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: INDEV | | id: VALUE | 31 * | data: | | data: 3 | 32 * +-----------+ +-----------+ 33 * | | 34 * ---> meta_ops[INT][INDEV](...) | 35 * | | 36 * ----------- | 37 * V V 38 * +-----------+ +-----------+ 39 * | type: INT | | type: INT | 40 * obj | id: INDEV | | 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/config.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/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 META_COLLECTOR(int_indev) 174 { 175 *err = int_dev(skb->input_dev, dst); 176 } 177 178 META_COLLECTOR(var_indev) 179 { 180 *err = var_dev(skb->input_dev, dst); 181 } 182 183 META_COLLECTOR(int_realdev) 184 { 185 *err = int_dev(skb->real_dev, dst); 186 } 187 188 META_COLLECTOR(var_realdev) 189 { 190 *err = var_dev(skb->real_dev, dst); 191 } 192 193 /************************************************************************** 194 * skb attributes 195 **************************************************************************/ 196 197 META_COLLECTOR(int_priority) 198 { 199 dst->value = skb->priority; 200 } 201 202 META_COLLECTOR(int_protocol) 203 { 204 /* Let userspace take care of the byte ordering */ 205 dst->value = skb->protocol; 206 } 207 208 META_COLLECTOR(int_pkttype) 209 { 210 dst->value = skb->pkt_type; 211 } 212 213 META_COLLECTOR(int_pktlen) 214 { 215 dst->value = skb->len; 216 } 217 218 META_COLLECTOR(int_datalen) 219 { 220 dst->value = skb->data_len; 221 } 222 223 META_COLLECTOR(int_maclen) 224 { 225 dst->value = skb->mac_len; 226 } 227 228 /************************************************************************** 229 * Netfilter 230 **************************************************************************/ 231 232 #ifdef CONFIG_NETFILTER 233 META_COLLECTOR(int_nfmark) 234 { 235 dst->value = skb->nfmark; 236 } 237 #endif 238 239 /************************************************************************** 240 * Traffic Control 241 **************************************************************************/ 242 243 META_COLLECTOR(int_tcindex) 244 { 245 dst->value = skb->tc_index; 246 } 247 248 #ifdef CONFIG_NET_CLS_ACT 249 META_COLLECTOR(int_tcverd) 250 { 251 dst->value = skb->tc_verd; 252 } 253 254 META_COLLECTOR(int_tcclassid) 255 { 256 dst->value = skb->tc_classid; 257 } 258 #endif 259 260 /************************************************************************** 261 * Routing 262 **************************************************************************/ 263 264 #ifdef CONFIG_NET_CLS_ROUTE 265 META_COLLECTOR(int_rtclassid) 266 { 267 if (unlikely(skb->dst == NULL)) 268 *err = -1; 269 else 270 dst->value = skb->dst->tclassid; 271 } 272 #endif 273 274 META_COLLECTOR(int_rtiif) 275 { 276 if (unlikely(skb->dst == NULL)) 277 *err = -1; 278 else 279 dst->value = ((struct rtable*) skb->dst)->fl.iif; 280 } 281 282 /************************************************************************** 283 * Socket Attributes 284 **************************************************************************/ 285 286 #define SKIP_NONLOCAL(skb) \ 287 if (unlikely(skb->sk == NULL)) { \ 288 *err = -1; \ 289 return; \ 290 } 291 292 META_COLLECTOR(int_sk_family) 293 { 294 SKIP_NONLOCAL(skb); 295 dst->value = skb->sk->sk_family; 296 } 297 298 META_COLLECTOR(int_sk_state) 299 { 300 SKIP_NONLOCAL(skb); 301 dst->value = skb->sk->sk_state; 302 } 303 304 META_COLLECTOR(int_sk_reuse) 305 { 306 SKIP_NONLOCAL(skb); 307 dst->value = skb->sk->sk_reuse; 308 } 309 310 META_COLLECTOR(int_sk_bound_if) 311 { 312 SKIP_NONLOCAL(skb); 313 /* No error if bound_dev_if is 0, legal userspace check */ 314 dst->value = skb->sk->sk_bound_dev_if; 315 } 316 317 META_COLLECTOR(var_sk_bound_if) 318 { 319 SKIP_NONLOCAL(skb); 320 321 if (skb->sk->sk_bound_dev_if == 0) { 322 dst->value = (unsigned long) "any"; 323 dst->len = 3; 324 } else { 325 struct net_device *dev; 326 327 dev = dev_get_by_index(skb->sk->sk_bound_dev_if); 328 *err = var_dev(dev, dst); 329 if (dev) 330 dev_put(dev); 331 } 332 } 333 334 META_COLLECTOR(int_sk_refcnt) 335 { 336 SKIP_NONLOCAL(skb); 337 dst->value = atomic_read(&skb->sk->sk_refcnt); 338 } 339 340 META_COLLECTOR(int_sk_rcvbuf) 341 { 342 SKIP_NONLOCAL(skb); 343 dst->value = skb->sk->sk_rcvbuf; 344 } 345 346 META_COLLECTOR(int_sk_shutdown) 347 { 348 SKIP_NONLOCAL(skb); 349 dst->value = skb->sk->sk_shutdown; 350 } 351 352 META_COLLECTOR(int_sk_proto) 353 { 354 SKIP_NONLOCAL(skb); 355 dst->value = skb->sk->sk_protocol; 356 } 357 358 META_COLLECTOR(int_sk_type) 359 { 360 SKIP_NONLOCAL(skb); 361 dst->value = skb->sk->sk_type; 362 } 363 364 META_COLLECTOR(int_sk_rmem_alloc) 365 { 366 SKIP_NONLOCAL(skb); 367 dst->value = atomic_read(&skb->sk->sk_rmem_alloc); 368 } 369 370 META_COLLECTOR(int_sk_wmem_alloc) 371 { 372 SKIP_NONLOCAL(skb); 373 dst->value = atomic_read(&skb->sk->sk_wmem_alloc); 374 } 375 376 META_COLLECTOR(int_sk_omem_alloc) 377 { 378 SKIP_NONLOCAL(skb); 379 dst->value = atomic_read(&skb->sk->sk_omem_alloc); 380 } 381 382 META_COLLECTOR(int_sk_rcv_qlen) 383 { 384 SKIP_NONLOCAL(skb); 385 dst->value = skb->sk->sk_receive_queue.qlen; 386 } 387 388 META_COLLECTOR(int_sk_snd_qlen) 389 { 390 SKIP_NONLOCAL(skb); 391 dst->value = skb->sk->sk_write_queue.qlen; 392 } 393 394 META_COLLECTOR(int_sk_wmem_queued) 395 { 396 SKIP_NONLOCAL(skb); 397 dst->value = skb->sk->sk_wmem_queued; 398 } 399 400 META_COLLECTOR(int_sk_fwd_alloc) 401 { 402 SKIP_NONLOCAL(skb); 403 dst->value = skb->sk->sk_forward_alloc; 404 } 405 406 META_COLLECTOR(int_sk_sndbuf) 407 { 408 SKIP_NONLOCAL(skb); 409 dst->value = skb->sk->sk_sndbuf; 410 } 411 412 META_COLLECTOR(int_sk_alloc) 413 { 414 SKIP_NONLOCAL(skb); 415 dst->value = skb->sk->sk_allocation; 416 } 417 418 META_COLLECTOR(int_sk_route_caps) 419 { 420 SKIP_NONLOCAL(skb); 421 dst->value = skb->sk->sk_route_caps; 422 } 423 424 META_COLLECTOR(int_sk_hashent) 425 { 426 SKIP_NONLOCAL(skb); 427 dst->value = skb->sk->sk_hashent; 428 } 429 430 META_COLLECTOR(int_sk_lingertime) 431 { 432 SKIP_NONLOCAL(skb); 433 dst->value = skb->sk->sk_lingertime / HZ; 434 } 435 436 META_COLLECTOR(int_sk_err_qlen) 437 { 438 SKIP_NONLOCAL(skb); 439 dst->value = skb->sk->sk_error_queue.qlen; 440 } 441 442 META_COLLECTOR(int_sk_ack_bl) 443 { 444 SKIP_NONLOCAL(skb); 445 dst->value = skb->sk->sk_ack_backlog; 446 } 447 448 META_COLLECTOR(int_sk_max_ack_bl) 449 { 450 SKIP_NONLOCAL(skb); 451 dst->value = skb->sk->sk_max_ack_backlog; 452 } 453 454 META_COLLECTOR(int_sk_prio) 455 { 456 SKIP_NONLOCAL(skb); 457 dst->value = skb->sk->sk_priority; 458 } 459 460 META_COLLECTOR(int_sk_rcvlowat) 461 { 462 SKIP_NONLOCAL(skb); 463 dst->value = skb->sk->sk_rcvlowat; 464 } 465 466 META_COLLECTOR(int_sk_rcvtimeo) 467 { 468 SKIP_NONLOCAL(skb); 469 dst->value = skb->sk->sk_rcvtimeo / HZ; 470 } 471 472 META_COLLECTOR(int_sk_sndtimeo) 473 { 474 SKIP_NONLOCAL(skb); 475 dst->value = skb->sk->sk_sndtimeo / HZ; 476 } 477 478 META_COLLECTOR(int_sk_sendmsg_off) 479 { 480 SKIP_NONLOCAL(skb); 481 dst->value = skb->sk->sk_sndmsg_off; 482 } 483 484 META_COLLECTOR(int_sk_write_pend) 485 { 486 SKIP_NONLOCAL(skb); 487 dst->value = skb->sk->sk_write_pending; 488 } 489 490 /************************************************************************** 491 * Meta value collectors assignment table 492 **************************************************************************/ 493 494 struct meta_ops 495 { 496 void (*get)(struct sk_buff *, struct tcf_pkt_info *, 497 struct meta_value *, struct meta_obj *, int *); 498 }; 499 500 #define META_ID(name) TCF_META_ID_##name 501 #define META_FUNC(name) { .get = meta_##name } 502 503 /* Meta value operations table listing all meta value collectors and 504 * assigns them to a type and meta id. */ 505 static struct meta_ops __meta_ops[TCF_META_TYPE_MAX+1][TCF_META_ID_MAX+1] = { 506 [TCF_META_TYPE_VAR] = { 507 [META_ID(DEV)] = META_FUNC(var_dev), 508 [META_ID(INDEV)] = META_FUNC(var_indev), 509 [META_ID(REALDEV)] = META_FUNC(var_realdev), 510 [META_ID(SK_BOUND_IF)] = META_FUNC(var_sk_bound_if), 511 }, 512 [TCF_META_TYPE_INT] = { 513 [META_ID(RANDOM)] = META_FUNC(int_random), 514 [META_ID(LOADAVG_0)] = META_FUNC(int_loadavg_0), 515 [META_ID(LOADAVG_1)] = META_FUNC(int_loadavg_1), 516 [META_ID(LOADAVG_2)] = META_FUNC(int_loadavg_2), 517 [META_ID(DEV)] = META_FUNC(int_dev), 518 [META_ID(INDEV)] = META_FUNC(int_indev), 519 [META_ID(REALDEV)] = META_FUNC(int_realdev), 520 [META_ID(PRIORITY)] = META_FUNC(int_priority), 521 [META_ID(PROTOCOL)] = META_FUNC(int_protocol), 522 [META_ID(PKTTYPE)] = META_FUNC(int_pkttype), 523 [META_ID(PKTLEN)] = META_FUNC(int_pktlen), 524 [META_ID(DATALEN)] = META_FUNC(int_datalen), 525 [META_ID(MACLEN)] = META_FUNC(int_maclen), 526 #ifdef CONFIG_NETFILTER 527 [META_ID(NFMARK)] = META_FUNC(int_nfmark), 528 #endif 529 [META_ID(TCINDEX)] = META_FUNC(int_tcindex), 530 #ifdef CONFIG_NET_CLS_ACT 531 [META_ID(TCVERDICT)] = META_FUNC(int_tcverd), 532 [META_ID(TCCLASSID)] = META_FUNC(int_tcclassid), 533 #endif 534 #ifdef CONFIG_NET_CLS_ROUTE 535 [META_ID(RTCLASSID)] = META_FUNC(int_rtclassid), 536 #endif 537 [META_ID(RTIIF)] = META_FUNC(int_rtiif), 538 [META_ID(SK_FAMILY)] = META_FUNC(int_sk_family), 539 [META_ID(SK_STATE)] = META_FUNC(int_sk_state), 540 [META_ID(SK_REUSE)] = META_FUNC(int_sk_reuse), 541 [META_ID(SK_BOUND_IF)] = META_FUNC(int_sk_bound_if), 542 [META_ID(SK_REFCNT)] = META_FUNC(int_sk_refcnt), 543 [META_ID(SK_RCVBUF)] = META_FUNC(int_sk_rcvbuf), 544 [META_ID(SK_SNDBUF)] = META_FUNC(int_sk_sndbuf), 545 [META_ID(SK_SHUTDOWN)] = META_FUNC(int_sk_shutdown), 546 [META_ID(SK_PROTO)] = META_FUNC(int_sk_proto), 547 [META_ID(SK_TYPE)] = META_FUNC(int_sk_type), 548 [META_ID(SK_RMEM_ALLOC)] = META_FUNC(int_sk_rmem_alloc), 549 [META_ID(SK_WMEM_ALLOC)] = META_FUNC(int_sk_wmem_alloc), 550 [META_ID(SK_OMEM_ALLOC)] = META_FUNC(int_sk_omem_alloc), 551 [META_ID(SK_WMEM_QUEUED)] = META_FUNC(int_sk_wmem_queued), 552 [META_ID(SK_RCV_QLEN)] = META_FUNC(int_sk_rcv_qlen), 553 [META_ID(SK_SND_QLEN)] = META_FUNC(int_sk_snd_qlen), 554 [META_ID(SK_ERR_QLEN)] = META_FUNC(int_sk_err_qlen), 555 [META_ID(SK_FORWARD_ALLOCS)] = META_FUNC(int_sk_fwd_alloc), 556 [META_ID(SK_ALLOCS)] = META_FUNC(int_sk_alloc), 557 [META_ID(SK_ROUTE_CAPS)] = META_FUNC(int_sk_route_caps), 558 [META_ID(SK_HASHENT)] = META_FUNC(int_sk_hashent), 559 [META_ID(SK_LINGERTIME)] = META_FUNC(int_sk_lingertime), 560 [META_ID(SK_ACK_BACKLOG)] = META_FUNC(int_sk_ack_bl), 561 [META_ID(SK_MAX_ACK_BACKLOG)] = META_FUNC(int_sk_max_ack_bl), 562 [META_ID(SK_PRIO)] = META_FUNC(int_sk_prio), 563 [META_ID(SK_RCVLOWAT)] = META_FUNC(int_sk_rcvlowat), 564 [META_ID(SK_RCVTIMEO)] = META_FUNC(int_sk_rcvtimeo), 565 [META_ID(SK_SNDTIMEO)] = META_FUNC(int_sk_sndtimeo), 566 [META_ID(SK_SENDMSG_OFF)] = META_FUNC(int_sk_sendmsg_off), 567 [META_ID(SK_WRITE_PENDING)] = META_FUNC(int_sk_write_pend), 568 } 569 }; 570 571 static inline struct meta_ops * meta_ops(struct meta_value *val) 572 { 573 return &__meta_ops[meta_type(val)][meta_id(val)]; 574 } 575 576 /************************************************************************** 577 * Type specific operations for TCF_META_TYPE_VAR 578 **************************************************************************/ 579 580 static int meta_var_compare(struct meta_obj *a, struct meta_obj *b) 581 { 582 int r = a->len - b->len; 583 584 if (r == 0) 585 r = memcmp((void *) a->value, (void *) b->value, a->len); 586 587 return r; 588 } 589 590 static int meta_var_change(struct meta_value *dst, struct rtattr *rta) 591 { 592 int len = RTA_PAYLOAD(rta); 593 594 dst->val = (unsigned long) kmalloc(len, GFP_KERNEL); 595 if (dst->val == 0UL) 596 return -ENOMEM; 597 memcpy((void *) dst->val, RTA_DATA(rta), len); 598 dst->len = len; 599 return 0; 600 } 601 602 static void meta_var_destroy(struct meta_value *v) 603 { 604 if (v->val) 605 kfree((void *) v->val); 606 } 607 608 static void meta_var_apply_extras(struct meta_value *v, 609 struct meta_obj *dst) 610 { 611 int shift = v->hdr.shift; 612 613 if (shift && shift < dst->len) 614 dst->len -= shift; 615 } 616 617 static int meta_var_dump(struct sk_buff *skb, struct meta_value *v, int tlv) 618 { 619 if (v->val && v->len) 620 RTA_PUT(skb, tlv, v->len, (void *) v->val); 621 return 0; 622 623 rtattr_failure: 624 return -1; 625 } 626 627 /************************************************************************** 628 * Type specific operations for TCF_META_TYPE_INT 629 **************************************************************************/ 630 631 static int meta_int_compare(struct meta_obj *a, struct meta_obj *b) 632 { 633 /* Let gcc optimize it, the unlikely is not really based on 634 * some numbers but jump free code for mismatches seems 635 * more logical. */ 636 if (unlikely(a->value == b->value)) 637 return 0; 638 else if (a->value < b->value) 639 return -1; 640 else 641 return 1; 642 } 643 644 static int meta_int_change(struct meta_value *dst, struct rtattr *rta) 645 { 646 if (RTA_PAYLOAD(rta) >= sizeof(unsigned long)) { 647 dst->val = *(unsigned long *) RTA_DATA(rta); 648 dst->len = sizeof(unsigned long); 649 } else if (RTA_PAYLOAD(rta) == sizeof(u32)) { 650 dst->val = *(u32 *) RTA_DATA(rta); 651 dst->len = sizeof(u32); 652 } else 653 return -EINVAL; 654 655 return 0; 656 } 657 658 static void meta_int_apply_extras(struct meta_value *v, 659 struct meta_obj *dst) 660 { 661 if (v->hdr.shift) 662 dst->value >>= v->hdr.shift; 663 664 if (v->val) 665 dst->value &= v->val; 666 } 667 668 static int meta_int_dump(struct sk_buff *skb, struct meta_value *v, int tlv) 669 { 670 if (v->len == sizeof(unsigned long)) 671 RTA_PUT(skb, tlv, sizeof(unsigned long), &v->val); 672 else if (v->len == sizeof(u32)) { 673 u32 d = v->val; 674 RTA_PUT(skb, tlv, sizeof(d), &d); 675 } 676 677 return 0; 678 679 rtattr_failure: 680 return -1; 681 } 682 683 /************************************************************************** 684 * Type specific operations table 685 **************************************************************************/ 686 687 struct meta_type_ops 688 { 689 void (*destroy)(struct meta_value *); 690 int (*compare)(struct meta_obj *, struct meta_obj *); 691 int (*change)(struct meta_value *, struct rtattr *); 692 void (*apply_extras)(struct meta_value *, struct meta_obj *); 693 int (*dump)(struct sk_buff *, struct meta_value *, int); 694 }; 695 696 static struct meta_type_ops __meta_type_ops[TCF_META_TYPE_MAX+1] = { 697 [TCF_META_TYPE_VAR] = { 698 .destroy = meta_var_destroy, 699 .compare = meta_var_compare, 700 .change = meta_var_change, 701 .apply_extras = meta_var_apply_extras, 702 .dump = meta_var_dump 703 }, 704 [TCF_META_TYPE_INT] = { 705 .compare = meta_int_compare, 706 .change = meta_int_change, 707 .apply_extras = meta_int_apply_extras, 708 .dump = meta_int_dump 709 } 710 }; 711 712 static inline struct meta_type_ops * meta_type_ops(struct meta_value *v) 713 { 714 return &__meta_type_ops[meta_type(v)]; 715 } 716 717 /************************************************************************** 718 * Core 719 **************************************************************************/ 720 721 static inline int meta_get(struct sk_buff *skb, struct tcf_pkt_info *info, 722 struct meta_value *v, struct meta_obj *dst) 723 { 724 int err = 0; 725 726 if (meta_id(v) == TCF_META_ID_VALUE) { 727 dst->value = v->val; 728 dst->len = v->len; 729 return 0; 730 } 731 732 meta_ops(v)->get(skb, info, v, dst, &err); 733 if (err < 0) 734 return err; 735 736 if (meta_type_ops(v)->apply_extras) 737 meta_type_ops(v)->apply_extras(v, dst); 738 739 return 0; 740 } 741 742 static int em_meta_match(struct sk_buff *skb, struct tcf_ematch *m, 743 struct tcf_pkt_info *info) 744 { 745 int r; 746 struct meta_match *meta = (struct meta_match *) m->data; 747 struct meta_obj l_value, r_value; 748 749 if (meta_get(skb, info, &meta->lvalue, &l_value) < 0 || 750 meta_get(skb, info, &meta->rvalue, &r_value) < 0) 751 return 0; 752 753 r = meta_type_ops(&meta->lvalue)->compare(&l_value, &r_value); 754 755 switch (meta->lvalue.hdr.op) { 756 case TCF_EM_OPND_EQ: 757 return !r; 758 case TCF_EM_OPND_LT: 759 return r < 0; 760 case TCF_EM_OPND_GT: 761 return r > 0; 762 } 763 764 return 0; 765 } 766 767 static inline void meta_delete(struct meta_match *meta) 768 { 769 struct meta_type_ops *ops = meta_type_ops(&meta->lvalue); 770 771 if (ops && ops->destroy) { 772 ops->destroy(&meta->lvalue); 773 ops->destroy(&meta->rvalue); 774 } 775 776 kfree(meta); 777 } 778 779 static inline int meta_change_data(struct meta_value *dst, struct rtattr *rta) 780 { 781 if (rta) { 782 if (RTA_PAYLOAD(rta) == 0) 783 return -EINVAL; 784 785 return meta_type_ops(dst)->change(dst, rta); 786 } 787 788 return 0; 789 } 790 791 static inline int meta_is_supported(struct meta_value *val) 792 { 793 return (!meta_id(val) || meta_ops(val)->get); 794 } 795 796 static int em_meta_change(struct tcf_proto *tp, void *data, int len, 797 struct tcf_ematch *m) 798 { 799 int err = -EINVAL; 800 struct rtattr *tb[TCA_EM_META_MAX]; 801 struct tcf_meta_hdr *hdr; 802 struct meta_match *meta = NULL; 803 804 if (rtattr_parse(tb, TCA_EM_META_MAX, data, len) < 0) 805 goto errout; 806 807 if (tb[TCA_EM_META_HDR-1] == NULL || 808 RTA_PAYLOAD(tb[TCA_EM_META_HDR-1]) < sizeof(*hdr)) 809 goto errout; 810 hdr = RTA_DATA(tb[TCA_EM_META_HDR-1]); 811 812 if (TCF_META_TYPE(hdr->left.kind) != TCF_META_TYPE(hdr->right.kind) || 813 TCF_META_TYPE(hdr->left.kind) > TCF_META_TYPE_MAX || 814 TCF_META_ID(hdr->left.kind) > TCF_META_ID_MAX || 815 TCF_META_ID(hdr->right.kind) > TCF_META_ID_MAX) 816 goto errout; 817 818 meta = kmalloc(sizeof(*meta), GFP_KERNEL); 819 if (meta == NULL) 820 goto errout; 821 memset(meta, 0, sizeof(*meta)); 822 823 memcpy(&meta->lvalue.hdr, &hdr->left, sizeof(hdr->left)); 824 memcpy(&meta->rvalue.hdr, &hdr->right, sizeof(hdr->right)); 825 826 if (!meta_is_supported(&meta->lvalue) || 827 !meta_is_supported(&meta->rvalue)) { 828 err = -EOPNOTSUPP; 829 goto errout; 830 } 831 832 if (meta_change_data(&meta->lvalue, tb[TCA_EM_META_LVALUE-1]) < 0 || 833 meta_change_data(&meta->rvalue, tb[TCA_EM_META_RVALUE-1]) < 0) 834 goto errout; 835 836 m->datalen = sizeof(*meta); 837 m->data = (unsigned long) meta; 838 839 err = 0; 840 errout: 841 if (err && meta) 842 meta_delete(meta); 843 return err; 844 } 845 846 static void em_meta_destroy(struct tcf_proto *tp, struct tcf_ematch *m) 847 { 848 if (m) 849 meta_delete((struct meta_match *) m->data); 850 } 851 852 static int em_meta_dump(struct sk_buff *skb, struct tcf_ematch *em) 853 { 854 struct meta_match *meta = (struct meta_match *) em->data; 855 struct tcf_meta_hdr hdr; 856 struct meta_type_ops *ops; 857 858 memset(&hdr, 0, sizeof(hdr)); 859 memcpy(&hdr.left, &meta->lvalue.hdr, sizeof(hdr.left)); 860 memcpy(&hdr.right, &meta->rvalue.hdr, sizeof(hdr.right)); 861 862 RTA_PUT(skb, TCA_EM_META_HDR, sizeof(hdr), &hdr); 863 864 ops = meta_type_ops(&meta->lvalue); 865 if (ops->dump(skb, &meta->lvalue, TCA_EM_META_LVALUE) < 0 || 866 ops->dump(skb, &meta->rvalue, TCA_EM_META_RVALUE) < 0) 867 goto rtattr_failure; 868 869 return 0; 870 871 rtattr_failure: 872 return -1; 873 } 874 875 static struct tcf_ematch_ops em_meta_ops = { 876 .kind = TCF_EM_META, 877 .change = em_meta_change, 878 .match = em_meta_match, 879 .destroy = em_meta_destroy, 880 .dump = em_meta_dump, 881 .owner = THIS_MODULE, 882 .link = LIST_HEAD_INIT(em_meta_ops.link) 883 }; 884 885 static int __init init_em_meta(void) 886 { 887 return tcf_em_register(&em_meta_ops); 888 } 889 890 static void __exit exit_em_meta(void) 891 { 892 tcf_em_unregister(&em_meta_ops); 893 } 894 895 MODULE_LICENSE("GPL"); 896 897 module_init(init_em_meta); 898 module_exit(exit_em_meta); 899