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