net/sched/em_meta.c

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