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