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