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