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