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 76struct meta_obj { 77 unsigned long value; 78 unsigned int len; 79}; 80 81struct meta_value { 82 struct tcf_meta_val hdr; 83 unsigned long val; 84 unsigned int len; 85}; 86 87struct meta_match { 88 struct meta_value lvalue; 89 struct meta_value rvalue; 90}; 91 92static inline int meta_id(struct meta_value *v) 93{ 94 return TCF_META_ID(v->hdr.kind); 95} 96 97static 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 110META_COLLECTOR(int_random) 111{ 112 get_random_bytes(&dst->value, sizeof(dst->value)); 113} 114 115static 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 123META_COLLECTOR(int_loadavg_0) 124{ 125 dst->value = fixed_loadavg(avenrun[0]); 126} 127 128META_COLLECTOR(int_loadavg_1) 129{ 130 dst->value = fixed_loadavg(avenrun[1]); 131} 132 133META_COLLECTOR(int_loadavg_2) 134{ 135 dst->value = fixed_loadavg(avenrun[2]); 136} 137 138/************************************************************************** 139 * Device names & indices 140 **************************************************************************/ 141 142static 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 151static 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 161META_COLLECTOR(int_dev) 162{ 163 *err = int_dev(skb->dev, dst); 164} 165 166META_COLLECTOR(var_dev) 167{ 168 *err = var_dev(skb->dev, dst); 169} 170 171/************************************************************************** 172 * vlan tag 173 **************************************************************************/ 174 175META_COLLECTOR(int_vlan_tag) 176{ 177 unsigned short tag; 178 179 tag = vlan_tx_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 192META_COLLECTOR(int_priority) 193{ 194 dst->value = skb->priority; 195} 196 197META_COLLECTOR(int_protocol) 198{ 199 /* Let userspace take care of the byte ordering */ 200 dst->value = skb->protocol; 201} 202 203META_COLLECTOR(int_pkttype) 204{ 205 dst->value = skb->pkt_type; 206} 207 208META_COLLECTOR(int_pktlen) 209{ 210 dst->value = skb->len; 211} 212 213META_COLLECTOR(int_datalen) 214{ 215 dst->value = skb->data_len; 216} 217 218META_COLLECTOR(int_maclen) 219{ 220 dst->value = skb->mac_len; 221} 222 223META_COLLECTOR(int_rxhash) 224{ 225 dst->value = skb_get_rxhash(skb); 226} 227 228/************************************************************************** 229 * Netfilter 230 **************************************************************************/ 231 232META_COLLECTOR(int_mark) 233{ 234 dst->value = skb->mark; 235} 236 237/************************************************************************** 238 * Traffic Control 239 **************************************************************************/ 240 241META_COLLECTOR(int_tcindex) 242{ 243 dst->value = skb->tc_index; 244} 245 246/************************************************************************** 247 * Routing 248 **************************************************************************/ 249 250META_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 262META_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 if (unlikely(skb->sk == NULL)) { \ 276 *err = -1; \ 277 return; \ 278 } 279 280META_COLLECTOR(int_sk_family) 281{ 282 SKIP_NONLOCAL(skb); 283 dst->value = skb->sk->sk_family; 284} 285 286META_COLLECTOR(int_sk_state) 287{ 288 SKIP_NONLOCAL(skb); 289 dst->value = skb->sk->sk_state; 290} 291 292META_COLLECTOR(int_sk_reuse) 293{ 294 SKIP_NONLOCAL(skb); 295 dst->value = skb->sk->sk_reuse; 296} 297 298META_COLLECTOR(int_sk_bound_if) 299{ 300 SKIP_NONLOCAL(skb); 301 /* No error if bound_dev_if is 0, legal userspace check */ 302 dst->value = skb->sk->sk_bound_dev_if; 303} 304 305META_COLLECTOR(var_sk_bound_if) 306{ 307 SKIP_NONLOCAL(skb); 308 309 if (skb->sk->sk_bound_dev_if == 0) { 310 dst->value = (unsigned long) "any"; 311 dst->len = 3; 312 } else { 313 struct net_device *dev; 314 315 rcu_read_lock(); 316 dev = dev_get_by_index_rcu(sock_net(skb->sk), 317 skb->sk->sk_bound_dev_if); 318 *err = var_dev(dev, dst); 319 rcu_read_unlock(); 320 } 321} 322 323META_COLLECTOR(int_sk_refcnt) 324{ 325 SKIP_NONLOCAL(skb); 326 dst->value = atomic_read(&skb->sk->sk_refcnt); 327} 328 329META_COLLECTOR(int_sk_rcvbuf) 330{ 331 SKIP_NONLOCAL(skb); 332 dst->value = skb->sk->sk_rcvbuf; 333} 334 335META_COLLECTOR(int_sk_shutdown) 336{ 337 SKIP_NONLOCAL(skb); 338 dst->value = skb->sk->sk_shutdown; 339} 340 341META_COLLECTOR(int_sk_proto) 342{ 343 SKIP_NONLOCAL(skb); 344 dst->value = skb->sk->sk_protocol; 345} 346 347META_COLLECTOR(int_sk_type) 348{ 349 SKIP_NONLOCAL(skb); 350 dst->value = skb->sk->sk_type; 351} 352 353META_COLLECTOR(int_sk_rmem_alloc) 354{ 355 SKIP_NONLOCAL(skb); 356 dst->value = sk_rmem_alloc_get(skb->sk); 357} 358 359META_COLLECTOR(int_sk_wmem_alloc) 360{ 361 SKIP_NONLOCAL(skb); 362 dst->value = sk_wmem_alloc_get(skb->sk); 363} 364 365META_COLLECTOR(int_sk_omem_alloc) 366{ 367 SKIP_NONLOCAL(skb); 368 dst->value = atomic_read(&skb->sk->sk_omem_alloc); 369} 370 371META_COLLECTOR(int_sk_rcv_qlen) 372{ 373 SKIP_NONLOCAL(skb); 374 dst->value = skb->sk->sk_receive_queue.qlen; 375} 376 377META_COLLECTOR(int_sk_snd_qlen) 378{ 379 SKIP_NONLOCAL(skb); 380 dst->value = skb->sk->sk_write_queue.qlen; 381} 382 383META_COLLECTOR(int_sk_wmem_queued) 384{ 385 SKIP_NONLOCAL(skb); 386 dst->value = skb->sk->sk_wmem_queued; 387} 388 389META_COLLECTOR(int_sk_fwd_alloc) 390{ 391 SKIP_NONLOCAL(skb); 392 dst->value = skb->sk->sk_forward_alloc; 393} 394 395META_COLLECTOR(int_sk_sndbuf) 396{ 397 SKIP_NONLOCAL(skb); 398 dst->value = skb->sk->sk_sndbuf; 399} 400 401META_COLLECTOR(int_sk_alloc) 402{ 403 SKIP_NONLOCAL(skb); 404 dst->value = (__force int) skb->sk->sk_allocation; 405} 406 407META_COLLECTOR(int_sk_hash) 408{ 409 SKIP_NONLOCAL(skb); 410 dst->value = skb->sk->sk_hash; 411} 412 413META_COLLECTOR(int_sk_lingertime) 414{ 415 SKIP_NONLOCAL(skb); 416 dst->value = skb->sk->sk_lingertime / HZ; 417} 418 419META_COLLECTOR(int_sk_err_qlen) 420{ 421 SKIP_NONLOCAL(skb); 422 dst->value = skb->sk->sk_error_queue.qlen; 423} 424 425META_COLLECTOR(int_sk_ack_bl) 426{ 427 SKIP_NONLOCAL(skb); 428 dst->value = skb->sk->sk_ack_backlog; 429} 430 431META_COLLECTOR(int_sk_max_ack_bl) 432{ 433 SKIP_NONLOCAL(skb); 434 dst->value = skb->sk->sk_max_ack_backlog; 435} 436 437META_COLLECTOR(int_sk_prio) 438{ 439 SKIP_NONLOCAL(skb); 440 dst->value = skb->sk->sk_priority; 441} 442 443META_COLLECTOR(int_sk_rcvlowat) 444{ 445 SKIP_NONLOCAL(skb); 446 dst->value = skb->sk->sk_rcvlowat; 447} 448 449META_COLLECTOR(int_sk_rcvtimeo) 450{ 451 SKIP_NONLOCAL(skb); 452 dst->value = skb->sk->sk_rcvtimeo / HZ; 453} 454 455META_COLLECTOR(int_sk_sndtimeo) 456{ 457 SKIP_NONLOCAL(skb); 458 dst->value = skb->sk->sk_sndtimeo / HZ; 459} 460 461META_COLLECTOR(int_sk_sendmsg_off) 462{ 463 SKIP_NONLOCAL(skb); 464 dst->value = skb->sk->sk_frag.offset; 465} 466 467META_COLLECTOR(int_sk_write_pend) 468{ 469 SKIP_NONLOCAL(skb); 470 dst->value = skb->sk->sk_write_pending; 471} 472 473/************************************************************************** 474 * Meta value collectors assignment table 475 **************************************************************************/ 476 477struct meta_ops { 478 void (*get)(struct sk_buff *, struct tcf_pkt_info *, 479 struct meta_value *, struct meta_obj *, int *); 480}; 481 482#define META_ID(name) TCF_META_ID_##name 483#define META_FUNC(name) { .get = meta_##name } 484 485/* Meta value operations table listing all meta value collectors and 486 * assigns them to a type and meta id. */ 487static struct meta_ops __meta_ops[TCF_META_TYPE_MAX + 1][TCF_META_ID_MAX + 1] = { 488 [TCF_META_TYPE_VAR] = { 489 [META_ID(DEV)] = META_FUNC(var_dev), 490 [META_ID(SK_BOUND_IF)] = META_FUNC(var_sk_bound_if), 491 }, 492 [TCF_META_TYPE_INT] = { 493 [META_ID(RANDOM)] = META_FUNC(int_random), 494 [META_ID(LOADAVG_0)] = META_FUNC(int_loadavg_0), 495 [META_ID(LOADAVG_1)] = META_FUNC(int_loadavg_1), 496 [META_ID(LOADAVG_2)] = META_FUNC(int_loadavg_2), 497 [META_ID(DEV)] = META_FUNC(int_dev), 498 [META_ID(PRIORITY)] = META_FUNC(int_priority), 499 [META_ID(PROTOCOL)] = META_FUNC(int_protocol), 500 [META_ID(PKTTYPE)] = META_FUNC(int_pkttype), 501 [META_ID(PKTLEN)] = META_FUNC(int_pktlen), 502 [META_ID(DATALEN)] = META_FUNC(int_datalen), 503 [META_ID(MACLEN)] = META_FUNC(int_maclen), 504 [META_ID(NFMARK)] = META_FUNC(int_mark), 505 [META_ID(TCINDEX)] = META_FUNC(int_tcindex), 506 [META_ID(RTCLASSID)] = META_FUNC(int_rtclassid), 507 [META_ID(RTIIF)] = META_FUNC(int_rtiif), 508 [META_ID(SK_FAMILY)] = META_FUNC(int_sk_family), 509 [META_ID(SK_STATE)] = META_FUNC(int_sk_state), 510 [META_ID(SK_REUSE)] = META_FUNC(int_sk_reuse), 511 [META_ID(SK_BOUND_IF)] = META_FUNC(int_sk_bound_if), 512 [META_ID(SK_REFCNT)] = META_FUNC(int_sk_refcnt), 513 [META_ID(SK_RCVBUF)] = META_FUNC(int_sk_rcvbuf), 514 [META_ID(SK_SNDBUF)] = META_FUNC(int_sk_sndbuf), 515 [META_ID(SK_SHUTDOWN)] = META_FUNC(int_sk_shutdown), 516 [META_ID(SK_PROTO)] = META_FUNC(int_sk_proto), 517 [META_ID(SK_TYPE)] = META_FUNC(int_sk_type), 518 [META_ID(SK_RMEM_ALLOC)] = META_FUNC(int_sk_rmem_alloc), 519 [META_ID(SK_WMEM_ALLOC)] = META_FUNC(int_sk_wmem_alloc), 520 [META_ID(SK_OMEM_ALLOC)] = META_FUNC(int_sk_omem_alloc), 521 [META_ID(SK_WMEM_QUEUED)] = META_FUNC(int_sk_wmem_queued), 522 [META_ID(SK_RCV_QLEN)] = META_FUNC(int_sk_rcv_qlen), 523 [META_ID(SK_SND_QLEN)] = META_FUNC(int_sk_snd_qlen), 524 [META_ID(SK_ERR_QLEN)] = META_FUNC(int_sk_err_qlen), 525 [META_ID(SK_FORWARD_ALLOCS)] = META_FUNC(int_sk_fwd_alloc), 526 [META_ID(SK_ALLOCS)] = META_FUNC(int_sk_alloc), 527 [META_ID(SK_HASH)] = META_FUNC(int_sk_hash), 528 [META_ID(SK_LINGERTIME)] = META_FUNC(int_sk_lingertime), 529 [META_ID(SK_ACK_BACKLOG)] = META_FUNC(int_sk_ack_bl), 530 [META_ID(SK_MAX_ACK_BACKLOG)] = META_FUNC(int_sk_max_ack_bl), 531 [META_ID(SK_PRIO)] = META_FUNC(int_sk_prio), 532 [META_ID(SK_RCVLOWAT)] = META_FUNC(int_sk_rcvlowat), 533 [META_ID(SK_RCVTIMEO)] = META_FUNC(int_sk_rcvtimeo), 534 [META_ID(SK_SNDTIMEO)] = META_FUNC(int_sk_sndtimeo), 535 [META_ID(SK_SENDMSG_OFF)] = META_FUNC(int_sk_sendmsg_off), 536 [META_ID(SK_WRITE_PENDING)] = META_FUNC(int_sk_write_pend), 537 [META_ID(VLAN_TAG)] = META_FUNC(int_vlan_tag), 538 [META_ID(RXHASH)] = META_FUNC(int_rxhash), 539 } 540}; 541 542static inline struct meta_ops *meta_ops(struct meta_value *val) 543{ 544 return &__meta_ops[meta_type(val)][meta_id(val)]; 545} 546 547/************************************************************************** 548 * Type specific operations for TCF_META_TYPE_VAR 549 **************************************************************************/ 550 551static int meta_var_compare(struct meta_obj *a, struct meta_obj *b) 552{ 553 int r = a->len - b->len; 554 555 if (r == 0) 556 r = memcmp((void *) a->value, (void *) b->value, a->len); 557 558 return r; 559} 560 561static int meta_var_change(struct meta_value *dst, struct nlattr *nla) 562{ 563 int len = nla_len(nla); 564 565 dst->val = (unsigned long)kmemdup(nla_data(nla), len, GFP_KERNEL); 566 if (dst->val == 0UL) 567 return -ENOMEM; 568 dst->len = len; 569 return 0; 570} 571 572static void meta_var_destroy(struct meta_value *v) 573{ 574 kfree((void *) v->val); 575} 576 577static void meta_var_apply_extras(struct meta_value *v, 578 struct meta_obj *dst) 579{ 580 int shift = v->hdr.shift; 581 582 if (shift && shift < dst->len) 583 dst->len -= shift; 584} 585 586static int meta_var_dump(struct sk_buff *skb, struct meta_value *v, int tlv) 587{ 588 if (v->val && v->len && 589 nla_put(skb, tlv, v->len, (void *) v->val)) 590 goto nla_put_failure; 591 return 0; 592 593nla_put_failure: 594 return -1; 595} 596 597/************************************************************************** 598 * Type specific operations for TCF_META_TYPE_INT 599 **************************************************************************/ 600 601static int meta_int_compare(struct meta_obj *a, struct meta_obj *b) 602{ 603 /* Let gcc optimize it, the unlikely is not really based on 604 * some numbers but jump free code for mismatches seems 605 * more logical. */ 606 if (unlikely(a->value == b->value)) 607 return 0; 608 else if (a->value < b->value) 609 return -1; 610 else 611 return 1; 612} 613 614static int meta_int_change(struct meta_value *dst, struct nlattr *nla) 615{ 616 if (nla_len(nla) >= sizeof(unsigned long)) { 617 dst->val = *(unsigned long *) nla_data(nla); 618 dst->len = sizeof(unsigned long); 619 } else if (nla_len(nla) == sizeof(u32)) { 620 dst->val = nla_get_u32(nla); 621 dst->len = sizeof(u32); 622 } else 623 return -EINVAL; 624 625 return 0; 626} 627 628static void meta_int_apply_extras(struct meta_value *v, 629 struct meta_obj *dst) 630{ 631 if (v->hdr.shift) 632 dst->value >>= v->hdr.shift; 633 634 if (v->val) 635 dst->value &= v->val; 636} 637 638static int meta_int_dump(struct sk_buff *skb, struct meta_value *v, int tlv) 639{ 640 if (v->len == sizeof(unsigned long)) { 641 if (nla_put(skb, tlv, sizeof(unsigned long), &v->val)) 642 goto nla_put_failure; 643 } else if (v->len == sizeof(u32)) { 644 if (nla_put_u32(skb, tlv, v->val)) 645 goto nla_put_failure; 646 } 647 648 return 0; 649 650nla_put_failure: 651 return -1; 652} 653 654/************************************************************************** 655 * Type specific operations table 656 **************************************************************************/ 657 658struct meta_type_ops { 659 void (*destroy)(struct meta_value *); 660 int (*compare)(struct meta_obj *, struct meta_obj *); 661 int (*change)(struct meta_value *, struct nlattr *); 662 void (*apply_extras)(struct meta_value *, struct meta_obj *); 663 int (*dump)(struct sk_buff *, struct meta_value *, int); 664}; 665 666static struct meta_type_ops __meta_type_ops[TCF_META_TYPE_MAX + 1] = { 667 [TCF_META_TYPE_VAR] = { 668 .destroy = meta_var_destroy, 669 .compare = meta_var_compare, 670 .change = meta_var_change, 671 .apply_extras = meta_var_apply_extras, 672 .dump = meta_var_dump 673 }, 674 [TCF_META_TYPE_INT] = { 675 .compare = meta_int_compare, 676 .change = meta_int_change, 677 .apply_extras = meta_int_apply_extras, 678 .dump = meta_int_dump 679 } 680}; 681 682static inline struct meta_type_ops *meta_type_ops(struct meta_value *v) 683{ 684 return &__meta_type_ops[meta_type(v)]; 685} 686 687/************************************************************************** 688 * Core 689 **************************************************************************/ 690 691static int meta_get(struct sk_buff *skb, struct tcf_pkt_info *info, 692 struct meta_value *v, struct meta_obj *dst) 693{ 694 int err = 0; 695 696 if (meta_id(v) == TCF_META_ID_VALUE) { 697 dst->value = v->val; 698 dst->len = v->len; 699 return 0; 700 } 701 702 meta_ops(v)->get(skb, info, v, dst, &err); 703 if (err < 0) 704 return err; 705 706 if (meta_type_ops(v)->apply_extras) 707 meta_type_ops(v)->apply_extras(v, dst); 708 709 return 0; 710} 711 712static int em_meta_match(struct sk_buff *skb, struct tcf_ematch *m, 713 struct tcf_pkt_info *info) 714{ 715 int r; 716 struct meta_match *meta = (struct meta_match *) m->data; 717 struct meta_obj l_value, r_value; 718 719 if (meta_get(skb, info, &meta->lvalue, &l_value) < 0 || 720 meta_get(skb, info, &meta->rvalue, &r_value) < 0) 721 return 0; 722 723 r = meta_type_ops(&meta->lvalue)->compare(&l_value, &r_value); 724 725 switch (meta->lvalue.hdr.op) { 726 case TCF_EM_OPND_EQ: 727 return !r; 728 case TCF_EM_OPND_LT: 729 return r < 0; 730 case TCF_EM_OPND_GT: 731 return r > 0; 732 } 733 734 return 0; 735} 736 737static void meta_delete(struct meta_match *meta) 738{ 739 if (meta) { 740 struct meta_type_ops *ops = meta_type_ops(&meta->lvalue); 741 742 if (ops && ops->destroy) { 743 ops->destroy(&meta->lvalue); 744 ops->destroy(&meta->rvalue); 745 } 746 } 747 748 kfree(meta); 749} 750 751static inline int meta_change_data(struct meta_value *dst, struct nlattr *nla) 752{ 753 if (nla) { 754 if (nla_len(nla) == 0) 755 return -EINVAL; 756 757 return meta_type_ops(dst)->change(dst, nla); 758 } 759 760 return 0; 761} 762 763static inline int meta_is_supported(struct meta_value *val) 764{ 765 return !meta_id(val) || meta_ops(val)->get; 766} 767 768static const struct nla_policy meta_policy[TCA_EM_META_MAX + 1] = { 769 [TCA_EM_META_HDR] = { .len = sizeof(struct tcf_meta_hdr) }, 770}; 771 772static int em_meta_change(struct tcf_proto *tp, void *data, int len, 773 struct tcf_ematch *m) 774{ 775 int err; 776 struct nlattr *tb[TCA_EM_META_MAX + 1]; 777 struct tcf_meta_hdr *hdr; 778 struct meta_match *meta = NULL; 779 780 err = nla_parse(tb, TCA_EM_META_MAX, data, len, meta_policy); 781 if (err < 0) 782 goto errout; 783 784 err = -EINVAL; 785 if (tb[TCA_EM_META_HDR] == NULL) 786 goto errout; 787 hdr = nla_data(tb[TCA_EM_META_HDR]); 788 789 if (TCF_META_TYPE(hdr->left.kind) != TCF_META_TYPE(hdr->right.kind) || 790 TCF_META_TYPE(hdr->left.kind) > TCF_META_TYPE_MAX || 791 TCF_META_ID(hdr->left.kind) > TCF_META_ID_MAX || 792 TCF_META_ID(hdr->right.kind) > TCF_META_ID_MAX) 793 goto errout; 794 795 meta = kzalloc(sizeof(*meta), GFP_KERNEL); 796 if (meta == NULL) 797 goto errout; 798 799 memcpy(&meta->lvalue.hdr, &hdr->left, sizeof(hdr->left)); 800 memcpy(&meta->rvalue.hdr, &hdr->right, sizeof(hdr->right)); 801 802 if (!meta_is_supported(&meta->lvalue) || 803 !meta_is_supported(&meta->rvalue)) { 804 err = -EOPNOTSUPP; 805 goto errout; 806 } 807 808 if (meta_change_data(&meta->lvalue, tb[TCA_EM_META_LVALUE]) < 0 || 809 meta_change_data(&meta->rvalue, tb[TCA_EM_META_RVALUE]) < 0) 810 goto errout; 811 812 m->datalen = sizeof(*meta); 813 m->data = (unsigned long) meta; 814 815 err = 0; 816errout: 817 if (err && meta) 818 meta_delete(meta); 819 return err; 820} 821 822static void em_meta_destroy(struct tcf_proto *tp, struct tcf_ematch *m) 823{ 824 if (m) 825 meta_delete((struct meta_match *) m->data); 826} 827 828static int em_meta_dump(struct sk_buff *skb, struct tcf_ematch *em) 829{ 830 struct meta_match *meta = (struct meta_match *) em->data; 831 struct tcf_meta_hdr hdr; 832 struct meta_type_ops *ops; 833 834 memset(&hdr, 0, sizeof(hdr)); 835 memcpy(&hdr.left, &meta->lvalue.hdr, sizeof(hdr.left)); 836 memcpy(&hdr.right, &meta->rvalue.hdr, sizeof(hdr.right)); 837 838 if (nla_put(skb, TCA_EM_META_HDR, sizeof(hdr), &hdr)) 839 goto nla_put_failure; 840 841 ops = meta_type_ops(&meta->lvalue); 842 if (ops->dump(skb, &meta->lvalue, TCA_EM_META_LVALUE) < 0 || 843 ops->dump(skb, &meta->rvalue, TCA_EM_META_RVALUE) < 0) 844 goto nla_put_failure; 845 846 return 0; 847 848nla_put_failure: 849 return -1; 850} 851 852static struct tcf_ematch_ops em_meta_ops = { 853 .kind = TCF_EM_META, 854 .change = em_meta_change, 855 .match = em_meta_match, 856 .destroy = em_meta_destroy, 857 .dump = em_meta_dump, 858 .owner = THIS_MODULE, 859 .link = LIST_HEAD_INIT(em_meta_ops.link) 860}; 861 862static int __init init_em_meta(void) 863{ 864 return tcf_em_register(&em_meta_ops); 865} 866 867static void __exit exit_em_meta(void) 868{ 869 tcf_em_unregister(&em_meta_ops); 870} 871 872MODULE_LICENSE("GPL"); 873 874module_init(init_em_meta); 875module_exit(exit_em_meta); 876 877MODULE_ALIAS_TCF_EMATCH(TCF_EM_META); 878