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->refcnt++;
 338         root_ht->handle = tp_c ? gen_new_htid(tp_c) : 0x80000000;
 339         root_ht->prio = tp->prio;
 340
 341         if (tp_c == NULL) {
 342                 tp_c = kzalloc(sizeof(*tp_c), GFP_KERNEL);
 343                 if (tp_c == NULL) {
 344                         kfree(root_ht);
 345                         return -ENOBUFS;
 346                 }
 347                 tp_c->q = tp->q;
 348                 tp->q->u32_node = tp_c;
 349         }
 350
 351         tp_c->refcnt++;
 352         RCU_INIT_POINTER(root_ht->next, tp_c->hlist);
 353         rcu_assign_pointer(tp_c->hlist, root_ht);
 354         root_ht->tp_c = tp_c;
 355
 356         rcu_assign_pointer(tp->root, root_ht);
 357         tp->data = tp_c;
 358         return 0;
 359 }
 360
 361 static int u32_destroy_key(struct tcf_proto *tp, struct tc_u_knode *n,
 362                            bool free_pf)
 363 {
 364         tcf_exts_destroy(&n->exts);
 365         if (n->ht_down)
 366                 n->ht_down->refcnt--;
 367 #ifdef CONFIG_CLS_U32_PERF
 368         if (free_pf)
 369                 free_percpu(n->pf);
 370 #endif
 371 #ifdef CONFIG_CLS_U32_MARK
 372         if (free_pf)
 373                 free_percpu(n->pcpu_success);
 374 #endif
 375         kfree(n);
 376         return 0;
 377 }
 378
 379 /* u32_delete_key_rcu should be called when free'ing a copied
 380  * version of a tc_u_knode obtained from u32_init_knode(). When
 381  * copies are obtained from u32_init_knode() the statistics are
 382  * shared between the old and new copies to allow readers to
 383  * continue to update the statistics during the copy. To support
 384  * this the u32_delete_key_rcu variant does not free the percpu
 385  * statistics.
 386  */
 387 static void u32_delete_key_rcu(struct rcu_head *rcu)
 388 {
 389         struct tc_u_knode *key = container_of(rcu, struct tc_u_knode, rcu);
 390
 391         u32_destroy_key(key->tp, key, false);
 392 }
 393
 394 /* u32_delete_key_freepf_rcu is the rcu callback variant
 395  * that free's the entire structure including the statistics
 396  * percpu variables. Only use this if the key is not a copy
 397  * returned by u32_init_knode(). See u32_delete_key_rcu()
 398  * for the variant that should be used with keys return from
 399  * u32_init_knode()
 400  */
 401 static void u32_delete_key_freepf_rcu(struct rcu_head *rcu)
 402 {
 403         struct tc_u_knode *key = container_of(rcu, struct tc_u_knode, rcu);
 404
 405         u32_destroy_key(key->tp, key, true);
 406 }
 407
 408 static int u32_delete_key(struct tcf_proto *tp, struct tc_u_knode *key)
 409 {
 410         struct tc_u_knode __rcu **kp;
 411         struct tc_u_knode *pkp;
 412         struct tc_u_hnode *ht = rtnl_dereference(key->ht_up);
 413
 414         if (ht) {
 415                 kp = &ht->ht[TC_U32_HASH(key->handle)];
 416                 for (pkp = rtnl_dereference(*kp); pkp;
 417                      kp = &pkp->next, pkp = rtnl_dereference(*kp)) {
 418                         if (pkp == key) {
 419                                 RCU_INIT_POINTER(*kp, key->next);
 420
 421                                 tcf_unbind_filter(tp, &key->res);
 422                                 call_rcu(&key->rcu, u32_delete_key_freepf_rcu);
 423                                 return 0;
 424                         }
 425                 }
 426         }
 427         WARN_ON(1);
 428         return 0;
 429 }
 430
 431 static void u32_remove_hw_knode(struct tcf_proto *tp, u32 handle)
 432 {
 433         struct net_device *dev = tp->q->dev_queue->dev;
 434         struct tc_cls_u32_offload u32_offload = {0};
 435         struct tc_to_netdev offload;
 436
 437         offload.type = TC_SETUP_CLSU32;
 438         offload.cls_u32 = &u32_offload;
 439
 440         if (tc_should_offload(dev, tp, 0)) {
 441                 offload.cls_u32->command = TC_CLSU32_DELETE_KNODE;
 442                 offload.cls_u32->knode.handle = handle;
 443                 dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
 444                                               tp->protocol, &offload);
 445         }
 446 }
 447
 448 static int u32_replace_hw_hnode(struct tcf_proto *tp, struct tc_u_hnode *h,
 449                                 u32 flags)
 450 {
 451         struct net_device *dev = tp->q->dev_queue->dev;
 452         struct tc_cls_u32_offload u32_offload = {0};
 453         struct tc_to_netdev offload;
 454         int err;
 455
 456         if (!tc_should_offload(dev, tp, flags))
 457                 return tc_skip_sw(flags) ? -EINVAL : 0;
 458
 459         offload.type = TC_SETUP_CLSU32;
 460         offload.cls_u32 = &u32_offload;
 461
 462         offload.cls_u32->command = TC_CLSU32_NEW_HNODE;
 463         offload.cls_u32->hnode.divisor = h->divisor;
 464         offload.cls_u32->hnode.handle = h->handle;
 465         offload.cls_u32->hnode.prio = h->prio;
 466
 467         err = dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
 468                                             tp->protocol, &offload);
 469         if (tc_skip_sw(flags))
 470                 return err;
 471
 472         return 0;
 473 }
 474
 475 static void u32_clear_hw_hnode(struct tcf_proto *tp, struct tc_u_hnode *h)
 476 {
 477         struct net_device *dev = tp->q->dev_queue->dev;
 478         struct tc_cls_u32_offload u32_offload = {0};
 479         struct tc_to_netdev offload;
 480
 481         offload.type = TC_SETUP_CLSU32;
 482         offload.cls_u32 = &u32_offload;
 483
 484         if (tc_should_offload(dev, tp, 0)) {
 485                 offload.cls_u32->command = TC_CLSU32_DELETE_HNODE;
 486                 offload.cls_u32->hnode.divisor = h->divisor;
 487                 offload.cls_u32->hnode.handle = h->handle;
 488                 offload.cls_u32->hnode.prio = h->prio;
 489
 490                 dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
 491                                               tp->protocol, &offload);
 492         }
 493 }
 494
 495 static int u32_replace_hw_knode(struct tcf_proto *tp, struct tc_u_knode *n,
 496                                 u32 flags)
 497 {
 498         struct net_device *dev = tp->q->dev_queue->dev;
 499         struct tc_cls_u32_offload u32_offload = {0};
 500         struct tc_to_netdev offload;
 501         int err;
 502
 503         offload.type = TC_SETUP_CLSU32;
 504         offload.cls_u32 = &u32_offload;
 505
 506         if (!tc_should_offload(dev, tp, flags))
 507                 return tc_skip_sw(flags) ? -EINVAL : 0;
 508
 509         offload.cls_u32->command = TC_CLSU32_REPLACE_KNODE;
 510         offload.cls_u32->knode.handle = n->handle;
 511         offload.cls_u32->knode.fshift = n->fshift;
 512 #ifdef CONFIG_CLS_U32_MARK
 513         offload.cls_u32->knode.val = n->val;
 514         offload.cls_u32->knode.mask = n->mask;
 515 #else
 516         offload.cls_u32->knode.val = 0;
 517         offload.cls_u32->knode.mask = 0;
 518 #endif
 519         offload.cls_u32->knode.sel = &n->sel;
 520         offload.cls_u32->knode.exts = &n->exts;
 521         if (n->ht_down)
 522                 offload.cls_u32->knode.link_handle = n->ht_down->handle;
 523
 524         err = dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
 525                                             tp->protocol, &offload);
 526
 527         if (!err)
 528                 n->flags |= TCA_CLS_FLAGS_IN_HW;
 529
 530         if (tc_skip_sw(flags))
 531                 return err;
 532
 533         return 0;
 534 }
 535
 536 static void u32_clear_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
 537 {
 538         struct tc_u_knode *n;
 539         unsigned int h;
 540
 541         for (h = 0; h <= ht->divisor; h++) {
 542                 while ((n = rtnl_dereference(ht->ht[h])) != NULL) {
 543                         RCU_INIT_POINTER(ht->ht[h],
 544                                          rtnl_dereference(n->next));
 545                         tcf_unbind_filter(tp, &n->res);
 546                         u32_remove_hw_knode(tp, n->handle);
 547                         call_rcu(&n->rcu, u32_delete_key_freepf_rcu);
 548                 }
 549         }
 550 }
 551
 552 static int u32_destroy_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
 553 {
 554         struct tc_u_common *tp_c = tp->data;
 555         struct tc_u_hnode __rcu **hn;
 556         struct tc_u_hnode *phn;
 557
 558         WARN_ON(ht->refcnt);
 559
 560         u32_clear_hnode(tp, ht);
 561
 562         hn = &tp_c->hlist;
 563         for (phn = rtnl_dereference(*hn);
 564              phn;
 565              hn = &phn->next, phn = rtnl_dereference(*hn)) {
 566                 if (phn == ht) {
 567                         u32_clear_hw_hnode(tp, ht);
 568                         RCU_INIT_POINTER(*hn, ht->next);
 569                         kfree_rcu(ht, rcu);
 570                         return 0;
 571                 }
 572         }
 573
 574         return -ENOENT;
 575 }
 576
 577 static bool ht_empty(struct tc_u_hnode *ht)
 578 {
 579         unsigned int h;
 580
 581         for (h = 0; h <= ht->divisor; h++)
 582                 if (rcu_access_pointer(ht->ht[h]))
 583                         return false;
 584
 585         return true;
 586 }
 587
 588 static void u32_destroy(struct tcf_proto *tp)
 589 {
 590         struct tc_u_common *tp_c = tp->data;
 591         struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);
 592
 593         WARN_ON(root_ht == NULL);
 594
 595         if (root_ht && --root_ht->refcnt == 0)
 596                 u32_destroy_hnode(tp, root_ht);
 597
 598         if (--tp_c->refcnt == 0) {
 599                 struct tc_u_hnode *ht;
 600
 601                 tp->q->u32_node = NULL;
 602
 603                 for (ht = rtnl_dereference(tp_c->hlist);
 604                      ht;
 605                      ht = rtnl_dereference(ht->next)) {
 606                         ht->refcnt--;
 607                         u32_clear_hnode(tp, ht);
 608                 }
 609
 610                 while ((ht = rtnl_dereference(tp_c->hlist)) != NULL) {
 611                         RCU_INIT_POINTER(tp_c->hlist, ht->next);
 612                         kfree_rcu(ht, rcu);
 613                 }
 614
 615                 kfree(tp_c);
 616         }
 617
 618         tp->data = NULL;
 619 }
 620
 621 static int u32_delete(struct tcf_proto *tp, unsigned long arg, bool *last)
 622 {
 623         struct tc_u_hnode *ht = (struct tc_u_hnode *)arg;
 624         struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);
 625         struct tc_u_common *tp_c = tp->data;
 626         int ret = 0;
 627
 628         if (ht == NULL)
 629                 goto out;
 630
 631         if (TC_U32_KEY(ht->handle)) {
 632                 u32_remove_hw_knode(tp, ht->handle);
 633                 ret = u32_delete_key(tp, (struct tc_u_knode *)ht);
 634                 goto out;
 635         }
 636
 637         if (root_ht == ht)
 638                 return -EINVAL;
 639
 640         if (ht->refcnt == 1) {
 641                 ht->refcnt--;
 642                 u32_destroy_hnode(tp, ht);
 643         } else {
 644                 return -EBUSY;
 645         }
 646
 647 out:
 648         *last = true;
 649         if (root_ht) {
 650                 if (root_ht->refcnt > 1) {
 651                         *last = false;
 652                         goto ret;
 653                 }
 654                 if (root_ht->refcnt == 1) {
 655                         if (!ht_empty(root_ht)) {
 656                                 *last = false;
 657                                 goto ret;
 658                         }
 659                 }
 660         }
 661
 662         if (tp_c->refcnt > 1) {
 663                 *last = false;
 664                 goto ret;
 665         }
 666
 667         if (tp_c->refcnt == 1) {
 668                 struct tc_u_hnode *ht;
 669
 670                 for (ht = rtnl_dereference(tp_c->hlist);
 671                      ht;
 672                      ht = rtnl_dereference(ht->next))
 673                         if (!ht_empty(ht)) {
 674                                 *last = false;
 675                                 break;
 676                         }
 677         }
 678
 679 ret:
 680         return ret;
 681 }
 682
 683 #define NR_U32_NODE (1<<12)
 684 static u32 gen_new_kid(struct tc_u_hnode *ht, u32 handle)
 685 {
 686         struct tc_u_knode *n;
 687         unsigned long i;
 688         unsigned long *bitmap = kzalloc(BITS_TO_LONGS(NR_U32_NODE) * sizeof(unsigned long),
 689                                         GFP_KERNEL);
 690         if (!bitmap)
 691                 return handle | 0xFFF;
 692
 693         for (n = rtnl_dereference(ht->ht[TC_U32_HASH(handle)]);
 694              n;
 695              n = rtnl_dereference(n->next))
 696                 set_bit(TC_U32_NODE(n->handle), bitmap);
 697
 698         i = find_next_zero_bit(bitmap, NR_U32_NODE, 0x800);
 699         if (i >= NR_U32_NODE)
 700                 i = find_next_zero_bit(bitmap, NR_U32_NODE, 1);
 701
 702         kfree(bitmap);
 703         return handle | (i >= NR_U32_NODE ? 0xFFF : i);
 704 }
 705
 706 static const struct nla_policy u32_policy[TCA_U32_MAX + 1] = {
 707         [TCA_U32_CLASSID]       = { .type = NLA_U32 },
 708         [TCA_U32_HASH]          = { .type = NLA_U32 },
 709         [TCA_U32_LINK]          = { .type = NLA_U32 },
 710         [TCA_U32_DIVISOR]       = { .type = NLA_U32 },
 711         [TCA_U32_SEL]           = { .len = sizeof(struct tc_u32_sel) },
 712         [TCA_U32_INDEV]         = { .type = NLA_STRING, .len = IFNAMSIZ },
 713         [TCA_U32_MARK]          = { .len = sizeof(struct tc_u32_mark) },
 714         [TCA_U32_FLAGS]         = { .type = NLA_U32 },
 715 };
 716
 717 static int u32_set_parms(struct net *net, struct tcf_proto *tp,
 718                          unsigned long base, struct tc_u_hnode *ht,
 719                          struct tc_u_knode *n, struct nlattr **tb,
 720                          struct nlattr *est, bool ovr)
 721 {
 722         struct tcf_exts e;
 723         int err;
 724
 725         err = tcf_exts_init(&e, TCA_U32_ACT, TCA_U32_POLICE);
 726         if (err < 0)
 727                 return err;
 728         err = tcf_exts_validate(net, tp, tb, est, &e, ovr);
 729         if (err < 0)
 730                 goto errout;
 731
 732         err = -EINVAL;
 733         if (tb[TCA_U32_LINK]) {
 734                 u32 handle = nla_get_u32(tb[TCA_U32_LINK]);
 735                 struct tc_u_hnode *ht_down = NULL, *ht_old;
 736
 737                 if (TC_U32_KEY(handle))
 738                         goto errout;
 739
 740                 if (handle) {
 741                         ht_down = u32_lookup_ht(ht->tp_c, handle);
 742
 743                         if (ht_down == NULL)
 744                                 goto errout;
 745                         ht_down->refcnt++;
 746                 }
 747
 748                 ht_old = rtnl_dereference(n->ht_down);
 749                 rcu_assign_pointer(n->ht_down, ht_down);
 750
 751                 if (ht_old)
 752                         ht_old->refcnt--;
 753         }
 754         if (tb[TCA_U32_CLASSID]) {
 755                 n->res.classid = nla_get_u32(tb[TCA_U32_CLASSID]);
 756                 tcf_bind_filter(tp, &n->res, base);
 757         }
 758
 759 #ifdef CONFIG_NET_CLS_IND
 760         if (tb[TCA_U32_INDEV]) {
 761                 int ret;
 762                 ret = tcf_change_indev(net, tb[TCA_U32_INDEV]);
 763                 if (ret < 0)
 764                         goto errout;
 765                 n->ifindex = ret;
 766         }
 767 #endif
 768         tcf_exts_change(tp, &n->exts, &e);
 769
 770         return 0;
 771 errout:
 772         tcf_exts_destroy(&e);
 773         return err;
 774 }
 775
 776 static void u32_replace_knode(struct tcf_proto *tp, struct tc_u_common *tp_c,
 777                               struct tc_u_knode *n)
 778 {
 779         struct tc_u_knode __rcu **ins;
 780         struct tc_u_knode *pins;
 781         struct tc_u_hnode *ht;
 782
 783         if (TC_U32_HTID(n->handle) == TC_U32_ROOT)
 784                 ht = rtnl_dereference(tp->root);
 785         else
 786                 ht = u32_lookup_ht(tp_c, TC_U32_HTID(n->handle));
 787
 788         ins = &ht->ht[TC_U32_HASH(n->handle)];
 789
 790         /* The node must always exist for it to be replaced if this is not the
 791          * case then something went very wrong elsewhere.
 792          */
 793         for (pins = rtnl_dereference(*ins); ;
 794              ins = &pins->next, pins = rtnl_dereference(*ins))
 795                 if (pins->handle == n->handle)
 796                         break;
 797
 798         RCU_INIT_POINTER(n->next, pins->next);
 799         rcu_assign_pointer(*ins, n);
 800 }
 801
 802 static struct tc_u_knode *u32_init_knode(struct tcf_proto *tp,
 803                                          struct tc_u_knode *n)
 804 {
 805         struct tc_u_knode *new;
 806         struct tc_u32_sel *s = &n->sel;
 807
 808         new = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key),
 809                       GFP_KERNEL);
 810
 811         if (!new)
 812                 return NULL;
 813
 814         RCU_INIT_POINTER(new->next, n->next);
 815         new->handle = n->handle;
 816         RCU_INIT_POINTER(new->ht_up, n->ht_up);
 817
 818 #ifdef CONFIG_NET_CLS_IND
 819         new->ifindex = n->ifindex;
 820 #endif
 821         new->fshift = n->fshift;
 822         new->res = n->res;
 823         new->flags = n->flags;
 824         RCU_INIT_POINTER(new->ht_down, n->ht_down);
 825
 826         /* bump reference count as long as we hold pointer to structure */
 827         if (new->ht_down)
 828                 new->ht_down->refcnt++;
 829
 830 #ifdef CONFIG_CLS_U32_PERF
 831         /* Statistics may be incremented by readers during update
 832          * so we must keep them in tact. When the node is later destroyed
 833          * a special destroy call must be made to not free the pf memory.
 834          */
 835         new->pf = n->pf;
 836 #endif
 837
 838 #ifdef CONFIG_CLS_U32_MARK
 839         new->val = n->val;
 840         new->mask = n->mask;
 841         /* Similarly success statistics must be moved as pointers */
 842         new->pcpu_success = n->pcpu_success;
 843 #endif
 844         new->tp = tp;
 845         memcpy(&new->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
 846
 847         if (tcf_exts_init(&new->exts, TCA_U32_ACT, TCA_U32_POLICE)) {
 848                 kfree(new);
 849                 return NULL;
 850         }
 851
 852         return new;
 853 }
 854
 855 static int u32_change(struct net *net, struct sk_buff *in_skb,
 856                       struct tcf_proto *tp, unsigned long base, u32 handle,
 857                       struct nlattr **tca, unsigned long *arg, bool ovr)
 858 {
 859         struct tc_u_common *tp_c = tp->data;
 860         struct tc_u_hnode *ht;
 861         struct tc_u_knode *n;
 862         struct tc_u32_sel *s;
 863         struct nlattr *opt = tca[TCA_OPTIONS];
 864         struct nlattr *tb[TCA_U32_MAX + 1];
 865         u32 htid, flags = 0;
 866         int err;
 867 #ifdef CONFIG_CLS_U32_PERF
 868         size_t size;
 869 #endif
 870
 871         if (opt == NULL)
 872                 return handle ? -EINVAL : 0;
 873
 874         err = nla_parse_nested(tb, TCA_U32_MAX, opt, u32_policy, NULL);
 875         if (err < 0)
 876                 return err;
 877
 878         if (tb[TCA_U32_FLAGS]) {
 879                 flags = nla_get_u32(tb[TCA_U32_FLAGS]);
 880                 if (!tc_flags_valid(flags))
 881                         return -EINVAL;
 882         }
 883
 884         n = (struct tc_u_knode *)*arg;
 885         if (n) {
 886                 struct tc_u_knode *new;
 887
 888                 if (TC_U32_KEY(n->handle) == 0)
 889                         return -EINVAL;
 890
 891                 if (n->flags != flags)
 892                         return -EINVAL;
 893
 894                 new = u32_init_knode(tp, n);
 895                 if (!new)
 896                         return -ENOMEM;
 897
 898                 err = u32_set_parms(net, tp, base,
 899                                     rtnl_dereference(n->ht_up), new, tb,
 900                                     tca[TCA_RATE], ovr);
 901
 902                 if (err) {
 903                         u32_destroy_key(tp, new, false);
 904                         return err;
 905                 }
 906
 907                 err = u32_replace_hw_knode(tp, new, flags);
 908                 if (err) {
 909                         u32_destroy_key(tp, new, false);
 910                         return err;
 911                 }
 912
 913                 if (!tc_in_hw(new->flags))
 914                         new->flags |= TCA_CLS_FLAGS_NOT_IN_HW;
 915
 916                 u32_replace_knode(tp, tp_c, new);
 917                 tcf_unbind_filter(tp, &n->res);
 918                 call_rcu(&n->rcu, u32_delete_key_rcu);
 919                 return 0;
 920         }
 921
 922         if (tb[TCA_U32_DIVISOR]) {
 923                 unsigned int divisor = nla_get_u32(tb[TCA_U32_DIVISOR]);
 924
 925                 if (--divisor > 0x100)
 926                         return -EINVAL;
 927                 if (TC_U32_KEY(handle))
 928                         return -EINVAL;
 929                 if (handle == 0) {
 930                         handle = gen_new_htid(tp->data);
 931                         if (handle == 0)
 932                                 return -ENOMEM;
 933                 }
 934                 ht = kzalloc(sizeof(*ht) + divisor*sizeof(void *), GFP_KERNEL);
 935                 if (ht == NULL)
 936                         return -ENOBUFS;
 937                 ht->tp_c = tp_c;
 938                 ht->refcnt = 1;
 939                 ht->divisor = divisor;
 940                 ht->handle = handle;
 941                 ht->prio = tp->prio;
 942
 943                 err = u32_replace_hw_hnode(tp, ht, flags);
 944                 if (err) {
 945                         kfree(ht);
 946                         return err;
 947                 }
 948
 949                 RCU_INIT_POINTER(ht->next, tp_c->hlist);
 950                 rcu_assign_pointer(tp_c->hlist, ht);
 951                 *arg = (unsigned long)ht;
 952
 953                 return 0;
 954         }
 955
 956         if (tb[TCA_U32_HASH]) {
 957                 htid = nla_get_u32(tb[TCA_U32_HASH]);
 958                 if (TC_U32_HTID(htid) == TC_U32_ROOT) {
 959                         ht = rtnl_dereference(tp->root);
 960                         htid = ht->handle;
 961                 } else {
 962                         ht = u32_lookup_ht(tp->data, TC_U32_HTID(htid));
 963                         if (ht == NULL)
 964                                 return -EINVAL;
 965                 }
 966         } else {
 967                 ht = rtnl_dereference(tp->root);
 968                 htid = ht->handle;
 969         }
 970
 971         if (ht->divisor < TC_U32_HASH(htid))
 972                 return -EINVAL;
 973
 974         if (handle) {
 975                 if (TC_U32_HTID(handle) && TC_U32_HTID(handle^htid))
 976                         return -EINVAL;
 977                 handle = htid | TC_U32_NODE(handle);
 978         } else
 979                 handle = gen_new_kid(ht, htid);
 980
 981         if (tb[TCA_U32_SEL] == NULL)
 982                 return -EINVAL;
 983
 984         s = nla_data(tb[TCA_U32_SEL]);
 985
 986         n = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key), GFP_KERNEL);
 987         if (n == NULL)
 988                 return -ENOBUFS;
 989
 990 #ifdef CONFIG_CLS_U32_PERF
 991         size = sizeof(struct tc_u32_pcnt) + s->nkeys * sizeof(u64);
 992         n->pf = __alloc_percpu(size, __alignof__(struct tc_u32_pcnt));
 993         if (!n->pf) {
 994                 kfree(n);
 995                 return -ENOBUFS;
 996         }
 997 #endif
 998
 999         memcpy(&n->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
1000         RCU_INIT_POINTER(n->ht_up, ht);
1001         n->handle = handle;
1002         n->fshift = s->hmask ? ffs(ntohl(s->hmask)) - 1 : 0;
1003         n->flags = flags;
1004         n->tp = tp;
1005
1006         err = tcf_exts_init(&n->exts, TCA_U32_ACT, TCA_U32_POLICE);
1007         if (err < 0)
1008                 goto errout;
1009
1010 #ifdef CONFIG_CLS_U32_MARK
1011         n->pcpu_success = alloc_percpu(u32);
1012         if (!n->pcpu_success) {
1013                 err = -ENOMEM;
1014                 goto errout;
1015         }
1016
1017         if (tb[TCA_U32_MARK]) {
1018                 struct tc_u32_mark *mark;
1019
1020                 mark = nla_data(tb[TCA_U32_MARK]);
1021                 n->val = mark->val;
1022                 n->mask = mark->mask;
1023         }
1024 #endif
1025
1026         err = u32_set_parms(net, tp, base, ht, n, tb, tca[TCA_RATE], ovr);
1027         if (err == 0) {
1028                 struct tc_u_knode __rcu **ins;
1029                 struct tc_u_knode *pins;
1030
1031                 err = u32_replace_hw_knode(tp, n, flags);
1032                 if (err)
1033                         goto errhw;
1034
1035                 if (!tc_in_hw(n->flags))
1036                         n->flags |= TCA_CLS_FLAGS_NOT_IN_HW;
1037
1038                 ins = &ht->ht[TC_U32_HASH(handle)];
1039                 for (pins = rtnl_dereference(*ins); pins;
1040                      ins = &pins->next, pins = rtnl_dereference(*ins))
1041                         if (TC_U32_NODE(handle) < TC_U32_NODE(pins->handle))
1042                                 break;
1043
1044                 RCU_INIT_POINTER(n->next, pins);
1045                 rcu_assign_pointer(*ins, n);
1046                 *arg = (unsigned long)n;
1047                 return 0;
1048         }
1049
1050 errhw:
1051 #ifdef CONFIG_CLS_U32_MARK
1052         free_percpu(n->pcpu_success);
1053 #endif
1054
1055 errout:
1056         tcf_exts_destroy(&n->exts);
1057 #ifdef CONFIG_CLS_U32_PERF
1058         free_percpu(n->pf);
1059 #endif
1060         kfree(n);
1061         return err;
1062 }
1063
1064 static void u32_walk(struct tcf_proto *tp, struct tcf_walker *arg)
1065 {
1066         struct tc_u_common *tp_c = tp->data;
1067         struct tc_u_hnode *ht;
1068         struct tc_u_knode *n;
1069         unsigned int h;
1070
1071         if (arg->stop)
1072                 return;
1073
1074         for (ht = rtnl_dereference(tp_c->hlist);
1075              ht;
1076              ht = rtnl_dereference(ht->next)) {
1077                 if (ht->prio != tp->prio)
1078                         continue;
1079                 if (arg->count >= arg->skip) {
1080                         if (arg->fn(tp, (unsigned long)ht, arg) < 0) {
1081                                 arg->stop = 1;
1082                                 return;
1083                         }
1084                 }
1085                 arg->count++;
1086                 for (h = 0; h <= ht->divisor; h++) {
1087                         for (n = rtnl_dereference(ht->ht[h]);
1088                              n;
1089                              n = rtnl_dereference(n->next)) {
1090                                 if (arg->count < arg->skip) {
1091                                         arg->count++;
1092                                         continue;
1093                                 }
1094                                 if (arg->fn(tp, (unsigned long)n, arg) < 0) {
1095                                         arg->stop = 1;
1096                                         return;
1097                                 }
1098                                 arg->count++;
1099                         }
1100                 }
1101         }
1102 }
1103
1104 static int u32_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
1105                     struct sk_buff *skb, struct tcmsg *t)
1106 {
1107         struct tc_u_knode *n = (struct tc_u_knode *)fh;
1108         struct tc_u_hnode *ht_up, *ht_down;
1109         struct nlattr *nest;
1110
1111         if (n == NULL)
1112                 return skb->len;
1113
1114         t->tcm_handle = n->handle;
1115
1116         nest = nla_nest_start(skb, TCA_OPTIONS);
1117         if (nest == NULL)
1118                 goto nla_put_failure;
1119
1120         if (TC_U32_KEY(n->handle) == 0) {
1121                 struct tc_u_hnode *ht = (struct tc_u_hnode *)fh;
1122                 u32 divisor = ht->divisor + 1;
1123
1124                 if (nla_put_u32(skb, TCA_U32_DIVISOR, divisor))
1125                         goto nla_put_failure;
1126         } else {
1127 #ifdef CONFIG_CLS_U32_PERF
1128                 struct tc_u32_pcnt *gpf;
1129                 int cpu;
1130 #endif
1131
1132                 if (nla_put(skb, TCA_U32_SEL,
1133                             sizeof(n->sel) + n->sel.nkeys*sizeof(struct tc_u32_key),
1134                             &n->sel))
1135                         goto nla_put_failure;
1136
1137                 ht_up = rtnl_dereference(n->ht_up);
1138                 if (ht_up) {
1139                         u32 htid = n->handle & 0xFFFFF000;
1140                         if (nla_put_u32(skb, TCA_U32_HASH, htid))
1141                                 goto nla_put_failure;
1142                 }
1143                 if (n->res.classid &&
1144                     nla_put_u32(skb, TCA_U32_CLASSID, n->res.classid))
1145                         goto nla_put_failure;
1146
1147                 ht_down = rtnl_dereference(n->ht_down);
1148                 if (ht_down &&
1149                     nla_put_u32(skb, TCA_U32_LINK, ht_down->handle))
1150                         goto nla_put_failure;
1151
1152                 if (n->flags && nla_put_u32(skb, TCA_U32_FLAGS, n->flags))
1153                         goto nla_put_failure;
1154
1155 #ifdef CONFIG_CLS_U32_MARK
1156                 if ((n->val || n->mask)) {
1157                         struct tc_u32_mark mark = {.val = n->val,
1158                                                    .mask = n->mask,
1159                                                    .success = 0};
1160                         int cpum;
1161
1162                         for_each_possible_cpu(cpum) {
1163                                 __u32 cnt = *per_cpu_ptr(n->pcpu_success, cpum);
1164
1165                                 mark.success += cnt;
1166                         }
1167
1168                         if (nla_put(skb, TCA_U32_MARK, sizeof(mark), &mark))
1169                                 goto nla_put_failure;
1170                 }
1171 #endif
1172
1173                 if (tcf_exts_dump(skb, &n->exts) < 0)
1174                         goto nla_put_failure;
1175
1176 #ifdef CONFIG_NET_CLS_IND
1177                 if (n->ifindex) {
1178                         struct net_device *dev;
1179                         dev = __dev_get_by_index(net, n->ifindex);
1180                         if (dev && nla_put_string(skb, TCA_U32_INDEV, dev->name))
1181                                 goto nla_put_failure;
1182                 }
1183 #endif
1184 #ifdef CONFIG_CLS_U32_PERF
1185                 gpf = kzalloc(sizeof(struct tc_u32_pcnt) +
1186                               n->sel.nkeys * sizeof(u64),
1187                               GFP_KERNEL);
1188                 if (!gpf)
1189                         goto nla_put_failure;
1190
1191                 for_each_possible_cpu(cpu) {
1192                         int i;
1193                         struct tc_u32_pcnt *pf = per_cpu_ptr(n->pf, cpu);
1194
1195                         gpf->rcnt += pf->rcnt;
1196                         gpf->rhit += pf->rhit;
1197                         for (i = 0; i < n->sel.nkeys; i++)
1198                                 gpf->kcnts[i] += pf->kcnts[i];
1199                 }
1200
1201                 if (nla_put_64bit(skb, TCA_U32_PCNT,
1202                                   sizeof(struct tc_u32_pcnt) +
1203                                   n->sel.nkeys * sizeof(u64),
1204                                   gpf, TCA_U32_PAD)) {
1205                         kfree(gpf);
1206                         goto nla_put_failure;
1207                 }
1208                 kfree(gpf);
1209 #endif
1210         }
1211
1212         nla_nest_end(skb, nest);
1213
1214         if (TC_U32_KEY(n->handle))
1215                 if (tcf_exts_dump_stats(skb, &n->exts) < 0)
1216                         goto nla_put_failure;
1217         return skb->len;
1218
1219 nla_put_failure:
1220         nla_nest_cancel(skb, nest);
1221         return -1;
1222 }
1223
1224 static struct tcf_proto_ops cls_u32_ops __read_mostly = {
1225         .kind           =       "u32",
1226         .classify       =       u32_classify,
1227         .init           =       u32_init,
1228         .destroy        =       u32_destroy,
1229         .get            =       u32_get,
1230         .change         =       u32_change,
1231         .delete         =       u32_delete,
1232         .walk           =       u32_walk,
1233         .dump           =       u32_dump,
1234         .owner          =       THIS_MODULE,
1235 };
1236
1237 static int __init init_u32(void)
1238 {
1239         pr_info("u32 classifier\n");
1240 #ifdef CONFIG_CLS_U32_PERF
1241         pr_info("    Performance counters on\n");
1242 #endif
1243 #ifdef CONFIG_NET_CLS_IND
1244         pr_info("    input device check on\n");
1245 #endif
1246 #ifdef CONFIG_NET_CLS_ACT
1247         pr_info("    Actions configured\n");
1248 #endif
1249         return register_tcf_proto_ops(&cls_u32_ops);
1250 }
1251
1252 static void __exit exit_u32(void)
1253 {
1254         unregister_tcf_proto_ops(&cls_u32_ops);
1255 }
1256
1257 module_init(init_u32)
1258 module_exit(exit_u32)
1259 MODULE_LICENSE("GPL");