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 subsytem 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/tc_ematch/tc_em_meta.h> 69 #include <net/dst.h> 70 #include <net/route.h> 71 #include <net/pkt_cls.h> 72 #include <net/sock.h> 73 74 struct meta_obj 75 { 76 unsigned long value; 77 unsigned int len; 78 }; 79 80 struct meta_value 81 { 82 struct tcf_meta_val hdr; 83 unsigned long val; 84 unsigned int len; 85 }; 86 87 struct meta_match 88 { 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 * skb attributes 174 **************************************************************************/ 175 176 META_COLLECTOR(int_priority) 177 { 178 dst->value = skb->priority; 179 } 180 181 META_COLLECTOR(int_protocol) 182 { 183 /* Let userspace take care of the byte ordering */ 184 dst->value = skb->protocol; 185 } 186 187 META_COLLECTOR(int_pkttype) 188 { 189 dst->value = skb->pkt_type; 190 } 191 192 META_COLLECTOR(int_pktlen) 193 { 194 dst->value = skb->len; 195 } 196 197 META_COLLECTOR(int_datalen) 198 { 199 dst->value = skb->data_len; 200 } 201 202 META_COLLECTOR(int_maclen) 203 { 204 dst->value = skb->mac_len; 205 } 206 207 /************************************************************************** 208 * Netfilter 209 **************************************************************************/ 210 211 META_COLLECTOR(int_mark) 212 { 213 dst->value = skb->mark; 214 } 215 216 /************************************************************************** 217 * Traffic Control 218 **************************************************************************/ 219 220 META_COLLECTOR(int_tcindex) 221 { 222 dst->value = skb->tc_index; 223 } 224 225 /************************************************************************** 226 * Routing 227 **************************************************************************/ 228 229 META_COLLECTOR(int_rtclassid) 230 { 231 if (unlikely(skb->dst == NULL)) 232 *err = -1; 233 else 234 #ifdef CONFIG_NET_CLS_ROUTE 235 dst->value = skb->dst->tclassid; 236 #else 237 dst->value = 0; 238 #endif 239 } 240 241 META_COLLECTOR(int_rtiif) 242 { 243 if (unlikely(skb->dst == NULL)) 244 *err = -1; 245 else 246 dst->value = ((struct rtable*) skb->dst)->fl.iif; 247 } 248 249 /************************************************************************** 250 * Socket Attributes 251 **************************************************************************/ 252 253 #define SKIP_NONLOCAL(skb) \ 254 if (unlikely(skb->sk == NULL)) { \ 255 *err = -1; \ 256 return; \ 257 } 258 259 META_COLLECTOR(int_sk_family) 260 { 261 SKIP_NONLOCAL(skb); 262 dst->value = skb->sk->sk_family; 263 } 264 265 META_COLLECTOR(int_sk_state) 266 { 267 SKIP_NONLOCAL(skb); 268 dst->value = skb->sk->sk_state; 269 } 270 271 META_COLLECTOR(int_sk_reuse) 272 { 273 SKIP_NONLOCAL(skb); 274 dst->value = skb->sk->sk_reuse; 275 } 276 277 META_COLLECTOR(int_sk_bound_if) 278 { 279 SKIP_NONLOCAL(skb); 280 /* No error if bound_dev_if is 0, legal userspace check */ 281 dst->value = skb->sk->sk_bound_dev_if; 282 } 283 284 META_COLLECTOR(var_sk_bound_if) 285 { 286 SKIP_NONLOCAL(skb); 287 288 if (skb->sk->sk_bound_dev_if == 0) { 289 dst->value = (unsigned long) "any"; 290 dst->len = 3; 291 } else { 292 struct net_device *dev; 293 294 dev = dev_get_by_index(skb->sk->sk_bound_dev_if); 295 *err = var_dev(dev, dst); 296 if (dev) 297 dev_put(dev); 298 } 299 } 300 301 META_COLLECTOR(int_sk_refcnt) 302 { 303 SKIP_NONLOCAL(skb); 304 dst->value = atomic_read(&skb->sk->sk_refcnt); 305 } 306 307 META_COLLECTOR(int_sk_rcvbuf) 308 { 309 SKIP_NONLOCAL(skb); 310 dst->value = skb->sk->sk_rcvbuf; 311 } 312 313 META_COLLECTOR(int_sk_shutdown) 314 { 315 SKIP_NONLOCAL(skb); 316 dst->value = skb->sk->sk_shutdown; 317 } 318 319 META_COLLECTOR(int_sk_proto) 320 { 321 SKIP_NONLOCAL(skb); 322 dst->value = skb->sk->sk_protocol; 323 } 324 325 META_COLLECTOR(int_sk_type) 326 { 327 SKIP_NONLOCAL(skb); 328 dst->value = skb->sk->sk_type; 329 } 330 331 META_COLLECTOR(int_sk_rmem_alloc) 332 { 333 SKIP_NONLOCAL(skb); 334 dst->value = atomic_read(&skb->sk->sk_rmem_alloc); 335 } 336 337 META_COLLECTOR(int_sk_wmem_alloc) 338 { 339 SKIP_NONLOCAL(skb); 340 dst->value = atomic_read(&skb->sk->sk_wmem_alloc); 341 } 342 343 META_COLLECTOR(int_sk_omem_alloc) 344 { 345 SKIP_NONLOCAL(skb); 346 dst->value = atomic_read(&skb->sk->sk_omem_alloc); 347 } 348 349 META_COLLECTOR(int_sk_rcv_qlen) 350 { 351 SKIP_NONLOCAL(skb); 352 dst->value = skb->sk->sk_receive_queue.qlen; 353 } 354 355 META_COLLECTOR(int_sk_snd_qlen) 356 { 357 SKIP_NONLOCAL(skb); 358 dst->value = skb->sk->sk_write_queue.qlen; 359 } 360 361 META_COLLECTOR(int_sk_wmem_queued) 362 { 363 SKIP_NONLOCAL(skb); 364 dst->value = skb->sk->sk_wmem_queued; 365 } 366 367 META_COLLECTOR(int_sk_fwd_alloc) 368 { 369 SKIP_NONLOCAL(skb); 370 dst->value = skb->sk->sk_forward_alloc; 371 } 372 373 META_COLLECTOR(int_sk_sndbuf) 374 { 375 SKIP_NONLOCAL(skb); 376 dst->value = skb->sk->sk_sndbuf; 377 } 378 379 META_COLLECTOR(int_sk_alloc) 380 { 381 SKIP_NONLOCAL(skb); 382 dst->value = skb->sk->sk_allocation; 383 } 384 385 META_COLLECTOR(int_sk_route_caps) 386 { 387 SKIP_NONLOCAL(skb); 388 dst->value = skb->sk->sk_route_caps; 389 } 390 391 META_COLLECTOR(int_sk_hash) 392 { 393 SKIP_NONLOCAL(skb); 394 dst->value = skb->sk->sk_hash; 395 } 396 397 META_COLLECTOR(int_sk_lingertime) 398 { 399 SKIP_NONLOCAL(skb); 400 dst->value = skb->sk->sk_lingertime / HZ; 401 } 402 403 META_COLLECTOR(int_sk_err_qlen) 404 { 405 SKIP_NONLOCAL(skb); 406 dst->value = skb->sk->sk_error_queue.qlen; 407 } 408 409 META_COLLECTOR(int_sk_ack_bl) 410 { 411 SKIP_NONLOCAL(skb); 412 dst->value = skb->sk->sk_ack_backlog; 413 } 414 415 META_COLLECTOR(int_sk_max_ack_bl) 416 { 417 SKIP_NONLOCAL(skb); 418 dst->value = skb->sk->sk_max_ack_backlog; 419 } 420 421 META_COLLECTOR(int_sk_prio) 422 { 423 SKIP_NONLOCAL(skb); 424 dst->value = skb->sk->sk_priority; 425 } 426 427 META_COLLECTOR(int_sk_rcvlowat) 428 { 429 SKIP_NONLOCAL(skb); 430 dst->value = skb->sk->sk_rcvlowat; 431 } 432 433 META_COLLECTOR(int_sk_rcvtimeo) 434 { 435 SKIP_NONLOCAL(skb); 436 dst->value = skb->sk->sk_rcvtimeo / HZ; 437 } 438 439 META_COLLECTOR(int_sk_sndtimeo) 440 { 441 SKIP_NONLOCAL(skb); 442 dst->value = skb->sk->sk_sndtimeo / HZ; 443 } 444 445 META_COLLECTOR(int_sk_sendmsg_off) 446 { 447 SKIP_NONLOCAL(skb); 448 dst->value = skb->sk->sk_sndmsg_off; 449 } 450 451 META_COLLECTOR(int_sk_write_pend) 452 { 453 SKIP_NONLOCAL(skb); 454 dst->value = skb->sk->sk_write_pending; 455 } 456 457 /************************************************************************** 458 * Meta value collectors assignment table 459 **************************************************************************/ 460 461 struct meta_ops 462 { 463 void (*get)(struct sk_buff *, struct tcf_pkt_info *, 464 struct meta_value *, struct meta_obj *, int *); 465 }; 466 467 #define META_ID(name) TCF_META_ID_##name 468 #define META_FUNC(name) { .get = meta_##name } 469 470 /* Meta value operations table listing all meta value collectors and 471 * assigns them to a type and meta id. */ 472 static struct meta_ops __meta_ops[TCF_META_TYPE_MAX+1][TCF_META_ID_MAX+1] = { 473 [TCF_META_TYPE_VAR] = { 474 [META_ID(DEV)] = META_FUNC(var_dev), 475 [META_ID(SK_BOUND_IF)] = META_FUNC(var_sk_bound_if), 476 }, 477 [TCF_META_TYPE_INT] = { 478 [META_ID(RANDOM)] = META_FUNC(int_random), 479 [META_ID(LOADAVG_0)] = META_FUNC(int_loadavg_0), 480 [META_ID(LOADAVG_1)] = META_FUNC(int_loadavg_1), 481 [META_ID(LOADAVG_2)] = META_FUNC(int_loadavg_2), 482 [META_ID(DEV)] = META_FUNC(int_dev), 483 [META_ID(PRIORITY)] = META_FUNC(int_priority), 484 [META_ID(PROTOCOL)] = META_FUNC(int_protocol), 485 [META_ID(PKTTYPE)] = META_FUNC(int_pkttype), 486 [META_ID(PKTLEN)] = META_FUNC(int_pktlen), 487 [META_ID(DATALEN)] = META_FUNC(int_datalen), 488 [META_ID(MACLEN)] = META_FUNC(int_maclen), 489 [META_ID(NFMARK)] = META_FUNC(int_mark), 490 [META_ID(TCINDEX)] = META_FUNC(int_tcindex), 491 [META_ID(RTCLASSID)] = META_FUNC(int_rtclassid), 492 [META_ID(RTIIF)] = META_FUNC(int_rtiif), 493 [META_ID(SK_FAMILY)] = META_FUNC(int_sk_family), 494 [META_ID(SK_STATE)] = META_FUNC(int_sk_state), 495 [META_ID(SK_REUSE)] = META_FUNC(int_sk_reuse), 496 [META_ID(SK_BOUND_IF)] = META_FUNC(int_sk_bound_if), 497 [META_ID(SK_REFCNT)] = META_FUNC(int_sk_refcnt), 498 [META_ID(SK_RCVBUF)] = META_FUNC(int_sk_rcvbuf), 499 [META_ID(SK_SNDBUF)] = META_FUNC(int_sk_sndbuf), 500 [META_ID(SK_SHUTDOWN)] = META_FUNC(int_sk_shutdown), 501 [META_ID(SK_PROTO)] = META_FUNC(int_sk_proto), 502 [META_ID(SK_TYPE)] = META_FUNC(int_sk_type), 503 [META_ID(SK_RMEM_ALLOC)] = META_FUNC(int_sk_rmem_alloc), 504 [META_ID(SK_WMEM_ALLOC)] = META_FUNC(int_sk_wmem_alloc), 505 [META_ID(SK_OMEM_ALLOC)] = META_FUNC(int_sk_omem_alloc), 506 [META_ID(SK_WMEM_QUEUED)] = META_FUNC(int_sk_wmem_queued), 507 [META_ID(SK_RCV_QLEN)] = META_FUNC(int_sk_rcv_qlen), 508 [META_ID(SK_SND_QLEN)] = META_FUNC(int_sk_snd_qlen), 509 [META_ID(SK_ERR_QLEN)] = META_FUNC(int_sk_err_qlen), 510 [META_ID(SK_FORWARD_ALLOCS)] = META_FUNC(int_sk_fwd_alloc), 511 [META_ID(SK_ALLOCS)] = META_FUNC(int_sk_alloc), 512 [META_ID(SK_ROUTE_CAPS)] = META_FUNC(int_sk_route_caps), 513 [META_ID(SK_HASH)] = META_FUNC(int_sk_hash), 514 [META_ID(SK_LINGERTIME)] = META_FUNC(int_sk_lingertime), 515 [META_ID(SK_ACK_BACKLOG)] = META_FUNC(int_sk_ack_bl), 516 [META_ID(SK_MAX_ACK_BACKLOG)] = META_FUNC(int_sk_max_ack_bl), 517 [META_ID(SK_PRIO)] = META_FUNC(int_sk_prio), 518 [META_ID(SK_RCVLOWAT)] = META_FUNC(int_sk_rcvlowat), 519 [META_ID(SK_RCVTIMEO)] = META_FUNC(int_sk_rcvtimeo), 520 [META_ID(SK_SNDTIMEO)] = META_FUNC(int_sk_sndtimeo), 521 [META_ID(SK_SENDMSG_OFF)] = META_FUNC(int_sk_sendmsg_off), 522 [META_ID(SK_WRITE_PENDING)] = META_FUNC(int_sk_write_pend), 523 } 524 }; 525 526 static inline struct meta_ops * meta_ops(struct meta_value *val) 527 { 528 return &__meta_ops[meta_type(val)][meta_id(val)]; 529 } 530 531 /************************************************************************** 532 * Type specific operations for TCF_META_TYPE_VAR 533 **************************************************************************/ 534 535 static int meta_var_compare(struct meta_obj *a, struct meta_obj *b) 536 { 537 int r = a->len - b->len; 538 539 if (r == 0) 540 r = memcmp((void *) a->value, (void *) b->value, a->len); 541 542 return r; 543 } 544 545 static int meta_var_change(struct meta_value *dst, struct rtattr *rta) 546 { 547 int len = RTA_PAYLOAD(rta); 548 549 dst->val = (unsigned long)kmemdup(RTA_DATA(rta), len, GFP_KERNEL); 550 if (dst->val == 0UL) 551 return -ENOMEM; 552 dst->len = len; 553 return 0; 554 } 555 556 static void meta_var_destroy(struct meta_value *v) 557 { 558 kfree((void *) v->val); 559 } 560 561 static void meta_var_apply_extras(struct meta_value *v, 562 struct meta_obj *dst) 563 { 564 int shift = v->hdr.shift; 565 566 if (shift && shift < dst->len) 567 dst->len -= shift; 568 } 569 570 static int meta_var_dump(struct sk_buff *skb, struct meta_value *v, int tlv) 571 { 572 if (v->val && v->len) 573 RTA_PUT(skb, tlv, v->len, (void *) v->val); 574 return 0; 575 576 rtattr_failure: 577 return -1; 578 } 579 580 /************************************************************************** 581 * Type specific operations for TCF_META_TYPE_INT 582 **************************************************************************/ 583 584 static int meta_int_compare(struct meta_obj *a, struct meta_obj *b) 585 { 586 /* Let gcc optimize it, the unlikely is not really based on 587 * some numbers but jump free code for mismatches seems 588 * more logical. */ 589 if (unlikely(a->value == b->value)) 590 return 0; 591 else if (a->value < b->value) 592 return -1; 593 else 594 return 1; 595 } 596 597 static int meta_int_change(struct meta_value *dst, struct rtattr *rta) 598 { 599 if (RTA_PAYLOAD(rta) >= sizeof(unsigned long)) { 600 dst->val = *(unsigned long *) RTA_DATA(rta); 601 dst->len = sizeof(unsigned long); 602 } else if (RTA_PAYLOAD(rta) == sizeof(u32)) { 603 dst->val = *(u32 *) RTA_DATA(rta); 604 dst->len = sizeof(u32); 605 } else 606 return -EINVAL; 607 608 return 0; 609 } 610 611 static void meta_int_apply_extras(struct meta_value *v, 612 struct meta_obj *dst) 613 { 614 if (v->hdr.shift) 615 dst->value >>= v->hdr.shift; 616 617 if (v->val) 618 dst->value &= v->val; 619 } 620 621 static int meta_int_dump(struct sk_buff *skb, struct meta_value *v, int tlv) 622 { 623 if (v->len == sizeof(unsigned long)) 624 RTA_PUT(skb, tlv, sizeof(unsigned long), &v->val); 625 else if (v->len == sizeof(u32)) { 626 u32 d = v->val; 627 RTA_PUT(skb, tlv, sizeof(d), &d); 628 } 629 630 return 0; 631 632 rtattr_failure: 633 return -1; 634 } 635 636 /************************************************************************** 637 * Type specific operations table 638 **************************************************************************/ 639 640 struct meta_type_ops 641 { 642 void (*destroy)(struct meta_value *); 643 int (*compare)(struct meta_obj *, struct meta_obj *); 644 int (*change)(struct meta_value *, struct rtattr *); 645 void (*apply_extras)(struct meta_value *, struct meta_obj *); 646 int (*dump)(struct sk_buff *, struct meta_value *, int); 647 }; 648 649 static struct meta_type_ops __meta_type_ops[TCF_META_TYPE_MAX+1] = { 650 [TCF_META_TYPE_VAR] = { 651 .destroy = meta_var_destroy, 652 .compare = meta_var_compare, 653 .change = meta_var_change, 654 .apply_extras = meta_var_apply_extras, 655 .dump = meta_var_dump 656 }, 657 [TCF_META_TYPE_INT] = { 658 .compare = meta_int_compare, 659 .change = meta_int_change, 660 .apply_extras = meta_int_apply_extras, 661 .dump = meta_int_dump 662 } 663 }; 664 665 static inline struct meta_type_ops * meta_type_ops(struct meta_value *v) 666 { 667 return &__meta_type_ops[meta_type(v)]; 668 } 669 670 /************************************************************************** 671 * Core 672 **************************************************************************/ 673 674 static inline int meta_get(struct sk_buff *skb, struct tcf_pkt_info *info, 675 struct meta_value *v, struct meta_obj *dst) 676 { 677 int err = 0; 678 679 if (meta_id(v) == TCF_META_ID_VALUE) { 680 dst->value = v->val; 681 dst->len = v->len; 682 return 0; 683 } 684 685 meta_ops(v)->get(skb, info, v, dst, &err); 686 if (err < 0) 687 return err; 688 689 if (meta_type_ops(v)->apply_extras) 690 meta_type_ops(v)->apply_extras(v, dst); 691 692 return 0; 693 } 694 695 static int em_meta_match(struct sk_buff *skb, struct tcf_ematch *m, 696 struct tcf_pkt_info *info) 697 { 698 int r; 699 struct meta_match *meta = (struct meta_match *) m->data; 700 struct meta_obj l_value, r_value; 701 702 if (meta_get(skb, info, &meta->lvalue, &l_value) < 0 || 703 meta_get(skb, info, &meta->rvalue, &r_value) < 0) 704 return 0; 705 706 r = meta_type_ops(&meta->lvalue)->compare(&l_value, &r_value); 707 708 switch (meta->lvalue.hdr.op) { 709 case TCF_EM_OPND_EQ: 710 return !r; 711 case TCF_EM_OPND_LT: 712 return r < 0; 713 case TCF_EM_OPND_GT: 714 return r > 0; 715 } 716 717 return 0; 718 } 719 720 static inline void meta_delete(struct meta_match *meta) 721 { 722 struct meta_type_ops *ops = meta_type_ops(&meta->lvalue); 723 724 if (ops && ops->destroy) { 725 ops->destroy(&meta->lvalue); 726 ops->destroy(&meta->rvalue); 727 } 728 729 kfree(meta); 730 } 731 732 static inline int meta_change_data(struct meta_value *dst, struct rtattr *rta) 733 { 734 if (rta) { 735 if (RTA_PAYLOAD(rta) == 0) 736 return -EINVAL; 737 738 return meta_type_ops(dst)->change(dst, rta); 739 } 740 741 return 0; 742 } 743 744 static inline int meta_is_supported(struct meta_value *val) 745 { 746 return (!meta_id(val) || meta_ops(val)->get); 747 } 748 749 static int em_meta_change(struct tcf_proto *tp, void *data, int len, 750 struct tcf_ematch *m) 751 { 752 int err = -EINVAL; 753 struct rtattr *tb[TCA_EM_META_MAX]; 754 struct tcf_meta_hdr *hdr; 755 struct meta_match *meta = NULL; 756 757 if (rtattr_parse(tb, TCA_EM_META_MAX, data, len) < 0) 758 goto errout; 759 760 if (tb[TCA_EM_META_HDR-1] == NULL || 761 RTA_PAYLOAD(tb[TCA_EM_META_HDR-1]) < sizeof(*hdr)) 762 goto errout; 763 hdr = RTA_DATA(tb[TCA_EM_META_HDR-1]); 764 765 if (TCF_META_TYPE(hdr->left.kind) != TCF_META_TYPE(hdr->right.kind) || 766 TCF_META_TYPE(hdr->left.kind) > TCF_META_TYPE_MAX || 767 TCF_META_ID(hdr->left.kind) > TCF_META_ID_MAX || 768 TCF_META_ID(hdr->right.kind) > TCF_META_ID_MAX) 769 goto errout; 770 771 meta = kzalloc(sizeof(*meta), GFP_KERNEL); 772 if (meta == NULL) 773 goto errout; 774 775 memcpy(&meta->lvalue.hdr, &hdr->left, sizeof(hdr->left)); 776 memcpy(&meta->rvalue.hdr, &hdr->right, sizeof(hdr->right)); 777 778 if (!meta_is_supported(&meta->lvalue) || 779 !meta_is_supported(&meta->rvalue)) { 780 err = -EOPNOTSUPP; 781 goto errout; 782 } 783 784 if (meta_change_data(&meta->lvalue, tb[TCA_EM_META_LVALUE-1]) < 0 || 785 meta_change_data(&meta->rvalue, tb[TCA_EM_META_RVALUE-1]) < 0) 786 goto errout; 787 788 m->datalen = sizeof(*meta); 789 m->data = (unsigned long) meta; 790 791 err = 0; 792 errout: 793 if (err && meta) 794 meta_delete(meta); 795 return err; 796 } 797 798 static void em_meta_destroy(struct tcf_proto *tp, struct tcf_ematch *m) 799 { 800 if (m) 801 meta_delete((struct meta_match *) m->data); 802 } 803 804 static int em_meta_dump(struct sk_buff *skb, struct tcf_ematch *em) 805 { 806 struct meta_match *meta = (struct meta_match *) em->data; 807 struct tcf_meta_hdr hdr; 808 struct meta_type_ops *ops; 809 810 memset(&hdr, 0, sizeof(hdr)); 811 memcpy(&hdr.left, &meta->lvalue.hdr, sizeof(hdr.left)); 812 memcpy(&hdr.right, &meta->rvalue.hdr, sizeof(hdr.right)); 813 814 RTA_PUT(skb, TCA_EM_META_HDR, sizeof(hdr), &hdr); 815 816 ops = meta_type_ops(&meta->lvalue); 817 if (ops->dump(skb, &meta->lvalue, TCA_EM_META_LVALUE) < 0 || 818 ops->dump(skb, &meta->rvalue, TCA_EM_META_RVALUE) < 0) 819 goto rtattr_failure; 820 821 return 0; 822 823 rtattr_failure: 824 return -1; 825 } 826 827 static struct tcf_ematch_ops em_meta_ops = { 828 .kind = TCF_EM_META, 829 .change = em_meta_change, 830 .match = em_meta_match, 831 .destroy = em_meta_destroy, 832 .dump = em_meta_dump, 833 .owner = THIS_MODULE, 834 .link = LIST_HEAD_INIT(em_meta_ops.link) 835 }; 836 837 static int __init init_em_meta(void) 838 { 839 return tcf_em_register(&em_meta_ops); 840 } 841 842 static void __exit exit_em_meta(void) 843 { 844 tcf_em_unregister(&em_meta_ops); 845 } 846 847 MODULE_LICENSE("GPL"); 848 849 module_init(init_em_meta); 850 module_exit(exit_em_meta); 851 852 MODULE_ALIAS_TCF_EMATCH(TCF_EM_META); 853