linux/net/sched/cls_u32.c
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   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
  47struct 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
  74struct 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
  88struct 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
  96static 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
 105static 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
 123next_ht:
 124        n = rcu_dereference_bh(ht->ht[sel]);
 125
 126next_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) {
 166check_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        }
 244out:
 245        return -1;
 246
 247deadloop:
 248        net_warn_ratelimited("cls_u32: dead loop\n");
 249        return -1;
 250}
 251
 252static struct tc_u_hnode *
 253u32_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
 266static struct tc_u_knode *
 267u32_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;
 281out:
 282        return n;
 283}
 284
 285
 286static 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
 305static 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
 320static 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
 356static 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 */
 383static 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 */
 397static 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
 404static 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
 427static 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
 442static 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
 466static 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
 477static 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
 535static 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)
 560static 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
 582static 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
 592static 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;
 644errout:
 645        tcf_exts_destroy(&e);
 646        return err;
 647}
 648
 649static 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
 676static 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
 725static 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);
 887errout:
 888#endif
 889
 890#ifdef CONFIG_CLS_U32_PERF
 891        free_percpu(n->pf);
 892#endif
 893        kfree(n);
 894        return err;
 895}
 896
 897static 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
 937static 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
1048nla_put_failure:
1049        nla_nest_cancel(skb, nest);
1050        return -1;
1051}
1052
1053static 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
1066static 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
1081static void __exit exit_u32(void)
1082{
1083        unregister_tcf_proto_ops(&cls_u32_ops);
1084}
1085
1086module_init(init_u32)
1087module_exit(exit_u32)
1088MODULE_LICENSE("GPL");
1089