         struct tcindex_filter_result result;
  43         struct tcindex_filter __rcu *next;
  44         struct rcu_work rwork;
  45 };
  46
  47
  48 struct tcindex_data {
  49         struct tcindex_filter_result *perfect; /* perfect hash; NULL if none */
  50         struct tcindex_filter __rcu **h; /* imperfect hash; */
  51         struct tcf_proto *tp;
  52         u16 mask;               /* AND key with mask */
  53         u32 shift;              /* shift ANDed key to the right */
  54         u32 hash;               /* hash table size; 0 if undefined */
  55         u32 alloc_hash;         /* allocated size */
  56         u32 fall_through;       /* 0: only classify if explicit match */
  57         refcount_t refcnt;      /* a temporary refcnt for perfect hash */
  58         struct rcu_work rwork;
  59 };
  60
  61 static inline int tcindex_filter_is_set(struct tcindex_filter_result *r)
  62 {
  63         return tcf_exts_has_actions(&r->exts) || r->res.classid;
  64 }
  65
  66 static void tcindex_data_get(struct tcindex_data *p)
  67 {
  68         refcount_inc(&p->refcnt);
  69 }
  70
  71 static void tcindex_data_put(struct tcindex_data *p)
  72 {
  73         if (refcount_dec_and_test(&p->refcnt)) {
  74                 kfree(p->perfect);
  75                 kfree(p->h);
  76                 kfree(p);
  77         }
  78 }
  79
  80 static struct tcindex_filter_result *tcindex_lookup(struct tcindex_data *p,
  81                                                     u16 key)
  82 {
  83         if (p->perfect) {
  84                 struct tcindex_filter_result *f = p->perfect + key;
  85
  86                 return tcindex_filter_is_set(f) ? f : NULL;
  87         } else if (p->h) {
  88                 struct tcindex_filter __rcu **fp;
  89                 struct tcindex_filter *f;
  90
  91                 fp = &p->h[key % p->hash];
  92                 for (f = rcu_dereference_bh_rtnl(*fp);
  93                      f;
  94                      fp = &f->next, f = rcu_dereference_bh_rtnl(*fp))
  95                         if (f->key == key)
  96                                 return &f->result;
  97         }
  98
  99         return NULL;
 100 }
 101
 102 TC_INDIRECT_SCOPE int tcindex_classify(struct sk_buff *skb,
 103                                        const struct tcf_proto *tp,
 104                                        struct tcf_result *res)
 105 {
 106         struct tcindex_data *p = rcu_dereference_bh(tp->root);
 107         struct tcindex_filter_result *f;
 108         int key = (skb->tc_index & p->mask) >> p->shift;
 109
 110         pr_debug("tcindex_classify(skb %p,tp %p,res %p),p %p\n",
 111                  skb, tp, res, p);
 112
 113         f = tcindex_lookup(p, key);
 114         if (!f) {
 115                 struct Qdisc *q = tcf_block_q(tp->chain->block);
 116
 117                 if (!p->fall_through)
 118                         return -1;
 119                 res->classid = TC_H_MAKE(TC_H_MAJ(q->handle), key);
 120                 res->class = 0;
 121                 pr_debug("alg 0x%x\n", res->classid);
 122                 return 0;
 123         }
 124         *res = f->res;
 125         pr_debug("map 0x%x\n", res->classid);
 126
 127         return tcf_exts_exec(skb, &f->exts, res);
 128 }
 129
 130
 131 static void *tcindex_get(struct tcf_proto *tp, u32 handle)
 132 {
 133         struct tcindex_data *p = rtnl_dereference(tp->root);
 134         struct tcindex_filter_result *r;
 135
 136         pr_debug("tcindex_get(tp %p,handle 0x%08x)\n", tp, handle);
 137         if (p->perfect && handle >= p->alloc_hash)
 138                 return NULL;
 139         r = tcindex_lookup(p, handle);
 140         return r && tcindex_filter_is_set(r) ? r : NULL;
 141 }
 142
 143 static int tcindex_init(struct tcf_proto *tp)
 144 {
 145         struct tcindex_data *p;
 146
 147         pr_debug("tcindex_init(tp %p)\n", tp);
 148         p = kzalloc(sizeof(struct tcindex_data), GFP_KERNEL);
 149         if (!p)
 150                 return -ENOMEM;
 151
 152         p->mask = 0xffff;
 153         p->hash = DEFAULT_HASH_SIZE;
 154         p->fall_through = 1;
 155         refcount_set(&p->refcnt, 1); /* Paired with tcindex_destroy_work() */
 156
 157         rcu_assign_pointer(tp->root, p);
 158         return 0;
 159 }
 160
 161 static void __tcindex_destroy_rexts(struct tcindex_filter_result *r)
 162 {
 163         tcf_exts_destroy(&r->exts);
 164         tcf_exts_put_net(&r->exts);
 165         tcindex_data_put(r->p);
 166 }
 167
 168 static void tcindex_destroy_rexts_work(struct work_struct *work)
 169 {
 170         struct tcindex_filter_result *r;
 171
 172         r = container_of(to_rcu_work(work),
 173                          struct tcindex_filter_result,
 174                          rwork);
 175         rtnl_lock();
 176         __tcindex_destroy_rexts(r);
 177         rtnl_unlock();
 178 }
 179
 180 static void __tcindex_destroy_fexts(struct tcindex_filter *f)
 181 {
 182         tcf_exts_destroy(&f->result.exts);
 183         tcf_exts_put_net(&f->result.exts);
 184         kfree(f);
 185 }
 186
 187 static void tcindex_destroy_fexts_work(struct work_struct *work)
 188 {
 189         struct tcindex_filter *f = container_of(to_rcu_work(work),
 190                                                 struct tcindex_filter,
 191                                                 rwork);
 192
 193         rtnl_lock();
 194         __tcindex_destroy_fexts(f);
 195         rtnl_unlock();
 196 }
 197
 198 static int tcindex_delete(struct tcf_proto *tp, void *arg, bool *last,
 199                           bool rtnl_held, struct netlink_ext_ack *extack)
 200 {
 201         struct tcindex_data *p = rtnl_dereference(tp->root);
 202         struct tcindex_filter_result *r = arg;
 203         struct tcindex_filter __rcu **walk;
 204         struct tcindex_filter *f = NULL;
 205
 206         pr_debug("tcindex_delete(tp %p,arg %p),p %p\n", tp, arg, p);
 207         if (p->perfect) {
 208                 if (!r->res.class)
 209                         return -ENOENT;
 210         } else {
 211                 int i;
 212
 213                 for (i = 0; i < p->hash; i++) {
 214                         walk = p->h + i;
 215                         for (f = rtnl_dereference(*walk); f;
 216                              walk = &f->next, f = rtnl_dereference(*walk)) {
 217                                 if (&f->result == r)
 218                                         goto found;
 219                         }
 220                 }
 221                 return -ENOENT;
 222
 223 found:
 224                 rcu_assign_pointer(*walk, rtnl_dereference(f->next));
 225         }
 226         tcf_unbind_filter(tp, &r->res);
 227         /* all classifiers are required to call tcf_exts_destroy() after rcu
 228          * grace period, since converted-to-rcu actions are relying on that
 229          * in cleanup() callback
 230          */
 231         if (f) {
 232                 if (tcf_exts_get_net(&f->result.exts))
 233                         tcf_queue_work(&f->rwork, tcindex_destroy_fexts_work);
 234                 else
 235                         __tcindex_destroy_fexts(f);
 236         } else {
 237                 tcindex_data_get(p);
 238
 239                 if (tcf_exts_get_net(&r->exts))
 240                         tcf_queue_work(&r->rwork, tcindex_destroy_rexts_work);
 241                 else
 242                         __tcindex_destroy_rexts(r);
 243         }
 244
 245         *last = false;
 246         return 0;
 247 }
 248
 249 static void tcindex_destroy_work(struct work_struct *work)
 250 {
 251         struct tcindex_data *p = container_of(to_rcu_work(work),
 252                                               struct tcindex_data,
 253                                               rwork);
 254
 255         tcindex_data_put(p);
 256 }
 257
 258 static inline int
 259 valid_perfect_hash(struct tcindex_data *p)
 260 {
 261         return  p->hash > (p->mask >> p->shift);
 262 }
 263
 264 static const struct nla_policy tcindex_policy[TCA_TCINDEX_MAX + 1] = {
 265         [TCA_TCINDEX_HASH]              = { .type = NLA_U32 },
 266         [TCA_TCINDEX_MASK]              = { .type = NLA_U16 },
 267         [TCA_TCINDEX_SHIFT]             = { .type = NLA_U32 },
 268         [TCA_TCINDEX_FALL_THROUGH]      = { .type = NLA_U32 },
 269         [TCA_TCINDEX_CLASSID]           = { .type = NLA_U32 },
 270 };
 271
 272 static int tcindex_filter_result_init(struct tcindex_filter_result *r,
 273                                       struct tcindex_data *p,
 274                                       struct net *net)
 275 {
 276         memset(r, 0, sizeof(*r));
 277         r->p = p;
 278         return tcf_exts_init(&r->exts, net, TCA_TCINDEX_ACT,
 279                              TCA_TCINDEX_POLICE);
 280 }
 281
 282 static void tcindex_free_perfect_hash(struct tcindex_data *cp);
 283
 284 static void tcindex_partial_destroy_work(struct work_struct *work)
 285 {
 286         struct tcindex_data *p = container_of(to_rcu_work(work),
 287                                               struct tcindex_data,
 288                                               rwork);
 289
 290         rtnl_lock();
 291         if (p->perfect)
 292                 tcindex_free_perfect_hash(p);
 293         kfree(p);
 294         rtnl_unlock();
 295 }
 296
 297 static void tcindex_free_perfect_hash(struct tcindex_data *cp)
 298 {
 299         int i;
 300
 301         for (i = 0; i < cp->hash; i++)
 302                 tcf_exts_destroy(&cp->perfect[i].exts);
 303         kfree(cp->perfect);
 304 }
 305
 306 static int tcindex_alloc_perfect_hash(struct net *net, struct tcindex_data *cp)
 307 {
 308         int i, err = 0;
 309
 310         cp->perfect = kcalloc(cp->hash, sizeof(struct tcindex_filter_result),
 311                               GFP_KERNEL | __GFP_NOWARN);
 312         if (!cp->perfect)
 313                 return -ENOMEM;
 314
 315         for (i = 0; i < cp->hash; i++) {
 316                 err = tcf_exts_init(&cp->perfect[i].exts, net,
 317                                     TCA_TCINDEX_ACT, TCA_TCINDEX_POLICE);
 318                 if (err < 0)
 319                         goto errout;
 320                 cp->perfect[i].p = cp;
 321         }
 322
 323         return 0;
 324
 325 errout:
 326         tcindex_free_perfect_hash(cp);
 327         return err;
 328 }
 329
 330 static int
 331 tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,
 332                   u32 handle, struct tcindex_data *p,
 333                   struct tcindex_filter_result *r, struct nlattr **tb,
 334                   struct nlattr *est, u32 flags, struct netlink_ext_ack *extack)
 335 {
 336         struct tcindex_filter_result new_filter_result;
 337         struct tcindex_data *cp = NULL, *oldp;
 338         struct tcindex_filter *f = NULL; /* make gcc behave */
 339         struct tcf_result cr = {};
 340         int err, balloc = 0;
 341         struct tcf_exts e;
 342
 343         err = tcf_exts_init(&e, net, TCA_TCINDEX_ACT, TCA_TCINDEX_POLICE);
 344         if (err < 0)
 345                 return err;
 346         err = tcf_exts_validate(net, tp, tb, est, &e, flags, extack);
 347         if (err < 0)
 348                 goto errout;
 349
 350         err = -ENOMEM;
 351         /* tcindex_data attributes must look atomic to classifier/lookup so
 352          * allocate new tcindex data and RCU assign it onto root. Keeping
 353          * perfect hash and hash pointers from old data.
 354          */
 355         cp = kzalloc(sizeof(*cp), GFP_KERNEL);
 356         if (!cp)
 357                 goto errout;
 358
 359         cp->mask = p->mask;
 360         cp->shift = p->shift;
 361         cp->hash = p->hash;
 362         cp->alloc_hash = p->alloc_hash;
 363         cp->fall_through = p->fall_through;
 364         cp->tp = tp;
 365         refcount_set(&cp->refcnt, 1); /* Paired with tcindex_destroy_work() */
 366
 367         if (tb[TCA_TCINDEX_HASH])
 368                 cp->hash = nla_get_u32(tb[TCA_TCINDEX_HASH]);
 369
 370         if (tb[TCA_TCINDEX_MASK])
 371                 cp->mask = nla_get_u16(tb[TCA_TCINDEX_MASK]);
 372
 373         if (tb[TCA_TCINDEX_SHIFT]) {
 374                 cp->shift = nla_get_u32(tb[TCA_TCINDEX_SHIFT]);
 375                 if (cp->shift > 16) {
 376                         err = -EINVAL;
 377                         goto errout;
 378                 }
 379         }
 380         if (!cp->hash) {
 381                 /* Hash not specified, use perfect hash if the upper limit
 382                  * of the hashing index is below the threshold.
 383                  */
 384                 if ((cp->mask >> cp->shift) < PERFECT_HASH_THRESHOLD)
 385                         cp->hash = (cp->mask >> cp->shift) + 1;
 386                 else
 387                         cp->hash = DEFAULT_HASH_SIZE;
 388         }
 389
 390         if (p->perfect) {
 391                 int i;
 392
 393                 if (tcindex_alloc_perfect_hash(net, cp) < 0)
 394                         goto errout;
 395                 cp->alloc_hash = cp->hash;
 396                 for (i = 0; i < min(cp->hash, p->hash); i++)
 397                         cp->perfect[i].res = p->perfect[i].res;
 398                 balloc = 1;
 399         }
 400         cp->h = p->h;
 401
 402         err = tcindex_filter_result_init(&new_filter_result, cp, net);
 403         if (err < 0)
 404                 goto errout_alloc;
 405         if (r)
 406                 cr = r->res;
 407
 408         err = -EBUSY;
 409
 410         /* Hash already allocated, make sure that we still meet the
 411          * requirements for the allocated hash.
 412          */
 413         if (cp->perfect) {
 414                 if (!valid_perfect_hash(cp) ||
 415                     cp->hash > cp->alloc_hash)
 416                         goto errout_alloc;
 417         } else if (cp->h && cp->hash != cp->alloc_hash) {
 418                 goto errout_alloc;
 419         }
 420
 421         err = -EINVAL;
 422         if (tb[TCA_TCINDEX_FALL_THROUGH])
 423                 cp->fall_through = nla_get_u32(tb[TCA_TCINDEX_FALL_THROUGH]);
 424
 425         if (!cp->perfect && !cp->h)
 426                 cp->alloc_hash = cp->hash;
 427
 428         /* Note: this could be as restrictive as if (handle & ~(mask >> shift))
 429          * but then, we'd fail handles that may become valid after some future
 430          * mask change. While this is extremely unlikely to ever matter,
 431          * the check below is safer (and also more backwards-compatible).
 432          */
 433         if (cp->perfect || valid_perfect_hash(cp))
 434                 if (handle >= cp->alloc_hash)
 435                         goto errout_alloc;
 436
 437
 438         err = -ENOMEM;
 439         if (!cp->perfect && !cp->h) {
 440                 if (valid_perfect_hash(cp)) {
 441                         if (tcindex_alloc_perfect_hash(net, cp) < 0)
 442                                 goto errout_alloc;
 443                         balloc = 1;
 444                 } else {
 445                         struct tcindex_filter __rcu **hash;
 446
 447                         hash = kcalloc(cp->hash,
 448                                        sizeof(struct tcindex_filter *),
 449                                        GFP_KERNEL);
 450
 451                         if (!hash)
 452                                 goto errout_alloc;
 453
 454                         cp->h = hash;
 455                         balloc = 2;
 456                 }
 457         }
 458
 459         if (cp->perfect)
 460                 r = cp->perfect + handle;
 461         else
 462                 r = tcindex_lookup(cp, handle) ? : &new_filter_result;
 463
 464         if (r == &new_filter_result) {
 465                 f = kzalloc(sizeof(*f), GFP_KERNEL);
 466                 if (!f)
 467                         goto errout_alloc;
 468                 f->key = handle;
 469                 f->next = NULL;
 470                 err = tcindex_filter_result_init(&f->result, cp, net);
 471                 if (err < 0) {
 472                         kfree(f);
 473                         goto errout_alloc;
 474                 }
 475         }
 476
 477         if (tb[TCA_TCINDEX_CLASSID]) {
 478                 cr.classid = nla_get_u32(tb[TCA_TCINDEX_CLASSID]);
 479                 tcf_bind_filter(tp, &cr, base);
 480         }
 481
 482         oldp = p;
 483         r->res = cr;
 484         tcf_exts_change(&r->exts, &e);
 485
 486         rcu_assign_pointer(tp->root, cp);
 487
 488         if (r == &new_filter_result) {
 489                 struct tcindex_filter *nfp;
 490                 struct tcindex_filter __rcu **fp;
 491
 492                 f->result.res = r->res;
 493                 tcf_exts_change(&f->result.exts, &r->exts);
 494
 495                 fp = cp->h + (handle % cp->hash);
 496                 for (nfp = rtnl_dereference(*fp);
 497                      nfp;
 498                      fp = &nfp->next, nfp = rtnl_dereference(*fp))
 499                                 ; /* nothing */
 500
 501                 rcu_assign_pointer(*fp, f);
 502         } else {
 503                 tcf_exts_destroy(&new_filter_result.exts);
 504         }
 505
 506         if (oldp)
 507                 tcf_queue_work(&oldp->rwork, tcindex_partial_destroy_work);
 508         return 0;
 509
 510 errout_alloc:
 511         if (balloc == 1)
 512                 tcindex_free_perfect_hash(cp);
 513         else if (balloc == 2)
 514                 kfree(cp->h);
 515         tcf_exts_destroy(&new_filter_result.exts);
 516 errout:
 517         kfree(cp);
 518         tcf_exts_destroy(&e);
 519         return err;
 520 }
 521
 522 static int
 523 tcindex_change(struct net *net, struct sk_buff *in_skb,
 524                struct tcf_proto *tp, unsigned long base, u32 handle,
 525                struct nlattr **tca, void **arg, u32 flags,
 526                struct netlink_ext_ack *extack)
 527 {
 528         struct nlattr *opt = tca[TCA_OPTIONS];
 529         struct nlattr *tb[TCA_TCINDEX_MAX + 1];
 530         struct tcindex_data *p = rtnl_dereference(tp->root);
 531         struct tcindex_filter_result *r = *arg;
 532         int err;
 533
 534         pr_debug("tcindex_change(tp %p,handle 0x%08x,tca %p,arg %p),opt %p,"
 535             "p %p,r %p,*arg %p\n",
 536             tp, handle, tca, arg, opt, p, r, *arg);
 537
 538         if (!opt)
 539                 return 0;
 540
 541         err = nla_parse_nested_deprecated(tb, TCA_TCINDEX_MAX, opt,
 542                                           tcindex_policy, NULL);
 543         if (err < 0)
 544                 return err;
 545
 546         return tcindex_set_parms(net, tp, base, handle, p, r, tb,
 547                                  tca[TCA_RATE], flags, extack);
 548 }
 549
 550 static void tcindex_walk(struct tcf_proto *tp, struct tcf_walker *walker,
 551                          bool rtnl_held)
 552 {
 553         struct tcindex_data *p = rtnl_dereference(tp->root);
 554         struct tcindex_filter *f, *next;
 555         int i;
 556
 557         pr_debug("tcindex_walk(tp %p,walker %p),p %p\n", tp, walker, p);
 558         if (p->perfect) {
 559                 for (i = 0; i < p->hash; i++) {
 560                         if (!p->perfect[i].res.class)
 561                                 continue;
 562                         if (!tc_cls_stats_dump(tp, walker, p->perfect + i))
 563                                 return;
 564                 }
 565         }
 566         if (!p->h)
 567                 return;
 568         for (i = 0; i < p->hash; i++) {
 569                 for (f = rtnl_dereference(p->h[i]); f; f = next) {
 570                         next = rtnl_dereference(f->next);
 571                         if (!tc_cls_stats_dump(tp, walker, &f->result))
 572                                 return;
 573                 }
 574         }
 575 }
 576
 577 static void tcindex_destroy(struct tcf_proto *tp, bool rtnl_held,
 578                             struct netlink_ext_ack *extack)
 579 {
 580         struct tcindex_data *p = rtnl_dereference(tp->root);
 581         int i;
 582
 583         pr_debug("tcindex_destroy(tp %p),p %p\n", tp, p);
 584
 585         if (p->perfect) {
 586                 for (i = 0; i < p->hash; i++) {
 587                         struct tcindex_filter_result *r = p->perfect + i;
 588
 589                         /* tcf_queue_work() does not guarantee the ordering we
 590                          * want, so we have to take this refcnt temporarily to
 591                          * ensure 'p' is freed after all tcindex_filter_result
 592                          * here. Imperfect hash does not need this, because it
 593                          * uses linked lists rather than an array.
 594                          */
 595                         tcindex_data_get(p);
 596
 597                         tcf_unbind_filter(tp, &r->res);
 598                         if (tcf_exts_get_net(&r->exts))
 599                                 tcf_queue_work(&r->rwork,
 600                                                tcindex_destroy_rexts_work);
 601                         else
 602                                 __tcindex_destroy_rexts(r);
 603                 }
 604         }
 605
 606         for (i = 0; p->h && i < p->hash; i++) {
 607                 struct tcindex_filter *f, *next;
 608                 bool last;
 609
 610                 for (f = rtnl_dereference(p->h[i]); f; f = next) {
 611                         next = rtnl_dereference(f->next);
 612                         tcindex_delete(tp, &f->result, &last, rtnl_held, NULL);
 613                 }
 614         }
 615
 616         tcf_queue_work(&p->rwork, tcindex_destroy_work);
 617 }
 618
 619
 620 static int tcindex_dump(struct net *net, struct tcf_proto *tp, void *fh,
 621                         struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
 622 {
 623         struct tcindex_data *p = rtnl_dereference(tp->root);
 624         struct tcindex_filter_result *r = fh;
 625         struct nlattr *nest;
 626
 627         pr_debug("tcindex_dump(tp %p,fh %p,skb %p,t %p),p %p,r %p\n",
 628                  tp, fh, skb, t, p, r);
 629         pr_debug("p->perfect %p p->h %p\n", p->perfect, p->h);
 630
 631         nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
 632         if (nest == NULL)
 633                 goto nla_put_failure;
 634
 635         if (!fh) {
 636                 t->tcm_handle = ~0; /* whatever ... */
 637                 if (nla_put_u32(skb, TCA_TCINDEX_HASH, p->hash) ||
 638                     nla_put_u16(skb, TCA_TCINDEX_MASK, p->mask) ||
 639                     nla_put_u32(skb, TCA_TCINDEX_SHIFT, p->shift) ||
 640                     nla_put_u32(skb, TCA_TCINDEX_FALL_THROUGH, p->fall_through))
 641                         goto nla_put_failure;
 642                 nla_nest_end(skb, nest);
 643         } else {
 644                 if (p->perfect) {
 645                         t->tcm_handle = r - p->perfect;
 646                 } else {
 647                         struct tcindex_filter *f;
 648                         struct tcindex_filter __rcu **fp;
 649                         int i;
 650
 651                         t->tcm_handle = 0;
 652                         for (i = 0; !t->tcm_handle && i < p->hash; i++) {
 653                                 fp = &p->h[i];
 654                                 for (f = rtnl_dereference(*fp);
 655                                      !t->tcm_handle && f;
 656                                      fp = &f->next, f = rtnl_dereference(*fp)) {
 657                                         if (&f->result == r)
 658                                                 t->tcm_handle = f->key;
 659                                 }
 660                         }
 661                 }
 662                 pr_debug("handle = %d\n", t->tcm_handle);
 663                 if (r->res.class &&
 664                     nla_put_u32(skb, TCA_TCINDEX_CLASSID, r->res.classid))
 665                         goto nla_put_failure;
 666
 667                 if (tcf_exts_dump(skb, &r->exts) < 0)
 668                         goto nla_put_failure;
 669                 nla_nest_end(skb, nest);
 670
 671                 if (tcf_exts_dump_stats(skb, &r->exts) < 0)
 672                         goto nla_put_failure;
 673         }
 674
 675         return skb->len;
 676
 677 nla_put_failure:
 678         nla_nest_cancel(skb, nest);
 679         return -1;
 680 }
 681
 682 static void tcindex_bind_class(void *fh, u32 classid, unsigned long cl,
 683                                void *q, unsigned long base)
 684 {
 685         struct tcindex_filter_result *r = fh;
 686
 687         tc_cls_bind_class(classid, cl, q, &r->res, base);
 688 }
 689
 690 static struct tcf_proto_ops cls_tcindex_ops __read_mostly = {
 691         .kind           =       "tcindex",
 692         .classify       =       tcindex_classify,
 693         .init           =       tcindex_init,
 694         .destroy        =       tcindex_destroy,
 695         .get            =       tcindex_get,
 696         .change         =       tcindex_change,
 697         .delete         =       tcindex_delete,
 698         .walk           =       tcindex_walk,
 699         .dump           =       tcindex_dump,
 700         .bind_class     =       tcindex_bind_class,
 701         .owner          =       THIS_MODULE,
 702 };
 703
 704 static int __init init_tcindex(void)
 705 {
 706         return register_tcf_proto_ops(&cls_tcindex_ops);
 707 }
 708
 709 static void __exit exit_tcindex(void)
 710 {
 711         unregister_tcf_proto_ops(&cls_tcindex_ops);
 712 }
 713
 714 module_init(init_tcindex)
 715 module_exit(exit_tcindex)
 716 MODULE_LICENSE("GPL");