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