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