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/sched/loadavg.h> 67 #include <linux/string.h> 68 #include <linux/skbuff.h> 69 #include <linux/random.h> 70 #include <linux/if_vlan.h> 71 #include <linux/tc_ematch/tc_em_meta.h> 72 #include <net/dst.h> 73 #include <net/route.h> 74 #include <net/pkt_cls.h> 75 #include <net/sock.h> 76 77 struct meta_obj { 78 unsigned long value; 79 unsigned int len; 80 }; 81 82 struct meta_value { 83 struct tcf_meta_val hdr; 84 unsigned long val; 85 unsigned int len; 86 }; 87 88 struct meta_match { 89 struct meta_value lvalue; 90 struct meta_value rvalue; 91 }; 92 93 static inline int meta_id(struct meta_value *v) 94 { 95 return TCF_META_ID(v->hdr.kind); 96 } 97 98 static inline int meta_type(struct meta_value *v) 99 { 100 return TCF_META_TYPE(v->hdr.kind); 101 } 102 103 #define META_COLLECTOR(FUNC) static void meta_##FUNC(struct sk_buff *skb, \ 104 struct tcf_pkt_info *info, struct meta_value *v, \ 105 struct meta_obj *dst, int *err) 106 107 /************************************************************************** 108 * System status & misc 109 **************************************************************************/ 110 111 META_COLLECTOR(int_random) 112 { 113 get_random_bytes(&dst->value, sizeof(dst->value)); 114 } 115 116 static inline unsigned long fixed_loadavg(int load) 117 { 118 int rnd_load = load + (FIXED_1/200); 119 int rnd_frac = ((rnd_load & (FIXED_1-1)) * 100) >> FSHIFT; 120 121 return ((rnd_load >> FSHIFT) * 100) + rnd_frac; 122 } 123 124 META_COLLECTOR(int_loadavg_0) 125 { 126 dst->value = fixed_loadavg(avenrun[0]); 127 } 128 129 META_COLLECTOR(int_loadavg_1) 130 { 131 dst->value = fixed_loadavg(avenrun[1]); 132 } 133 134 META_COLLECTOR(int_loadavg_2) 135 { 136 dst->value = fixed_loadavg(avenrun[2]); 137 } 138 139 /************************************************************************** 140 * Device names & indices 141 **************************************************************************/ 142 143 static inline int int_dev(struct net_device *dev, struct meta_obj *dst) 144 { 145 if (unlikely(dev == NULL)) 146 return -1; 147 148 dst->value = dev->ifindex; 149 return 0; 150 } 151 152 static inline int var_dev(struct net_device *dev, struct meta_obj *dst) 153 { 154 if (unlikely(dev == NULL)) 155 return -1; 156 157 dst->value = (unsigned long) dev->name; 158 dst->len = strlen(dev->name); 159 return 0; 160 } 161 162 META_COLLECTOR(int_dev) 163 { 164 *err = int_dev(skb->dev, dst); 165 } 166 167 META_COLLECTOR(var_dev) 168 { 169 *err = var_dev(skb->dev, dst); 170 } 171 172 /************************************************************************** 173 * vlan tag 174 **************************************************************************/ 175 176 META_COLLECTOR(int_vlan_tag) 177 { 178 unsigned short tag; 179 180 if (skb_vlan_tag_present(skb)) 181 dst->value = skb_vlan_tag_get(skb); 182 else if (!__vlan_get_tag(skb, &tag)) 183 dst->value = tag; 184 else 185 *err = -1; 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 = tc_skb_protocol(skb); 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 META_COLLECTOR(int_rxhash) 226 { 227 dst->value = skb_get_hash(skb); 228 } 229 230 /************************************************************************** 231 * Netfilter 232 **************************************************************************/ 233 234 META_COLLECTOR(int_mark) 235 { 236 dst->value = skb->mark; 237 } 238 239 /************************************************************************** 240 * Traffic Control 241 **************************************************************************/ 242 243 META_COLLECTOR(int_tcindex) 244 { 245 dst->value = skb->tc_index; 246 } 247 248 /************************************************************************** 249 * Routing 250 **************************************************************************/ 251 252 META_COLLECTOR(int_rtclassid) 253 { 254 if (unlikely(skb_dst(skb) == NULL)) 255 *err = -1; 256 else 257 #ifdef CONFIG_IP_ROUTE_CLASSID 258 dst->value = skb_dst(skb)->tclassid; 259 #else 260 dst->value = 0; 261 #endif 262 } 263 264 META_COLLECTOR(int_rtiif) 265 { 266 if (unlikely(skb_rtable(skb) == NULL)) 267 *err = -1; 268 else 269 dst->value = inet_iif(skb); 270 } 271 272 /************************************************************************** 273 * Socket Attributes 274 **************************************************************************/ 275 276 #define skip_nonlocal(skb) \ 277 (unlikely(skb->sk == NULL)) 278 279 META_COLLECTOR(int_sk_family) 280 { 281 if (skip_nonlocal(skb)) { 282 *err = -1; 283 return; 284 } 285 dst->value = skb->sk->sk_family; 286 } 287 288 META_COLLECTOR(int_sk_state) 289 { 290 if (skip_nonlocal(skb)) { 291 *err = -1; 292 return; 293 } 294 dst->value = skb->sk->sk_state; 295 } 296 297 META_COLLECTOR(int_sk_reuse) 298 { 299 if (skip_nonlocal(skb)) { 300 *err = -1; 301 return; 302 } 303 dst->value = skb->sk->sk_reuse; 304 } 305 306 META_COLLECTOR(int_sk_bound_if) 307 { 308 if (skip_nonlocal(skb)) { 309 *err = -1; 310 return; 311 } 312 /* No error if bound_dev_if is 0, legal userspace check */ 313 dst->value = skb->sk->sk_bound_dev_if; 314 } 315 316 META_COLLECTOR(var_sk_bound_if) 317 { 318 if (skip_nonlocal(skb)) { 319 *err = -1; 320 return; 321 } 322 323 if (skb->sk->sk_bound_dev_if == 0) { 324 dst->value = (unsigned long) "any"; 325 dst->len = 3; 326 } else { 327 struct net_device *dev; 328 329 rcu_read_lock(); 330 dev = dev_get_by_index_rcu(sock_net(skb->sk), 331 skb->sk->sk_bound_dev_if); 332 *err = var_dev(dev, dst); 333 rcu_read_unlock(); 334 } 335 } 336 337 META_COLLECTOR(int_sk_refcnt) 338 { 339 if (skip_nonlocal(skb)) { 340 *err = -1; 341 return; 342 } 343 dst->value = atomic_read(&skb->sk->sk_refcnt); 344 } 345 346 META_COLLECTOR(int_sk_rcvbuf) 347 { 348 const struct sock *sk = skb_to_full_sk(skb); 349 350 if (!sk) { 351 *err = -1; 352 return; 353 } 354 dst->value = sk->sk_rcvbuf; 355 } 356 357 META_COLLECTOR(int_sk_shutdown) 358 { 359 const struct sock *sk = skb_to_full_sk(skb); 360 361 if (!sk) { 362 *err = -1; 363 return; 364 } 365 dst->value = sk->sk_shutdown; 366 } 367 368 META_COLLECTOR(int_sk_proto) 369 { 370 const struct sock *sk = skb_to_full_sk(skb); 371 372 if (!sk) { 373 *err = -1; 374 return; 375 } 376 dst->value = sk->sk_protocol; 377 } 378 379 META_COLLECTOR(int_sk_type) 380 { 381 const struct sock *sk = skb_to_full_sk(skb); 382 383 if (!sk) { 384 *err = -1; 385 return; 386 } 387 dst->value = sk->sk_type; 388 } 389 390 META_COLLECTOR(int_sk_rmem_alloc) 391 { 392 const struct sock *sk = skb_to_full_sk(skb); 393 394 if (!sk) { 395 *err = -1; 396 return; 397 } 398 dst->value = sk_rmem_alloc_get(sk); 399 } 400 401 META_COLLECTOR(int_sk_wmem_alloc) 402 { 403 const struct sock *sk = skb_to_full_sk(skb); 404 405 if (!sk) { 406 *err = -1; 407 return; 408 } 409 dst->value = sk_wmem_alloc_get(sk); 410 } 411 412 META_COLLECTOR(int_sk_omem_alloc) 413 { 414 const struct sock *sk = skb_to_full_sk(skb); 415 416 if (!sk) { 417 *err = -1; 418 return; 419 } 420 dst->value = atomic_read(&sk->sk_omem_alloc); 421 } 422 423 META_COLLECTOR(int_sk_rcv_qlen) 424 { 425 const struct sock *sk = skb_to_full_sk(skb); 426 427 if (!sk) { 428 *err = -1; 429 return; 430 } 431 dst->value = sk->sk_receive_queue.qlen; 432 } 433 434 META_COLLECTOR(int_sk_snd_qlen) 435 { 436 const struct sock *sk = skb_to_full_sk(skb); 437 438 if (!sk) { 439 *err = -1; 440 return; 441 } 442 dst->value = sk->sk_write_queue.qlen; 443 } 444 445 META_COLLECTOR(int_sk_wmem_queued) 446 { 447 const struct sock *sk = skb_to_full_sk(skb); 448 449 if (!sk) { 450 *err = -1; 451 return; 452 } 453 dst->value = sk->sk_wmem_queued; 454 } 455 456 META_COLLECTOR(int_sk_fwd_alloc) 457 { 458 const struct sock *sk = skb_to_full_sk(skb); 459 460 if (!sk) { 461 *err = -1; 462 return; 463 } 464 dst->value = sk->sk_forward_alloc; 465 } 466 467 META_COLLECTOR(int_sk_sndbuf) 468 { 469 const struct sock *sk = skb_to_full_sk(skb); 470 471 if (!sk) { 472 *err = -1; 473 return; 474 } 475 dst->value = sk->sk_sndbuf; 476 } 477 478 META_COLLECTOR(int_sk_alloc) 479 { 480 const struct sock *sk = skb_to_full_sk(skb); 481 482 if (!sk) { 483 *err = -1; 484 return; 485 } 486 dst->value = (__force int) sk->sk_allocation; 487 } 488 489 META_COLLECTOR(int_sk_hash) 490 { 491 if (skip_nonlocal(skb)) { 492 *err = -1; 493 return; 494 } 495 dst->value = skb->sk->sk_hash; 496 } 497 498 META_COLLECTOR(int_sk_lingertime) 499 { 500 const struct sock *sk = skb_to_full_sk(skb); 501 502 if (!sk) { 503 *err = -1; 504 return; 505 } 506 dst->value = sk->sk_lingertime / HZ; 507 } 508 509 META_COLLECTOR(int_sk_err_qlen) 510 { 511 const struct sock *sk = skb_to_full_sk(skb); 512 513 if (!sk) { 514 *err = -1; 515 return; 516 } 517 dst->value = sk->sk_error_queue.qlen; 518 } 519 520 META_COLLECTOR(int_sk_ack_bl) 521 { 522 const struct sock *sk = skb_to_full_sk(skb); 523 524 if (!sk) { 525 *err = -1; 526 return; 527 } 528 dst->value = sk->sk_ack_backlog; 529 } 530 531 META_COLLECTOR(int_sk_max_ack_bl) 532 { 533 const struct sock *sk = skb_to_full_sk(skb); 534 535 if (!sk) { 536 *err = -1; 537 return; 538 } 539 dst->value = sk->sk_max_ack_backlog; 540 } 541 542 META_COLLECTOR(int_sk_prio) 543 { 544 const struct sock *sk = skb_to_full_sk(skb); 545 546 if (!sk) { 547 *err = -1; 548 return; 549 } 550 dst->value = sk->sk_priority; 551 } 552 553 META_COLLECTOR(int_sk_rcvlowat) 554 { 555 const struct sock *sk = skb_to_full_sk(skb); 556 557 if (!sk) { 558 *err = -1; 559 return; 560 } 561 dst->value = sk->sk_rcvlowat; 562 } 563 564 META_COLLECTOR(int_sk_rcvtimeo) 565 { 566 const struct sock *sk = skb_to_full_sk(skb); 567 568 if (!sk) { 569 *err = -1; 570 return; 571 } 572 dst->value = sk->sk_rcvtimeo / HZ; 573 } 574 575 META_COLLECTOR(int_sk_sndtimeo) 576 { 577 const struct sock *sk = skb_to_full_sk(skb); 578 579 if (!sk) { 580 *err = -1; 581 return; 582 } 583 dst->value = sk->sk_sndtimeo / HZ; 584 } 585 586 META_COLLECTOR(int_sk_sendmsg_off) 587 { 588 const struct sock *sk = skb_to_full_sk(skb); 589 590 if (!sk) { 591 *err = -1; 592 return; 593 } 594 dst->value = sk->sk_frag.offset; 595 } 596 597 META_COLLECTOR(int_sk_write_pend) 598 { 599 const struct sock *sk = skb_to_full_sk(skb); 600 601 if (!sk) { 602 *err = -1; 603 return; 604 } 605 dst->value = sk->sk_write_pending; 606 } 607 608 /************************************************************************** 609 * Meta value collectors assignment table 610 **************************************************************************/ 611 612 struct meta_ops { 613 void (*get)(struct sk_buff *, struct tcf_pkt_info *, 614 struct meta_value *, struct meta_obj *, int *); 615 }; 616 617 #define META_ID(name) TCF_META_ID_##name 618 #define META_FUNC(name) { .get = meta_##name } 619 620 /* Meta value operations table listing all meta value collectors and 621 * assigns them to a type and meta id. */ 622 static struct meta_ops __meta_ops[TCF_META_TYPE_MAX + 1][TCF_META_ID_MAX + 1] = { 623 [TCF_META_TYPE_VAR] = { 624 [META_ID(DEV)] = META_FUNC(var_dev), 625 [META_ID(SK_BOUND_IF)] = META_FUNC(var_sk_bound_if), 626 }, 627 [TCF_META_TYPE_INT] = { 628 [META_ID(RANDOM)] = META_FUNC(int_random), 629 [META_ID(LOADAVG_0)] = META_FUNC(int_loadavg_0), 630 [META_ID(LOADAVG_1)] = META_FUNC(int_loadavg_1), 631 [META_ID(LOADAVG_2)] = META_FUNC(int_loadavg_2), 632 [META_ID(DEV)] = META_FUNC(int_dev), 633 [META_ID(PRIORITY)] = META_FUNC(int_priority), 634 [META_ID(PROTOCOL)] = META_FUNC(int_protocol), 635 [META_ID(PKTTYPE)] = META_FUNC(int_pkttype), 636 [META_ID(PKTLEN)] = META_FUNC(int_pktlen), 637 [META_ID(DATALEN)] = META_FUNC(int_datalen), 638 [META_ID(MACLEN)] = META_FUNC(int_maclen), 639 [META_ID(NFMARK)] = META_FUNC(int_mark), 640 [META_ID(TCINDEX)] = META_FUNC(int_tcindex), 641 [META_ID(RTCLASSID)] = META_FUNC(int_rtclassid), 642 [META_ID(RTIIF)] = META_FUNC(int_rtiif), 643 [META_ID(SK_FAMILY)] = META_FUNC(int_sk_family), 644 [META_ID(SK_STATE)] = META_FUNC(int_sk_state), 645 [META_ID(SK_REUSE)] = META_FUNC(int_sk_reuse), 646 [META_ID(SK_BOUND_IF)] = META_FUNC(int_sk_bound_if), 647 [META_ID(SK_REFCNT)] = META_FUNC(int_sk_refcnt), 648 [META_ID(SK_RCVBUF)] = META_FUNC(int_sk_rcvbuf), 649 [META_ID(SK_SNDBUF)] = META_FUNC(int_sk_sndbuf), 650 [META_ID(SK_SHUTDOWN)] = META_FUNC(int_sk_shutdown), 651 [META_ID(SK_PROTO)] = META_FUNC(int_sk_proto), 652 [META_ID(SK_TYPE)] = META_FUNC(int_sk_type), 653 [META_ID(SK_RMEM_ALLOC)] = META_FUNC(int_sk_rmem_alloc), 654 [META_ID(SK_WMEM_ALLOC)] = META_FUNC(int_sk_wmem_alloc), 655 [META_ID(SK_OMEM_ALLOC)] = META_FUNC(int_sk_omem_alloc), 656 [META_ID(SK_WMEM_QUEUED)] = META_FUNC(int_sk_wmem_queued), 657 [META_ID(SK_RCV_QLEN)] = META_FUNC(int_sk_rcv_qlen), 658 [META_ID(SK_SND_QLEN)] = META_FUNC(int_sk_snd_qlen), 659 [META_ID(SK_ERR_QLEN)] = META_FUNC(int_sk_err_qlen), 660 [META_ID(SK_FORWARD_ALLOCS)] = META_FUNC(int_sk_fwd_alloc), 661 [META_ID(SK_ALLOCS)] = META_FUNC(int_sk_alloc), 662 [META_ID(SK_HASH)] = META_FUNC(int_sk_hash), 663 [META_ID(SK_LINGERTIME)] = META_FUNC(int_sk_lingertime), 664 [META_ID(SK_ACK_BACKLOG)] = META_FUNC(int_sk_ack_bl), 665 [META_ID(SK_MAX_ACK_BACKLOG)] = META_FUNC(int_sk_max_ack_bl), 666 [META_ID(SK_PRIO)] = META_FUNC(int_sk_prio), 667 [META_ID(SK_RCVLOWAT)] = META_FUNC(int_sk_rcvlowat), 668 [META_ID(SK_RCVTIMEO)] = META_FUNC(int_sk_rcvtimeo), 669 [META_ID(SK_SNDTIMEO)] = META_FUNC(int_sk_sndtimeo), 670 [META_ID(SK_SENDMSG_OFF)] = META_FUNC(int_sk_sendmsg_off), 671 [META_ID(SK_WRITE_PENDING)] = META_FUNC(int_sk_write_pend), 672 [META_ID(VLAN_TAG)] = META_FUNC(int_vlan_tag), 673 [META_ID(RXHASH)] = META_FUNC(int_rxhash), 674 } 675 }; 676 677 static inline struct meta_ops *meta_ops(struct meta_value *val) 678 { 679 return &__meta_ops[meta_type(val)][meta_id(val)]; 680 } 681 682 /************************************************************************** 683 * Type specific operations for TCF_META_TYPE_VAR 684 **************************************************************************/ 685 686 static int meta_var_compare(struct meta_obj *a, struct meta_obj *b) 687 { 688 int r = a->len - b->len; 689 690 if (r == 0) 691 r = memcmp((void *) a->value, (void *) b->value, a->len); 692 693 return r; 694 } 695 696 static int meta_var_change(struct meta_value *dst, struct nlattr *nla) 697 { 698 int len = nla_len(nla); 699 700 dst->val = (unsigned long)kmemdup(nla_data(nla), len, GFP_KERNEL); 701 if (dst->val == 0UL) 702 return -ENOMEM; 703 dst->len = len; 704 return 0; 705 } 706 707 static void meta_var_destroy(struct meta_value *v) 708 { 709 kfree((void *) v->val); 710 } 711 712 static void meta_var_apply_extras(struct meta_value *v, 713 struct meta_obj *dst) 714 { 715 int shift = v->hdr.shift; 716 717 if (shift && shift < dst->len) 718 dst->len -= shift; 719 } 720 721 static int meta_var_dump(struct sk_buff *skb, struct meta_value *v, int tlv) 722 { 723 if (v->val && v->len && 724 nla_put(skb, tlv, v->len, (void *) v->val)) 725 goto nla_put_failure; 726 return 0; 727 728 nla_put_failure: 729 return -1; 730 } 731 732 /************************************************************************** 733 * Type specific operations for TCF_META_TYPE_INT 734 **************************************************************************/ 735 736 static int meta_int_compare(struct meta_obj *a, struct meta_obj *b) 737 { 738 /* Let gcc optimize it, the unlikely is not really based on 739 * some numbers but jump free code for mismatches seems 740 * more logical. */ 741 if (unlikely(a->value == b->value)) 742 return 0; 743 else if (a->value < b->value) 744 return -1; 745 else 746 return 1; 747 } 748 749 static int meta_int_change(struct meta_value *dst, struct nlattr *nla) 750 { 751 if (nla_len(nla) >= sizeof(unsigned long)) { 752 dst->val = *(unsigned long *) nla_data(nla); 753 dst->len = sizeof(unsigned long); 754 } else if (nla_len(nla) == sizeof(u32)) { 755 dst->val = nla_get_u32(nla); 756 dst->len = sizeof(u32); 757 } else 758 return -EINVAL; 759 760 return 0; 761 } 762 763 static void meta_int_apply_extras(struct meta_value *v, 764 struct meta_obj *dst) 765 { 766 if (v->hdr.shift) 767 dst->value >>= v->hdr.shift; 768 769 if (v->val) 770 dst->value &= v->val; 771 } 772 773 static int meta_int_dump(struct sk_buff *skb, struct meta_value *v, int tlv) 774 { 775 if (v->len == sizeof(unsigned long)) { 776 if (nla_put(skb, tlv, sizeof(unsigned long), &v->val)) 777 goto nla_put_failure; 778 } else if (v->len == sizeof(u32)) { 779 if (nla_put_u32(skb, tlv, v->val)) 780 goto nla_put_failure; 781 } 782 783 return 0; 784 785 nla_put_failure: 786 return -1; 787 } 788 789 /************************************************************************** 790 * Type specific operations table 791 **************************************************************************/ 792 793 struct meta_type_ops { 794 void (*destroy)(struct meta_value *); 795 int (*compare)(struct meta_obj *, struct meta_obj *); 796 int (*change)(struct meta_value *, struct nlattr *); 797 void (*apply_extras)(struct meta_value *, struct meta_obj *); 798 int (*dump)(struct sk_buff *, struct meta_value *, int); 799 }; 800 801 static const struct meta_type_ops __meta_type_ops[TCF_META_TYPE_MAX + 1] = { 802 [TCF_META_TYPE_VAR] = { 803 .destroy = meta_var_destroy, 804 .compare = meta_var_compare, 805 .change = meta_var_change, 806 .apply_extras = meta_var_apply_extras, 807 .dump = meta_var_dump 808 }, 809 [TCF_META_TYPE_INT] = { 810 .compare = meta_int_compare, 811 .change = meta_int_change, 812 .apply_extras = meta_int_apply_extras, 813 .dump = meta_int_dump 814 } 815 }; 816 817 static inline const struct meta_type_ops *meta_type_ops(struct meta_value *v) 818 { 819 return &__meta_type_ops[meta_type(v)]; 820 } 821 822 /************************************************************************** 823 * Core 824 **************************************************************************/ 825 826 static int meta_get(struct sk_buff *skb, struct tcf_pkt_info *info, 827 struct meta_value *v, struct meta_obj *dst) 828 { 829 int err = 0; 830 831 if (meta_id(v) == TCF_META_ID_VALUE) { 832 dst->value = v->val; 833 dst->len = v->len; 834 return 0; 835 } 836 837 meta_ops(v)->get(skb, info, v, dst, &err); 838 if (err < 0) 839 return err; 840 841 if (meta_type_ops(v)->apply_extras) 842 meta_type_ops(v)->apply_extras(v, dst); 843 844 return 0; 845 } 846 847 static int em_meta_match(struct sk_buff *skb, struct tcf_ematch *m, 848 struct tcf_pkt_info *info) 849 { 850 int r; 851 struct meta_match *meta = (struct meta_match *) m->data; 852 struct meta_obj l_value, r_value; 853 854 if (meta_get(skb, info, &meta->lvalue, &l_value) < 0 || 855 meta_get(skb, info, &meta->rvalue, &r_value) < 0) 856 return 0; 857 858 r = meta_type_ops(&meta->lvalue)->compare(&l_value, &r_value); 859 860 switch (meta->lvalue.hdr.op) { 861 case TCF_EM_OPND_EQ: 862 return !r; 863 case TCF_EM_OPND_LT: 864 return r < 0; 865 case TCF_EM_OPND_GT: 866 return r > 0; 867 } 868 869 return 0; 870 } 871 872 static void meta_delete(struct meta_match *meta) 873 { 874 if (meta) { 875 const struct meta_type_ops *ops = meta_type_ops(&meta->lvalue); 876 877 if (ops && ops->destroy) { 878 ops->destroy(&meta->lvalue); 879 ops->destroy(&meta->rvalue); 880 } 881 } 882 883 kfree(meta); 884 } 885 886 static inline int meta_change_data(struct meta_value *dst, struct nlattr *nla) 887 { 888 if (nla) { 889 if (nla_len(nla) == 0) 890 return -EINVAL; 891 892 return meta_type_ops(dst)->change(dst, nla); 893 } 894 895 return 0; 896 } 897 898 static inline int meta_is_supported(struct meta_value *val) 899 { 900 return !meta_id(val) || meta_ops(val)->get; 901 } 902 903 static const struct nla_policy meta_policy[TCA_EM_META_MAX + 1] = { 904 [TCA_EM_META_HDR] = { .len = sizeof(struct tcf_meta_hdr) }, 905 }; 906 907 static int em_meta_change(struct net *net, void *data, int len, 908 struct tcf_ematch *m) 909 { 910 int err; 911 struct nlattr *tb[TCA_EM_META_MAX + 1]; 912 struct tcf_meta_hdr *hdr; 913 struct meta_match *meta = NULL; 914 915 err = nla_parse(tb, TCA_EM_META_MAX, data, len, meta_policy, NULL); 916 if (err < 0) 917 goto errout; 918 919 err = -EINVAL; 920 if (tb[TCA_EM_META_HDR] == NULL) 921 goto errout; 922 hdr = nla_data(tb[TCA_EM_META_HDR]); 923 924 if (TCF_META_TYPE(hdr->left.kind) != TCF_META_TYPE(hdr->right.kind) || 925 TCF_META_TYPE(hdr->left.kind) > TCF_META_TYPE_MAX || 926 TCF_META_ID(hdr->left.kind) > TCF_META_ID_MAX || 927 TCF_META_ID(hdr->right.kind) > TCF_META_ID_MAX) 928 goto errout; 929 930 meta = kzalloc(sizeof(*meta), GFP_KERNEL); 931 if (meta == NULL) { 932 err = -ENOMEM; 933 goto errout; 934 } 935 936 memcpy(&meta->lvalue.hdr, &hdr->left, sizeof(hdr->left)); 937 memcpy(&meta->rvalue.hdr, &hdr->right, sizeof(hdr->right)); 938 939 if (!meta_is_supported(&meta->lvalue) || 940 !meta_is_supported(&meta->rvalue)) { 941 err = -EOPNOTSUPP; 942 goto errout; 943 } 944 945 if (meta_change_data(&meta->lvalue, tb[TCA_EM_META_LVALUE]) < 0 || 946 meta_change_data(&meta->rvalue, tb[TCA_EM_META_RVALUE]) < 0) 947 goto errout; 948 949 m->datalen = sizeof(*meta); 950 m->data = (unsigned long) meta; 951 952 err = 0; 953 errout: 954 if (err && meta) 955 meta_delete(meta); 956 return err; 957 } 958 959 static void em_meta_destroy(struct tcf_ematch *m) 960 { 961 if (m) 962 meta_delete((struct meta_match *) m->data); 963 } 964 965 static int em_meta_dump(struct sk_buff *skb, struct tcf_ematch *em) 966 { 967 struct meta_match *meta = (struct meta_match *) em->data; 968 struct tcf_meta_hdr hdr; 969 const struct meta_type_ops *ops; 970 971 memset(&hdr, 0, sizeof(hdr)); 972 memcpy(&hdr.left, &meta->lvalue.hdr, sizeof(hdr.left)); 973 memcpy(&hdr.right, &meta->rvalue.hdr, sizeof(hdr.right)); 974 975 if (nla_put(skb, TCA_EM_META_HDR, sizeof(hdr), &hdr)) 976 goto nla_put_failure; 977 978 ops = meta_type_ops(&meta->lvalue); 979 if (ops->dump(skb, &meta->lvalue, TCA_EM_META_LVALUE) < 0 || 980 ops->dump(skb, &meta->rvalue, TCA_EM_META_RVALUE) < 0) 981 goto nla_put_failure; 982 983 return 0; 984 985 nla_put_failure: 986 return -1; 987 } 988 989 static struct tcf_ematch_ops em_meta_ops = { 990 .kind = TCF_EM_META, 991 .change = em_meta_change, 992 .match = em_meta_match, 993 .destroy = em_meta_destroy, 994 .dump = em_meta_dump, 995 .owner = THIS_MODULE, 996 .link = LIST_HEAD_INIT(em_meta_ops.link) 997 }; 998 999 static int __init init_em_meta(void) 1000 { 1001 return tcf_em_register(&em_meta_ops); 1002 } 1003 1004 static void __exit exit_em_meta(void) 1005 { 1006 tcf_em_unregister(&em_meta_ops); 1007 } 1008 1009 MODULE_LICENSE("GPL"); 1010 1011 module_init(init_em_meta); 1012 module_exit(exit_em_meta); 1013 1014 MODULE_ALIAS_TCF_EMATCH(TCF_EM_META); 1015