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