net/sched/em_meta.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * net/sched/em_meta.c  Metadata ematch
   4  *
   5  * Authors:     Thomas Graf <tgraf@suug.ch>
   6  *
   7  * ==========================================================================
   8  *
   9  *      The metadata ematch compares two meta objects where each object
  10  *      represents either a meta value stored in the kernel or a static
  11  *      value provided by userspace. The objects are not provided by
  12  *      userspace itself but rather a definition providing the information
  13  *      to build them. Every object is of a certain type which must be
  14  *      equal to the object it is being compared to.
  15  *
  16  *      The definition of a objects conists of the type (meta type), a
  17  *      identifier (meta id) and additional type specific information.
  18  *      The meta id is either TCF_META_TYPE_VALUE for values provided by
  19  *      userspace or a index to the meta operations table consisting of
  20  *      function pointers to type specific meta data collectors returning
  21  *      the value of the requested meta value.
  22  *
  23  *               lvalue                                   rvalue
  24  *            +-----------+                           +-----------+
  25  *            | type: INT |                           | type: INT |
  26  *       def  | id: DEV   |                           | id: VALUE |
  27  *            | data:     |                           | data: 3   |
  28  *            +-----------+                           +-----------+
  29  *                  |                                       |
  30  *                  ---> meta_ops[INT][DEV](...)            |
  31  *                            |                             |
  32  *                  -----------                             |
  33  *                  V                                       V
  34  *            +-----------+                           +-----------+
  35  *            | type: INT |                           | type: INT |
  36  *       obj  | id: DEV |                             | id: VALUE |
  37  *            | data: 2   |<--data got filled out     | data: 3   |
  38  *            +-----------+                           +-----------+
  39  *                  |                                         |
  40  *                  --------------> 2  equals 3 <--------------
  41  *
  42  *      This is a simplified schema, the complexity varies depending
  43  *      on the meta type. Obviously, the length of the data must also
  44  *      be provided for non-numeric types.
  45  *
  46  *      Additionally, type dependent modifiers such as shift operators
  47  *      or mask may be applied to extend the functionaliy. As of now,
  48  *      the variable length type supports shifting the byte string to
  49  *      the right, eating up any number of octets and thus supporting
  50  *      wildcard interface name comparisons such as "ppp%" matching
  51  *      ppp0..9.
  52  *
  53  *      NOTE: Certain meta values depend on other subsystems and are
  54  *            only available if that subsystem is enabled in the kernel.
  55  */
  56
  57 #include <linux/slab.h>
  58 #include <linux/module.h>
  59 #include <linux/types.h>
  60 #include <linux/kernel.h>
  61 #include <linux/sched.h>
  62 #include <linux/sched/loadavg.h>
  63 #include <linux/string.h>
  64 #include <linux/skbuff.h>
  65 #include <linux/random.h>
  66 #include <linux/if_vlan.h>
  67 #include <linux/tc_ematch/tc_em_meta.h>
  68 #include <net/dst.h>
  69 #include <net/route.h>
  70 #include <net/pkt_cls.h>
  71 #include <net/sock.h>
  72
  73 struct meta_obj {
  74         unsigned long           value;
  75         unsigned int            len;
  76 };
  77
  78 struct meta_value {
  79         struct tcf_meta_val     hdr;
  80         unsigned long           val;
  81         unsigned int            len;
  82 };
  83
  84 struct meta_match {
  85         struct meta_value       lvalue;
  86         struct meta_value       rvalue;
  87 };
  88
  89 static inline int meta_id(struct meta_value *v)
  90 {
  91         return TCF_META_ID(v->hdr.kind);
  92 }
  93
  94 static inline int meta_type(struct meta_value *v)
  95 {
  96         return TCF_META_TYPE(v->hdr.kind);
  97 }
  98
  99 #define META_COLLECTOR(FUNC) static void meta_##FUNC(struct sk_buff *skb, \
 100         struct tcf_pkt_info *info, struct meta_value *v, \
 101         struct meta_obj *dst, int *err)
 102
 103 /**************************************************************************
 104  * System status & misc
 105  **************************************************************************/
 106
 107 META_COLLECTOR(int_random)
 108 {
 109         get_random_bytes(&dst->value, sizeof(dst->value));
 110 }
 111
 112 static inline unsigned long fixed_loadavg(int load)
 113 {
 114         int rnd_load = load + (FIXED_1/200);
 115         int rnd_frac = ((rnd_load & (FIXED_1-1)) * 100) >> FSHIFT;
 116
 117         return ((rnd_load >> FSHIFT) * 100) + rnd_frac;
 118 }
 119
 120 META_COLLECTOR(int_loadavg_0)
 121 {
 122         dst->value = fixed_loadavg(avenrun[0]);
 123 }
 124
 125 META_COLLECTOR(int_loadavg_1)
 126 {
 127         dst->value = fixed_loadavg(avenrun[1]);
 128 }
 129
 130 META_COLLECTOR(int_loadavg_2)
 131 {
 132         dst->value = fixed_loadavg(avenrun[2]);
 133 }
 134
 135 /**************************************************************************
 136  * Device names & indices
 137  **************************************************************************/
 138
 139 static inline int int_dev(struct net_device *dev, struct meta_obj *dst)
 140 {
 141         if (unlikely(dev == NULL))
 142                 return -1;
 143
 144         dst->value = dev->ifindex;
 145         return 0;
 146 }
 147
 148 static inline int var_dev(struct net_device *dev, struct meta_obj *dst)
 149 {
 150         if (unlikely(dev == NULL))
 151                 return -1;
 152
 153         dst->value = (unsigned long) dev->name;
 154         dst->len = strlen(dev->name);
 155         return 0;
 156 }
 157
 158 META_COLLECTOR(int_dev)
 159 {
 160         *err = int_dev(skb->dev, dst);
 161 }
 162
 163 META_COLLECTOR(var_dev)
 164 {
 165         *err = var_dev(skb->dev, dst);
 166 }
 167
 168 /**************************************************************************
 169  * vlan tag
 170  **************************************************************************/
 171
 172 META_COLLECTOR(int_vlan_tag)
 173 {
 174         unsigned short tag;
 175
 176         if (skb_vlan_tag_present(skb))
 177                 dst->value = skb_vlan_tag_get(skb);
 178         else if (!__vlan_get_tag(skb, &tag))
 179                 dst->value = tag;
 180         else
 181                 *err = -1;
 182 }
 183
 184
 185
 186 /**************************************************************************
 187  * skb attributes
 188  **************************************************************************/
 189
 190 META_COLLECTOR(int_priority)
 191 {
 192         dst->value = skb->priority;
 193 }
 194
 195 META_COLLECTOR(int_protocol)
 196 {
 197         /* Let userspace take care of the byte ordering */
 198         dst->value = skb_protocol(skb, false);
 199 }
 200
 201 META_COLLECTOR(int_pkttype)
 202 {
 203         dst->value = skb->pkt_type;
 204 }
 205
 206 META_COLLECTOR(int_pktlen)
 207 {
 208         dst->value = skb->len;
 209 }
 210
 211 META_COLLECTOR(int_datalen)
 212 {
 213         dst->value = skb->data_len;
 214 }
 215
 216 META_COLLECTOR(int_maclen)
 217 {
 218         dst->value = skb->mac_len;
 219 }
 220
 221 META_COLLECTOR(int_rxhash)
 222 {
 223         dst->value = skb_get_hash(skb);
 224 }
 225
 226 /**************************************************************************
 227  * Netfilter
 228  **************************************************************************/
 229
 230 META_COLLECTOR(int_mark)
 231 {
 232         dst->value = skb->mark;
 233 }
 234
 235 /**************************************************************************
 236  * Traffic Control
 237  **************************************************************************/
 238
 239 META_COLLECTOR(int_tcindex)
 240 {
 241         dst->value = skb->tc_index;
 242 }
 243
 244 /**************************************************************************
 245  * Routing
 246  **************************************************************************/
 247
 248 META_COLLECTOR(int_rtclassid)
 249 {
 250         if (unlikely(skb_dst(skb) == NULL))
 251                 *err = -1;
 252         else
 253 #ifdef CONFIG_IP_ROUTE_CLASSID
 254                 dst->value = skb_dst(skb)->tclassid;
 255 #else
 256                 dst->value = 0;
 257 #endif
 258 }
 259
 260 META_COLLECTOR(int_rtiif)
 261 {
 262         if (unlikely(skb_rtable(skb) == NULL))
 263                 *err = -1;
 264         else
 265                 dst->value = inet_iif(skb);
 266 }
 267
 268 /**************************************************************************
 269  * Socket Attributes
 270  **************************************************************************/
 271
 272 #define skip_nonlocal(skb) \
 273         (unlikely(skb->sk == NULL))
 274
 275 META_COLLECTOR(int_sk_family)
 276 {
 277         if (skip_nonlocal(skb)) {
 278                 *err = -1;
 279                 return;
 280         }
 281         dst->value = skb->sk->sk_family;
 282 }
 283
 284 META_COLLECTOR(int_sk_state)
 285 {
 286         if (skip_nonlocal(skb)) {
 287                 *err = -1;
 288                 return;
 289         }
 290         dst->value = skb->sk->sk_state;
 291 }
 292
 293 META_COLLECTOR(int_sk_reuse)
 294 {
 295         if (skip_nonlocal(skb)) {
 296                 *err = -1;
 297                 return;
 298         }
 299         dst->value = skb->sk->sk_reuse;
 300 }
 301
 302 META_COLLECTOR(int_sk_bound_if)
 303 {
 304         if (skip_nonlocal(skb)) {
 305                 *err = -1;
 306                 return;
 307         }
 308         /* No error if bound_dev_if is 0, legal userspace check */
 309         dst->value = skb->sk->sk_bound_dev_if;
 310 }
 311
 312 META_COLLECTOR(var_sk_bound_if)
 313 {
 314         if (skip_nonlocal(skb)) {
 315                 *err = -1;
 316                 return;
 317         }
 318
 319         if (skb->sk->sk_bound_dev_if == 0) {
 320                 dst->value = (unsigned long) "any";
 321                 dst->len = 3;
 322         } else {
 323                 struct net_device *dev;
 324
 325                 rcu_read_lock();
 326                 dev = dev_get_by_index_rcu(sock_net(skb->sk),
 327                                            skb->sk->sk_bound_dev_if);
 328                 *err = var_dev(dev, dst);
 329                 rcu_read_unlock();
 330         }
 331 }
 332
 333 META_COLLECTOR(int_sk_refcnt)
 334 {
 335         if (skip_nonlocal(skb)) {
 336                 *err = -1;
 337                 return;
 338         }
 339         dst->value = refcount_read(&skb->sk->sk_refcnt);
 340 }
 341
 342 META_COLLECTOR(int_sk_rcvbuf)
 343 {
 344         const struct sock *sk = skb_to_full_sk(skb);
 345
 346         if (!sk) {
 347                 *err = -1;
 348                 return;
 349         }
 350         dst->value = sk->sk_rcvbuf;
 351 }
 352
 353 META_COLLECTOR(int_sk_shutdown)
 354 {
 355         const struct sock *sk = skb_to_full_sk(skb);
 356
 357         if (!sk) {
 358                 *err = -1;
 359                 return;
 360         }
 361         dst->value = sk->sk_shutdown;
 362 }
 363
 364 META_COLLECTOR(int_sk_proto)
 365 {
 366         const struct sock *sk = skb_to_full_sk(skb);
 367
 368         if (!sk) {
 369                 *err = -1;
 370                 return;
 371         }
 372         dst->value = sk->sk_protocol;
 373 }
 374
 375 META_COLLECTOR(int_sk_type)
 376 {
 377         const struct sock *sk = skb_to_full_sk(skb);
 378
 379         if (!sk) {
 380                 *err = -1;
 381                 return;
 382         }
 383         dst->value = sk->sk_type;
 384 }
 385
 386 META_COLLECTOR(int_sk_rmem_alloc)
 387 {
 388         const struct sock *sk = skb_to_full_sk(skb);
 389
 390         if (!sk) {
 391                 *err = -1;
 392                 return;
 393         }
 394         dst->value = sk_rmem_alloc_get(sk);
 395 }
 396
 397 META_COLLECTOR(int_sk_wmem_alloc)
 398 {
 399         const struct sock *sk = skb_to_full_sk(skb);
 400
 401         if (!sk) {
 402                 *err = -1;
 403                 return;
 404         }
 405         dst->value = sk_wmem_alloc_get(sk);
 406 }
 407
 408 META_COLLECTOR(int_sk_omem_alloc)
 409 {
 410         const struct sock *sk = skb_to_full_sk(skb);
 411
 412         if (!sk) {
 413                 *err = -1;
 414                 return;
 415         }
 416         dst->value = atomic_read(&sk->sk_omem_alloc);
 417 }
 418
 419 META_COLLECTOR(int_sk_rcv_qlen)
 420 {
 421         const struct sock *sk = skb_to_full_sk(skb);
 422
 423         if (!sk) {
 424                 *err = -1;
 425                 return;
 426         }
 427         dst->value = sk->sk_receive_queue.qlen;
 428 }
 429
 430 META_COLLECTOR(int_sk_snd_qlen)
 431 {
 432         const struct sock *sk = skb_to_full_sk(skb);
 433
 434         if (!sk) {
 435                 *err = -1;
 436                 return;
 437         }
 438         dst->value = sk->sk_write_queue.qlen;
 439 }
 440
 441 META_COLLECTOR(int_sk_wmem_queued)
 442 {
 443         const struct sock *sk = skb_to_full_sk(skb);
 444
 445         if (!sk) {
 446                 *err = -1;
 447                 return;
 448         }
 449         dst->value = READ_ONCE(sk->sk_wmem_queued);
 450 }
 451
 452 META_COLLECTOR(int_sk_fwd_alloc)
 453 {
 454         const struct sock *sk = skb_to_full_sk(skb);
 455
 456         if (!sk) {
 457                 *err = -1;
 458                 return;
 459         }
 460         dst->value = sk->sk_forward_alloc;
 461 }
 462
 463 META_COLLECTOR(int_sk_sndbuf)
 464 {
 465         const struct sock *sk = skb_to_full_sk(skb);
 466
 467         if (!sk) {
 468                 *err = -1;
 469                 return;
 470         }
 471         dst->value = sk->sk_sndbuf;
 472 }
 473
 474 META_COLLECTOR(int_sk_alloc)
 475 {
 476         const struct sock *sk = skb_to_full_sk(skb);
 477
 478         if (!sk) {
 479                 *err = -1;
 480                 return;
 481         }
 482         dst->value = (__force int) sk->sk_allocation;
 483 }
 484
 485 META_COLLECTOR(int_sk_hash)
 486 {
 487         if (skip_nonlocal(skb)) {
 488                 *err = -1;
 489                 return;
 490         }
 491         dst->value = skb->sk->sk_hash;
 492 }
 493
 494 META_COLLECTOR(int_sk_lingertime)
 495 {
 496         const struct sock *sk = skb_to_full_sk(skb);
 497
 498         if (!sk) {
 499                 *err = -1;
 500                 return;
 501         }
 502         dst->value = sk->sk_lingertime / HZ;
 503 }
 504
 505 META_COLLECTOR(int_sk_err_qlen)
 506 {
 507         const struct sock *sk = skb_to_full_sk(skb);
 508
 509         if (!sk) {
 510                 *err = -1;
 511                 return;
 512         }
 513         dst->value = sk->sk_error_queue.qlen;
 514 }
 515
 516 META_COLLECTOR(int_sk_ack_bl)
 517 {
 518         const struct sock *sk = skb_to_full_sk(skb);
 519
 520         if (!sk) {
 521                 *err = -1;
 522                 return;
 523         }
 524         dst->value = READ_ONCE(sk->sk_ack_backlog);
 525 }
 526
 527 META_COLLECTOR(int_sk_max_ack_bl)
 528 {
 529         const struct sock *sk = skb_to_full_sk(skb);
 530
 531         if (!sk) {
 532                 *err = -1;
 533                 return;
 534         }
 535         dst->value = READ_ONCE(sk->sk_max_ack_backlog);
 536 }
 537
 538 META_COLLECTOR(int_sk_prio)
 539 {
 540         const struct sock *sk = skb_to_full_sk(skb);
 541
 542         if (!sk) {
 543                 *err = -1;
 544                 return;
 545         }
 546         dst->value = sk->sk_priority;
 547 }
 548
 549 META_COLLECTOR(int_sk_rcvlowat)
 550 {
 551         const struct sock *sk = skb_to_full_sk(skb);
 552
 553         if (!sk) {
 554                 *err = -1;
 555                 return;
 556         }
 557         dst->value = READ_ONCE(sk->sk_rcvlowat);
 558 }
 559
 560 META_COLLECTOR(int_sk_rcvtimeo)
 561 {
 562         const struct sock *sk = skb_to_full_sk(skb);
 563
 564         if (!sk) {
 565                 *err = -1;
 566                 return;
 567         }
 568         dst->value = sk->sk_rcvtimeo / HZ;
 569 }
 570
 571 META_COLLECTOR(int_sk_sndtimeo)
 572 {
 573         const struct sock *sk = skb_to_full_sk(skb);
 574
 575         if (!sk) {
 576                 *err = -1;
 577                 return;
 578         }
 579         dst->value = sk->sk_sndtimeo / HZ;
 580 }
 581
 582 META_COLLECTOR(int_sk_sendmsg_off)
 583 {
 584         const struct sock *sk = skb_to_full_sk(skb);
 585
 586         if (!sk) {
 587                 *err = -1;
 588                 return;
 589         }
 590         dst->value = sk->sk_frag.offset;
 591 }
 592
 593 META_COLLECTOR(int_sk_write_pend)
 594 {
 595         const struct sock *sk = skb_to_full_sk(skb);
 596
 597         if (!sk) {
 598                 *err = -1;
 599                 return;
 600         }
 601         dst->value = sk->sk_write_pending;
 602 }
 603
 604 /**************************************************************************
 605  * Meta value collectors assignment table
 606  **************************************************************************/
 607
 608 struct meta_ops {
 609         void            (*get)(struct sk_buff *, struct tcf_pkt_info *,
 610                                struct meta_value *, struct meta_obj *, int *);
 611 };
 612
 613 #define META_ID(name) TCF_META_ID_##name
 614 #define META_FUNC(name) { .get = meta_##name }
 615
 616 /* Meta value operations table listing all meta value collectors and
 617  * assigns them to a type and meta id. */
 618 static struct meta_ops __meta_ops[TCF_META_TYPE_MAX + 1][TCF_META_ID_MAX + 1] = {
 619         [TCF_META_TYPE_VAR] = {
 620                 [META_ID(DEV)]                  = META_FUNC(var_dev),
 621                 [META_ID(SK_BOUND_IF)]          = META_FUNC(var_sk_bound_if),
 622         },
 623         [TCF_META_TYPE_INT] = {
 624                 [META_ID(RANDOM)]               = META_FUNC(int_random),
 625                 [META_ID(LOADAVG_0)]            = META_FUNC(int_loadavg_0),
 626                 [META_ID(LOADAVG_1)]            = META_FUNC(int_loadavg_1),
 627                 [META_ID(LOADAVG_2)]            = META_FUNC(int_loadavg_2),
 628                 [META_ID(DEV)]                  = META_FUNC(int_dev),
 629                 [META_ID(PRIORITY)]             = META_FUNC(int_priority),
 630                 [META_ID(PROTOCOL)]             = META_FUNC(int_protocol),
 631                 [META_ID(PKTTYPE)]              = META_FUNC(int_pkttype),
 632                 [META_ID(PKTLEN)]               = META_FUNC(int_pktlen),
 633                 [META_ID(DATALEN)]              = META_FUNC(int_datalen),
 634                 [META_ID(MACLEN)]               = META_FUNC(int_maclen),
 635                 [META_ID(NFMARK)]               = META_FUNC(int_mark),
 636                 [META_ID(TCINDEX)]              = META_FUNC(int_tcindex),
 637                 [META_ID(RTCLASSID)]            = META_FUNC(int_rtclassid),
 638                 [META_ID(RTIIF)]                = META_FUNC(int_rtiif),
 639                 [META_ID(SK_FAMILY)]            = META_FUNC(int_sk_family),
 640                 [META_ID(SK_STATE)]             = META_FUNC(int_sk_state),
 641                 [META_ID(SK_REUSE)]             = META_FUNC(int_sk_reuse),
 642                 [META_ID(SK_BOUND_IF)]          = META_FUNC(int_sk_bound_if),
 643                 [META_ID(SK_REFCNT)]            = META_FUNC(int_sk_refcnt),
 644                 [META_ID(SK_RCVBUF)]            = META_FUNC(int_sk_rcvbuf),
 645                 [META_ID(SK_SNDBUF)]            = META_FUNC(int_sk_sndbuf),
 646                 [META_ID(SK_SHUTDOWN)]          = META_FUNC(int_sk_shutdown),
 647                 [META_ID(SK_PROTO)]             = META_FUNC(int_sk_proto),
 648                 [META_ID(SK_TYPE)]              = META_FUNC(int_sk_type),
 649                 [META_ID(SK_RMEM_ALLOC)]        = META_FUNC(int_sk_rmem_alloc),
 650                 [META_ID(SK_WMEM_ALLOC)]        = META_FUNC(int_sk_wmem_alloc),
 651                 [META_ID(SK_OMEM_ALLOC)]        = META_FUNC(int_sk_omem_alloc),
 652                 [META_ID(SK_WMEM_QUEUED)]       = META_FUNC(int_sk_wmem_queued),
 653                 [META_ID(SK_RCV_QLEN)]          = META_FUNC(int_sk_rcv_qlen),
 654                 [META_ID(SK_SND_QLEN)]          = META_FUNC(int_sk_snd_qlen),
 655                 [META_ID(SK_ERR_QLEN)]          = META_FUNC(int_sk_err_qlen),
 656                 [META_ID(SK_FORWARD_ALLOCS)]    = META_FUNC(int_sk_fwd_alloc),
 657                 [META_ID(SK_ALLOCS)]            = META_FUNC(int_sk_alloc),
 658                 [META_ID(SK_HASH)]              = META_FUNC(int_sk_hash),
 659                 [META_ID(SK_LINGERTIME)]        = META_FUNC(int_sk_lingertime),
 660                 [META_ID(SK_ACK_BACKLOG)]       = META_FUNC(int_sk_ack_bl),
 661                 [META_ID(SK_MAX_ACK_BACKLOG)]   = META_FUNC(int_sk_max_ack_bl),
 662                 [META_ID(SK_PRIO)]              = META_FUNC(int_sk_prio),
 663                 [META_ID(SK_RCVLOWAT)]          = META_FUNC(int_sk_rcvlowat),
 664                 [META_ID(SK_RCVTIMEO)]          = META_FUNC(int_sk_rcvtimeo),
 665                 [META_ID(SK_SNDTIMEO)]          = META_FUNC(int_sk_sndtimeo),
 666                 [META_ID(SK_SENDMSG_OFF)]       = META_FUNC(int_sk_sendmsg_off),
 667                 [META_ID(SK_WRITE_PENDING)]     = META_FUNC(int_sk_write_pend),
 668                 [META_ID(VLAN_TAG)]             = META_FUNC(int_vlan_tag),
 669                 [META_ID(RXHASH)]               = META_FUNC(int_rxhash),
 670         }
 671 };
 672
 673 static inline struct meta_ops *meta_ops(struct meta_value *val)
 674 {
 675         return &__meta_ops[meta_type(val)][meta_id(val)];
 676 }
 677
 678 /**************************************************************************
 679  * Type specific operations for TCF_META_TYPE_VAR
 680  **************************************************************************/
 681
 682 static int meta_var_compare(struct meta_obj *a, struct meta_obj *b)
 683 {
 684         int r = a->len - b->len;
 685
 686         if (r == 0)
 687                 r = memcmp((void *) a->value, (void *) b->value, a->len);
 688
 689         return r;
 690 }
 691
 692 static int meta_var_change(struct meta_value *dst, struct nlattr *nla)
 693 {
 694         int len = nla_len(nla);
 695
 696         dst->val = (unsigned long)kmemdup(nla_data(nla), len, GFP_KERNEL);
 697         if (dst->val == 0UL)
 698                 return -ENOMEM;
 699         dst->len = len;
 700         return 0;
 701 }
 702
 703 static void meta_var_destroy(struct meta_value *v)
 704 {
 705         kfree((void *) v->val);
 706 }
 707
 708 static void meta_var_apply_extras(struct meta_value *v,
 709                                   struct meta_obj *dst)
 710 {
 711         int shift = v->hdr.shift;
 712
 713         if (shift && shift < dst->len)
 714                 dst->len -= shift;
 715 }
 716
 717 static int meta_var_dump(struct sk_buff *skb, struct meta_value *v, int tlv)
 718 {
 719         if (v->val && v->len &&
 720             nla_put(skb, tlv, v->len, (void *) v->val))
 721                 goto nla_put_failure;
 722         return 0;
 723
 724 nla_put_failure:
 725         return -1;
 726 }
 727
 728 /**************************************************************************
 729  * Type specific operations for TCF_META_TYPE_INT
 730  **************************************************************************/
 731
 732 static int meta_int_compare(struct meta_obj *a, struct meta_obj *b)
 733 {
 734         /* Let gcc optimize it, the unlikely is not really based on
 735          * some numbers but jump free code for mismatches seems
 736          * more logical. */
 737         if (unlikely(a->value == b->value))
 738                 return 0;
 739         else if (a->value < b->value)
 740                 return -1;
 741         else
 742                 return 1;
 743 }
 744
 745 static int meta_int_change(struct meta_value *dst, struct nlattr *nla)
 746 {
 747         if (nla_len(nla) >= sizeof(unsigned long)) {
 748                 dst->val = *(unsigned long *) nla_data(nla);
 749                 dst->len = sizeof(unsigned long);
 750         } else if (nla_len(nla) == sizeof(u32)) {
 751                 dst->val = nla_get_u32(nla);
 752                 dst->len = sizeof(u32);
 753         } else
 754                 return -EINVAL;
 755
 756         return 0;
 757 }
 758
 759 static void meta_int_apply_extras(struct meta_value *v,
 760                                   struct meta_obj *dst)
 761 {
 762         if (v->hdr.shift)
 763                 dst->value >>= v->hdr.shift;
 764
 765         if (v->val)
 766                 dst->value &= v->val;
 767 }
 768
 769 static int meta_int_dump(struct sk_buff *skb, struct meta_value *v, int tlv)
 770 {
 771         if (v->len == sizeof(unsigned long)) {
 772                 if (nla_put(skb, tlv, sizeof(unsigned long), &v->val))
 773                         goto nla_put_failure;
 774         } else if (v->len == sizeof(u32)) {
 775                 if (nla_put_u32(skb, tlv, v->val))
 776                         goto nla_put_failure;
 777         }
 778
 779         return 0;
 780
 781 nla_put_failure:
 782         return -1;
 783 }
 784
 785 /**************************************************************************
 786  * Type specific operations table
 787  **************************************************************************/
 788
 789 struct meta_type_ops {
 790         void    (*destroy)(struct meta_value *);
 791         int     (*compare)(struct meta_obj *, struct meta_obj *);
 792         int     (*change)(struct meta_value *, struct nlattr *);
 793         void    (*apply_extras)(struct meta_value *, struct meta_obj *);
 794         int     (*dump)(struct sk_buff *, struct meta_value *, int);
 795 };
 796
 797 static const struct meta_type_ops __meta_type_ops[TCF_META_TYPE_MAX + 1] = {
 798         [TCF_META_TYPE_VAR] = {
 799                 .destroy = meta_var_destroy,
 800                 .compare = meta_var_compare,
 801                 .change = meta_var_change,
 802                 .apply_extras = meta_var_apply_extras,
 803                 .dump = meta_var_dump
 804         },
 805         [TCF_META_TYPE_INT] = {
 806                 .compare = meta_int_compare,
 807                 .change = meta_int_change,
 808                 .apply_extras = meta_int_apply_extras,
 809                 .dump = meta_int_dump
 810         }
 811 };
 812
 813 static inline const struct meta_type_ops *meta_type_ops(struct meta_value *v)
 814 {
 815         return &__meta_type_ops[meta_type(v)];
 816 }
 817
 818 /**************************************************************************
 819  * Core
 820  **************************************************************************/
 821
 822 static int meta_get(struct sk_buff *skb, struct tcf_pkt_info *info,
 823                     struct meta_value *v, struct meta_obj *dst)
 824 {
 825         int err = 0;
 826
 827         if (meta_id(v) == TCF_META_ID_VALUE) {
 828                 dst->value = v->val;
 829                 dst->len = v->len;
 830                 return 0;
 831         }
 832
 833         meta_ops(v)->get(skb, info, v, dst, &err);
 834         if (err < 0)
 835                 return err;
 836
 837         if (meta_type_ops(v)->apply_extras)
 838                 meta_type_ops(v)->apply_extras(v, dst);
 839
 840         return 0;
 841 }
 842
 843 static int em_meta_match(struct sk_buff *skb, struct tcf_ematch *m,
 844                          struct tcf_pkt_info *info)
 845 {
 846         int r;
 847         struct meta_match *meta = (struct meta_match *) m->data;
 848         struct meta_obj l_value, r_value;
 849
 850         if (meta_get(skb, info, &meta->lvalue, &l_value) < 0 ||
 851             meta_get(skb, info, &meta->rvalue, &r_value) < 0)
 852                 return 0;
 853
 854         r = meta_type_ops(&meta->lvalue)->compare(&l_value, &r_value);
 855
 856         switch (meta->lvalue.hdr.op) {
 857         case TCF_EM_OPND_EQ:
 858                 return !r;
 859         case TCF_EM_OPND_LT:
 860                 return r < 0;
 861         case TCF_EM_OPND_GT:
 862                 return r > 0;
 863         }
 864
 865         return 0;
 866 }
 867
 868 static void meta_delete(struct meta_match *meta)
 869 {
 870         if (meta) {
 871                 const struct meta_type_ops *ops = meta_type_ops(&meta->lvalue);
 872
 873                 if (ops && ops->destroy) {
 874                         ops->destroy(&meta->lvalue);
 875                         ops->destroy(&meta->rvalue);
 876                 }
 877         }
 878
 879         kfree(meta);
 880 }
 881
 882 static inline int meta_change_data(struct meta_value *dst, struct nlattr *nla)
 883 {
 884         if (nla) {
 885                 if (nla_len(nla) == 0)
 886                         return -EINVAL;
 887
 888                 return meta_type_ops(dst)->change(dst, nla);
 889         }
 890
 891         return 0;
 892 }
 893
 894 static inline int meta_is_supported(struct meta_value *val)
 895 {
 896         return !meta_id(val) || meta_ops(val)->get;
 897 }
 898
 899 static const struct nla_policy meta_policy[TCA_EM_META_MAX + 1] = {
 900         [TCA_EM_META_HDR]       = { .len = sizeof(struct tcf_meta_hdr) },
 901 };
 902
 903 static int em_meta_change(struct net *net, void *data, int len,
 904                           struct tcf_ematch *m)
 905 {
 906         int err;
 907         struct nlattr *tb[TCA_EM_META_MAX + 1];
 908         struct tcf_meta_hdr *hdr;
 909         struct meta_match *meta = NULL;
 910
 911         err = nla_parse_deprecated(tb, TCA_EM_META_MAX, data, len,
 912                                    meta_policy, NULL);
 913         if (err < 0)
 914                 goto errout;
 915
 916         err = -EINVAL;
 917         if (tb[TCA_EM_META_HDR] == NULL)
 918                 goto errout;
 919         hdr = nla_data(tb[TCA_EM_META_HDR]);
 920
 921         if (TCF_META_TYPE(hdr->left.kind) != TCF_META_TYPE(hdr->right.kind) ||
 922             TCF_META_TYPE(hdr->left.kind) > TCF_META_TYPE_MAX ||
 923             TCF_META_ID(hdr->left.kind) > TCF_META_ID_MAX ||
 924             TCF_META_ID(hdr->right.kind) > TCF_META_ID_MAX)
 925                 goto errout;
 926
 927         meta = kzalloc(sizeof(*meta), GFP_KERNEL);
 928         if (meta == NULL) {
 929                 err = -ENOMEM;
 930                 goto errout;
 931         }
 932
 933         memcpy(&meta->lvalue.hdr, &hdr->left, sizeof(hdr->left));
 934         memcpy(&meta->rvalue.hdr, &hdr->right, sizeof(hdr->right));
 935
 936         if (!meta_is_supported(&meta->lvalue) ||
 937             !meta_is_supported(&meta->rvalue)) {
 938                 err = -EOPNOTSUPP;
 939                 goto errout;
 940         }
 941
 942         if (meta_change_data(&meta->lvalue, tb[TCA_EM_META_LVALUE]) < 0 ||
 943             meta_change_data(&meta->rvalue, tb[TCA_EM_META_RVALUE]) < 0)
 944                 goto errout;
 945
 946         m->datalen = sizeof(*meta);
 947         m->data = (unsigned long) meta;
 948
 949         err = 0;
 950 errout:
 951         if (err && meta)
 952                 meta_delete(meta);
 953         return err;
 954 }
 955
 956 static void em_meta_destroy(struct tcf_ematch *m)
 957 {
 958         if (m)
 959                 meta_delete((struct meta_match *) m->data);
 960 }
 961
 962 static int em_meta_dump(struct sk_buff *skb, struct tcf_ematch *em)
 963 {
 964         struct meta_match *meta = (struct meta_match *) em->data;
 965         struct tcf_meta_hdr hdr;
 966         const struct meta_type_ops *ops;
 967
 968         memset(&hdr, 0, sizeof(hdr));
 969         memcpy(&hdr.left, &meta->lvalue.hdr, sizeof(hdr.left));
 970         memcpy(&hdr.right, &meta->rvalue.hdr, sizeof(hdr.right));
 971
 972         if (nla_put(skb, TCA_EM_META_HDR, sizeof(hdr), &hdr))
 973                 goto nla_put_failure;
 974
 975         ops = meta_type_ops(&meta->lvalue);
 976         if (ops->dump(skb, &meta->lvalue, TCA_EM_META_LVALUE) < 0 ||
 977             ops->dump(skb, &meta->rvalue, TCA_EM_META_RVALUE) < 0)
 978                 goto nla_put_failure;
 979
 980         return 0;
 981
 982 nla_put_failure:
 983         return -1;
 984 }
 985
 986 static struct tcf_ematch_ops em_meta_ops = {
 987         .kind     = TCF_EM_META,
 988         .change   = em_meta_change,
 989         .match    = em_meta_match,
 990         .destroy  = em_meta_destroy,
 991         .dump     = em_meta_dump,
 992         .owner    = THIS_MODULE,
 993         .link     = LIST_HEAD_INIT(em_meta_ops.link)
 994 };
 995
 996 static int __init init_em_meta(void)
 997 {
 998         return tcf_em_register(&em_meta_ops);
 999 }
1000
1001 static void __exit exit_em_meta(void)
1002 {
1003         tcf_em_unregister(&em_meta_ops);
1004 }
1005
1006 MODULE_LICENSE("GPL");
1007
1008 module_init(init_em_meta);
1009 module_exit(exit_em_meta);
1010
1011 MODULE_ALIAS_TCF_EMATCH(TCF_EM_META);