linux/net/sched/em_meta.c
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   1/*
   2 * net/sched/em_meta.c  Metadata ematch
   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:     Thomas Graf <tgraf@suug.ch>
  10 *
  11 * ==========================================================================
  12 *
  13 *      The metadata ematch compares two meta objects where each object
  14 *      represents either a meta value stored in the kernel or a static
  15 *      value provided by userspace. The objects are not provided by
  16 *      userspace itself but rather a definition providing the information
  17 *      to build them. Every object is of a certain type which must be
  18 *      equal to the object it is being compared to.
  19 *
  20 *      The definition of a objects conists of the type (meta type), a
  21 *      identifier (meta id) and additional type specific information.
  22 *      The meta id is either TCF_META_TYPE_VALUE for values provided by
  23 *      userspace or a index to the meta operations table consisting of
  24 *      function pointers to type specific meta data collectors returning
  25 *      the value of the requested meta value.
  26 *
  27 *               lvalue                                   rvalue
  28 *            +-----------+                           +-----------+
  29 *            | type: INT |                           | type: INT |
  30 *       def  | id: DEV   |                           | id: VALUE |
  31 *            | data:     |                           | data: 3   |
  32 *            +-----------+                           +-----------+
  33 *                  |                                       |
  34 *                  ---> meta_ops[INT][DEV](...)            |
  35 *                            |                             |
  36 *                  -----------                             |
  37 *                  V                                       V
  38 *            +-----------+                           +-----------+
  39 *            | type: INT |                           | type: INT |
  40 *       obj  | id: DEV |                             | id: VALUE |
  41 *            | data: 2   |<--data got filled out     | data: 3   |
  42 *            +-----------+                           +-----------+
  43 *                  |                                         |
  44 *                  --------------> 2  equals 3 <--------------
  45 *
  46 *      This is a simplified schema, the complexity varies depending
  47 *      on the meta type. Obviously, the length of the data must also
  48 *      be provided for non-numeric types.
  49 *
  50 *      Additionaly, type dependant modifiers such as shift operators
  51 *      or mask may be applied to extend the functionaliy. As of now,
  52 *      the variable length type supports shifting the byte string to
  53 *      the right, eating up any number of octets and thus supporting
  54 *      wildcard interface name comparisons such as "ppp%" matching
  55 *      ppp0..9.
  56 *
  57 *      NOTE: Certain meta values depend on other subsystems and are
  58 *            only available if that subsystem is enabled in the kernel.
  59 */
  60
  61#include <linux/slab.h>
  62#include <linux/module.h>
  63#include <linux/types.h>
  64#include <linux/kernel.h>
  65#include <linux/sched.h>
  66#include <linux/string.h>
  67#include <linux/skbuff.h>
  68#include <linux/random.h>
  69#include <linux/if_vlan.h>
  70#include <linux/tc_ematch/tc_em_meta.h>
  71#include <net/dst.h>
  72#include <net/route.h>
  73#include <net/pkt_cls.h>
  74#include <net/sock.h>
  75
  76struct meta_obj
  77{
  78        unsigned long           value;
  79        unsigned int            len;
  80};
  81
  82struct meta_value
  83{
  84        struct tcf_meta_val     hdr;
  85        unsigned long           val;
  86        unsigned int            len;
  87};
  88
  89struct meta_match
  90{
  91        struct meta_value       lvalue;
  92        struct meta_value       rvalue;
  93};
  94
  95static inline int meta_id(struct meta_value *v)
  96{
  97        return TCF_META_ID(v->hdr.kind);
  98}
  99
 100static inline int meta_type(struct meta_value *v)
 101{
 102        return TCF_META_TYPE(v->hdr.kind);
 103}
 104
 105#define META_COLLECTOR(FUNC) static void meta_##FUNC(struct sk_buff *skb, \
 106        struct tcf_pkt_info *info, struct meta_value *v, \
 107        struct meta_obj *dst, int *err)
 108
 109/**************************************************************************
 110 * System status & misc
 111 **************************************************************************/
 112
 113META_COLLECTOR(int_random)
 114{
 115        get_random_bytes(&dst->value, sizeof(dst->value));
 116}
 117
 118static inline unsigned long fixed_loadavg(int load)
 119{
 120        int rnd_load = load + (FIXED_1/200);
 121        int rnd_frac = ((rnd_load & (FIXED_1-1)) * 100) >> FSHIFT;
 122
 123        return ((rnd_load >> FSHIFT) * 100) + rnd_frac;
 124}
 125
 126META_COLLECTOR(int_loadavg_0)
 127{
 128        dst->value = fixed_loadavg(avenrun[0]);
 129}
 130
 131META_COLLECTOR(int_loadavg_1)
 132{
 133        dst->value = fixed_loadavg(avenrun[1]);
 134}
 135
 136META_COLLECTOR(int_loadavg_2)
 137{
 138        dst->value = fixed_loadavg(avenrun[2]);
 139}
 140
 141/**************************************************************************
 142 * Device names & indices
 143 **************************************************************************/
 144
 145static inline int int_dev(struct net_device *dev, struct meta_obj *dst)
 146{
 147        if (unlikely(dev == NULL))
 148                return -1;
 149
 150        dst->value = dev->ifindex;
 151        return 0;
 152}
 153
 154static inline int var_dev(struct net_device *dev, struct meta_obj *dst)
 155{
 156        if (unlikely(dev == NULL))
 157                return -1;
 158
 159        dst->value = (unsigned long) dev->name;
 160        dst->len = strlen(dev->name);
 161        return 0;
 162}
 163
 164META_COLLECTOR(int_dev)
 165{
 166        *err = int_dev(skb->dev, dst);
 167}
 168
 169META_COLLECTOR(var_dev)
 170{
 171        *err = var_dev(skb->dev, dst);
 172}
 173
 174/**************************************************************************
 175 * vlan tag
 176 **************************************************************************/
 177
 178META_COLLECTOR(int_vlan_tag)
 179{
 180        unsigned short tag;
 181
 182        tag = vlan_tx_tag_get(skb);
 183        if (!tag && __vlan_get_tag(skb, &tag))
 184                *err = -1;
 185        else
 186                dst->value = tag;
 187}
 188
 189
 190
 191/**************************************************************************
 192 * skb attributes
 193 **************************************************************************/
 194
 195META_COLLECTOR(int_priority)
 196{
 197        dst->value = skb->priority;
 198}
 199
 200META_COLLECTOR(int_protocol)
 201{
 202        /* Let userspace take care of the byte ordering */
 203        dst->value = skb->protocol;
 204}
 205
 206META_COLLECTOR(int_pkttype)
 207{
 208        dst->value = skb->pkt_type;
 209}
 210
 211META_COLLECTOR(int_pktlen)
 212{
 213        dst->value = skb->len;
 214}
 215
 216META_COLLECTOR(int_datalen)
 217{
 218        dst->value = skb->data_len;
 219}
 220
 221META_COLLECTOR(int_maclen)
 222{
 223        dst->value = skb->mac_len;
 224}
 225
 226META_COLLECTOR(int_rxhash)
 227{
 228        dst->value = skb_get_rxhash(skb);
 229}
 230
 231/**************************************************************************
 232 * Netfilter
 233 **************************************************************************/
 234
 235META_COLLECTOR(int_mark)
 236{
 237        dst->value = skb->mark;
 238}
 239
 240/**************************************************************************
 241 * Traffic Control
 242 **************************************************************************/
 243
 244META_COLLECTOR(int_tcindex)
 245{
 246        dst->value = skb->tc_index;
 247}
 248
 249/**************************************************************************
 250 * Routing
 251 **************************************************************************/
 252
 253META_COLLECTOR(int_rtclassid)
 254{
 255        if (unlikely(skb_dst(skb) == NULL))
 256                *err = -1;
 257        else
 258#ifdef CONFIG_NET_CLS_ROUTE
 259                dst->value = skb_dst(skb)->tclassid;
 260#else
 261                dst->value = 0;
 262#endif
 263}
 264
 265META_COLLECTOR(int_rtiif)
 266{
 267        if (unlikely(skb_rtable(skb) == NULL))
 268                *err = -1;
 269        else
 270                dst->value = skb_rtable(skb)->fl.iif;
 271}
 272
 273/**************************************************************************
 274 * Socket Attributes
 275 **************************************************************************/
 276
 277#define SKIP_NONLOCAL(skb)                      \
 278        if (unlikely(skb->sk == NULL)) {        \
 279                *err = -1;                      \
 280                return;                         \
 281        }
 282
 283META_COLLECTOR(int_sk_family)
 284{
 285        SKIP_NONLOCAL(skb);
 286        dst->value = skb->sk->sk_family;
 287}
 288
 289META_COLLECTOR(int_sk_state)
 290{
 291        SKIP_NONLOCAL(skb);
 292        dst->value = skb->sk->sk_state;
 293}
 294
 295META_COLLECTOR(int_sk_reuse)
 296{
 297        SKIP_NONLOCAL(skb);
 298        dst->value = skb->sk->sk_reuse;
 299}
 300
 301META_COLLECTOR(int_sk_bound_if)
 302{
 303        SKIP_NONLOCAL(skb);
 304        /* No error if bound_dev_if is 0, legal userspace check */
 305        dst->value = skb->sk->sk_bound_dev_if;
 306}
 307
 308META_COLLECTOR(var_sk_bound_if)
 309{
 310        SKIP_NONLOCAL(skb);
 311
 312        if (skb->sk->sk_bound_dev_if == 0) {
 313                dst->value = (unsigned long) "any";
 314                dst->len = 3;
 315        } else {
 316                struct net_device *dev;
 317
 318                rcu_read_lock();
 319                dev = dev_get_by_index_rcu(sock_net(skb->sk),
 320                                           skb->sk->sk_bound_dev_if);
 321                *err = var_dev(dev, dst);
 322                rcu_read_unlock();
 323        }
 324}
 325
 326META_COLLECTOR(int_sk_refcnt)
 327{
 328        SKIP_NONLOCAL(skb);
 329        dst->value = atomic_read(&skb->sk->sk_refcnt);
 330}
 331
 332META_COLLECTOR(int_sk_rcvbuf)
 333{
 334        SKIP_NONLOCAL(skb);
 335        dst->value = skb->sk->sk_rcvbuf;
 336}
 337
 338META_COLLECTOR(int_sk_shutdown)
 339{
 340        SKIP_NONLOCAL(skb);
 341        dst->value = skb->sk->sk_shutdown;
 342}
 343
 344META_COLLECTOR(int_sk_proto)
 345{
 346        SKIP_NONLOCAL(skb);
 347        dst->value = skb->sk->sk_protocol;
 348}
 349
 350META_COLLECTOR(int_sk_type)
 351{
 352        SKIP_NONLOCAL(skb);
 353        dst->value = skb->sk->sk_type;
 354}
 355
 356META_COLLECTOR(int_sk_rmem_alloc)
 357{
 358        SKIP_NONLOCAL(skb);
 359        dst->value = sk_rmem_alloc_get(skb->sk);
 360}
 361
 362META_COLLECTOR(int_sk_wmem_alloc)
 363{
 364        SKIP_NONLOCAL(skb);
 365        dst->value = sk_wmem_alloc_get(skb->sk);
 366}
 367
 368META_COLLECTOR(int_sk_omem_alloc)
 369{
 370        SKIP_NONLOCAL(skb);
 371        dst->value = atomic_read(&skb->sk->sk_omem_alloc);
 372}
 373
 374META_COLLECTOR(int_sk_rcv_qlen)
 375{
 376        SKIP_NONLOCAL(skb);
 377        dst->value = skb->sk->sk_receive_queue.qlen;
 378}
 379
 380META_COLLECTOR(int_sk_snd_qlen)
 381{
 382        SKIP_NONLOCAL(skb);
 383        dst->value = skb->sk->sk_write_queue.qlen;
 384}
 385
 386META_COLLECTOR(int_sk_wmem_queued)
 387{
 388        SKIP_NONLOCAL(skb);
 389        dst->value = skb->sk->sk_wmem_queued;
 390}
 391
 392META_COLLECTOR(int_sk_fwd_alloc)
 393{
 394        SKIP_NONLOCAL(skb);
 395        dst->value = skb->sk->sk_forward_alloc;
 396}
 397
 398META_COLLECTOR(int_sk_sndbuf)
 399{
 400        SKIP_NONLOCAL(skb);
 401        dst->value = skb->sk->sk_sndbuf;
 402}
 403
 404META_COLLECTOR(int_sk_alloc)
 405{
 406        SKIP_NONLOCAL(skb);
 407        dst->value = skb->sk->sk_allocation;
 408}
 409
 410META_COLLECTOR(int_sk_route_caps)
 411{
 412        SKIP_NONLOCAL(skb);
 413        dst->value = skb->sk->sk_route_caps;
 414}
 415
 416META_COLLECTOR(int_sk_hash)
 417{
 418        SKIP_NONLOCAL(skb);
 419        dst->value = skb->sk->sk_hash;
 420}
 421
 422META_COLLECTOR(int_sk_lingertime)
 423{
 424        SKIP_NONLOCAL(skb);
 425        dst->value = skb->sk->sk_lingertime / HZ;
 426}
 427
 428META_COLLECTOR(int_sk_err_qlen)
 429{
 430        SKIP_NONLOCAL(skb);
 431        dst->value = skb->sk->sk_error_queue.qlen;
 432}
 433
 434META_COLLECTOR(int_sk_ack_bl)
 435{
 436        SKIP_NONLOCAL(skb);
 437        dst->value = skb->sk->sk_ack_backlog;
 438}
 439
 440META_COLLECTOR(int_sk_max_ack_bl)
 441{
 442        SKIP_NONLOCAL(skb);
 443        dst->value = skb->sk->sk_max_ack_backlog;
 444}
 445
 446META_COLLECTOR(int_sk_prio)
 447{
 448        SKIP_NONLOCAL(skb);
 449        dst->value = skb->sk->sk_priority;
 450}
 451
 452META_COLLECTOR(int_sk_rcvlowat)
 453{
 454        SKIP_NONLOCAL(skb);
 455        dst->value = skb->sk->sk_rcvlowat;
 456}
 457
 458META_COLLECTOR(int_sk_rcvtimeo)
 459{
 460        SKIP_NONLOCAL(skb);
 461        dst->value = skb->sk->sk_rcvtimeo / HZ;
 462}
 463
 464META_COLLECTOR(int_sk_sndtimeo)
 465{
 466        SKIP_NONLOCAL(skb);
 467        dst->value = skb->sk->sk_sndtimeo / HZ;
 468}
 469
 470META_COLLECTOR(int_sk_sendmsg_off)
 471{
 472        SKIP_NONLOCAL(skb);
 473        dst->value = skb->sk->sk_sndmsg_off;
 474}
 475
 476META_COLLECTOR(int_sk_write_pend)
 477{
 478        SKIP_NONLOCAL(skb);
 479        dst->value = skb->sk->sk_write_pending;
 480}
 481
 482/**************************************************************************
 483 * Meta value collectors assignment table
 484 **************************************************************************/
 485
 486struct meta_ops
 487{
 488        void            (*get)(struct sk_buff *, struct tcf_pkt_info *,
 489                               struct meta_value *, struct meta_obj *, int *);
 490};
 491
 492#define META_ID(name) TCF_META_ID_##name
 493#define META_FUNC(name) { .get = meta_##name }
 494
 495/* Meta value operations table listing all meta value collectors and
 496 * assigns them to a type and meta id. */
 497static struct meta_ops __meta_ops[TCF_META_TYPE_MAX+1][TCF_META_ID_MAX+1] = {
 498        [TCF_META_TYPE_VAR] = {
 499                [META_ID(DEV)]                  = META_FUNC(var_dev),
 500                [META_ID(SK_BOUND_IF)]          = META_FUNC(var_sk_bound_if),
 501        },
 502        [TCF_META_TYPE_INT] = {
 503                [META_ID(RANDOM)]               = META_FUNC(int_random),
 504                [META_ID(LOADAVG_0)]            = META_FUNC(int_loadavg_0),
 505                [META_ID(LOADAVG_1)]            = META_FUNC(int_loadavg_1),
 506                [META_ID(LOADAVG_2)]            = META_FUNC(int_loadavg_2),
 507                [META_ID(DEV)]                  = META_FUNC(int_dev),
 508                [META_ID(PRIORITY)]             = META_FUNC(int_priority),
 509                [META_ID(PROTOCOL)]             = META_FUNC(int_protocol),
 510                [META_ID(PKTTYPE)]              = META_FUNC(int_pkttype),
 511                [META_ID(PKTLEN)]               = META_FUNC(int_pktlen),
 512                [META_ID(DATALEN)]              = META_FUNC(int_datalen),
 513                [META_ID(MACLEN)]               = META_FUNC(int_maclen),
 514                [META_ID(NFMARK)]               = META_FUNC(int_mark),
 515                [META_ID(TCINDEX)]              = META_FUNC(int_tcindex),
 516                [META_ID(RTCLASSID)]            = META_FUNC(int_rtclassid),
 517                [META_ID(RTIIF)]                = META_FUNC(int_rtiif),
 518                [META_ID(SK_FAMILY)]            = META_FUNC(int_sk_family),
 519                [META_ID(SK_STATE)]             = META_FUNC(int_sk_state),
 520                [META_ID(SK_REUSE)]             = META_FUNC(int_sk_reuse),
 521                [META_ID(SK_BOUND_IF)]          = META_FUNC(int_sk_bound_if),
 522                [META_ID(SK_REFCNT)]            = META_FUNC(int_sk_refcnt),
 523                [META_ID(SK_RCVBUF)]            = META_FUNC(int_sk_rcvbuf),
 524                [META_ID(SK_SNDBUF)]            = META_FUNC(int_sk_sndbuf),
 525                [META_ID(SK_SHUTDOWN)]          = META_FUNC(int_sk_shutdown),
 526                [META_ID(SK_PROTO)]             = META_FUNC(int_sk_proto),
 527                [META_ID(SK_TYPE)]              = META_FUNC(int_sk_type),
 528                [META_ID(SK_RMEM_ALLOC)]        = META_FUNC(int_sk_rmem_alloc),
 529                [META_ID(SK_WMEM_ALLOC)]        = META_FUNC(int_sk_wmem_alloc),
 530                [META_ID(SK_OMEM_ALLOC)]        = META_FUNC(int_sk_omem_alloc),
 531                [META_ID(SK_WMEM_QUEUED)]       = META_FUNC(int_sk_wmem_queued),
 532                [META_ID(SK_RCV_QLEN)]          = META_FUNC(int_sk_rcv_qlen),
 533                [META_ID(SK_SND_QLEN)]          = META_FUNC(int_sk_snd_qlen),
 534                [META_ID(SK_ERR_QLEN)]          = META_FUNC(int_sk_err_qlen),
 535                [META_ID(SK_FORWARD_ALLOCS)]    = META_FUNC(int_sk_fwd_alloc),
 536                [META_ID(SK_ALLOCS)]            = META_FUNC(int_sk_alloc),
 537                [META_ID(SK_ROUTE_CAPS)]        = META_FUNC(int_sk_route_caps),
 538                [META_ID(SK_HASH)]              = META_FUNC(int_sk_hash),
 539                [META_ID(SK_LINGERTIME)]        = META_FUNC(int_sk_lingertime),
 540                [META_ID(SK_ACK_BACKLOG)]       = META_FUNC(int_sk_ack_bl),
 541                [META_ID(SK_MAX_ACK_BACKLOG)]   = META_FUNC(int_sk_max_ack_bl),
 542                [META_ID(SK_PRIO)]              = META_FUNC(int_sk_prio),
 543                [META_ID(SK_RCVLOWAT)]          = META_FUNC(int_sk_rcvlowat),
 544                [META_ID(SK_RCVTIMEO)]          = META_FUNC(int_sk_rcvtimeo),
 545                [META_ID(SK_SNDTIMEO)]          = META_FUNC(int_sk_sndtimeo),
 546                [META_ID(SK_SENDMSG_OFF)]       = META_FUNC(int_sk_sendmsg_off),
 547                [META_ID(SK_WRITE_PENDING)]     = META_FUNC(int_sk_write_pend),
 548                [META_ID(VLAN_TAG)]             = META_FUNC(int_vlan_tag),
 549                [META_ID(RXHASH)]               = META_FUNC(int_rxhash),
 550        }
 551};
 552
 553static inline struct meta_ops * meta_ops(struct meta_value *val)
 554{
 555        return &__meta_ops[meta_type(val)][meta_id(val)];
 556}
 557
 558/**************************************************************************
 559 * Type specific operations for TCF_META_TYPE_VAR
 560 **************************************************************************/
 561
 562static int meta_var_compare(struct meta_obj *a, struct meta_obj *b)
 563{
 564        int r = a->len - b->len;
 565
 566        if (r == 0)
 567                r = memcmp((void *) a->value, (void *) b->value, a->len);
 568
 569        return r;
 570}
 571
 572static int meta_var_change(struct meta_value *dst, struct nlattr *nla)
 573{
 574        int len = nla_len(nla);
 575
 576        dst->val = (unsigned long)kmemdup(nla_data(nla), len, GFP_KERNEL);
 577        if (dst->val == 0UL)
 578                return -ENOMEM;
 579        dst->len = len;
 580        return 0;
 581}
 582
 583static void meta_var_destroy(struct meta_value *v)
 584{
 585        kfree((void *) v->val);
 586}
 587
 588static void meta_var_apply_extras(struct meta_value *v,
 589                                  struct meta_obj *dst)
 590{
 591        int shift = v->hdr.shift;
 592
 593        if (shift && shift < dst->len)
 594                dst->len -= shift;
 595}
 596
 597static int meta_var_dump(struct sk_buff *skb, struct meta_value *v, int tlv)
 598{
 599        if (v->val && v->len)
 600                NLA_PUT(skb, tlv, v->len, (void *) v->val);
 601        return 0;
 602
 603nla_put_failure:
 604        return -1;
 605}
 606
 607/**************************************************************************
 608 * Type specific operations for TCF_META_TYPE_INT
 609 **************************************************************************/
 610
 611static int meta_int_compare(struct meta_obj *a, struct meta_obj *b)
 612{
 613        /* Let gcc optimize it, the unlikely is not really based on
 614         * some numbers but jump free code for mismatches seems
 615         * more logical. */
 616        if (unlikely(a->value == b->value))
 617                return 0;
 618        else if (a->value < b->value)
 619                return -1;
 620        else
 621                return 1;
 622}
 623
 624static int meta_int_change(struct meta_value *dst, struct nlattr *nla)
 625{
 626        if (nla_len(nla) >= sizeof(unsigned long)) {
 627                dst->val = *(unsigned long *) nla_data(nla);
 628                dst->len = sizeof(unsigned long);
 629        } else if (nla_len(nla) == sizeof(u32)) {
 630                dst->val = nla_get_u32(nla);
 631                dst->len = sizeof(u32);
 632        } else
 633                return -EINVAL;
 634
 635        return 0;
 636}
 637
 638static void meta_int_apply_extras(struct meta_value *v,
 639                                  struct meta_obj *dst)
 640{
 641        if (v->hdr.shift)
 642                dst->value >>= v->hdr.shift;
 643
 644        if (v->val)
 645                dst->value &= v->val;
 646}
 647
 648static int meta_int_dump(struct sk_buff *skb, struct meta_value *v, int tlv)
 649{
 650        if (v->len == sizeof(unsigned long))
 651                NLA_PUT(skb, tlv, sizeof(unsigned long), &v->val);
 652        else if (v->len == sizeof(u32)) {
 653                NLA_PUT_U32(skb, tlv, v->val);
 654        }
 655
 656        return 0;
 657
 658nla_put_failure:
 659        return -1;
 660}
 661
 662/**************************************************************************
 663 * Type specific operations table
 664 **************************************************************************/
 665
 666struct meta_type_ops
 667{
 668        void    (*destroy)(struct meta_value *);
 669        int     (*compare)(struct meta_obj *, struct meta_obj *);
 670        int     (*change)(struct meta_value *, struct nlattr *);
 671        void    (*apply_extras)(struct meta_value *, struct meta_obj *);
 672        int     (*dump)(struct sk_buff *, struct meta_value *, int);
 673};
 674
 675static struct meta_type_ops __meta_type_ops[TCF_META_TYPE_MAX+1] = {
 676        [TCF_META_TYPE_VAR] = {
 677                .destroy = meta_var_destroy,
 678                .compare = meta_var_compare,
 679                .change = meta_var_change,
 680                .apply_extras = meta_var_apply_extras,
 681                .dump = meta_var_dump
 682        },
 683        [TCF_META_TYPE_INT] = {
 684                .compare = meta_int_compare,
 685                .change = meta_int_change,
 686                .apply_extras = meta_int_apply_extras,
 687                .dump = meta_int_dump
 688        }
 689};
 690
 691static inline struct meta_type_ops * meta_type_ops(struct meta_value *v)
 692{
 693        return &__meta_type_ops[meta_type(v)];
 694}
 695
 696/**************************************************************************
 697 * Core
 698 **************************************************************************/
 699
 700static int meta_get(struct sk_buff *skb, struct tcf_pkt_info *info,
 701                    struct meta_value *v, struct meta_obj *dst)
 702{
 703        int err = 0;
 704
 705        if (meta_id(v) == TCF_META_ID_VALUE) {
 706                dst->value = v->val;
 707                dst->len = v->len;
 708                return 0;
 709        }
 710
 711        meta_ops(v)->get(skb, info, v, dst, &err);
 712        if (err < 0)
 713                return err;
 714
 715        if (meta_type_ops(v)->apply_extras)
 716            meta_type_ops(v)->apply_extras(v, dst);
 717
 718        return 0;
 719}
 720
 721static int em_meta_match(struct sk_buff *skb, struct tcf_ematch *m,
 722                         struct tcf_pkt_info *info)
 723{
 724        int r;
 725        struct meta_match *meta = (struct meta_match *) m->data;
 726        struct meta_obj l_value, r_value;
 727
 728        if (meta_get(skb, info, &meta->lvalue, &l_value) < 0 ||
 729            meta_get(skb, info, &meta->rvalue, &r_value) < 0)
 730                return 0;
 731
 732        r = meta_type_ops(&meta->lvalue)->compare(&l_value, &r_value);
 733
 734        switch (meta->lvalue.hdr.op) {
 735                case TCF_EM_OPND_EQ:
 736                        return !r;
 737                case TCF_EM_OPND_LT:
 738                        return r < 0;
 739                case TCF_EM_OPND_GT:
 740                        return r > 0;
 741        }
 742
 743        return 0;
 744}
 745
 746static void meta_delete(struct meta_match *meta)
 747{
 748        if (meta) {
 749                struct meta_type_ops *ops = meta_type_ops(&meta->lvalue);
 750
 751                if (ops && ops->destroy) {
 752                        ops->destroy(&meta->lvalue);
 753                        ops->destroy(&meta->rvalue);
 754                }
 755        }
 756
 757        kfree(meta);
 758}
 759
 760static inline int meta_change_data(struct meta_value *dst, struct nlattr *nla)
 761{
 762        if (nla) {
 763                if (nla_len(nla) == 0)
 764                        return -EINVAL;
 765
 766                return meta_type_ops(dst)->change(dst, nla);
 767        }
 768
 769        return 0;
 770}
 771
 772static inline int meta_is_supported(struct meta_value *val)
 773{
 774        return (!meta_id(val) || meta_ops(val)->get);
 775}
 776
 777static const struct nla_policy meta_policy[TCA_EM_META_MAX + 1] = {
 778        [TCA_EM_META_HDR]       = { .len = sizeof(struct tcf_meta_hdr) },
 779};
 780
 781static int em_meta_change(struct tcf_proto *tp, void *data, int len,
 782                          struct tcf_ematch *m)
 783{
 784        int err;
 785        struct nlattr *tb[TCA_EM_META_MAX + 1];
 786        struct tcf_meta_hdr *hdr;
 787        struct meta_match *meta = NULL;
 788
 789        err = nla_parse(tb, TCA_EM_META_MAX, data, len, meta_policy);
 790        if (err < 0)
 791                goto errout;
 792
 793        err = -EINVAL;
 794        if (tb[TCA_EM_META_HDR] == NULL)
 795                goto errout;
 796        hdr = nla_data(tb[TCA_EM_META_HDR]);
 797
 798        if (TCF_META_TYPE(hdr->left.kind) != TCF_META_TYPE(hdr->right.kind) ||
 799            TCF_META_TYPE(hdr->left.kind) > TCF_META_TYPE_MAX ||
 800            TCF_META_ID(hdr->left.kind) > TCF_META_ID_MAX ||
 801            TCF_META_ID(hdr->right.kind) > TCF_META_ID_MAX)
 802                goto errout;
 803
 804        meta = kzalloc(sizeof(*meta), GFP_KERNEL);
 805        if (meta == NULL)
 806                goto errout;
 807
 808        memcpy(&meta->lvalue.hdr, &hdr->left, sizeof(hdr->left));
 809        memcpy(&meta->rvalue.hdr, &hdr->right, sizeof(hdr->right));
 810
 811        if (!meta_is_supported(&meta->lvalue) ||
 812            !meta_is_supported(&meta->rvalue)) {
 813                err = -EOPNOTSUPP;
 814                goto errout;
 815        }
 816
 817        if (meta_change_data(&meta->lvalue, tb[TCA_EM_META_LVALUE]) < 0 ||
 818            meta_change_data(&meta->rvalue, tb[TCA_EM_META_RVALUE]) < 0)
 819                goto errout;
 820
 821        m->datalen = sizeof(*meta);
 822        m->data = (unsigned long) meta;
 823
 824        err = 0;
 825errout:
 826        if (err && meta)
 827                meta_delete(meta);
 828        return err;
 829}
 830
 831static void em_meta_destroy(struct tcf_proto *tp, struct tcf_ematch *m)
 832{
 833        if (m)
 834                meta_delete((struct meta_match *) m->data);
 835}
 836
 837static int em_meta_dump(struct sk_buff *skb, struct tcf_ematch *em)
 838{
 839        struct meta_match *meta = (struct meta_match *) em->data;
 840        struct tcf_meta_hdr hdr;
 841        struct meta_type_ops *ops;
 842
 843        memset(&hdr, 0, sizeof(hdr));
 844        memcpy(&hdr.left, &meta->lvalue.hdr, sizeof(hdr.left));
 845        memcpy(&hdr.right, &meta->rvalue.hdr, sizeof(hdr.right));
 846
 847        NLA_PUT(skb, TCA_EM_META_HDR, sizeof(hdr), &hdr);
 848
 849        ops = meta_type_ops(&meta->lvalue);
 850        if (ops->dump(skb, &meta->lvalue, TCA_EM_META_LVALUE) < 0 ||
 851            ops->dump(skb, &meta->rvalue, TCA_EM_META_RVALUE) < 0)
 852                goto nla_put_failure;
 853
 854        return 0;
 855
 856nla_put_failure:
 857        return -1;
 858}
 859
 860static struct tcf_ematch_ops em_meta_ops = {
 861        .kind     = TCF_EM_META,
 862        .change   = em_meta_change,
 863        .match    = em_meta_match,
 864        .destroy  = em_meta_destroy,
 865        .dump     = em_meta_dump,
 866        .owner    = THIS_MODULE,
 867        .link     = LIST_HEAD_INIT(em_meta_ops.link)
 868};
 869
 870static int __init init_em_meta(void)
 871{
 872        return tcf_em_register(&em_meta_ops);
 873}
 874
 875static void __exit exit_em_meta(void)
 876{
 877        tcf_em_unregister(&em_meta_ops);
 878}
 879
 880MODULE_LICENSE("GPL");
 881
 882module_init(init_em_meta);
 883module_exit(exit_em_meta);
 884
 885MODULE_ALIAS_TCF_EMATCH(TCF_EM_META);
 886