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 META_COLLECTOR(int_rxhash)
 227 {
 228         dst->value = skb_get_rxhash(skb);
 229 }
 230
 231 /**************************************************************************
 232  * Netfilter
 233  **************************************************************************/
 234
 235 META_COLLECTOR(int_mark)
 236 {
 237         dst->value = skb->mark;
 238 }
 239
 240 /**************************************************************************
 241  * Traffic Control
 242  **************************************************************************/
 243
 244 META_COLLECTOR(int_tcindex)
 245 {
 246         dst->value = skb->tc_index;
 247 }
 248
 249 /**************************************************************************
 250  * Routing
 251  **************************************************************************/
 252
 253 META_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
 265 META_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
 283 META_COLLECTOR(int_sk_family)
 284 {
 285         SKIP_NONLOCAL(skb);
 286         dst->value = skb->sk->sk_family;
 287 }
 288
 289 META_COLLECTOR(int_sk_state)
 290 {
 291         SKIP_NONLOCAL(skb);
 292         dst->value = skb->sk->sk_state;
 293 }
 294
 295 META_COLLECTOR(int_sk_reuse)
 296 {
 297         SKIP_NONLOCAL(skb);
 298         dst->value = skb->sk->sk_reuse;
 299 }
 300
 301 META_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
 308 META_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
 326 META_COLLECTOR(int_sk_refcnt)
 327 {
 328         SKIP_NONLOCAL(skb);
 329         dst->value = atomic_read(&skb->sk->sk_refcnt);
 330 }
 331
 332 META_COLLECTOR(int_sk_rcvbuf)
 333 {
 334         SKIP_NONLOCAL(skb);
 335         dst->value = skb->sk->sk_rcvbuf;
 336 }
 337
 338 META_COLLECTOR(int_sk_shutdown)
 339 {
 340         SKIP_NONLOCAL(skb);
 341         dst->value = skb->sk->sk_shutdown;
 342 }
 343
 344 META_COLLECTOR(int_sk_proto)
 345 {
 346         SKIP_NONLOCAL(skb);
 347         dst->value = skb->sk->sk_protocol;
 348 }
 349
 350 META_COLLECTOR(int_sk_type)
 351 {
 352         SKIP_NONLOCAL(skb);
 353         dst->value = skb->sk->sk_type;
 354 }
 355
 356 META_COLLECTOR(int_sk_rmem_alloc)
 357 {
 358         SKIP_NONLOCAL(skb);
 359         dst->value = sk_rmem_alloc_get(skb->sk);
 360 }
 361
 362 META_COLLECTOR(int_sk_wmem_alloc)
 363 {
 364         SKIP_NONLOCAL(skb);
 365         dst->value = sk_wmem_alloc_get(skb->sk);
 366 }
 367
 368 META_COLLECTOR(int_sk_omem_alloc)
 369 {
 370         SKIP_NONLOCAL(skb);
 371         dst->value = atomic_read(&skb->sk->sk_omem_alloc);
 372 }
 373
 374 META_COLLECTOR(int_sk_rcv_qlen)
 375 {
 376         SKIP_NONLOCAL(skb);
 377         dst->value = skb->sk->sk_receive_queue.qlen;
 378 }
 379
 380 META_COLLECTOR(int_sk_snd_qlen)
 381 {
 382         SKIP_NONLOCAL(skb);
 383         dst->value = skb->sk->sk_write_queue.qlen;
 384 }
 385
 386 META_COLLECTOR(int_sk_wmem_queued)
 387 {
 388         SKIP_NONLOCAL(skb);
 389         dst->value = skb->sk->sk_wmem_queued;
 390 }
 391
 392 META_COLLECTOR(int_sk_fwd_alloc)
 393 {
 394         SKIP_NONLOCAL(skb);
 395         dst->value = skb->sk->sk_forward_alloc;
 396 }
 397
 398 META_COLLECTOR(int_sk_sndbuf)
 399 {
 400         SKIP_NONLOCAL(skb);
 401         dst->value = skb->sk->sk_sndbuf;
 402 }
 403
 404 META_COLLECTOR(int_sk_alloc)
 405 {
 406         SKIP_NONLOCAL(skb);
 407         dst->value = skb->sk->sk_allocation;
 408 }
 409
 410 META_COLLECTOR(int_sk_route_caps)
 411 {
 412         SKIP_NONLOCAL(skb);
 413         dst->value = skb->sk->sk_route_caps;
 414 }
 415
 416 META_COLLECTOR(int_sk_hash)
 417 {
 418         SKIP_NONLOCAL(skb);
 419         dst->value = skb->sk->sk_hash;
 420 }
 421
 422 META_COLLECTOR(int_sk_lingertime)
 423 {
 424         SKIP_NONLOCAL(skb);
 425         dst->value = skb->sk->sk_lingertime / HZ;
 426 }
 427
 428 META_COLLECTOR(int_sk_err_qlen)
 429 {
 430         SKIP_NONLOCAL(skb);
 431         dst->value = skb->sk->sk_error_queue.qlen;
 432 }
 433
 434 META_COLLECTOR(int_sk_ack_bl)
 435 {
 436         SKIP_NONLOCAL(skb);
 437         dst->value = skb->sk->sk_ack_backlog;
 438 }
 439
 440 META_COLLECTOR(int_sk_max_ack_bl)
 441 {
 442         SKIP_NONLOCAL(skb);
 443         dst->value = skb->sk->sk_max_ack_backlog;
 444 }
 445
 446 META_COLLECTOR(int_sk_prio)
 447 {
 448         SKIP_NONLOCAL(skb);
 449         dst->value = skb->sk->sk_priority;
 450 }
 451
 452 META_COLLECTOR(int_sk_rcvlowat)
 453 {
 454         SKIP_NONLOCAL(skb);
 455         dst->value = skb->sk->sk_rcvlowat;
 456 }
 457
 458 META_COLLECTOR(int_sk_rcvtimeo)
 459 {
 460         SKIP_NONLOCAL(skb);
 461         dst->value = skb->sk->sk_rcvtimeo / HZ;
 462 }
 463
 464 META_COLLECTOR(int_sk_sndtimeo)
 465 {
 466         SKIP_NONLOCAL(skb);
 467         dst->value = skb->sk->sk_sndtimeo / HZ;
 468 }
 469
 470 META_COLLECTOR(int_sk_sendmsg_off)
 471 {
 472         SKIP_NONLOCAL(skb);
 473         dst->value = skb->sk->sk_sndmsg_off;
 474 }
 475
 476 META_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
 486 struct 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. */
 497 static 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
 553 static 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
 562 static 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
 572 static 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
 583 static void meta_var_destroy(struct meta_value *v)
 584 {
 585         kfree((void *) v->val);
 586 }
 587
 588 static 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
 597 static 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
 603 nla_put_failure:
 604         return -1;
 605 }
 606
 607 /**************************************************************************
 608  * Type specific operations for TCF_META_TYPE_INT
 609  **************************************************************************/
 610
 611 static 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
 624 static 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
 638 static 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
 648 static 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
 658 nla_put_failure:
 659         return -1;
 660 }
 661
 662 /**************************************************************************
 663  * Type specific operations table
 664  **************************************************************************/
 665
 666 struct 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
 675 static 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
 691 static 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
 700 static 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
 721 static 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
 746 static 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
 760 static 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
 772 static inline int meta_is_supported(struct meta_value *val)
 773 {
 774         return (!meta_id(val) || meta_ops(val)->get);
 775 }
 776
 777 static const struct nla_policy meta_policy[TCA_EM_META_MAX + 1] = {
 778         [TCA_EM_META_HDR]       = { .len = sizeof(struct tcf_meta_hdr) },
 779 };
 780
 781 static 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;
 825 errout:
 826         if (err && meta)
 827                 meta_delete(meta);
 828         return err;
 829 }
 830
 831 static 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
 837 static 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
 856 nla_put_failure:
 857         return -1;
 858 }
 859
 860 static 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
 870 static int __init init_em_meta(void)
 871 {
 872         return tcf_em_register(&em_meta_ops);
 873 }
 874
 875 static void __exit exit_em_meta(void)
 876 {
 877         tcf_em_unregister(&em_meta_ops);
 878 }
 879
 880 MODULE_LICENSE("GPL");
 881
 882 module_init(init_em_meta);
 883 module_exit(exit_em_meta);
 884
 885 MODULE_ALIAS_TCF_EMATCH(TCF_EM_META);