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  *      JHS: We should remove the CONFIG_NET_CLS_IND from here
  28  *      eventually when the meta match extension is made available
  29  *
  30  *      nfmark match added by Catalin(ux aka Dino) BOIE <catab at umbrella.ro>
  31  */
  32
  33 #include <linux/module.h>
  34 #include <linux/slab.h>
  35 #include <linux/types.h>
  36 #include <linux/kernel.h>
  37 #include <linux/string.h>
  38 #include <linux/errno.h>
  39 #include <linux/percpu.h>
  40 #include <linux/rtnetlink.h>
  41 #include <linux/skbuff.h>
  42 #include <linux/bitmap.h>
  43 #include <net/netlink.h>
  44 #include <net/act_api.h>
  45 #include <net/pkt_cls.h>
  46 #include <linux/netdevice.h>
  47
  48 struct tc_u_knode {
  49         struct tc_u_knode __rcu *next;
  50         u32                     handle;
  51         struct tc_u_hnode __rcu *ht_up;
  52         struct tcf_exts         exts;
  53 #ifdef CONFIG_NET_CLS_IND
  54         int                     ifindex;
  55 #endif
  56         u8                      fshift;
  57         struct tcf_result       res;
  58         struct tc_u_hnode __rcu *ht_down;
  59 #ifdef CONFIG_CLS_U32_PERF
  60         struct tc_u32_pcnt __percpu *pf;
  61 #endif
  62         u32                     flags;
  63 #ifdef CONFIG_CLS_U32_MARK
  64         u32                     val;
  65         u32                     mask;
  66         u32 __percpu            *pcpu_success;
  67 #endif
  68         struct tcf_proto        *tp;
  69         struct rcu_head         rcu;
  70         /* The 'sel' field MUST be the last field in structure to allow for
  71          * tc_u32_keys allocated at end of structure.
  72          */
  73         struct tc_u32_sel       sel;
  74 };
  75
  76 struct tc_u_hnode {
  77         struct tc_u_hnode __rcu *next;
  78         u32                     handle;
  79         u32                     prio;
  80         struct tc_u_common      *tp_c;
  81         int                     refcnt;
  82         unsigned int            divisor;
  83         struct rcu_head         rcu;
  84         /* The 'ht' field MUST be the last field in structure to allow for
  85          * more entries allocated at end of structure.
  86          */
  87         struct tc_u_knode __rcu *ht[1];
  88 };
  89
  90 struct tc_u_common {
  91         struct tc_u_hnode __rcu *hlist;
  92         struct Qdisc            *q;
  93         int                     refcnt;
  94         u32                     hgenerator;
  95         struct rcu_head         rcu;
  96 };
  97
  98 static inline unsigned int u32_hash_fold(__be32 key,
  99                                          const struct tc_u32_sel *sel,
 100                                          u8 fshift)
 101 {
 102         unsigned int h = ntohl(key & sel->hmask) >> fshift;
 103
 104         return h;
 105 }
 106
 107 static int u32_classify(struct sk_buff *skb, const struct tcf_proto *tp,
 108                         struct tcf_result *res)
 109 {
 110         struct {
 111                 struct tc_u_knode *knode;
 112                 unsigned int      off;
 113         } stack[TC_U32_MAXDEPTH];
 114
 115         struct tc_u_hnode *ht = rcu_dereference_bh(tp->root);
 116         unsigned int off = skb_network_offset(skb);
 117         struct tc_u_knode *n;
 118         int sdepth = 0;
 119         int off2 = 0;
 120         int sel = 0;
 121 #ifdef CONFIG_CLS_U32_PERF
 122         int j;
 123 #endif
 124         int i, r;
 125
 126 next_ht:
 127         n = rcu_dereference_bh(ht->ht[sel]);
 128
 129 next_knode:
 130         if (n) {
 131                 struct tc_u32_key *key = n->sel.keys;
 132
 133 #ifdef CONFIG_CLS_U32_PERF
 134                 __this_cpu_inc(n->pf->rcnt);
 135                 j = 0;
 136 #endif
 137
 138                 if (tc_skip_sw(n->flags)) {
 139                         n = rcu_dereference_bh(n->next);
 140                         goto next_knode;
 141                 }
 142
 143 #ifdef CONFIG_CLS_U32_MARK
 144                 if ((skb->mark & n->mask) != n->val) {
 145                         n = rcu_dereference_bh(n->next);
 146                         goto next_knode;
 147                 } else {
 148                         __this_cpu_inc(*n->pcpu_success);
 149                 }
 150 #endif
 151
 152                 for (i = n->sel.nkeys; i > 0; i--, key++) {
 153                         int toff = off + key->off + (off2 & key->offmask);
 154                         __be32 *data, hdata;
 155
 156                         if (skb_headroom(skb) + toff > INT_MAX)
 157                                 goto out;
 158
 159                         data = skb_header_pointer(skb, toff, 4, &hdata);
 160                         if (!data)
 161                                 goto out;
 162                         if ((*data ^ key->val) & key->mask) {
 163                                 n = rcu_dereference_bh(n->next);
 164                                 goto next_knode;
 165                         }
 166 #ifdef CONFIG_CLS_U32_PERF
 167                         __this_cpu_inc(n->pf->kcnts[j]);
 168                         j++;
 169 #endif
 170                 }
 171
 172                 ht = rcu_dereference_bh(n->ht_down);
 173                 if (!ht) {
 174 check_terminal:
 175                         if (n->sel.flags & TC_U32_TERMINAL) {
 176
 177                                 *res = n->res;
 178 #ifdef CONFIG_NET_CLS_IND
 179                                 if (!tcf_match_indev(skb, n->ifindex)) {
 180                                         n = rcu_dereference_bh(n->next);
 181                                         goto next_knode;
 182                                 }
 183 #endif
 184 #ifdef CONFIG_CLS_U32_PERF
 185                                 __this_cpu_inc(n->pf->rhit);
 186 #endif
 187                                 r = tcf_exts_exec(skb, &n->exts, res);
 188                                 if (r < 0) {
 189                                         n = rcu_dereference_bh(n->next);
 190                                         goto next_knode;
 191                                 }
 192
 193                                 return r;
 194                         }
 195                         n = rcu_dereference_bh(n->next);
 196                         goto next_knode;
 197                 }
 198
 199                 /* PUSH */
 200                 if (sdepth >= TC_U32_MAXDEPTH)
 201                         goto deadloop;
 202                 stack[sdepth].knode = n;
 203                 stack[sdepth].off = off;
 204                 sdepth++;
 205
 206                 ht = rcu_dereference_bh(n->ht_down);
 207                 sel = 0;
 208                 if (ht->divisor) {
 209                         __be32 *data, hdata;
 210
 211                         data = skb_header_pointer(skb, off + n->sel.hoff, 4,
 212                                                   &hdata);
 213                         if (!data)
 214                                 goto out;
 215                         sel = ht->divisor & u32_hash_fold(*data, &n->sel,
 216                                                           n->fshift);
 217                 }
 218                 if (!(n->sel.flags & (TC_U32_VAROFFSET | TC_U32_OFFSET | TC_U32_EAT)))
 219                         goto next_ht;
 220
 221                 if (n->sel.flags & (TC_U32_OFFSET | TC_U32_VAROFFSET)) {
 222                         off2 = n->sel.off + 3;
 223                         if (n->sel.flags & TC_U32_VAROFFSET) {
 224                                 __be16 *data, hdata;
 225
 226                                 data = skb_header_pointer(skb,
 227                                                           off + n->sel.offoff,
 228                                                           2, &hdata);
 229                                 if (!data)
 230                                         goto out;
 231                                 off2 += ntohs(n->sel.offmask & *data) >>
 232                                         n->sel.offshift;
 233                         }
 234                         off2 &= ~3;
 235                 }
 236                 if (n->sel.flags & TC_U32_EAT) {
 237                         off += off2;
 238                         off2 = 0;
 239                 }
 240
 241                 if (off < skb->len)
 242                         goto next_ht;
 243         }
 244
 245         /* POP */
 246         if (sdepth--) {
 247                 n = stack[sdepth].knode;
 248                 ht = rcu_dereference_bh(n->ht_up);
 249                 off = stack[sdepth].off;
 250                 goto check_terminal;
 251         }
 252 out:
 253         return -1;
 254
 255 deadloop:
 256         net_warn_ratelimited("cls_u32: dead loop\n");
 257         return -1;
 258 }
 259
 260 static struct tc_u_hnode *u32_lookup_ht(struct tc_u_common *tp_c, u32 handle)
 261 {
 262         struct tc_u_hnode *ht;
 263
 264         for (ht = rtnl_dereference(tp_c->hlist);
 265              ht;
 266              ht = rtnl_dereference(ht->next))
 267                 if (ht->handle == handle)
 268                         break;
 269
 270         return ht;
 271 }
 272
 273 static struct tc_u_knode *u32_lookup_key(struct tc_u_hnode *ht, u32 handle)
 274 {
 275         unsigned int sel;
 276         struct tc_u_knode *n = NULL;
 277
 278         sel = TC_U32_HASH(handle);
 279         if (sel > ht->divisor)
 280                 goto out;
 281
 282         for (n = rtnl_dereference(ht->ht[sel]);
 283              n;
 284              n = rtnl_dereference(n->next))
 285                 if (n->handle == handle)
 286                         break;
 287 out:
 288         return n;
 289 }
 290
 291
 292 static unsigned long u32_get(struct tcf_proto *tp, u32 handle)
 293 {
 294         struct tc_u_hnode *ht;
 295         struct tc_u_common *tp_c = tp->data;
 296
 297         if (TC_U32_HTID(handle) == TC_U32_ROOT)
 298                 ht = rtnl_dereference(tp->root);
 299         else
 300                 ht = u32_lookup_ht(tp_c, TC_U32_HTID(handle));
 301
 302         if (!ht)
 303                 return 0;
 304
 305         if (TC_U32_KEY(handle) == 0)
 306                 return (unsigned long)ht;
 307
 308         return (unsigned long)u32_lookup_key(ht, handle);
 309 }
 310
 311 static u32 gen_new_htid(struct tc_u_common *tp_c)
 312 {
 313         int i = 0x800;
 314
 315         /* hgenerator only used inside rtnl lock it is safe to increment
 316          * without read _copy_ update semantics
 317          */
 318         do {
 319                 if (++tp_c->hgenerator == 0x7FF)
 320                         tp_c->hgenerator = 1;
 321         } while (--i > 0 && u32_lookup_ht(tp_c, (tp_c->hgenerator|0x800)<<20));
 322
 323         return i > 0 ? (tp_c->hgenerator|0x800)<<20 : 0;
 324 }
 325
 326 static int u32_init(struct tcf_proto *tp)
 327 {
 328         struct tc_u_hnode *root_ht;
 329         struct tc_u_common *tp_c;
 330
 331         tp_c = tp->q->u32_node;
 332
 333         root_ht = kzalloc(sizeof(*root_ht), GFP_KERNEL);
 334         if (root_ht == NULL)
 335                 return -ENOBUFS;
 336
 337         root_ht->divisor = 0;
 338         root_ht->refcnt++;
 339         root_ht->handle = tp_c ? gen_new_htid(tp_c) : 0x80000000;
 340         root_ht->prio = tp->prio;
 341
 342         if (tp_c == NULL) {
 343                 tp_c = kzalloc(sizeof(*tp_c), GFP_KERNEL);
 344                 if (tp_c == NULL) {
 345                         kfree(root_ht);
 346                         return -ENOBUFS;
 347                 }
 348                 tp_c->q = tp->q;
 349                 tp->q->u32_node = tp_c;
 350         }
 351
 352         tp_c->refcnt++;
 353         RCU_INIT_POINTER(root_ht->next, tp_c->hlist);
 354         rcu_assign_pointer(tp_c->hlist, root_ht);
 355         root_ht->tp_c = tp_c;
 356
 357         rcu_assign_pointer(tp->root, root_ht);
 358         tp->data = tp_c;
 359         return 0;
 360 }
 361
 362 static int u32_destroy_key(struct tcf_proto *tp, struct tc_u_knode *n,
 363                            bool free_pf)
 364 {
 365         tcf_exts_destroy(&n->exts);
 366         if (n->ht_down)
 367                 n->ht_down->refcnt--;
 368 #ifdef CONFIG_CLS_U32_PERF
 369         if (free_pf)
 370                 free_percpu(n->pf);
 371 #endif
 372 #ifdef CONFIG_CLS_U32_MARK
 373         if (free_pf)
 374                 free_percpu(n->pcpu_success);
 375 #endif
 376         kfree(n);
 377         return 0;
 378 }
 379
 380 /* u32_delete_key_rcu should be called when free'ing a copied
 381  * version of a tc_u_knode obtained from u32_init_knode(). When
 382  * copies are obtained from u32_init_knode() the statistics are
 383  * shared between the old and new copies to allow readers to
 384  * continue to update the statistics during the copy. To support
 385  * this the u32_delete_key_rcu variant does not free the percpu
 386  * statistics.
 387  */
 388 static void u32_delete_key_rcu(struct rcu_head *rcu)
 389 {
 390         struct tc_u_knode *key = container_of(rcu, struct tc_u_knode, rcu);
 391
 392         u32_destroy_key(key->tp, key, false);
 393 }
 394
 395 /* u32_delete_key_freepf_rcu is the rcu callback variant
 396  * that free's the entire structure including the statistics
 397  * percpu variables. Only use this if the key is not a copy
 398  * returned by u32_init_knode(). See u32_delete_key_rcu()
 399  * for the variant that should be used with keys return from
 400  * u32_init_knode()
 401  */
 402 static void u32_delete_key_freepf_rcu(struct rcu_head *rcu)
 403 {
 404         struct tc_u_knode *key = container_of(rcu, struct tc_u_knode, rcu);
 405
 406         u32_destroy_key(key->tp, key, true);
 407 }
 408
 409 static int u32_delete_key(struct tcf_proto *tp, struct tc_u_knode *key)
 410 {
 411         struct tc_u_knode __rcu **kp;
 412         struct tc_u_knode *pkp;
 413         struct tc_u_hnode *ht = rtnl_dereference(key->ht_up);
 414
 415         if (ht) {
 416                 kp = &ht->ht[TC_U32_HASH(key->handle)];
 417                 for (pkp = rtnl_dereference(*kp); pkp;
 418                      kp = &pkp->next, pkp = rtnl_dereference(*kp)) {
 419                         if (pkp == key) {
 420                                 RCU_INIT_POINTER(*kp, key->next);
 421
 422                                 tcf_unbind_filter(tp, &key->res);
 423                                 call_rcu(&key->rcu, u32_delete_key_freepf_rcu);
 424                                 return 0;
 425                         }
 426                 }
 427         }
 428         WARN_ON(1);
 429         return 0;
 430 }
 431
 432 static void u32_remove_hw_knode(struct tcf_proto *tp, u32 handle)
 433 {
 434         struct net_device *dev = tp->q->dev_queue->dev;
 435         struct tc_cls_u32_offload u32_offload = {0};
 436         struct tc_to_netdev offload;
 437
 438         offload.type = TC_SETUP_CLSU32;
 439         offload.cls_u32 = &u32_offload;
 440
 441         if (tc_should_offload(dev, tp, 0)) {
 442                 offload.cls_u32->command = TC_CLSU32_DELETE_KNODE;
 443                 offload.cls_u32->knode.handle = handle;
 444                 dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
 445                                               tp->protocol, &offload);
 446         }
 447 }
 448
 449 static int u32_replace_hw_hnode(struct tcf_proto *tp, struct tc_u_hnode *h,
 450                                 u32 flags)
 451 {
 452         struct net_device *dev = tp->q->dev_queue->dev;
 453         struct tc_cls_u32_offload u32_offload = {0};
 454         struct tc_to_netdev offload;
 455         int err;
 456
 457         if (!tc_should_offload(dev, tp, flags))
 458                 return tc_skip_sw(flags) ? -EINVAL : 0;
 459
 460         offload.type = TC_SETUP_CLSU32;
 461         offload.cls_u32 = &u32_offload;
 462
 463         offload.cls_u32->command = TC_CLSU32_NEW_HNODE;
 464         offload.cls_u32->hnode.divisor = h->divisor;
 465         offload.cls_u32->hnode.handle = h->handle;
 466         offload.cls_u32->hnode.prio = h->prio;
 467
 468         err = dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
 469                                             tp->protocol, &offload);
 470         if (tc_skip_sw(flags))
 471                 return err;
 472
 473         return 0;
 474 }
 475
 476 static void u32_clear_hw_hnode(struct tcf_proto *tp, struct tc_u_hnode *h)
 477 {
 478         struct net_device *dev = tp->q->dev_queue->dev;
 479         struct tc_cls_u32_offload u32_offload = {0};
 480         struct tc_to_netdev offload;
 481
 482         offload.type = TC_SETUP_CLSU32;
 483         offload.cls_u32 = &u32_offload;
 484
 485         if (tc_should_offload(dev, tp, 0)) {
 486                 offload.cls_u32->command = TC_CLSU32_DELETE_HNODE;
 487                 offload.cls_u32->hnode.divisor = h->divisor;
 488                 offload.cls_u32->hnode.handle = h->handle;
 489                 offload.cls_u32->hnode.prio = h->prio;
 490
 491                 dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
 492                                               tp->protocol, &offload);
 493         }
 494 }
 495
 496 static int u32_replace_hw_knode(struct tcf_proto *tp, struct tc_u_knode *n,
 497                                 u32 flags)
 498 {
 499         struct net_device *dev = tp->q->dev_queue->dev;
 500         struct tc_cls_u32_offload u32_offload = {0};
 501         struct tc_to_netdev offload;
 502         int err;
 503
 504         offload.type = TC_SETUP_CLSU32;
 505         offload.cls_u32 = &u32_offload;
 506
 507         if (!tc_should_offload(dev, tp, flags))
 508                 return tc_skip_sw(flags) ? -EINVAL : 0;
 509
 510         offload.cls_u32->command = TC_CLSU32_REPLACE_KNODE;
 511         offload.cls_u32->knode.handle = n->handle;
 512         offload.cls_u32->knode.fshift = n->fshift;
 513 #ifdef CONFIG_CLS_U32_MARK
 514         offload.cls_u32->knode.val = n->val;
 515         offload.cls_u32->knode.mask = n->mask;
 516 #else
 517         offload.cls_u32->knode.val = 0;
 518         offload.cls_u32->knode.mask = 0;
 519 #endif
 520         offload.cls_u32->knode.sel = &n->sel;
 521         offload.cls_u32->knode.exts = &n->exts;
 522         if (n->ht_down)
 523                 offload.cls_u32->knode.link_handle = n->ht_down->handle;
 524
 525         err = dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
 526                                             tp->protocol, &offload);
 527         if (tc_skip_sw(flags))
 528                 return err;
 529
 530         return 0;
 531 }
 532
 533 static void u32_clear_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
 534 {
 535         struct tc_u_knode *n;
 536         unsigned int h;
 537
 538         for (h = 0; h <= ht->divisor; h++) {
 539                 while ((n = rtnl_dereference(ht->ht[h])) != NULL) {
 540                         RCU_INIT_POINTER(ht->ht[h],
 541                                          rtnl_dereference(n->next));
 542                         tcf_unbind_filter(tp, &n->res);
 543                         u32_remove_hw_knode(tp, n->handle);
 544                         call_rcu(&n->rcu, u32_delete_key_freepf_rcu);
 545                 }
 546         }
 547 }
 548
 549 static int u32_destroy_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
 550 {
 551         struct tc_u_common *tp_c = tp->data;
 552         struct tc_u_hnode __rcu **hn;
 553         struct tc_u_hnode *phn;
 554
 555         WARN_ON(ht->refcnt);
 556
 557         u32_clear_hnode(tp, ht);
 558
 559         hn = &tp_c->hlist;
 560         for (phn = rtnl_dereference(*hn);
 561              phn;
 562              hn = &phn->next, phn = rtnl_dereference(*hn)) {
 563                 if (phn == ht) {
 564                         u32_clear_hw_hnode(tp, ht);
 565                         RCU_INIT_POINTER(*hn, ht->next);
 566                         kfree_rcu(ht, rcu);
 567                         return 0;
 568                 }
 569         }
 570
 571         return -ENOENT;
 572 }
 573
 574 static bool ht_empty(struct tc_u_hnode *ht)
 575 {
 576         unsigned int h;
 577
 578         for (h = 0; h <= ht->divisor; h++)
 579                 if (rcu_access_pointer(ht->ht[h]))
 580                         return false;
 581
 582         return true;
 583 }
 584
 585 static bool u32_destroy(struct tcf_proto *tp, bool force)
 586 {
 587         struct tc_u_common *tp_c = tp->data;
 588         struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);
 589
 590         WARN_ON(root_ht == NULL);
 591
 592         if (!force) {
 593                 if (root_ht) {
 594                         if (root_ht->refcnt > 1)
 595                                 return false;
 596                         if (root_ht->refcnt == 1) {
 597                                 if (!ht_empty(root_ht))
 598                                         return false;
 599                         }
 600                 }
 601
 602                 if (tp_c->refcnt > 1)
 603                         return false;
 604
 605                 if (tp_c->refcnt == 1) {
 606                         struct tc_u_hnode *ht;
 607
 608                         for (ht = rtnl_dereference(tp_c->hlist);
 609                              ht;
 610                              ht = rtnl_dereference(ht->next))
 611                                 if (!ht_empty(ht))
 612                                         return false;
 613                 }
 614         }
 615
 616         if (root_ht && --root_ht->refcnt == 0)
 617                 u32_destroy_hnode(tp, root_ht);
 618
 619         if (--tp_c->refcnt == 0) {
 620                 struct tc_u_hnode *ht;
 621
 622                 tp->q->u32_node = NULL;
 623
 624                 for (ht = rtnl_dereference(tp_c->hlist);
 625                      ht;
 626                      ht = rtnl_dereference(ht->next)) {
 627                         ht->refcnt--;
 628                         u32_clear_hnode(tp, ht);
 629                 }
 630
 631                 while ((ht = rtnl_dereference(tp_c->hlist)) != NULL) {
 632                         RCU_INIT_POINTER(tp_c->hlist, ht->next);
 633                         kfree_rcu(ht, rcu);
 634                 }
 635
 636                 kfree(tp_c);
 637         }
 638
 639         tp->data = NULL;
 640         return true;
 641 }
 642
 643 static int u32_delete(struct tcf_proto *tp, unsigned long arg)
 644 {
 645         struct tc_u_hnode *ht = (struct tc_u_hnode *)arg;
 646         struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);
 647
 648         if (ht == NULL)
 649                 return 0;
 650
 651         if (TC_U32_KEY(ht->handle)) {
 652                 u32_remove_hw_knode(tp, ht->handle);
 653                 return u32_delete_key(tp, (struct tc_u_knode *)ht);
 654         }
 655
 656         if (root_ht == ht)
 657                 return -EINVAL;
 658
 659         if (ht->refcnt == 1) {
 660                 ht->refcnt--;
 661                 u32_destroy_hnode(tp, ht);
 662         } else {
 663                 return -EBUSY;
 664         }
 665
 666         return 0;
 667 }
 668
 669 #define NR_U32_NODE (1<<12)
 670 static u32 gen_new_kid(struct tc_u_hnode *ht, u32 handle)
 671 {
 672         struct tc_u_knode *n;
 673         unsigned long i;
 674         unsigned long *bitmap = kzalloc(BITS_TO_LONGS(NR_U32_NODE) * sizeof(unsigned long),
 675                                         GFP_KERNEL);
 676         if (!bitmap)
 677                 return handle | 0xFFF;
 678
 679         for (n = rtnl_dereference(ht->ht[TC_U32_HASH(handle)]);
 680              n;
 681              n = rtnl_dereference(n->next))
 682                 set_bit(TC_U32_NODE(n->handle), bitmap);
 683
 684         i = find_next_zero_bit(bitmap, NR_U32_NODE, 0x800);
 685         if (i >= NR_U32_NODE)
 686                 i = find_next_zero_bit(bitmap, NR_U32_NODE, 1);
 687
 688         kfree(bitmap);
 689         return handle | (i >= NR_U32_NODE ? 0xFFF : i);
 690 }
 691
 692 static const struct nla_policy u32_policy[TCA_U32_MAX + 1] = {
 693         [TCA_U32_CLASSID]       = { .type = NLA_U32 },
 694         [TCA_U32_HASH]          = { .type = NLA_U32 },
 695         [TCA_U32_LINK]          = { .type = NLA_U32 },
 696         [TCA_U32_DIVISOR]       = { .type = NLA_U32 },
 697         [TCA_U32_SEL]           = { .len = sizeof(struct tc_u32_sel) },
 698         [TCA_U32_INDEV]         = { .type = NLA_STRING, .len = IFNAMSIZ },
 699         [TCA_U32_MARK]          = { .len = sizeof(struct tc_u32_mark) },
 700         [TCA_U32_FLAGS]         = { .type = NLA_U32 },
 701 };
 702
 703 static int u32_set_parms(struct net *net, struct tcf_proto *tp,
 704                          unsigned long base, struct tc_u_hnode *ht,
 705                          struct tc_u_knode *n, struct nlattr **tb,
 706                          struct nlattr *est, bool ovr)
 707 {
 708         struct tcf_exts e;
 709         int err;
 710
 711         err = tcf_exts_init(&e, TCA_U32_ACT, TCA_U32_POLICE);
 712         if (err < 0)
 713                 return err;
 714         err = tcf_exts_validate(net, tp, tb, est, &e, ovr);
 715         if (err < 0)
 716                 goto errout;
 717
 718         err = -EINVAL;
 719         if (tb[TCA_U32_LINK]) {
 720                 u32 handle = nla_get_u32(tb[TCA_U32_LINK]);
 721                 struct tc_u_hnode *ht_down = NULL, *ht_old;
 722
 723                 if (TC_U32_KEY(handle))
 724                         goto errout;
 725
 726                 if (handle) {
 727                         ht_down = u32_lookup_ht(ht->tp_c, handle);
 728
 729                         if (ht_down == NULL)
 730                                 goto errout;
 731                         ht_down->refcnt++;
 732                 }
 733
 734                 ht_old = rtnl_dereference(n->ht_down);
 735                 rcu_assign_pointer(n->ht_down, ht_down);
 736
 737                 if (ht_old)
 738                         ht_old->refcnt--;
 739         }
 740         if (tb[TCA_U32_CLASSID]) {
 741                 n->res.classid = nla_get_u32(tb[TCA_U32_CLASSID]);
 742                 tcf_bind_filter(tp, &n->res, base);
 743         }
 744
 745 #ifdef CONFIG_NET_CLS_IND
 746         if (tb[TCA_U32_INDEV]) {
 747                 int ret;
 748                 ret = tcf_change_indev(net, tb[TCA_U32_INDEV]);
 749                 if (ret < 0)
 750                         goto errout;
 751                 n->ifindex = ret;
 752         }
 753 #endif
 754         tcf_exts_change(tp, &n->exts, &e);
 755
 756         return 0;
 757 errout:
 758         tcf_exts_destroy(&e);
 759         return err;
 760 }
 761
 762 static void u32_replace_knode(struct tcf_proto *tp, struct tc_u_common *tp_c,
 763                               struct tc_u_knode *n)
 764 {
 765         struct tc_u_knode __rcu **ins;
 766         struct tc_u_knode *pins;
 767         struct tc_u_hnode *ht;
 768
 769         if (TC_U32_HTID(n->handle) == TC_U32_ROOT)
 770                 ht = rtnl_dereference(tp->root);
 771         else
 772                 ht = u32_lookup_ht(tp_c, TC_U32_HTID(n->handle));
 773
 774         ins = &ht->ht[TC_U32_HASH(n->handle)];
 775
 776         /* The node must always exist for it to be replaced if this is not the
 777          * case then something went very wrong elsewhere.
 778          */
 779         for (pins = rtnl_dereference(*ins); ;
 780              ins = &pins->next, pins = rtnl_dereference(*ins))
 781                 if (pins->handle == n->handle)
 782                         break;
 783
 784         RCU_INIT_POINTER(n->next, pins->next);
 785         rcu_assign_pointer(*ins, n);
 786 }
 787
 788 static struct tc_u_knode *u32_init_knode(struct tcf_proto *tp,
 789                                          struct tc_u_knode *n)
 790 {
 791         struct tc_u_knode *new;
 792         struct tc_u32_sel *s = &n->sel;
 793
 794         new = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key),
 795                       GFP_KERNEL);
 796
 797         if (!new)
 798                 return NULL;
 799
 800         RCU_INIT_POINTER(new->next, n->next);
 801         new->handle = n->handle;
 802         RCU_INIT_POINTER(new->ht_up, n->ht_up);
 803
 804 #ifdef CONFIG_NET_CLS_IND
 805         new->ifindex = n->ifindex;
 806 #endif
 807         new->fshift = n->fshift;
 808         new->res = n->res;
 809         new->flags = n->flags;
 810         RCU_INIT_POINTER(new->ht_down, n->ht_down);
 811
 812         /* bump reference count as long as we hold pointer to structure */
 813         if (new->ht_down)
 814                 new->ht_down->refcnt++;
 815
 816 #ifdef CONFIG_CLS_U32_PERF
 817         /* Statistics may be incremented by readers during update
 818          * so we must keep them in tact. When the node is later destroyed
 819          * a special destroy call must be made to not free the pf memory.
 820          */
 821         new->pf = n->pf;
 822 #endif
 823
 824 #ifdef CONFIG_CLS_U32_MARK
 825         new->val = n->val;
 826         new->mask = n->mask;
 827         /* Similarly success statistics must be moved as pointers */
 828         new->pcpu_success = n->pcpu_success;
 829 #endif
 830         new->tp = tp;
 831         memcpy(&new->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
 832
 833         if (tcf_exts_init(&new->exts, TCA_U32_ACT, TCA_U32_POLICE)) {
 834                 kfree(new);
 835                 return NULL;
 836         }
 837
 838         return new;
 839 }
 840
 841 static int u32_change(struct net *net, struct sk_buff *in_skb,
 842                       struct tcf_proto *tp, unsigned long base, u32 handle,
 843                       struct nlattr **tca, unsigned long *arg, bool ovr)
 844 {
 845         struct tc_u_common *tp_c = tp->data;
 846         struct tc_u_hnode *ht;
 847         struct tc_u_knode *n;
 848         struct tc_u32_sel *s;
 849         struct nlattr *opt = tca[TCA_OPTIONS];
 850         struct nlattr *tb[TCA_U32_MAX + 1];
 851         u32 htid, flags = 0;
 852         int err;
 853 #ifdef CONFIG_CLS_U32_PERF
 854         size_t size;
 855 #endif
 856
 857         if (opt == NULL)
 858                 return handle ? -EINVAL : 0;
 859
 860         err = nla_parse_nested(tb, TCA_U32_MAX, opt, u32_policy);
 861         if (err < 0)
 862                 return err;
 863
 864         if (tb[TCA_U32_FLAGS]) {
 865                 flags = nla_get_u32(tb[TCA_U32_FLAGS]);
 866                 if (!tc_flags_valid(flags))
 867                         return -EINVAL;
 868         }
 869
 870         n = (struct tc_u_knode *)*arg;
 871         if (n) {
 872                 struct tc_u_knode *new;
 873
 874                 if (TC_U32_KEY(n->handle) == 0)
 875                         return -EINVAL;
 876
 877                 if (n->flags != flags)
 878                         return -EINVAL;
 879
 880                 new = u32_init_knode(tp, n);
 881                 if (!new)
 882                         return -ENOMEM;
 883
 884                 err = u32_set_parms(net, tp, base,
 885                                     rtnl_dereference(n->ht_up), new, tb,
 886                                     tca[TCA_RATE], ovr);
 887
 888                 if (err) {
 889                         u32_destroy_key(tp, new, false);
 890                         return err;
 891                 }
 892
 893                 err = u32_replace_hw_knode(tp, new, flags);
 894                 if (err) {
 895                         u32_destroy_key(tp, new, false);
 896                         return err;
 897                 }
 898
 899                 u32_replace_knode(tp, tp_c, new);
 900                 tcf_unbind_filter(tp, &n->res);
 901                 call_rcu(&n->rcu, u32_delete_key_rcu);
 902                 return 0;
 903         }
 904
 905         if (tb[TCA_U32_DIVISOR]) {
 906                 unsigned int divisor = nla_get_u32(tb[TCA_U32_DIVISOR]);
 907
 908                 if (--divisor > 0x100)
 909                         return -EINVAL;
 910                 if (TC_U32_KEY(handle))
 911                         return -EINVAL;
 912                 if (handle == 0) {
 913                         handle = gen_new_htid(tp->data);
 914                         if (handle == 0)
 915                                 return -ENOMEM;
 916                 }
 917                 ht = kzalloc(sizeof(*ht) + divisor*sizeof(void *), GFP_KERNEL);
 918                 if (ht == NULL)
 919                         return -ENOBUFS;
 920                 ht->tp_c = tp_c;
 921                 ht->refcnt = 1;
 922                 ht->divisor = divisor;
 923                 ht->handle = handle;
 924                 ht->prio = tp->prio;
 925
 926                 err = u32_replace_hw_hnode(tp, ht, flags);
 927                 if (err) {
 928                         kfree(ht);
 929                         return err;
 930                 }
 931
 932                 RCU_INIT_POINTER(ht->next, tp_c->hlist);
 933                 rcu_assign_pointer(tp_c->hlist, ht);
 934                 *arg = (unsigned long)ht;
 935
 936                 return 0;
 937         }
 938
 939         if (tb[TCA_U32_HASH]) {
 940                 htid = nla_get_u32(tb[TCA_U32_HASH]);
 941                 if (TC_U32_HTID(htid) == TC_U32_ROOT) {
 942                         ht = rtnl_dereference(tp->root);
 943                         htid = ht->handle;
 944                 } else {
 945                         ht = u32_lookup_ht(tp->data, TC_U32_HTID(htid));
 946                         if (ht == NULL)
 947                                 return -EINVAL;
 948                 }
 949         } else {
 950                 ht = rtnl_dereference(tp->root);
 951                 htid = ht->handle;
 952         }
 953
 954         if (ht->divisor < TC_U32_HASH(htid))
 955                 return -EINVAL;
 956
 957         if (handle) {
 958                 if (TC_U32_HTID(handle) && TC_U32_HTID(handle^htid))
 959                         return -EINVAL;
 960                 handle = htid | TC_U32_NODE(handle);
 961         } else
 962                 handle = gen_new_kid(ht, htid);
 963
 964         if (tb[TCA_U32_SEL] == NULL)
 965                 return -EINVAL;
 966
 967         s = nla_data(tb[TCA_U32_SEL]);
 968
 969         n = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key), GFP_KERNEL);
 970         if (n == NULL)
 971                 return -ENOBUFS;
 972
 973 #ifdef CONFIG_CLS_U32_PERF
 974         size = sizeof(struct tc_u32_pcnt) + s->nkeys * sizeof(u64);
 975         n->pf = __alloc_percpu(size, __alignof__(struct tc_u32_pcnt));
 976         if (!n->pf) {
 977                 kfree(n);
 978                 return -ENOBUFS;
 979         }
 980 #endif
 981
 982         memcpy(&n->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
 983         RCU_INIT_POINTER(n->ht_up, ht);
 984         n->handle = handle;
 985         n->fshift = s->hmask ? ffs(ntohl(s->hmask)) - 1 : 0;
 986         n->flags = flags;
 987         n->tp = tp;
 988
 989         err = tcf_exts_init(&n->exts, TCA_U32_ACT, TCA_U32_POLICE);
 990         if (err < 0)
 991                 goto errout;
 992
 993 #ifdef CONFIG_CLS_U32_MARK
 994         n->pcpu_success = alloc_percpu(u32);
 995         if (!n->pcpu_success) {
 996                 err = -ENOMEM;
 997                 goto errout;
 998         }
 999
1000         if (tb[TCA_U32_MARK]) {
1001                 struct tc_u32_mark *mark;
1002
1003                 mark = nla_data(tb[TCA_U32_MARK]);
1004                 n->val = mark->val;
1005                 n->mask = mark->mask;
1006         }
1007 #endif
1008
1009         err = u32_set_parms(net, tp, base, ht, n, tb, tca[TCA_RATE], ovr);
1010         if (err == 0) {
1011                 struct tc_u_knode __rcu **ins;
1012                 struct tc_u_knode *pins;
1013
1014                 err = u32_replace_hw_knode(tp, n, flags);
1015                 if (err)
1016                         goto errhw;
1017
1018                 ins = &ht->ht[TC_U32_HASH(handle)];
1019                 for (pins = rtnl_dereference(*ins); pins;
1020                      ins = &pins->next, pins = rtnl_dereference(*ins))
1021                         if (TC_U32_NODE(handle) < TC_U32_NODE(pins->handle))
1022                                 break;
1023
1024                 RCU_INIT_POINTER(n->next, pins);
1025                 rcu_assign_pointer(*ins, n);
1026                 *arg = (unsigned long)n;
1027                 return 0;
1028         }
1029
1030 errhw:
1031 #ifdef CONFIG_CLS_U32_MARK
1032         free_percpu(n->pcpu_success);
1033 #endif
1034
1035 errout:
1036         tcf_exts_destroy(&n->exts);
1037 #ifdef CONFIG_CLS_U32_PERF
1038         free_percpu(n->pf);
1039 #endif
1040         kfree(n);
1041         return err;
1042 }
1043
1044 static void u32_walk(struct tcf_proto *tp, struct tcf_walker *arg)
1045 {
1046         struct tc_u_common *tp_c = tp->data;
1047         struct tc_u_hnode *ht;
1048         struct tc_u_knode *n;
1049         unsigned int h;
1050
1051         if (arg->stop)
1052                 return;
1053
1054         for (ht = rtnl_dereference(tp_c->hlist);
1055              ht;
1056              ht = rtnl_dereference(ht->next)) {
1057                 if (ht->prio != tp->prio)
1058                         continue;
1059                 if (arg->count >= arg->skip) {
1060                         if (arg->fn(tp, (unsigned long)ht, arg) < 0) {
1061                                 arg->stop = 1;
1062                                 return;
1063                         }
1064                 }
1065                 arg->count++;
1066                 for (h = 0; h <= ht->divisor; h++) {
1067                         for (n = rtnl_dereference(ht->ht[h]);
1068                              n;
1069                              n = rtnl_dereference(n->next)) {
1070                                 if (arg->count < arg->skip) {
1071                                         arg->count++;
1072                                         continue;
1073                                 }
1074                                 if (arg->fn(tp, (unsigned long)n, arg) < 0) {
1075                                         arg->stop = 1;
1076                                         return;
1077                                 }
1078                                 arg->count++;
1079                         }
1080                 }
1081         }
1082 }
1083
1084 static int u32_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
1085                     struct sk_buff *skb, struct tcmsg *t)
1086 {
1087         struct tc_u_knode *n = (struct tc_u_knode *)fh;
1088         struct tc_u_hnode *ht_up, *ht_down;
1089         struct nlattr *nest;
1090
1091         if (n == NULL)
1092                 return skb->len;
1093
1094         t->tcm_handle = n->handle;
1095
1096         nest = nla_nest_start(skb, TCA_OPTIONS);
1097         if (nest == NULL)
1098                 goto nla_put_failure;
1099
1100         if (TC_U32_KEY(n->handle) == 0) {
1101                 struct tc_u_hnode *ht = (struct tc_u_hnode *)fh;
1102                 u32 divisor = ht->divisor + 1;
1103
1104                 if (nla_put_u32(skb, TCA_U32_DIVISOR, divisor))
1105                         goto nla_put_failure;
1106         } else {
1107 #ifdef CONFIG_CLS_U32_PERF
1108                 struct tc_u32_pcnt *gpf;
1109                 int cpu;
1110 #endif
1111
1112                 if (nla_put(skb, TCA_U32_SEL,
1113                             sizeof(n->sel) + n->sel.nkeys*sizeof(struct tc_u32_key),
1114                             &n->sel))
1115                         goto nla_put_failure;
1116
1117                 ht_up = rtnl_dereference(n->ht_up);
1118                 if (ht_up) {
1119                         u32 htid = n->handle & 0xFFFFF000;
1120                         if (nla_put_u32(skb, TCA_U32_HASH, htid))
1121                                 goto nla_put_failure;
1122                 }
1123                 if (n->res.classid &&
1124                     nla_put_u32(skb, TCA_U32_CLASSID, n->res.classid))
1125                         goto nla_put_failure;
1126
1127                 ht_down = rtnl_dereference(n->ht_down);
1128                 if (ht_down &&
1129                     nla_put_u32(skb, TCA_U32_LINK, ht_down->handle))
1130                         goto nla_put_failure;
1131
1132                 if (n->flags && nla_put_u32(skb, TCA_U32_FLAGS, n->flags))
1133                         goto nla_put_failure;
1134
1135 #ifdef CONFIG_CLS_U32_MARK
1136                 if ((n->val || n->mask)) {
1137                         struct tc_u32_mark mark = {.val = n->val,
1138                                                    .mask = n->mask,
1139                                                    .success = 0};
1140                         int cpum;
1141
1142                         for_each_possible_cpu(cpum) {
1143                                 __u32 cnt = *per_cpu_ptr(n->pcpu_success, cpum);
1144
1145                                 mark.success += cnt;
1146                         }
1147
1148                         if (nla_put(skb, TCA_U32_MARK, sizeof(mark), &mark))
1149                                 goto nla_put_failure;
1150                 }
1151 #endif
1152
1153                 if (tcf_exts_dump(skb, &n->exts) < 0)
1154                         goto nla_put_failure;
1155
1156 #ifdef CONFIG_NET_CLS_IND
1157                 if (n->ifindex) {
1158                         struct net_device *dev;
1159                         dev = __dev_get_by_index(net, n->ifindex);
1160                         if (dev && nla_put_string(skb, TCA_U32_INDEV, dev->name))
1161                                 goto nla_put_failure;
1162                 }
1163 #endif
1164 #ifdef CONFIG_CLS_U32_PERF
1165                 gpf = kzalloc(sizeof(struct tc_u32_pcnt) +
1166                               n->sel.nkeys * sizeof(u64),
1167                               GFP_KERNEL);
1168                 if (!gpf)
1169                         goto nla_put_failure;
1170
1171                 for_each_possible_cpu(cpu) {
1172                         int i;
1173                         struct tc_u32_pcnt *pf = per_cpu_ptr(n->pf, cpu);
1174
1175                         gpf->rcnt += pf->rcnt;
1176                         gpf->rhit += pf->rhit;
1177                         for (i = 0; i < n->sel.nkeys; i++)
1178                                 gpf->kcnts[i] += pf->kcnts[i];
1179                 }
1180
1181                 if (nla_put_64bit(skb, TCA_U32_PCNT,
1182                                   sizeof(struct tc_u32_pcnt) +
1183                                   n->sel.nkeys * sizeof(u64),
1184                                   gpf, TCA_U32_PAD)) {
1185                         kfree(gpf);
1186                         goto nla_put_failure;
1187                 }
1188                 kfree(gpf);
1189 #endif
1190         }
1191
1192         nla_nest_end(skb, nest);
1193
1194         if (TC_U32_KEY(n->handle))
1195                 if (tcf_exts_dump_stats(skb, &n->exts) < 0)
1196                         goto nla_put_failure;
1197         return skb->len;
1198
1199 nla_put_failure:
1200         nla_nest_cancel(skb, nest);
1201         return -1;
1202 }
1203
1204 static struct tcf_proto_ops cls_u32_ops __read_mostly = {
1205         .kind           =       "u32",
1206         .classify       =       u32_classify,
1207         .init           =       u32_init,
1208         .destroy        =       u32_destroy,
1209         .get            =       u32_get,
1210         .change         =       u32_change,
1211         .delete         =       u32_delete,
1212         .walk           =       u32_walk,
1213         .dump           =       u32_dump,
1214         .owner          =       THIS_MODULE,
1215 };
1216
1217 static int __init init_u32(void)
1218 {
1219         pr_info("u32 classifier\n");
1220 #ifdef CONFIG_CLS_U32_PERF
1221         pr_info("    Performance counters on\n");
1222 #endif
1223 #ifdef CONFIG_NET_CLS_IND
1224         pr_info("    input device check on\n");
1225 #endif
1226 #ifdef CONFIG_NET_CLS_ACT
1227         pr_info("    Actions configured\n");
1228 #endif
1229         return register_tcf_proto_ops(&cls_u32_ops);
1230 }
1231
1232 static void __exit exit_u32(void)
1233 {
1234         unregister_tcf_proto_ops(&cls_u32_ops);
1235 }
1236
1237 module_init(init_u32)
1238 module_exit(exit_u32)
1239 MODULE_LICENSE("GPL");