1 /* 2 * net/sched/em_meta.c Metadata ematch 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 * 9 * Authors: Thomas Graf <tgraf@suug.ch> 10 * 11 * ========================================================================== 12 * 13 * The metadata ematch compares two meta objects where each object 14 * represents either a meta value stored in the kernel or a static 15 * value provided by userspace. The objects are not provided by 16 * userspace itself but rather a definition providing the information 17 * to build them. Every object is of a certain type which must be 18 * equal to the object it is being compared to. 19 * 20 * The definition of a objects conists of the type (meta type), a 21 * identifier (meta id) and additional type specific information. 22 * The meta id is either TCF_META_TYPE_VALUE for values provided by 23 * userspace or a index to the meta operations table consisting of 24 * function pointers to type specific meta data collectors returning 25 * the value of the requested meta value. 26 * 27 * lvalue rvalue 28 * +-----------+ +-----------+ 29 * | type: INT | | type: INT | 30 * def | id: DEV | | id: VALUE | 31 * | data: | | data: 3 | 32 * +-----------+ +-----------+ 33 * | | 34 * ---> meta_ops[INT][DEV](...) | 35 * | | 36 * ----------- | 37 * V V 38 * +-----------+ +-----------+ 39 * | type: INT | | type: INT | 40 * obj | id: DEV | | id: VALUE | 41 * | data: 2 |<--data got filled out | data: 3 | 42 * +-----------+ +-----------+ 43 * | | 44 * --------------> 2 equals 3 <-------------- 45 * 46 * This is a simplified schema, the complexity varies depending 47 * on the meta type. Obviously, the length of the data must also 48 * be provided for non-numeric types. 49 * 50 * Additionaly, type dependant modifiers such as shift operators 51 * or mask may be applied to extend the functionaliy. As of now, 52 * the variable length type supports shifting the byte string to 53 * the right, eating up any number of octets and thus supporting 54 * wildcard interface name comparisons such as "ppp%" matching 55 * ppp0..9. 56 * 57 * NOTE: Certain meta values depend on other subsystems and are 58 * only available if that subsystem is enabled in the kernel. 59 */ 60 61 #include <linux/module.h> 62 #include <linux/types.h> 63 #include <linux/kernel.h> 64 #include <linux/sched.h> 65 #include <linux/string.h> 66 #include <linux/skbuff.h> 67 #include <linux/random.h> 68 #include <linux/if_vlan.h> 69 #include <linux/tc_ematch/tc_em_meta.h> 70 #include <net/dst.h> 71 #include <net/route.h> 72 #include <net/pkt_cls.h> 73 #include <net/sock.h> 74 75 struct meta_obj 76 { 77 unsigned long value; 78 unsigned int len; 79 }; 80 81 struct meta_value 82 { 83 struct tcf_meta_val hdr; 84 unsigned long val; 85 unsigned int len; 86 }; 87 88 struct meta_match 89 { 90 struct meta_value lvalue; 91 struct meta_value rvalue; 92 }; 93 94 static inline int meta_id(struct meta_value *v) 95 { 96 return TCF_META_ID(v->hdr.kind); 97 } 98 99 static inline int meta_type(struct meta_value *v) 100 { 101 return TCF_META_TYPE(v->hdr.kind); 102 } 103 104 #define META_COLLECTOR(FUNC) static void meta_##FUNC(struct sk_buff *skb, \ 105 struct tcf_pkt_info *info, struct meta_value *v, \ 106 struct meta_obj *dst, int *err) 107 108 /************************************************************************** 109 * System status & misc 110 **************************************************************************/ 111 112 META_COLLECTOR(int_random) 113 { 114 get_random_bytes(&dst->value, sizeof(dst->value)); 115 } 116 117 static inline unsigned long fixed_loadavg(int load) 118 { 119 int rnd_load = load + (FIXED_1/200); 120 int rnd_frac = ((rnd_load & (FIXED_1-1)) * 100) >> FSHIFT; 121 122 return ((rnd_load >> FSHIFT) * 100) + rnd_frac; 123 } 124 125 META_COLLECTOR(int_loadavg_0) 126 { 127 dst->value = fixed_loadavg(avenrun[0]); 128 } 129 130 META_COLLECTOR(int_loadavg_1) 131 { 132 dst->value = fixed_loadavg(avenrun[1]); 133 } 134 135 META_COLLECTOR(int_loadavg_2) 136 { 137 dst->value = fixed_loadavg(avenrun[2]); 138 } 139 140 /************************************************************************** 141 * Device names & indices 142 **************************************************************************/ 143 144 static inline int int_dev(struct net_device *dev, struct meta_obj *dst) 145 { 146 if (unlikely(dev == NULL)) 147 return -1; 148 149 dst->value = dev->ifindex; 150 return 0; 151 } 152 153 static inline int var_dev(struct net_device *dev, struct meta_obj *dst) 154 { 155 if (unlikely(dev == NULL)) 156 return -1; 157 158 dst->value = (unsigned long) dev->name; 159 dst->len = strlen(dev->name); 160 return 0; 161 } 162 163 META_COLLECTOR(int_dev) 164 { 165 *err = int_dev(skb->dev, dst); 166 } 167 168 META_COLLECTOR(var_dev) 169 { 170 *err = var_dev(skb->dev, dst); 171 } 172 173 /************************************************************************** 174 * vlan tag 175 **************************************************************************/ 176 177 META_COLLECTOR(int_vlan_tag) 178 { 179 unsigned short uninitialized_var(tag); 180 if (vlan_get_tag(skb, &tag) < 0) 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 = skb->protocol; 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 /************************************************************************** 224 * Netfilter 225 **************************************************************************/ 226 227 META_COLLECTOR(int_mark) 228 { 229 dst->value = skb->mark; 230 } 231 232 /************************************************************************** 233 * Traffic Control 234 **************************************************************************/ 235 236 META_COLLECTOR(int_tcindex) 237 { 238 dst->value = skb->tc_index; 239 } 240 241 /************************************************************************** 242 * Routing 243 **************************************************************************/ 244 245 META_COLLECTOR(int_rtclassid) 246 { 247 if (unlikely(skb->dst == NULL)) 248 *err = -1; 249 else 250 #ifdef CONFIG_NET_CLS_ROUTE 251 dst->value = skb->dst->tclassid; 252 #else 253 dst->value = 0; 254 #endif 255 } 256 257 META_COLLECTOR(int_rtiif) 258 { 259 if (unlikely(skb->rtable == NULL)) 260 *err = -1; 261 else 262 dst->value = skb->rtable->fl.iif; 263 } 264 265 /************************************************************************** 266 * Socket Attributes 267 **************************************************************************/ 268 269 #define SKIP_NONLOCAL(skb) \ 270 if (unlikely(skb->sk == NULL)) { \ 271 *err = -1; \ 272 return; \ 273 } 274 275 META_COLLECTOR(int_sk_family) 276 { 277 SKIP_NONLOCAL(skb); 278 dst->value = skb->sk->sk_family; 279 } 280 281 META_COLLECTOR(int_sk_state) 282 { 283 SKIP_NONLOCAL(skb); 284 dst->value = skb->sk->sk_state; 285 } 286 287 META_COLLECTOR(int_sk_reuse) 288 { 289 SKIP_NONLOCAL(skb); 290 dst->value = skb->sk->sk_reuse; 291 } 292 293 META_COLLECTOR(int_sk_bound_if) 294 { 295 SKIP_NONLOCAL(skb); 296 /* No error if bound_dev_if is 0, legal userspace check */ 297 dst->value = skb->sk->sk_bound_dev_if; 298 } 299 300 META_COLLECTOR(var_sk_bound_if) 301 { 302 SKIP_NONLOCAL(skb); 303 304 if (skb->sk->sk_bound_dev_if == 0) { 305 dst->value = (unsigned long) "any"; 306 dst->len = 3; 307 } else { 308 struct net_device *dev; 309 310 dev = dev_get_by_index(&init_net, skb->sk->sk_bound_dev_if); 311 *err = var_dev(dev, dst); 312 if (dev) 313 dev_put(dev); 314 } 315 } 316 317 META_COLLECTOR(int_sk_refcnt) 318 { 319 SKIP_NONLOCAL(skb); 320 dst->value = atomic_read(&skb->sk->sk_refcnt); 321 } 322 323 META_COLLECTOR(int_sk_rcvbuf) 324 { 325 SKIP_NONLOCAL(skb); 326 dst->value = skb->sk->sk_rcvbuf; 327 } 328 329 META_COLLECTOR(int_sk_shutdown) 330 { 331 SKIP_NONLOCAL(skb); 332 dst->value = skb->sk->sk_shutdown; 333 } 334 335 META_COLLECTOR(int_sk_proto) 336 { 337 SKIP_NONLOCAL(skb); 338 dst->value = skb->sk->sk_protocol; 339 } 340 341 META_COLLECTOR(int_sk_type) 342 { 343 SKIP_NONLOCAL(skb); 344 dst->value = skb->sk->sk_type; 345 } 346 347 META_COLLECTOR(int_sk_rmem_alloc) 348 { 349 SKIP_NONLOCAL(skb); 350 dst->value = atomic_read(&skb->sk->sk_rmem_alloc); 351 } 352 353 META_COLLECTOR(int_sk_wmem_alloc) 354 { 355 SKIP_NONLOCAL(skb); 356 dst->value = atomic_read(&skb->sk->sk_wmem_alloc); 357 } 358 359 META_COLLECTOR(int_sk_omem_alloc) 360 { 361 SKIP_NONLOCAL(skb); 362 dst->value = atomic_read(&skb->sk->sk_omem_alloc); 363 } 364 365 META_COLLECTOR(int_sk_rcv_qlen) 366 { 367 SKIP_NONLOCAL(skb); 368 dst->value = skb->sk->sk_receive_queue.qlen; 369 } 370 371 META_COLLECTOR(int_sk_snd_qlen) 372 { 373 SKIP_NONLOCAL(skb); 374 dst->value = skb->sk->sk_write_queue.qlen; 375 } 376 377 META_COLLECTOR(int_sk_wmem_queued) 378 { 379 SKIP_NONLOCAL(skb); 380 dst->value = skb->sk->sk_wmem_queued; 381 } 382 383 META_COLLECTOR(int_sk_fwd_alloc) 384 { 385 SKIP_NONLOCAL(skb); 386 dst->value = skb->sk->sk_forward_alloc; 387 } 388 389 META_COLLECTOR(int_sk_sndbuf) 390 { 391 SKIP_NONLOCAL(skb); 392 dst->value = skb->sk->sk_sndbuf; 393 } 394 395 META_COLLECTOR(int_sk_alloc) 396 { 397 SKIP_NONLOCAL(skb); 398 dst->value = skb->sk->sk_allocation; 399 } 400 401 META_COLLECTOR(int_sk_route_caps) 402 { 403 SKIP_NONLOCAL(skb); 404 dst->value = skb->sk->sk_route_caps; 405 } 406 407 META_COLLECTOR(int_sk_hash) 408 { 409 SKIP_NONLOCAL(skb); 410 dst->value = skb->sk->sk_hash; 411 } 412 413 META_COLLECTOR(int_sk_lingertime) 414 { 415 SKIP_NONLOCAL(skb); 416 dst->value = skb->sk->sk_lingertime / HZ; 417 } 418 419 META_COLLECTOR(int_sk_err_qlen) 420 { 421 SKIP_NONLOCAL(skb); 422 dst->value = skb->sk->sk_error_queue.qlen; 423 } 424 425 META_COLLECTOR(int_sk_ack_bl) 426 { 427 SKIP_NONLOCAL(skb); 428 dst->value = skb->sk->sk_ack_backlog; 429 } 430 431 META_COLLECTOR(int_sk_max_ack_bl) 432 { 433 SKIP_NONLOCAL(skb); 434 dst->value = skb->sk->sk_max_ack_backlog; 435 } 436 437 META_COLLECTOR(int_sk_prio) 438 { 439 SKIP_NONLOCAL(skb); 440 dst->value = skb->sk->sk_priority; 441 } 442 443 META_COLLECTOR(int_sk_rcvlowat) 444 { 445 SKIP_NONLOCAL(skb); 446 dst->value = skb->sk->sk_rcvlowat; 447 } 448 449 META_COLLECTOR(int_sk_rcvtimeo) 450 { 451 SKIP_NONLOCAL(skb); 452 dst->value = skb->sk->sk_rcvtimeo / HZ; 453 } 454 455 META_COLLECTOR(int_sk_sndtimeo) 456 { 457 SKIP_NONLOCAL(skb); 458 dst->value = skb->sk->sk_sndtimeo / HZ; 459 } 460 461 META_COLLECTOR(int_sk_sendmsg_off) 462 { 463 SKIP_NONLOCAL(skb); 464 dst->value = skb->sk->sk_sndmsg_off; 465 } 466 467 META_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 **************************************************************************/ 476 477 struct meta_ops 478 { 479 void (*get)(struct sk_buff *, struct tcf_pkt_info *, 480 struct meta_value *, struct meta_obj *, int *); 481 }; 482 483 #define META_ID(name) TCF_META_ID_##name 484 #define META_FUNC(name) { .get = meta_##name } 485 486 /* Meta value operations table listing all meta value collectors and 487 * assigns them to a type and meta id. */ 488 static struct meta_ops __meta_ops[TCF_META_TYPE_MAX+1][TCF_META_ID_MAX+1] = { 489 [TCF_META_TYPE_VAR] = { 490 [META_ID(DEV)] = META_FUNC(var_dev), 491 [META_ID(SK_BOUND_IF)] = META_FUNC(var_sk_bound_if), 492 }, 493 [TCF_META_TYPE_INT] = { 494 [META_ID(RANDOM)] = META_FUNC(int_random), 495 [META_ID(LOADAVG_0)] = META_FUNC(int_loadavg_0), 496 [META_ID(LOADAVG_1)] = META_FUNC(int_loadavg_1), 497 [META_ID(LOADAVG_2)] = META_FUNC(int_loadavg_2), 498 [META_ID(DEV)] = META_FUNC(int_dev), 499 [META_ID(PRIORITY)] = META_FUNC(int_priority), 500 [META_ID(PROTOCOL)] = META_FUNC(int_protocol), 501 [META_ID(PKTTYPE)] = META_FUNC(int_pkttype), 502 [META_ID(PKTLEN)] = META_FUNC(int_pktlen), 503 [META_ID(DATALEN)] = META_FUNC(int_datalen), 504 [META_ID(MACLEN)] = META_FUNC(int_maclen), 505 [META_ID(NFMARK)] = META_FUNC(int_mark), 506 [META_ID(TCINDEX)] = META_FUNC(int_tcindex), 507 [META_ID(RTCLASSID)] = META_FUNC(int_rtclassid), 508 [META_ID(RTIIF)] = META_FUNC(int_rtiif), 509 [META_ID(SK_FAMILY)] = META_FUNC(int_sk_family), 510 [META_ID(SK_STATE)] = META_FUNC(int_sk_state), 511 [META_ID(SK_REUSE)] = META_FUNC(int_sk_reuse), 512 [META_ID(SK_BOUND_IF)] = META_FUNC(int_sk_bound_if), 513 [META_ID(SK_REFCNT)] = META_FUNC(int_sk_refcnt), 514 [META_ID(SK_RCVBUF)] = META_FUNC(int_sk_rcvbuf), 515 [META_ID(SK_SNDBUF)] = META_FUNC(int_sk_sndbuf), 516 [META_ID(SK_SHUTDOWN)] = META_FUNC(int_sk_shutdown), 517 [META_ID(SK_PROTO)] = META_FUNC(int_sk_proto), 518 [META_ID(SK_TYPE)] = META_FUNC(int_sk_type), 519 [META_ID(SK_RMEM_ALLOC)] = META_FUNC(int_sk_rmem_alloc), 520 [META_ID(SK_WMEM_ALLOC)] = META_FUNC(int_sk_wmem_alloc), 521 [META_ID(SK_OMEM_ALLOC)] = META_FUNC(int_sk_omem_alloc), 522 [META_ID(SK_WMEM_QUEUED)] = META_FUNC(int_sk_wmem_queued), 523 [META_ID(SK_RCV_QLEN)] = META_FUNC(int_sk_rcv_qlen), 524 [META_ID(SK_SND_QLEN)] = META_FUNC(int_sk_snd_qlen), 525 [META_ID(SK_ERR_QLEN)] = META_FUNC(int_sk_err_qlen), 526 [META_ID(SK_FORWARD_ALLOCS)] = META_FUNC(int_sk_fwd_alloc), 527 [META_ID(SK_ALLOCS)] = META_FUNC(int_sk_alloc), 528 [META_ID(SK_ROUTE_CAPS)] = META_FUNC(int_sk_route_caps), 529 [META_ID(SK_HASH)] = META_FUNC(int_sk_hash), 530 [META_ID(SK_LINGERTIME)] = META_FUNC(int_sk_lingertime), 531 [META_ID(SK_ACK_BACKLOG)] = META_FUNC(int_sk_ack_bl), 532 [META_ID(SK_MAX_ACK_BACKLOG)] = META_FUNC(int_sk_max_ack_bl), 533 [META_ID(SK_PRIO)] = META_FUNC(int_sk_prio), 534 [META_ID(SK_RCVLOWAT)] = META_FUNC(int_sk_rcvlowat), 535 [META_ID(SK_RCVTIMEO)] = META_FUNC(int_sk_rcvtimeo), 536 [META_ID(SK_SNDTIMEO)] = META_FUNC(int_sk_sndtimeo), 537 [META_ID(SK_SENDMSG_OFF)] = META_FUNC(int_sk_sendmsg_off), 538 [META_ID(SK_WRITE_PENDING)] = META_FUNC(int_sk_write_pend), 539 [META_ID(VLAN_TAG)] = META_FUNC(int_vlan_tag), 540 } 541 }; 542 543 static inline struct meta_ops * meta_ops(struct meta_value *val) 544 { 545 return &__meta_ops[meta_type(val)][meta_id(val)]; 546 } 547 548 /************************************************************************** 549 * Type specific operations for TCF_META_TYPE_VAR 550 **************************************************************************/ 551 552 static int meta_var_compare(struct meta_obj *a, struct meta_obj *b) 553 { 554 int r = a->len - b->len; 555 556 if (r == 0) 557 r = memcmp((void *) a->value, (void *) b->value, a->len); 558 559 return r; 560 } 561 562 static int meta_var_change(struct meta_value *dst, struct nlattr *nla) 563 { 564 int len = nla_len(nla); 565 566 dst->val = (unsigned long)kmemdup(nla_data(nla), len, GFP_KERNEL); 567 if (dst->val == 0UL) 568 return -ENOMEM; 569 dst->len = len; 570 return 0; 571 } 572 573 static void meta_var_destroy(struct meta_value *v) 574 { 575 kfree((void *) v->val); 576 } 577 578 static void meta_var_apply_extras(struct meta_value *v, 579 struct meta_obj *dst) 580 { 581 int shift = v->hdr.shift; 582 583 if (shift && shift < dst->len) 584 dst->len -= shift; 585 } 586 587 static int meta_var_dump(struct sk_buff *skb, struct meta_value *v, int tlv) 588 { 589 if (v->val && v->len) 590 NLA_PUT(skb, tlv, v->len, (void *) v->val); 591 return 0; 592 593 nla_put_failure: 594 return -1; 595 } 596 597 /************************************************************************** 598 * Type specific operations for TCF_META_TYPE_INT 599 **************************************************************************/ 600 601 static 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 } 613 614 static 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 } 627 628 static 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 } 637 638 static int meta_int_dump(struct sk_buff *skb, struct meta_value *v, int tlv) 639 { 640 if (v->len == sizeof(unsigned long)) 641 NLA_PUT(skb, tlv, sizeof(unsigned long), &v->val); 642 else if (v->len == sizeof(u32)) { 643 NLA_PUT_U32(skb, tlv, v->val); 644 } 645 646 return 0; 647 648 nla_put_failure: 649 return -1; 650 } 651 652 /************************************************************************** 653 * Type specific operations table 654 **************************************************************************/ 655 656 struct meta_type_ops 657 { 658 void (*destroy)(struct meta_value *); 659 int (*compare)(struct meta_obj *, struct meta_obj *); 660 int (*change)(struct meta_value *, struct nlattr *); 661 void (*apply_extras)(struct meta_value *, struct meta_obj *); 662 int (*dump)(struct sk_buff *, struct meta_value *, int); 663 }; 664 665 static struct meta_type_ops __meta_type_ops[TCF_META_TYPE_MAX+1] = { 666 [TCF_META_TYPE_VAR] = { 667 .destroy = meta_var_destroy, 668 .compare = meta_var_compare, 669 .change = meta_var_change, 670 .apply_extras = meta_var_apply_extras, 671 .dump = meta_var_dump 672 }, 673 [TCF_META_TYPE_INT] = { 674 .compare = meta_int_compare, 675 .change = meta_int_change, 676 .apply_extras = meta_int_apply_extras, 677 .dump = meta_int_dump 678 } 679 }; 680 681 static inline struct meta_type_ops * meta_type_ops(struct meta_value *v) 682 { 683 return &__meta_type_ops[meta_type(v)]; 684 } 685 686 /************************************************************************** 687 * Core 688 **************************************************************************/ 689 690 static int meta_get(struct sk_buff *skb, struct tcf_pkt_info *info, 691 struct meta_value *v, struct meta_obj *dst) 692 { 693 int err = 0; 694 695 if (meta_id(v) == TCF_META_ID_VALUE) { 696 dst->value = v->val; 697 dst->len = v->len; 698 return 0; 699 } 700 701 meta_ops(v)->get(skb, info, v, dst, &err); 702 if (err < 0) 703 return err; 704 705 if (meta_type_ops(v)->apply_extras) 706 meta_type_ops(v)->apply_extras(v, dst); 707 708 return 0; 709 } 710 711 static int em_meta_match(struct sk_buff *skb, struct tcf_ematch *m, 712 struct tcf_pkt_info *info) 713 { 714 int r; 715 struct meta_match *meta = (struct meta_match *) m->data; 716 struct meta_obj l_value, r_value; 717 718 if (meta_get(skb, info, &meta->lvalue, &l_value) < 0 || 719 meta_get(skb, info, &meta->rvalue, &r_value) < 0) 720 return 0; 721 722 r = meta_type_ops(&meta->lvalue)->compare(&l_value, &r_value); 723 724 switch (meta->lvalue.hdr.op) { 725 case TCF_EM_OPND_EQ: 726 return !r; 727 case TCF_EM_OPND_LT: 728 return r < 0; 729 case TCF_EM_OPND_GT: 730 return r > 0; 731 } 732 733 return 0; 734 } 735 736 static void meta_delete(struct meta_match *meta) 737 { 738 if (meta) { 739 struct meta_type_ops *ops = meta_type_ops(&meta->lvalue); 740 741 if (ops && ops->destroy) { 742 ops->destroy(&meta->lvalue); 743 ops->destroy(&meta->rvalue); 744 } 745 } 746 747 kfree(meta); 748 } 749 750 static inline int meta_change_data(struct meta_value *dst, struct nlattr *nla) 751 { 752 if (nla) { 753 if (nla_len(nla) == 0) 754 return -EINVAL; 755 756 return meta_type_ops(dst)->change(dst, nla); 757 } 758 759 return 0; 760 } 761 762 static inline int meta_is_supported(struct meta_value *val) 763 { 764 return (!meta_id(val) || meta_ops(val)->get); 765 } 766 767 static const struct nla_policy meta_policy[TCA_EM_META_MAX + 1] = { 768 [TCA_EM_META_HDR] = { .len = sizeof(struct tcf_meta_hdr) }, 769 }; 770 771 static int em_meta_change(struct tcf_proto *tp, void *data, int len, 772 struct tcf_ematch *m) 773 { 774 int err; 775 struct nlattr *tb[TCA_EM_META_MAX + 1]; 776 struct tcf_meta_hdr *hdr; 777 struct meta_match *meta = NULL; 778 779 err = nla_parse(tb, TCA_EM_META_MAX, data, len, meta_policy); 780 if (err < 0) 781 goto errout; 782 783 err = -EINVAL; 784 if (tb[TCA_EM_META_HDR] == NULL) 785 goto errout; 786 hdr = nla_data(tb[TCA_EM_META_HDR]); 787 788 if (TCF_META_TYPE(hdr->left.kind) != TCF_META_TYPE(hdr->right.kind) || 789 TCF_META_TYPE(hdr->left.kind) > TCF_META_TYPE_MAX || 790 TCF_META_ID(hdr->left.kind) > TCF_META_ID_MAX || 791 TCF_META_ID(hdr->right.kind) > TCF_META_ID_MAX) 792 goto errout; 793 794 meta = kzalloc(sizeof(*meta), GFP_KERNEL); 795 if (meta == NULL) 796 goto errout; 797 798 memcpy(&meta->lvalue.hdr, &hdr->left, sizeof(hdr->left)); 799 memcpy(&meta->rvalue.hdr, &hdr->right, sizeof(hdr->right)); 800 801 if (!meta_is_supported(&meta->lvalue) || 802 !meta_is_supported(&meta->rvalue)) { 803 err = -EOPNOTSUPP; 804 goto errout; 805 } 806 807 if (meta_change_data(&meta->lvalue, tb[TCA_EM_META_LVALUE]) < 0 || 808 meta_change_data(&meta->rvalue, tb[TCA_EM_META_RVALUE]) < 0) 809 goto errout; 810 811 m->datalen = sizeof(*meta); 812 m->data = (unsigned long) meta; 813 814 err = 0; 815 errout: 816 if (err && meta) 817 meta_delete(meta); 818 return err; 819 } 820 821 static void em_meta_destroy(struct tcf_proto *tp, struct tcf_ematch *m) 822 { 823 if (m) 824 meta_delete((struct meta_match *) m->data); 825 } 826 827 static int em_meta_dump(struct sk_buff *skb, struct tcf_ematch *em) 828 { 829 struct meta_match *meta = (struct meta_match *) em->data; 830 struct tcf_meta_hdr hdr; 831 struct meta_type_ops *ops; 832 833 memset(&hdr, 0, sizeof(hdr)); 834 memcpy(&hdr.left, &meta->lvalue.hdr, sizeof(hdr.left)); 835 memcpy(&hdr.right, &meta->rvalue.hdr, sizeof(hdr.right)); 836 837 NLA_PUT(skb, TCA_EM_META_HDR, sizeof(hdr), &hdr); 838 839 ops = meta_type_ops(&meta->lvalue); 840 if (ops->dump(skb, &meta->lvalue, TCA_EM_META_LVALUE) < 0 || 841 ops->dump(skb, &meta->rvalue, TCA_EM_META_RVALUE) < 0) 842 goto nla_put_failure; 843 844 return 0; 845 846 nla_put_failure: 847 return -1; 848 } 849 850 static struct tcf_ematch_ops em_meta_ops = { 851 .kind = TCF_EM_META, 852 .change = em_meta_change, 853 .match = em_meta_match, 854 .destroy = em_meta_destroy, 855 .dump = em_meta_dump, 856 .owner = THIS_MODULE, 857 .link = LIST_HEAD_INIT(em_meta_ops.link) 858 }; 859 860 static int __init init_em_meta(void) 861 { 862 return tcf_em_register(&em_meta_ops); 863 } 864 865 static void __exit exit_em_meta(void) 866 { 867 tcf_em_unregister(&em_meta_ops); 868 } 869 870 MODULE_LICENSE("GPL"); 871 872 module_init(init_em_meta); 873 module_exit(exit_em_meta); 874 875 MODULE_ALIAS_TCF_EMATCH(TCF_EM_META); 876