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
  20 /*
  21  * Passing parameters to the root seems to be done more awkwardly than really
  22  * necessary. At least, u32 doesn't seem to use such dirty hacks. To be
  23  * verified. FIXME.
  24  */
  25
  26 #define PERFECT_HASH_THRESHOLD  64      /* use perfect hash if not bigger */
  27 #define DEFAULT_HASH_SIZE       64      /* optimized for diffserv */
  28
  29
  30 struct tcindex_data;
  31
  32 struct tcindex_filter_result {
  33         struct tcf_exts         exts;
  34         struct tcf_result       res;
  35         struct tcindex_data     *p;
  36         struct rcu_work         rwork;
  37 };
  38
  39 struct tcindex_filter {
  40         u16 key;
  41         struct tcindex_filter_result result;
  42         struct tcindex_filter __rcu *next;
  43         struct rcu_work rwork;
  44 };
  45
  46
  47 struct tcindex_data {
  48         struct tcindex_filter_result *perfect; /* perfect hash; NULL if none */
  49         struct tcindex_filter __rcu **h; /* imperfect hash; */
  50         struct tcf_proto *tp;
  51         u16 mask;               /* AND key with mask */
  52         u32 shift;              /* shift ANDed key to the right */
  53         u32 hash;               /* hash table size; 0 if undefined */
  54         u32 alloc_hash;         /* allocated size */
  55         u32 fall_through;       /* 0: only classify if explicit match */
  56         refcount_t refcnt;      /* a temporary refcnt for perfect hash */
  57         struct rcu_work rwork;
  58 };
  59
  60 static inline int tcindex_filter_is_set(struct tcindex_filter_result *r)
  61 {
  62         return tcf_exts_has_actions(&r->exts) || r->res.classid;
  63 }
  64
  65 static void tcindex_data_get(struct tcindex_data *p)
  66 {
  67         refcount_inc(&p->refcnt);
  68 }
  69
  70 static void tcindex_data_put(struct tcindex_data *p)
  71 {
  72         if (refcount_dec_and_test(&p->refcnt)) {
  73                 kfree(p->perfect);
  74                 kfree(p->h);
  75                 kfree(p);
  76         }
  77 }
  78
  79 static struct tcindex_filter_result *tcindex_lookup(struct tcindex_data *p,
  80                                                     u16 key)
  81 {
  82         if (p->perfect) {
  83                 struct tcindex_filter_result *f = p->perfect + key;
  84
  85                 return tcindex_filter_is_set(f) ? f : NULL;
  86         } else if (p->h) {
  87                 struct tcindex_filter __rcu **fp;
  88                 struct tcindex_filter *f;
  89
  90                 fp = &p->h[key % p->hash];
  91                 for (f = rcu_dereference_bh_rtnl(*fp);
  92                      f;
  93                      fp = &f->next, f = rcu_dereference_bh_rtnl(*fp))
  94                         if (f->key == key)
  95                                 return &f->result;
  96         }
  97
  98         return NULL;
  99 }
 100
 101
 102 static int tcindex_classify(struct sk_buff *skb, const struct tcf_proto *tp,
 103                             struct tcf_result *res)
 104 {
 105         struct tcindex_data *p = rcu_dereference_bh(tp->root);
 106         struct tcindex_filter_result *f;
 107         int key = (skb->tc_index & p->mask) >> p->shift;
 108
 109         pr_debug("tcindex_classify(skb %p,tp %p,res %p),p %p\n",
 110                  skb, tp, res, p);
 111
 112         f = tcindex_lookup(p, key);
 113         if (!f) {
 114                 struct Qdisc *q = tcf_block_q(tp->chain->block);
 115
 116                 if (!p->fall_through)
 117                         return -1;
 118                 res->classid = TC_H_MAKE(TC_H_MAJ(q->handle), key);
 119                 res->class = 0;
 120                 pr_debug("alg 0x%x\n", res->classid);
 121                 return 0;
 122         }
 123         *res = f->res;
 124         pr_debug("map 0x%x\n", res->classid);
 125
 126         return tcf_exts_exec(skb, &f->exts, res);
 127 }
 128
 129
 130 static void *tcindex_get(struct tcf_proto *tp, u32 handle)
 131 {
 132         struct tcindex_data *p = rtnl_dereference(tp->root);
 133         struct tcindex_filter_result *r;
 134
 135         pr_debug("tcindex_get(tp %p,handle 0x%08x)\n", tp, handle);
 136         if (p->perfect && handle >= p->alloc_hash)
 137                 return NULL;
 138         r = tcindex_lookup(p, handle);
 139         return r && tcindex_filter_is_set(r) ? r : NULL;
 140 }
 141
 142 static int tcindex_init(struct tcf_proto *tp)
 143 {
 144         struct tcindex_data *p;
 145
 146         pr_debug("tcindex_init(tp %p)\n", tp);
 147         p = kzalloc(sizeof(struct tcindex_data), GFP_KERNEL);
 148         if (!p)
 149                 return -ENOMEM;
 150
 151         p->mask = 0xffff;
 152         p->hash = DEFAULT_HASH_SIZE;
 153         p->fall_through = 1;
 154         refcount_set(&p->refcnt, 1); /* Paired with tcindex_destroy_work() */
 155
 156         rcu_assign_pointer(tp->root, p);
 157         return 0;
 158 }
 159
 160 static void __tcindex_destroy_rexts(struct tcindex_filter_result *r)
 161 {
 162         tcf_exts_destroy(&r->exts);
 163         tcf_exts_put_net(&r->exts);
 164         tcindex_data_put(r->p);
 165 }
 166
 167 static void tcindex_destroy_rexts_work(struct work_struct *work)
 168 {
 169         struct tcindex_filter_result *r;
 170
 171         r = container_of(to_rcu_work(work),
 172                          struct tcindex_filter_result,
 173                          rwork);
 174         rtnl_lock();
 175         __tcindex_destroy_rexts(r);
 176         rtnl_unlock();
 177 }
 178
 179 static void __tcindex_destroy_fexts(struct tcindex_filter *f)
 180 {
 181         tcf_exts_destroy(&f->result.exts);
 182         tcf_exts_put_net(&f->result.exts);
 183         kfree(f);
 184 }
 185
 186 static void tcindex_destroy_fexts_work(struct work_struct *work)
 187 {
 188         struct tcindex_filter *f = container_of(to_rcu_work(work),
 189                                                 struct tcindex_filter,
 190                                                 rwork);
 191
 192         rtnl_lock();
 193         __tcindex_destroy_fexts(f);
 194         rtnl_unlock();
 195 }
 196
 197 static int tcindex_delete(struct tcf_proto *tp, void *arg, bool *last,
 198                           bool rtnl_held, struct netlink_ext_ack *extack)
 199 {
 200         struct tcindex_data *p = rtnl_dereference(tp->root);
 201         struct tcindex_filter_result *r = arg;
 202         struct tcindex_filter __rcu **walk;
 203         struct tcindex_filter *f = NULL;
 204
 205         pr_debug("tcindex_delete(tp %p,arg %p),p %p\n", tp, arg, p);
 206         if (p->perfect) {
 207                 if (!r->res.class)
 208                         return -ENOENT;
 209         } else {
 210                 int i;
 211
 212                 for (i = 0; i < p->hash; i++) {
 213                         walk = p->h + i;
 214                         for (f = rtnl_dereference(*walk); f;
 215                              walk = &f->next, f = rtnl_dereference(*walk)) {
 216                                 if (&f->result == r)
 217                                         goto found;
 218                         }
 219                 }
 220                 return -ENOENT;
 221
 222 found:
 223                 rcu_assign_pointer(*walk, rtnl_dereference(f->next));
 224         }
 225         tcf_unbind_filter(tp, &r->res);
 226         /* all classifiers are required to call tcf_exts_destroy() after rcu
 227          * grace period, since converted-to-rcu actions are relying on that
 228          * in cleanup() callback
 229          */
 230         if (f) {
 231                 if (tcf_exts_get_net(&f->result.exts))
 232                         tcf_queue_work(&f->rwork, tcindex_destroy_fexts_work);
 233                 else
 234                         __tcindex_destroy_fexts(f);
 235         } else {
 236                 tcindex_data_get(p);
 237
 238                 if (tcf_exts_get_net(&r->exts))
 239                         tcf_queue_work(&r->rwork, tcindex_destroy_rexts_work);
 240                 else
 241                         __tcindex_destroy_rexts(r);
 242         }
 243
 244         *last = false;
 245         return 0;
 246 }
 247
 248 static void tcindex_destroy_work(struct work_struct *work)
 249 {
 250         struct tcindex_data *p = container_of(to_rcu_work(work),
 251                                               struct tcindex_data,
 252                                               rwork);
 253
 254         tcindex_data_put(p);
 255 }
 256
 257 static inline int
 258 valid_perfect_hash(struct tcindex_data *p)
 259 {
 260         return  p->hash > (p->mask >> p->shift);
 261 }
 262
 263 static const struct nla_policy tcindex_policy[TCA_TCINDEX_MAX + 1] = {
 264         [TCA_TCINDEX_HASH]              = { .type = NLA_U32 },
 265         [TCA_TCINDEX_MASK]              = { .type = NLA_U16 },
 266         [TCA_TCINDEX_SHIFT]             = { .type = NLA_U32 },
 267         [TCA_TCINDEX_FALL_THROUGH]      = { .type = NLA_U32 },
 268         [TCA_TCINDEX_CLASSID]           = { .type = NLA_U32 },
 269 };
 270
 271 static int tcindex_filter_result_init(struct tcindex_filter_result *r,
 272                                       struct tcindex_data *p,
 273                                       struct net *net)
 274 {
 275         memset(r, 0, sizeof(*r));
 276         r->p = p;
 277         return tcf_exts_init(&r->exts, net, TCA_TCINDEX_ACT,
 278                              TCA_TCINDEX_POLICE);
 279 }
 280
 281 static void tcindex_free_perfect_hash(struct tcindex_data *cp);
 282
 283 static void tcindex_partial_destroy_work(struct work_struct *work)
 284 {
 285         struct tcindex_data *p = container_of(to_rcu_work(work),
 286                                               struct tcindex_data,
 287                                               rwork);
 288
 289         rtnl_lock();
 290         if (p->perfect)
 291                 tcindex_free_perfect_hash(p);
 292         kfree(p);
 293         rtnl_unlock();
 294 }
 295
 296 static void tcindex_free_perfect_hash(struct tcindex_data *cp)
 297 {
 298         int i;
 299
 300         for (i = 0; i < cp->hash; i++)
 301                 tcf_exts_destroy(&cp->perfect[i].exts);
 302         kfree(cp->perfect);
 303 }
 304
 305 static int tcindex_alloc_perfect_hash(struct net *net, struct tcindex_data *cp)
 306 {
 307         int i, err = 0;
 308
 309         cp->perfect = kcalloc(cp->hash, sizeof(struct tcindex_filter_result),
 310                               GFP_KERNEL | __GFP_NOWARN);
 311         if (!cp->perfect)
 312                 return -ENOMEM;
 313
 314         for (i = 0; i < cp->hash; i++) {
 315                 err = tcf_exts_init(&cp->perfect[i].exts, net,
 316                                     TCA_TCINDEX_ACT, TCA_TCINDEX_POLICE);
 317                 if (err < 0)
 318                         goto errout;
 319                 cp->perfect[i].p = cp;
 320         }
 321
 322         return 0;
 323
 324 errout:
 325         tcindex_free_perfect_hash(cp);
 326         return err;
 327 }
 328
 329 static int
 330 tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,
 331                   u32 handle, struct tcindex_data *p,
 332                   struct tcindex_filter_result *r, struct nlattr **tb,
 333                   struct nlattr *est, u32 flags, struct netlink_ext_ack *extack)
 334 {
 335         struct tcindex_filter_result new_filter_result, *old_r = r;
 336         struct tcindex_data *cp = NULL, *oldp;
 337         struct tcindex_filter *f = NULL; /* make gcc behave */
 338         struct tcf_result cr = {};
 339         int err, balloc = 0;
 340         struct tcf_exts e;
 341
 342         err = tcf_exts_init(&e, net, TCA_TCINDEX_ACT, TCA_TCINDEX_POLICE);
 343         if (err < 0)
 344                 return err;
 345         err = tcf_exts_validate(net, tp, tb, est, &e, flags, extack);
 346         if (err < 0)
 347                 goto errout;
 348
 349         err = -ENOMEM;
 350         /* tcindex_data attributes must look atomic to classifier/lookup so
 351          * allocate new tcindex data and RCU assign it onto root. Keeping
 352          * perfect hash and hash pointers from old data.
 353          */
 354         cp = kzalloc(sizeof(*cp), GFP_KERNEL);
 355         if (!cp)
 356                 goto errout;
 357
 358         cp->mask = p->mask;
 359         cp->shift = p->shift;
 360         cp->hash = p->hash;
 361         cp->alloc_hash = p->alloc_hash;
 362         cp->fall_through = p->fall_through;
 363         cp->tp = tp;
 364         refcount_set(&cp->refcnt, 1); /* Paired with tcindex_destroy_work() */
 365
 366         if (tb[TCA_TCINDEX_HASH])
 367                 cp->hash = nla_get_u32(tb[TCA_TCINDEX_HASH]);
 368
 369         if (tb[TCA_TCINDEX_MASK])
 370                 cp->mask = nla_get_u16(tb[TCA_TCINDEX_MASK]);
 371
 372         if (tb[TCA_TCINDEX_SHIFT]) {
 373                 cp->shift = nla_get_u32(tb[TCA_TCINDEX_SHIFT]);
 374                 if (cp->shift > 16) {
 375                         err = -EINVAL;
 376                         goto errout;
 377                 }
 378         }
 379         if (!cp->hash) {
 380                 /* Hash not specified, use perfect hash if the upper limit
 381                  * of the hashing index is below the threshold.
 382                  */
 383                 if ((cp->mask >> cp->shift) < PERFECT_HASH_THRESHOLD)
 384                         cp->hash = (cp->mask >> cp->shift) + 1;
 385                 else
 386                         cp->hash = DEFAULT_HASH_SIZE;
 387         }
 388
 389         if (p->perfect) {
 390                 int i;
 391
 392                 if (tcindex_alloc_perfect_hash(net, cp) < 0)
 393                         goto errout;
 394                 cp->alloc_hash = cp->hash;
 395                 for (i = 0; i < min(cp->hash, p->hash); i++)
 396                         cp->perfect[i].res = p->perfect[i].res;
 397                 balloc = 1;
 398         }
 399         cp->h = p->h;
 400
 401         err = tcindex_filter_result_init(&new_filter_result, cp, net);
 402         if (err < 0)
 403                 goto errout_alloc;
 404         if (old_r)
 405                 cr = r->res;
 406
 407         err = -EBUSY;
 408
 409         /* Hash already allocated, make sure that we still meet the
 410          * requirements for the allocated hash.
 411          */
 412         if (cp->perfect) {
 413                 if (!valid_perfect_hash(cp) ||
 414                     cp->hash > cp->alloc_hash)
 415                         goto errout_alloc;
 416         } else if (cp->h && cp->hash != cp->alloc_hash) {
 417                 goto errout_alloc;
 418         }
 419
 420         err = -EINVAL;
 421         if (tb[TCA_TCINDEX_FALL_THROUGH])
 422                 cp->fall_through = nla_get_u32(tb[TCA_TCINDEX_FALL_THROUGH]);
 423
 424         if (!cp->perfect && !cp->h)
 425                 cp->alloc_hash = cp->hash;
 426
 427         /* Note: this could be as restrictive as if (handle & ~(mask >> shift))
 428          * but then, we'd fail handles that may become valid after some future
 429          * mask change. While this is extremely unlikely to ever matter,
 430          * the check below is safer (and also more backwards-compatible).
 431          */
 432         if (cp->perfect || valid_perfect_hash(cp))
 433                 if (handle >= cp->alloc_hash)
 434                         goto errout_alloc;
 435
 436
 437         err = -ENOMEM;
 438         if (!cp->perfect && !cp->h) {
 439                 if (valid_perfect_hash(cp)) {
 440                         if (tcindex_alloc_perfect_hash(net, cp) < 0)
 441                                 goto errout_alloc;
 442                         balloc = 1;
 443                 } else {
 444                         struct tcindex_filter __rcu **hash;
 445
 446                         hash = kcalloc(cp->hash,
 447                                        sizeof(struct tcindex_filter *),
 448                                        GFP_KERNEL);
 449
 450                         if (!hash)
 451                                 goto errout_alloc;
 452
 453                         cp->h = hash;
 454                         balloc = 2;
 455                 }
 456         }
 457
 458         if (cp->perfect)
 459                 r = cp->perfect + handle;
 460         else
 461                 r = tcindex_lookup(cp, handle) ? : &new_filter_result;
 462
 463         if (r == &new_filter_result) {
 464                 f = kzalloc(sizeof(*f), GFP_KERNEL);
 465                 if (!f)
 466                         goto errout_alloc;
 467                 f->key = handle;
 468                 f->next = NULL;
 469                 err = tcindex_filter_result_init(&f->result, cp, net);
 470                 if (err < 0) {
 471                         kfree(f);
 472                         goto errout_alloc;
 473                 }
 474         }
 475
 476         if (tb[TCA_TCINDEX_CLASSID]) {
 477                 cr.classid = nla_get_u32(tb[TCA_TCINDEX_CLASSID]);
 478                 tcf_bind_filter(tp, &cr, base);
 479         }
 480
 481         if (old_r && old_r != r) {
 482                 err = tcindex_filter_result_init(old_r, cp, net);
 483                 if (err < 0) {
 484                         kfree(f);
 485                         goto errout_alloc;
 486                 }
 487         }
 488
 489         oldp = p;
 490         r->res = cr;
 491         tcf_exts_change(&r->exts, &e);
 492
 493         rcu_assign_pointer(tp->root, cp);
 494
 495         if (r == &new_filter_result) {
 496                 struct tcindex_filter *nfp;
 497                 struct tcindex_filter __rcu **fp;
 498
 499                 f->result.res = r->res;
 500                 tcf_exts_change(&f->result.exts, &r->exts);
 501
 502                 fp = cp->h + (handle % cp->hash);
 503                 for (nfp = rtnl_dereference(*fp);
 504                      nfp;
 505                      fp = &nfp->next, nfp = rtnl_dereference(*fp))
 506                                 ; /* nothing */
 507
 508                 rcu_assign_pointer(*fp, f);
 509         } else {
 510                 tcf_exts_destroy(&new_filter_result.exts);
 511         }
 512
 513         if (oldp)
 514                 tcf_queue_work(&oldp->rwork, tcindex_partial_destroy_work);
 515         return 0;
 516
 517 errout_alloc:
 518         if (balloc == 1)
 519                 tcindex_free_perfect_hash(cp);
 520         else if (balloc == 2)
 521                 kfree(cp->h);
 522         tcf_exts_destroy(&new_filter_result.exts);
 523 errout:
 524         kfree(cp);
 525         tcf_exts_destroy(&e);
 526         return err;
 527 }
 528
 529 static int
 530 tcindex_change(struct net *net, struct sk_buff *in_skb,
 531                struct tcf_proto *tp, unsigned long base, u32 handle,
 532                struct nlattr **tca, void **arg, u32 flags,
 533                struct netlink_ext_ack *extack)
 534 {
 535         struct nlattr *opt = tca[TCA_OPTIONS];
 536         struct nlattr *tb[TCA_TCINDEX_MAX + 1];
 537         struct tcindex_data *p = rtnl_dereference(tp->root);
 538         struct tcindex_filter_result *r = *arg;
 539         int err;
 540
 541         pr_debug("tcindex_change(tp %p,handle 0x%08x,tca %p,arg %p),opt %p,"
 542             "p %p,r %p,*arg %p\n",
 543             tp, handle, tca, arg, opt, p, r, *arg);
 544
 545         if (!opt)
 546                 return 0;
 547
 548         err = nla_parse_nested_deprecated(tb, TCA_TCINDEX_MAX, opt,
 549                                           tcindex_policy, NULL);
 550         if (err < 0)
 551                 return err;
 552
 553         return tcindex_set_parms(net, tp, base, handle, p, r, tb,
 554                                  tca[TCA_RATE], flags, extack);
 555 }
 556
 557 static void tcindex_walk(struct tcf_proto *tp, struct tcf_walker *walker,
 558                          bool rtnl_held)
 559 {
 560         struct tcindex_data *p = rtnl_dereference(tp->root);
 561         struct tcindex_filter *f, *next;
 562         int i;
 563
 564         pr_debug("tcindex_walk(tp %p,walker %p),p %p\n", tp, walker, p);
 565         if (p->perfect) {
 566                 for (i = 0; i < p->hash; i++) {
 567                         if (!p->perfect[i].res.class)
 568                                 continue;
 569                         if (!tc_cls_stats_dump(tp, walker, p->perfect + i))
 570                                 return;
 571                 }
 572         }
 573         if (!p->h)
 574                 return;
 575         for (i = 0; i < p->hash; i++) {
 576                 for (f = rtnl_dereference(p->h[i]); f; f = next) {
 577                         next = rtnl_dereference(f->next);
 578                         if (!tc_cls_stats_dump(tp, walker, &f->result))
 579                                 return;
 580                 }
 581         }
 582 }
 583
 584 static void tcindex_destroy(struct tcf_proto *tp, bool rtnl_held,
 585                             struct netlink_ext_ack *extack)
 586 {
 587         struct tcindex_data *p = rtnl_dereference(tp->root);
 588         int i;
 589
 590         pr_debug("tcindex_destroy(tp %p),p %p\n", tp, p);
 591
 592         if (p->perfect) {
 593                 for (i = 0; i < p->hash; i++) {
 594                         struct tcindex_filter_result *r = p->perfect + i;
 595
 596                         /* tcf_queue_work() does not guarantee the ordering we
 597                          * want, so we have to take this refcnt temporarily to
 598                          * ensure 'p' is freed after all tcindex_filter_result
 599                          * here. Imperfect hash does not need this, because it
 600                          * uses linked lists rather than an array.
 601                          */
 602                         tcindex_data_get(p);
 603
 604                         tcf_unbind_filter(tp, &r->res);
 605                         if (tcf_exts_get_net(&r->exts))
 606                                 tcf_queue_work(&r->rwork,
 607                                                tcindex_destroy_rexts_work);
 608                         else
 609                                 __tcindex_destroy_rexts(r);
 610                 }
 611         }
 612
 613         for (i = 0; p->h && i < p->hash; i++) {
 614                 struct tcindex_filter *f, *next;
 615                 bool last;
 616
 617                 for (f = rtnl_dereference(p->h[i]); f; f = next) {
 618                         next = rtnl_dereference(f->next);
 619                         tcindex_delete(tp, &f->result, &last, rtnl_held, NULL);
 620                 }
 621         }
 622
 623         tcf_queue_work(&p->rwork, tcindex_destroy_work);
 624 }
 625
 626
 627 static int tcindex_dump(struct net *net, struct tcf_proto *tp, void *fh,
 628                         struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
 629 {
 630         struct tcindex_data *p = rtnl_dereference(tp->root);
 631         struct tcindex_filter_result *r = fh;
 632         struct nlattr *nest;
 633
 634         pr_debug("tcindex_dump(tp %p,fh %p,skb %p,t %p),p %p,r %p\n",
 635                  tp, fh, skb, t, p, r);
 636         pr_debug("p->perfect %p p->h %p\n", p->perfect, p->h);
 637
 638         nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
 639         if (nest == NULL)
 640                 goto nla_put_failure;
 641
 642         if (!fh) {
 643                 t->tcm_handle = ~0; /* whatever ... */
 644                 if (nla_put_u32(skb, TCA_TCINDEX_HASH, p->hash) ||
 645                     nla_put_u16(skb, TCA_TCINDEX_MASK, p->mask) ||
 646                     nla_put_u32(skb, TCA_TCINDEX_SHIFT, p->shift) ||
 647                     nla_put_u32(skb, TCA_TCINDEX_FALL_THROUGH, p->fall_through))
 648                         goto nla_put_failure;
 649                 nla_nest_end(skb, nest);
 650         } else {
 651                 if (p->perfect) {
 652                         t->tcm_handle = r - p->perfect;
 653                 } else {
 654                         struct tcindex_filter *f;
 655                         struct tcindex_filter __rcu **fp;
 656                         int i;
 657
 658                         t->tcm_handle = 0;
 659                         for (i = 0; !t->tcm_handle && i < p->hash; i++) {
 660                                 fp = &p->h[i];
 661                                 for (f = rtnl_dereference(*fp);
 662                                      !t->tcm_handle && f;
 663                                      fp = &f->next, f = rtnl_dereference(*fp)) {
 664                                         if (&f->result == r)
 665                                                 t->tcm_handle = f->key;
 666                                 }
 667                         }
 668                 }
 669                 pr_debug("handle = %d\n", t->tcm_handle);
 670                 if (r->res.class &&
 671                     nla_put_u32(skb, TCA_TCINDEX_CLASSID, r->res.classid))
 672                         goto nla_put_failure;
 673
 674                 if (tcf_exts_dump(skb, &r->exts) < 0)
 675                         goto nla_put_failure;
 676                 nla_nest_end(skb, nest);
 677
 678                 if (tcf_exts_dump_stats(skb, &r->exts) < 0)
 679                         goto nla_put_failure;
 680         }
 681
 682         return skb->len;
 683
 684 nla_put_failure:
 685         nla_nest_cancel(skb, nest);
 686         return -1;
 687 }
 688
 689 static void tcindex_bind_class(void *fh, u32 classid, unsigned long cl,
 690                                void *q, unsigned long base)
 691 {
 692         struct tcindex_filter_result *r = fh;
 693
 694         tc_cls_bind_class(classid, cl, q, &r->res, base);
 695 }
 696
 697 static struct tcf_proto_ops cls_tcindex_ops __read_mostly = {
 698         .kind           =       "tcindex",
 699         .classify       =       tcindex_classify,
 700         .init           =       tcindex_init,
 701         .destroy        =       tcindex_destroy,
 702         .get            =       tcindex_get,
 703         .change         =       tcindex_change,
 704         .delete         =       tcindex_delete,
 705         .walk           =       tcindex_walk,
 706         .dump           =       tcindex_dump,
 707         .bind_class     =       tcindex_bind_class,
 708         .owner          =       THIS_MODULE,
 709 };
 710
 711 static int __init init_tcindex(void)
 712 {
 713         return register_tcf_proto_ops(&cls_tcindex_ops);
 714 }
 715
 716 static void __exit exit_tcindex(void)
 717 {
 718         unregister_tcf_proto_ops(&cls_tcindex_ops);
 719 }
 720
 721 module_init(init_tcindex)
 722 module_exit(exit_tcindex)
 723 MODULE_LICENSE("GPL");