1 /*#define CHASE_CHAIN*/ 2 /* 3 * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998 4 * The Regents of the University of California. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that: (1) source code distributions 8 * retain the above copyright notice and this paragraph in its entirety, (2) 9 * distributions including binary code include the above copyright notice and 10 * this paragraph in its entirety in the documentation or other materials 11 * provided with the distribution, and (3) all advertising materials mentioning 12 * features or use of this software display the following acknowledgement: 13 * ``This product includes software developed by the University of California, 14 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of 15 * the University nor the names of its contributors may be used to endorse 16 * or promote products derived from this software without specific prior 17 * written permission. 18 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED 19 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF 20 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 21 */ 22 #ifndef lint 23 static const char rcsid[] _U_ = 24 "@(#) $Header: /tcpdump/master/libpcap/gencode.c,v 1.309 2008-12-23 20:13:29 guy Exp $ (LBL)"; 25 #endif 26 27 #ifdef HAVE_CONFIG_H 28 #include "config.h" 29 #endif 30 31 #ifdef WIN32 32 #include <pcap-stdinc.h> 33 #else /* WIN32 */ 34 #if HAVE_INTTYPES_H 35 #include <inttypes.h> 36 #elif HAVE_STDINT_H 37 #include <stdint.h> 38 #endif 39 #ifdef HAVE_SYS_BITYPES_H 40 #include <sys/bitypes.h> 41 #endif 42 #include <sys/types.h> 43 #include <sys/socket.h> 44 #endif /* WIN32 */ 45 46 /* 47 * XXX - why was this included even on UNIX? 48 */ 49 #ifdef __MINGW32__ 50 #include "ip6_misc.h" 51 #endif 52 53 #ifndef WIN32 54 55 #ifdef __NetBSD__ 56 #include <sys/param.h> 57 #endif 58 59 #include <netinet/in.h> 60 #include <arpa/inet.h> 61 62 #endif /* WIN32 */ 63 64 #include <stdlib.h> 65 #include <string.h> 66 #include <memory.h> 67 #include <setjmp.h> 68 #include <stdarg.h> 69 70 #ifdef MSDOS 71 #include "pcap-dos.h" 72 #endif 73 74 #include "pcap-int.h" 75 76 #include "ethertype.h" 77 #include "nlpid.h" 78 #include "llc.h" 79 #include "gencode.h" 80 #include "ieee80211.h" 81 #include "atmuni31.h" 82 #include "sunatmpos.h" 83 #include "ppp.h" 84 #include "pcap/sll.h" 85 #include "pcap/ipnet.h" 86 #include "arcnet.h" 87 #ifdef HAVE_NET_PFVAR_H 88 #include <sys/socket.h> 89 #include <net/if.h> 90 #include <net/pf/pfvar.h> 91 #include <net/pf/if_pflog.h> 92 #endif 93 #ifndef offsetof 94 #define offsetof(s, e) ((size_t)&((s *)0)->e) 95 #endif 96 #ifdef INET6 97 #ifndef WIN32 98 #include <netdb.h> /* for "struct addrinfo" */ 99 #endif /* WIN32 */ 100 #endif /*INET6*/ 101 #include <pcap/namedb.h> 102 103 #define ETHERMTU 1500 104 105 #ifndef IPPROTO_SCTP 106 #define IPPROTO_SCTP 132 107 #endif 108 109 #ifdef HAVE_OS_PROTO_H 110 #include "os-proto.h" 111 #endif 112 113 #define JMP(c) ((c)|BPF_JMP|BPF_K) 114 115 /* Locals */ 116 static jmp_buf top_ctx; 117 static pcap_t *bpf_pcap; 118 119 /* Hack for updating VLAN, MPLS, and PPPoE offsets. */ 120 #ifdef WIN32 121 static u_int orig_linktype = (u_int)-1, orig_nl = (u_int)-1, label_stack_depth = (u_int)-1; 122 #else 123 static u_int orig_linktype = -1U, orig_nl = -1U, label_stack_depth = -1U; 124 #endif 125 126 /* XXX */ 127 #ifdef PCAP_FDDIPAD 128 static int pcap_fddipad; 129 #endif 130 131 /* VARARGS */ 132 void 133 bpf_error(const char *fmt, ...) 134 { 135 va_list ap; 136 137 va_start(ap, fmt); 138 if (bpf_pcap != NULL) 139 (void)vsnprintf(pcap_geterr(bpf_pcap), PCAP_ERRBUF_SIZE, 140 fmt, ap); 141 va_end(ap); 142 longjmp(top_ctx, 1); 143 /* NOTREACHED */ 144 } 145 146 static void init_linktype(pcap_t *); 147 148 static void init_regs(void); 149 static int alloc_reg(void); 150 static void free_reg(int); 151 152 static struct block *root; 153 154 /* 155 * Value passed to gen_load_a() to indicate what the offset argument 156 * is relative to. 157 */ 158 enum e_offrel { 159 OR_PACKET, /* relative to the beginning of the packet */ 160 OR_LINK, /* relative to the beginning of the link-layer header */ 161 OR_MACPL, /* relative to the end of the MAC-layer header */ 162 OR_NET, /* relative to the network-layer header */ 163 OR_NET_NOSNAP, /* relative to the network-layer header, with no SNAP header at the link layer */ 164 OR_TRAN_IPV4, /* relative to the transport-layer header, with IPv4 network layer */ 165 OR_TRAN_IPV6 /* relative to the transport-layer header, with IPv6 network layer */ 166 }; 167 168 #ifdef INET6 169 /* 170 * As errors are handled by a longjmp, anything allocated must be freed 171 * in the longjmp handler, so it must be reachable from that handler. 172 * One thing that's allocated is the result of pcap_nametoaddrinfo(); 173 * it must be freed with freeaddrinfo(). This variable points to any 174 * addrinfo structure that would need to be freed. 175 */ 176 static struct addrinfo *ai; 177 #endif 178 179 /* 180 * We divy out chunks of memory rather than call malloc each time so 181 * we don't have to worry about leaking memory. It's probably 182 * not a big deal if all this memory was wasted but if this ever 183 * goes into a library that would probably not be a good idea. 184 * 185 * XXX - this *is* in a library.... 186 */ 187 #define NCHUNKS 16 188 #define CHUNK0SIZE 1024 189 struct chunk { 190 u_int n_left; 191 void *m; 192 }; 193 194 static struct chunk chunks[NCHUNKS]; 195 static int cur_chunk; 196 197 static void *newchunk(u_int); 198 static void freechunks(void); 199 static inline struct block *new_block(int); 200 static inline struct slist *new_stmt(int); 201 static struct block *gen_retblk(int); 202 static inline void syntax(void); 203 204 static void backpatch(struct block *, struct block *); 205 static void merge(struct block *, struct block *); 206 static struct block *gen_cmp(enum e_offrel, u_int, u_int, bpf_int32); 207 static struct block *gen_cmp_gt(enum e_offrel, u_int, u_int, bpf_int32); 208 static struct block *gen_cmp_ge(enum e_offrel, u_int, u_int, bpf_int32); 209 static struct block *gen_cmp_lt(enum e_offrel, u_int, u_int, bpf_int32); 210 static struct block *gen_cmp_le(enum e_offrel, u_int, u_int, bpf_int32); 211 static struct block *gen_mcmp(enum e_offrel, u_int, u_int, bpf_int32, 212 bpf_u_int32); 213 static struct block *gen_bcmp(enum e_offrel, u_int, u_int, const u_char *); 214 static struct block *gen_ncmp(enum e_offrel, bpf_u_int32, bpf_u_int32, 215 bpf_u_int32, bpf_u_int32, int, bpf_int32); 216 static struct slist *gen_load_llrel(u_int, u_int); 217 static struct slist *gen_load_macplrel(u_int, u_int); 218 static struct slist *gen_load_a(enum e_offrel, u_int, u_int); 219 static struct slist *gen_loadx_iphdrlen(void); 220 static struct block *gen_uncond(int); 221 static inline struct block *gen_true(void); 222 static inline struct block *gen_false(void); 223 static struct block *gen_ether_linktype(int); 224 static struct block *gen_ipnet_linktype(int); 225 static struct block *gen_linux_sll_linktype(int); 226 static struct slist *gen_load_prism_llprefixlen(void); 227 static struct slist *gen_load_avs_llprefixlen(void); 228 static struct slist *gen_load_radiotap_llprefixlen(void); 229 static struct slist *gen_load_ppi_llprefixlen(void); 230 static void insert_compute_vloffsets(struct block *); 231 static struct slist *gen_llprefixlen(void); 232 static struct slist *gen_off_macpl(void); 233 static int ethertype_to_ppptype(int); 234 static struct block *gen_linktype(int); 235 static struct block *gen_snap(bpf_u_int32, bpf_u_int32); 236 static struct block *gen_llc_linktype(int); 237 static struct block *gen_hostop(bpf_u_int32, bpf_u_int32, int, int, u_int, u_int); 238 #ifdef INET6 239 static struct block *gen_hostop6(struct in6_addr *, struct in6_addr *, int, int, u_int, u_int); 240 #endif 241 static struct block *gen_ahostop(const u_char *, int); 242 static struct block *gen_ehostop(const u_char *, int); 243 static struct block *gen_fhostop(const u_char *, int); 244 static struct block *gen_thostop(const u_char *, int); 245 static struct block *gen_wlanhostop(const u_char *, int); 246 static struct block *gen_ipfchostop(const u_char *, int); 247 static struct block *gen_dnhostop(bpf_u_int32, int); 248 static struct block *gen_mpls_linktype(int); 249 static struct block *gen_host(bpf_u_int32, bpf_u_int32, int, int, int); 250 #ifdef INET6 251 static struct block *gen_host6(struct in6_addr *, struct in6_addr *, int, int, int); 252 #endif 253 #ifndef INET6 254 static struct block *gen_gateway(const u_char *, bpf_u_int32 **, int, int); 255 #endif 256 static struct block *gen_ipfrag(void); 257 static struct block *gen_portatom(int, bpf_int32); 258 static struct block *gen_portrangeatom(int, bpf_int32, bpf_int32); 259 #ifdef INET6 260 static struct block *gen_portatom6(int, bpf_int32); 261 static struct block *gen_portrangeatom6(int, bpf_int32, bpf_int32); 262 #endif 263 struct block *gen_portop(int, int, int); 264 static struct block *gen_port(int, int, int); 265 struct block *gen_portrangeop(int, int, int, int); 266 static struct block *gen_portrange(int, int, int, int); 267 #ifdef INET6 268 struct block *gen_portop6(int, int, int); 269 static struct block *gen_port6(int, int, int); 270 struct block *gen_portrangeop6(int, int, int, int); 271 static struct block *gen_portrange6(int, int, int, int); 272 #endif 273 static int lookup_proto(const char *, int); 274 static struct block *gen_protochain(int, int, int); 275 static struct block *gen_proto(int, int, int); 276 static struct slist *xfer_to_x(struct arth *); 277 static struct slist *xfer_to_a(struct arth *); 278 static struct block *gen_mac_multicast(int); 279 static struct block *gen_len(int, int); 280 static struct block *gen_check_802_11_data_frame(void); 281 282 static struct block *gen_ppi_dlt_check(void); 283 static struct block *gen_msg_abbrev(int type); 284 285 static void * 286 newchunk(n) 287 u_int n; 288 { 289 struct chunk *cp; 290 int k; 291 size_t size; 292 293 #ifndef __NetBSD__ 294 /* XXX Round up to nearest long. */ 295 n = (n + sizeof(long) - 1) & ~(sizeof(long) - 1); 296 #else 297 /* XXX Round up to structure boundary. */ 298 n = ALIGN(n); 299 #endif 300 301 cp = &chunks[cur_chunk]; 302 if (n > cp->n_left) { 303 ++cp, k = ++cur_chunk; 304 if (k >= NCHUNKS) 305 bpf_error("out of memory"); 306 size = CHUNK0SIZE << k; 307 cp->m = (void *)malloc(size); 308 if (cp->m == NULL) 309 bpf_error("out of memory"); 310 memset((char *)cp->m, 0, size); 311 cp->n_left = size; 312 if (n > size) 313 bpf_error("out of memory"); 314 } 315 cp->n_left -= n; 316 return (void *)((char *)cp->m + cp->n_left); 317 } 318 319 static void 320 freechunks() 321 { 322 int i; 323 324 cur_chunk = 0; 325 for (i = 0; i < NCHUNKS; ++i) 326 if (chunks[i].m != NULL) { 327 free(chunks[i].m); 328 chunks[i].m = NULL; 329 } 330 } 331 332 /* 333 * A strdup whose allocations are freed after code generation is over. 334 */ 335 char * 336 sdup(s) 337 register const char *s; 338 { 339 int n = strlen(s) + 1; 340 char *cp = newchunk(n); 341 342 strlcpy(cp, s, n); 343 return (cp); 344 } 345 346 static inline struct block * 347 new_block(code) 348 int code; 349 { 350 struct block *p; 351 352 p = (struct block *)newchunk(sizeof(*p)); 353 p->s.code = code; 354 p->head = p; 355 356 return p; 357 } 358 359 static inline struct slist * 360 new_stmt(code) 361 int code; 362 { 363 struct slist *p; 364 365 p = (struct slist *)newchunk(sizeof(*p)); 366 p->s.code = code; 367 368 return p; 369 } 370 371 static struct block * 372 gen_retblk(v) 373 int v; 374 { 375 struct block *b = new_block(BPF_RET|BPF_K); 376 377 b->s.k = v; 378 return b; 379 } 380 381 static inline void 382 syntax() 383 { 384 bpf_error("syntax error in filter expression"); 385 } 386 387 static bpf_u_int32 netmask; 388 static int snaplen; 389 int no_optimize; 390 #ifdef WIN32 391 static int 392 pcap_compile_unsafe(pcap_t *p, struct bpf_program *program, 393 const char *buf, int optimize, bpf_u_int32 mask); 394 395 int 396 pcap_compile(pcap_t *p, struct bpf_program *program, 397 const char *buf, int optimize, bpf_u_int32 mask) 398 { 399 int result; 400 401 EnterCriticalSection(&g_PcapCompileCriticalSection); 402 403 result = pcap_compile_unsafe(p, program, buf, optimize, mask); 404 405 LeaveCriticalSection(&g_PcapCompileCriticalSection); 406 407 return result; 408 } 409 410 static int 411 pcap_compile_unsafe(pcap_t *p, struct bpf_program *program, 412 const char *buf, int optimize, bpf_u_int32 mask) 413 #else /* WIN32 */ 414 int 415 pcap_compile(pcap_t *p, struct bpf_program *program, 416 const char *buf, int optimize, bpf_u_int32 mask) 417 #endif /* WIN32 */ 418 { 419 extern int n_errors; 420 const char * volatile xbuf = buf; 421 int len; 422 423 no_optimize = 0; 424 n_errors = 0; 425 root = NULL; 426 bpf_pcap = p; 427 init_regs(); 428 if (setjmp(top_ctx)) { 429 #ifdef INET6 430 if (ai != NULL) { 431 freeaddrinfo(ai); 432 ai = NULL; 433 } 434 #endif 435 lex_cleanup(); 436 freechunks(); 437 return (-1); 438 } 439 440 netmask = mask; 441 442 snaplen = pcap_snapshot(p); 443 if (snaplen == 0) { 444 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 445 "snaplen of 0 rejects all packets"); 446 return -1; 447 } 448 449 lex_init(xbuf ? xbuf : ""); 450 init_linktype(p); 451 (void)pcap_parse(); 452 453 if (n_errors) 454 syntax(); 455 456 if (root == NULL) 457 root = gen_retblk(snaplen); 458 459 if (optimize && !no_optimize) { 460 bpf_optimize(&root); 461 if (root == NULL || 462 (root->s.code == (BPF_RET|BPF_K) && root->s.k == 0)) 463 bpf_error("expression rejects all packets"); 464 } 465 program->bf_insns = icode_to_fcode(root, &len); 466 program->bf_len = len; 467 468 lex_cleanup(); 469 freechunks(); 470 return (0); 471 } 472 473 /* 474 * entry point for using the compiler with no pcap open 475 * pass in all the stuff that is needed explicitly instead. 476 */ 477 int 478 pcap_compile_nopcap(int snaplen_arg, int linktype_arg, 479 struct bpf_program *program, 480 const char *buf, int optimize, bpf_u_int32 mask) 481 { 482 pcap_t *p; 483 int ret; 484 485 p = pcap_open_dead(linktype_arg, snaplen_arg); 486 if (p == NULL) 487 return (-1); 488 ret = pcap_compile(p, program, buf, optimize, mask); 489 pcap_close(p); 490 return (ret); 491 } 492 493 /* 494 * Clean up a "struct bpf_program" by freeing all the memory allocated 495 * in it. 496 */ 497 void 498 pcap_freecode(struct bpf_program *program) 499 { 500 program->bf_len = 0; 501 if (program->bf_insns != NULL) { 502 free((char *)program->bf_insns); 503 program->bf_insns = NULL; 504 } 505 } 506 507 /* 508 * Backpatch the blocks in 'list' to 'target'. The 'sense' field indicates 509 * which of the jt and jf fields has been resolved and which is a pointer 510 * back to another unresolved block (or nil). At least one of the fields 511 * in each block is already resolved. 512 */ 513 static void 514 backpatch(list, target) 515 struct block *list, *target; 516 { 517 struct block *next; 518 519 while (list) { 520 if (!list->sense) { 521 next = JT(list); 522 JT(list) = target; 523 } else { 524 next = JF(list); 525 JF(list) = target; 526 } 527 list = next; 528 } 529 } 530 531 /* 532 * Merge the lists in b0 and b1, using the 'sense' field to indicate 533 * which of jt and jf is the link. 534 */ 535 static void 536 merge(b0, b1) 537 struct block *b0, *b1; 538 { 539 register struct block **p = &b0; 540 541 /* Find end of list. */ 542 while (*p) 543 p = !((*p)->sense) ? &JT(*p) : &JF(*p); 544 545 /* Concatenate the lists. */ 546 *p = b1; 547 } 548 549 void 550 finish_parse(p) 551 struct block *p; 552 { 553 struct block *ppi_dlt_check; 554 555 /* 556 * Insert before the statements of the first (root) block any 557 * statements needed to load the lengths of any variable-length 558 * headers into registers. 559 * 560 * XXX - a fancier strategy would be to insert those before the 561 * statements of all blocks that use those lengths and that 562 * have no predecessors that use them, so that we only compute 563 * the lengths if we need them. There might be even better 564 * approaches than that. 565 * 566 * However, those strategies would be more complicated, and 567 * as we don't generate code to compute a length if the 568 * program has no tests that use the length, and as most 569 * tests will probably use those lengths, we would just 570 * postpone computing the lengths so that it's not done 571 * for tests that fail early, and it's not clear that's 572 * worth the effort. 573 */ 574 insert_compute_vloffsets(p->head); 575 576 /* 577 * For DLT_PPI captures, generate a check of the per-packet 578 * DLT value to make sure it's DLT_IEEE802_11. 579 */ 580 ppi_dlt_check = gen_ppi_dlt_check(); 581 if (ppi_dlt_check != NULL) 582 gen_and(ppi_dlt_check, p); 583 584 backpatch(p, gen_retblk(snaplen)); 585 p->sense = !p->sense; 586 backpatch(p, gen_retblk(0)); 587 root = p->head; 588 } 589 590 void 591 gen_and(b0, b1) 592 struct block *b0, *b1; 593 { 594 backpatch(b0, b1->head); 595 b0->sense = !b0->sense; 596 b1->sense = !b1->sense; 597 merge(b1, b0); 598 b1->sense = !b1->sense; 599 b1->head = b0->head; 600 } 601 602 void 603 gen_or(b0, b1) 604 struct block *b0, *b1; 605 { 606 b0->sense = !b0->sense; 607 backpatch(b0, b1->head); 608 b0->sense = !b0->sense; 609 merge(b1, b0); 610 b1->head = b0->head; 611 } 612 613 void 614 gen_not(b) 615 struct block *b; 616 { 617 b->sense = !b->sense; 618 } 619 620 static struct block * 621 gen_cmp(offrel, offset, size, v) 622 enum e_offrel offrel; 623 u_int offset, size; 624 bpf_int32 v; 625 { 626 return gen_ncmp(offrel, offset, size, 0xffffffff, BPF_JEQ, 0, v); 627 } 628 629 static struct block * 630 gen_cmp_gt(offrel, offset, size, v) 631 enum e_offrel offrel; 632 u_int offset, size; 633 bpf_int32 v; 634 { 635 return gen_ncmp(offrel, offset, size, 0xffffffff, BPF_JGT, 0, v); 636 } 637 638 static struct block * 639 gen_cmp_ge(offrel, offset, size, v) 640 enum e_offrel offrel; 641 u_int offset, size; 642 bpf_int32 v; 643 { 644 return gen_ncmp(offrel, offset, size, 0xffffffff, BPF_JGE, 0, v); 645 } 646 647 static struct block * 648 gen_cmp_lt(offrel, offset, size, v) 649 enum e_offrel offrel; 650 u_int offset, size; 651 bpf_int32 v; 652 { 653 return gen_ncmp(offrel, offset, size, 0xffffffff, BPF_JGE, 1, v); 654 } 655 656 static struct block * 657 gen_cmp_le(offrel, offset, size, v) 658 enum e_offrel offrel; 659 u_int offset, size; 660 bpf_int32 v; 661 { 662 return gen_ncmp(offrel, offset, size, 0xffffffff, BPF_JGT, 1, v); 663 } 664 665 static struct block * 666 gen_mcmp(offrel, offset, size, v, mask) 667 enum e_offrel offrel; 668 u_int offset, size; 669 bpf_int32 v; 670 bpf_u_int32 mask; 671 { 672 return gen_ncmp(offrel, offset, size, mask, BPF_JEQ, 0, v); 673 } 674 675 static struct block * 676 gen_bcmp(offrel, offset, size, v) 677 enum e_offrel offrel; 678 register u_int offset, size; 679 register const u_char *v; 680 { 681 register struct block *b, *tmp; 682 683 b = NULL; 684 while (size >= 4) { 685 register const u_char *p = &v[size - 4]; 686 bpf_int32 w = ((bpf_int32)p[0] << 24) | 687 ((bpf_int32)p[1] << 16) | ((bpf_int32)p[2] << 8) | p[3]; 688 689 tmp = gen_cmp(offrel, offset + size - 4, BPF_W, w); 690 if (b != NULL) 691 gen_and(b, tmp); 692 b = tmp; 693 size -= 4; 694 } 695 while (size >= 2) { 696 register const u_char *p = &v[size - 2]; 697 bpf_int32 w = ((bpf_int32)p[0] << 8) | p[1]; 698 699 tmp = gen_cmp(offrel, offset + size - 2, BPF_H, w); 700 if (b != NULL) 701 gen_and(b, tmp); 702 b = tmp; 703 size -= 2; 704 } 705 if (size > 0) { 706 tmp = gen_cmp(offrel, offset, BPF_B, (bpf_int32)v[0]); 707 if (b != NULL) 708 gen_and(b, tmp); 709 b = tmp; 710 } 711 return b; 712 } 713 714 /* 715 * AND the field of size "size" at offset "offset" relative to the header 716 * specified by "offrel" with "mask", and compare it with the value "v" 717 * with the test specified by "jtype"; if "reverse" is true, the test 718 * should test the opposite of "jtype". 719 */ 720 static struct block * 721 gen_ncmp(offrel, offset, size, mask, jtype, reverse, v) 722 enum e_offrel offrel; 723 bpf_int32 v; 724 bpf_u_int32 offset, size, mask, jtype; 725 int reverse; 726 { 727 struct slist *s, *s2; 728 struct block *b; 729 730 s = gen_load_a(offrel, offset, size); 731 732 if (mask != 0xffffffff) { 733 s2 = new_stmt(BPF_ALU|BPF_AND|BPF_K); 734 s2->s.k = mask; 735 sappend(s, s2); 736 } 737 738 b = new_block(JMP(jtype)); 739 b->stmts = s; 740 b->s.k = v; 741 if (reverse && (jtype == BPF_JGT || jtype == BPF_JGE)) 742 gen_not(b); 743 return b; 744 } 745 746 /* 747 * Various code constructs need to know the layout of the data link 748 * layer. These variables give the necessary offsets from the beginning 749 * of the packet data. 750 */ 751 752 /* 753 * This is the offset of the beginning of the link-layer header from 754 * the beginning of the raw packet data. 755 * 756 * It's usually 0, except for 802.11 with a fixed-length radio header. 757 * (For 802.11 with a variable-length radio header, we have to generate 758 * code to compute that offset; off_ll is 0 in that case.) 759 */ 760 static u_int off_ll; 761 762 /* 763 * If there's a variable-length header preceding the link-layer header, 764 * "reg_off_ll" is the register number for a register containing the 765 * length of that header, and therefore the offset of the link-layer 766 * header from the beginning of the raw packet data. Otherwise, 767 * "reg_off_ll" is -1. 768 */ 769 static int reg_off_ll; 770 771 /* 772 * This is the offset of the beginning of the MAC-layer header from 773 * the beginning of the link-layer header. 774 * It's usually 0, except for ATM LANE, where it's the offset, relative 775 * to the beginning of the raw packet data, of the Ethernet header, and 776 * for Ethernet with various additional information. 777 */ 778 static u_int off_mac; 779 780 /* 781 * This is the offset of the beginning of the MAC-layer payload, 782 * from the beginning of the raw packet data. 783 * 784 * I.e., it's the sum of the length of the link-layer header (without, 785 * for example, any 802.2 LLC header, so it's the MAC-layer 786 * portion of that header), plus any prefix preceding the 787 * link-layer header. 788 */ 789 static u_int off_macpl; 790 791 /* 792 * This is 1 if the offset of the beginning of the MAC-layer payload 793 * from the beginning of the link-layer header is variable-length. 794 */ 795 static int off_macpl_is_variable; 796 797 /* 798 * If the link layer has variable_length headers, "reg_off_macpl" 799 * is the register number for a register containing the length of the 800 * link-layer header plus the length of any variable-length header 801 * preceding the link-layer header. Otherwise, "reg_off_macpl" 802 * is -1. 803 */ 804 static int reg_off_macpl; 805 806 /* 807 * "off_linktype" is the offset to information in the link-layer header 808 * giving the packet type. This offset is relative to the beginning 809 * of the link-layer header (i.e., it doesn't include off_ll). 810 * 811 * For Ethernet, it's the offset of the Ethernet type field. 812 * 813 * For link-layer types that always use 802.2 headers, it's the 814 * offset of the LLC header. 815 * 816 * For PPP, it's the offset of the PPP type field. 817 * 818 * For Cisco HDLC, it's the offset of the CHDLC type field. 819 * 820 * For BSD loopback, it's the offset of the AF_ value. 821 * 822 * For Linux cooked sockets, it's the offset of the type field. 823 * 824 * It's set to -1 for no encapsulation, in which case, IP is assumed. 825 */ 826 static u_int off_linktype; 827 828 /* 829 * TRUE if "pppoes" appeared in the filter; it causes link-layer type 830 * checks to check the PPP header, assumed to follow a LAN-style link- 831 * layer header and a PPPoE session header. 832 */ 833 static int is_pppoes = 0; 834 835 /* 836 * TRUE if the link layer includes an ATM pseudo-header. 837 */ 838 static int is_atm = 0; 839 840 /* 841 * TRUE if "lane" appeared in the filter; it causes us to generate 842 * code that assumes LANE rather than LLC-encapsulated traffic in SunATM. 843 */ 844 static int is_lane = 0; 845 846 /* 847 * These are offsets for the ATM pseudo-header. 848 */ 849 static u_int off_vpi; 850 static u_int off_vci; 851 static u_int off_proto; 852 853 /* 854 * These are offsets for the MTP2 fields. 855 */ 856 static u_int off_li; 857 858 /* 859 * These are offsets for the MTP3 fields. 860 */ 861 static u_int off_sio; 862 static u_int off_opc; 863 static u_int off_dpc; 864 static u_int off_sls; 865 866 /* 867 * This is the offset of the first byte after the ATM pseudo_header, 868 * or -1 if there is no ATM pseudo-header. 869 */ 870 static u_int off_payload; 871 872 /* 873 * These are offsets to the beginning of the network-layer header. 874 * They are relative to the beginning of the MAC-layer payload (i.e., 875 * they don't include off_ll or off_macpl). 876 * 877 * If the link layer never uses 802.2 LLC: 878 * 879 * "off_nl" and "off_nl_nosnap" are the same. 880 * 881 * If the link layer always uses 802.2 LLC: 882 * 883 * "off_nl" is the offset if there's a SNAP header following 884 * the 802.2 header; 885 * 886 * "off_nl_nosnap" is the offset if there's no SNAP header. 887 * 888 * If the link layer is Ethernet: 889 * 890 * "off_nl" is the offset if the packet is an Ethernet II packet 891 * (we assume no 802.3+802.2+SNAP); 892 * 893 * "off_nl_nosnap" is the offset if the packet is an 802.3 packet 894 * with an 802.2 header following it. 895 */ 896 static u_int off_nl; 897 static u_int off_nl_nosnap; 898 899 static int linktype; 900 901 static void 902 init_linktype(p) 903 pcap_t *p; 904 { 905 linktype = pcap_datalink(p); 906 #ifdef PCAP_FDDIPAD 907 pcap_fddipad = p->fddipad; 908 #endif 909 910 /* 911 * Assume it's not raw ATM with a pseudo-header, for now. 912 */ 913 off_mac = 0; 914 is_atm = 0; 915 is_lane = 0; 916 off_vpi = -1; 917 off_vci = -1; 918 off_proto = -1; 919 off_payload = -1; 920 921 /* 922 * And that we're not doing PPPoE. 923 */ 924 is_pppoes = 0; 925 926 /* 927 * And assume we're not doing SS7. 928 */ 929 off_li = -1; 930 off_sio = -1; 931 off_opc = -1; 932 off_dpc = -1; 933 off_sls = -1; 934 935 /* 936 * Also assume it's not 802.11. 937 */ 938 off_ll = 0; 939 off_macpl = 0; 940 off_macpl_is_variable = 0; 941 942 orig_linktype = -1; 943 orig_nl = -1; 944 label_stack_depth = 0; 945 946 reg_off_ll = -1; 947 reg_off_macpl = -1; 948 949 switch (linktype) { 950 951 case DLT_ARCNET: 952 off_linktype = 2; 953 off_macpl = 6; 954 off_nl = 0; /* XXX in reality, variable! */ 955 off_nl_nosnap = 0; /* no 802.2 LLC */ 956 return; 957 958 case DLT_ARCNET_LINUX: 959 off_linktype = 4; 960 off_macpl = 8; 961 off_nl = 0; /* XXX in reality, variable! */ 962 off_nl_nosnap = 0; /* no 802.2 LLC */ 963 return; 964 965 case DLT_EN10MB: 966 off_linktype = 12; 967 off_macpl = 14; /* Ethernet header length */ 968 off_nl = 0; /* Ethernet II */ 969 off_nl_nosnap = 3; /* 802.3+802.2 */ 970 return; 971 972 case DLT_SLIP: 973 /* 974 * SLIP doesn't have a link level type. The 16 byte 975 * header is hacked into our SLIP driver. 976 */ 977 off_linktype = -1; 978 off_macpl = 16; 979 off_nl = 0; 980 off_nl_nosnap = 0; /* no 802.2 LLC */ 981 return; 982 983 case DLT_SLIP_BSDOS: 984 /* XXX this may be the same as the DLT_PPP_BSDOS case */ 985 off_linktype = -1; 986 /* XXX end */ 987 off_macpl = 24; 988 off_nl = 0; 989 off_nl_nosnap = 0; /* no 802.2 LLC */ 990 return; 991 992 case DLT_NULL: 993 case DLT_LOOP: 994 off_linktype = 0; 995 off_macpl = 4; 996 off_nl = 0; 997 off_nl_nosnap = 0; /* no 802.2 LLC */ 998 return; 999 1000 case DLT_ENC: 1001 off_linktype = 0; 1002 off_macpl = 12; 1003 off_nl = 0; 1004 off_nl_nosnap = 0; /* no 802.2 LLC */ 1005 return; 1006 1007 case DLT_PPP: 1008 case DLT_PPP_PPPD: 1009 case DLT_C_HDLC: /* BSD/OS Cisco HDLC */ 1010 case DLT_PPP_SERIAL: /* NetBSD sync/async serial PPP */ 1011 off_linktype = 2; 1012 off_macpl = 4; 1013 off_nl = 0; 1014 off_nl_nosnap = 0; /* no 802.2 LLC */ 1015 return; 1016 1017 case DLT_PPP_ETHER: 1018 /* 1019 * This does no include the Ethernet header, and 1020 * only covers session state. 1021 */ 1022 off_linktype = 6; 1023 off_macpl = 8; 1024 off_nl = 0; 1025 off_nl_nosnap = 0; /* no 802.2 LLC */ 1026 return; 1027 1028 case DLT_PPP_BSDOS: 1029 off_linktype = 5; 1030 off_macpl = 24; 1031 off_nl = 0; 1032 off_nl_nosnap = 0; /* no 802.2 LLC */ 1033 return; 1034 1035 case DLT_FDDI: 1036 /* 1037 * FDDI doesn't really have a link-level type field. 1038 * We set "off_linktype" to the offset of the LLC header. 1039 * 1040 * To check for Ethernet types, we assume that SSAP = SNAP 1041 * is being used and pick out the encapsulated Ethernet type. 1042 * XXX - should we generate code to check for SNAP? 1043 */ 1044 off_linktype = 13; 1045 #ifdef PCAP_FDDIPAD 1046 off_linktype += pcap_fddipad; 1047 #endif 1048 off_macpl = 13; /* FDDI MAC header length */ 1049 #ifdef PCAP_FDDIPAD 1050 off_macpl += pcap_fddipad; 1051 #endif 1052 off_nl = 8; /* 802.2+SNAP */ 1053 off_nl_nosnap = 3; /* 802.2 */ 1054 return; 1055 1056 case DLT_IEEE802: 1057 /* 1058 * Token Ring doesn't really have a link-level type field. 1059 * We set "off_linktype" to the offset of the LLC header. 1060 * 1061 * To check for Ethernet types, we assume that SSAP = SNAP 1062 * is being used and pick out the encapsulated Ethernet type. 1063 * XXX - should we generate code to check for SNAP? 1064 * 1065 * XXX - the header is actually variable-length. 1066 * Some various Linux patched versions gave 38 1067 * as "off_linktype" and 40 as "off_nl"; however, 1068 * if a token ring packet has *no* routing 1069 * information, i.e. is not source-routed, the correct 1070 * values are 20 and 22, as they are in the vanilla code. 1071 * 1072 * A packet is source-routed iff the uppermost bit 1073 * of the first byte of the source address, at an 1074 * offset of 8, has the uppermost bit set. If the 1075 * packet is source-routed, the total number of bytes 1076 * of routing information is 2 plus bits 0x1F00 of 1077 * the 16-bit value at an offset of 14 (shifted right 1078 * 8 - figure out which byte that is). 1079 */ 1080 off_linktype = 14; 1081 off_macpl = 14; /* Token Ring MAC header length */ 1082 off_nl = 8; /* 802.2+SNAP */ 1083 off_nl_nosnap = 3; /* 802.2 */ 1084 return; 1085 1086 case DLT_IEEE802_11: 1087 case DLT_PRISM_HEADER: 1088 case DLT_IEEE802_11_RADIO_AVS: 1089 case DLT_IEEE802_11_RADIO: 1090 /* 1091 * 802.11 doesn't really have a link-level type field. 1092 * We set "off_linktype" to the offset of the LLC header. 1093 * 1094 * To check for Ethernet types, we assume that SSAP = SNAP 1095 * is being used and pick out the encapsulated Ethernet type. 1096 * XXX - should we generate code to check for SNAP? 1097 * 1098 * We also handle variable-length radio headers here. 1099 * The Prism header is in theory variable-length, but in 1100 * practice it's always 144 bytes long. However, some 1101 * drivers on Linux use ARPHRD_IEEE80211_PRISM, but 1102 * sometimes or always supply an AVS header, so we 1103 * have to check whether the radio header is a Prism 1104 * header or an AVS header, so, in practice, it's 1105 * variable-length. 1106 */ 1107 off_linktype = 24; 1108 off_macpl = 0; /* link-layer header is variable-length */ 1109 off_macpl_is_variable = 1; 1110 off_nl = 8; /* 802.2+SNAP */ 1111 off_nl_nosnap = 3; /* 802.2 */ 1112 return; 1113 1114 case DLT_PPI: 1115 /* 1116 * At the moment we treat PPI the same way that we treat 1117 * normal Radiotap encoded packets. The difference is in 1118 * the function that generates the code at the beginning 1119 * to compute the header length. Since this code generator 1120 * of PPI supports bare 802.11 encapsulation only (i.e. 1121 * the encapsulated DLT should be DLT_IEEE802_11) we 1122 * generate code to check for this too. 1123 */ 1124 off_linktype = 24; 1125 off_macpl = 0; /* link-layer header is variable-length */ 1126 off_macpl_is_variable = 1; 1127 off_nl = 8; /* 802.2+SNAP */ 1128 off_nl_nosnap = 3; /* 802.2 */ 1129 return; 1130 1131 case DLT_ATM_RFC1483: 1132 case DLT_ATM_CLIP: /* Linux ATM defines this */ 1133 /* 1134 * assume routed, non-ISO PDUs 1135 * (i.e., LLC = 0xAA-AA-03, OUT = 0x00-00-00) 1136 * 1137 * XXX - what about ISO PDUs, e.g. CLNP, ISIS, ESIS, 1138 * or PPP with the PPP NLPID (e.g., PPPoA)? The 1139 * latter would presumably be treated the way PPPoE 1140 * should be, so you can do "pppoe and udp port 2049" 1141 * or "pppoa and tcp port 80" and have it check for 1142 * PPPo{A,E} and a PPP protocol of IP and.... 1143 */ 1144 off_linktype = 0; 1145 off_macpl = 0; /* packet begins with LLC header */ 1146 off_nl = 8; /* 802.2+SNAP */ 1147 off_nl_nosnap = 3; /* 802.2 */ 1148 return; 1149 1150 case DLT_SUNATM: 1151 /* 1152 * Full Frontal ATM; you get AALn PDUs with an ATM 1153 * pseudo-header. 1154 */ 1155 is_atm = 1; 1156 off_vpi = SUNATM_VPI_POS; 1157 off_vci = SUNATM_VCI_POS; 1158 off_proto = PROTO_POS; 1159 off_mac = -1; /* assume LLC-encapsulated, so no MAC-layer header */ 1160 off_payload = SUNATM_PKT_BEGIN_POS; 1161 off_linktype = off_payload; 1162 off_macpl = off_payload; /* if LLC-encapsulated */ 1163 off_nl = 8; /* 802.2+SNAP */ 1164 off_nl_nosnap = 3; /* 802.2 */ 1165 return; 1166 1167 case DLT_RAW: 1168 case DLT_IPV4: 1169 case DLT_IPV6: 1170 off_linktype = -1; 1171 off_macpl = 0; 1172 off_nl = 0; 1173 off_nl_nosnap = 0; /* no 802.2 LLC */ 1174 return; 1175 1176 case DLT_LINUX_SLL: /* fake header for Linux cooked socket */ 1177 off_linktype = 14; 1178 off_macpl = 16; 1179 off_nl = 0; 1180 off_nl_nosnap = 0; /* no 802.2 LLC */ 1181 return; 1182 1183 case DLT_LTALK: 1184 /* 1185 * LocalTalk does have a 1-byte type field in the LLAP header, 1186 * but really it just indicates whether there is a "short" or 1187 * "long" DDP packet following. 1188 */ 1189 off_linktype = -1; 1190 off_macpl = 0; 1191 off_nl = 0; 1192 off_nl_nosnap = 0; /* no 802.2 LLC */ 1193 return; 1194 1195 case DLT_IP_OVER_FC: 1196 /* 1197 * RFC 2625 IP-over-Fibre-Channel doesn't really have a 1198 * link-level type field. We set "off_linktype" to the 1199 * offset of the LLC header. 1200 * 1201 * To check for Ethernet types, we assume that SSAP = SNAP 1202 * is being used and pick out the encapsulated Ethernet type. 1203 * XXX - should we generate code to check for SNAP? RFC 1204 * 2625 says SNAP should be used. 1205 */ 1206 off_linktype = 16; 1207 off_macpl = 16; 1208 off_nl = 8; /* 802.2+SNAP */ 1209 off_nl_nosnap = 3; /* 802.2 */ 1210 return; 1211 1212 case DLT_FRELAY: 1213 /* 1214 * XXX - we should set this to handle SNAP-encapsulated 1215 * frames (NLPID of 0x80). 1216 */ 1217 off_linktype = -1; 1218 off_macpl = 0; 1219 off_nl = 0; 1220 off_nl_nosnap = 0; /* no 802.2 LLC */ 1221 return; 1222 1223 /* 1224 * the only BPF-interesting FRF.16 frames are non-control frames; 1225 * Frame Relay has a variable length link-layer 1226 * so lets start with offset 4 for now and increments later on (FIXME); 1227 */ 1228 case DLT_MFR: 1229 off_linktype = -1; 1230 off_macpl = 0; 1231 off_nl = 4; 1232 off_nl_nosnap = 0; /* XXX - for now -> no 802.2 LLC */ 1233 return; 1234 1235 case DLT_APPLE_IP_OVER_IEEE1394: 1236 off_linktype = 16; 1237 off_macpl = 18; 1238 off_nl = 0; 1239 off_nl_nosnap = 0; /* no 802.2 LLC */ 1240 return; 1241 1242 case DLT_SYMANTEC_FIREWALL: 1243 off_linktype = 6; 1244 off_macpl = 44; 1245 off_nl = 0; /* Ethernet II */ 1246 off_nl_nosnap = 0; /* XXX - what does it do with 802.3 packets? */ 1247 return; 1248 1249 #ifdef HAVE_NET_PFVAR_H 1250 case DLT_PFLOG: 1251 off_linktype = 0; 1252 off_macpl = PFLOG_HDRLEN; 1253 off_nl = 0; 1254 off_nl_nosnap = 0; /* no 802.2 LLC */ 1255 return; 1256 #endif 1257 1258 case DLT_JUNIPER_MFR: 1259 case DLT_JUNIPER_MLFR: 1260 case DLT_JUNIPER_MLPPP: 1261 case DLT_JUNIPER_PPP: 1262 case DLT_JUNIPER_CHDLC: 1263 case DLT_JUNIPER_FRELAY: 1264 off_linktype = 4; 1265 off_macpl = 4; 1266 off_nl = 0; 1267 off_nl_nosnap = -1; /* no 802.2 LLC */ 1268 return; 1269 1270 case DLT_JUNIPER_ATM1: 1271 off_linktype = 4; /* in reality variable between 4-8 */ 1272 off_macpl = 4; /* in reality variable between 4-8 */ 1273 off_nl = 0; 1274 off_nl_nosnap = 10; 1275 return; 1276 1277 case DLT_JUNIPER_ATM2: 1278 off_linktype = 8; /* in reality variable between 8-12 */ 1279 off_macpl = 8; /* in reality variable between 8-12 */ 1280 off_nl = 0; 1281 off_nl_nosnap = 10; 1282 return; 1283 1284 /* frames captured on a Juniper PPPoE service PIC 1285 * contain raw ethernet frames */ 1286 case DLT_JUNIPER_PPPOE: 1287 case DLT_JUNIPER_ETHER: 1288 off_macpl = 14; 1289 off_linktype = 16; 1290 off_nl = 18; /* Ethernet II */ 1291 off_nl_nosnap = 21; /* 802.3+802.2 */ 1292 return; 1293 1294 case DLT_JUNIPER_PPPOE_ATM: 1295 off_linktype = 4; 1296 off_macpl = 6; 1297 off_nl = 0; 1298 off_nl_nosnap = -1; /* no 802.2 LLC */ 1299 return; 1300 1301 case DLT_JUNIPER_GGSN: 1302 off_linktype = 6; 1303 off_macpl = 12; 1304 off_nl = 0; 1305 off_nl_nosnap = -1; /* no 802.2 LLC */ 1306 return; 1307 1308 case DLT_JUNIPER_ES: 1309 off_linktype = 6; 1310 off_macpl = -1; /* not really a network layer but raw IP addresses */ 1311 off_nl = -1; /* not really a network layer but raw IP addresses */ 1312 off_nl_nosnap = -1; /* no 802.2 LLC */ 1313 return; 1314 1315 case DLT_JUNIPER_MONITOR: 1316 off_linktype = 12; 1317 off_macpl = 12; 1318 off_nl = 0; /* raw IP/IP6 header */ 1319 off_nl_nosnap = -1; /* no 802.2 LLC */ 1320 return; 1321 1322 case DLT_JUNIPER_SERVICES: 1323 off_linktype = 12; 1324 off_macpl = -1; /* L3 proto location dep. on cookie type */ 1325 off_nl = -1; /* L3 proto location dep. on cookie type */ 1326 off_nl_nosnap = -1; /* no 802.2 LLC */ 1327 return; 1328 1329 case DLT_JUNIPER_VP: 1330 off_linktype = 18; 1331 off_macpl = -1; 1332 off_nl = -1; 1333 off_nl_nosnap = -1; 1334 return; 1335 1336 case DLT_JUNIPER_ST: 1337 off_linktype = 18; 1338 off_macpl = -1; 1339 off_nl = -1; 1340 off_nl_nosnap = -1; 1341 return; 1342 1343 case DLT_JUNIPER_ISM: 1344 off_linktype = 8; 1345 off_macpl = -1; 1346 off_nl = -1; 1347 off_nl_nosnap = -1; 1348 return; 1349 1350 case DLT_JUNIPER_VS: 1351 case DLT_JUNIPER_SRX_E2E: 1352 case DLT_JUNIPER_FIBRECHANNEL: 1353 case DLT_JUNIPER_ATM_CEMIC: 1354 off_linktype = 8; 1355 off_macpl = -1; 1356 off_nl = -1; 1357 off_nl_nosnap = -1; 1358 return; 1359 1360 case DLT_MTP2: 1361 off_li = 2; 1362 off_sio = 3; 1363 off_opc = 4; 1364 off_dpc = 4; 1365 off_sls = 7; 1366 off_linktype = -1; 1367 off_macpl = -1; 1368 off_nl = -1; 1369 off_nl_nosnap = -1; 1370 return; 1371 1372 case DLT_MTP2_WITH_PHDR: 1373 off_li = 6; 1374 off_sio = 7; 1375 off_opc = 8; 1376 off_dpc = 8; 1377 off_sls = 11; 1378 off_linktype = -1; 1379 off_macpl = -1; 1380 off_nl = -1; 1381 off_nl_nosnap = -1; 1382 return; 1383 1384 case DLT_ERF: 1385 off_li = 22; 1386 off_sio = 23; 1387 off_opc = 24; 1388 off_dpc = 24; 1389 off_sls = 27; 1390 off_linktype = -1; 1391 off_macpl = -1; 1392 off_nl = -1; 1393 off_nl_nosnap = -1; 1394 return; 1395 1396 #ifdef DLT_PFSYNC 1397 case DLT_PFSYNC: 1398 off_linktype = -1; 1399 off_macpl = 4; 1400 off_nl = 0; 1401 off_nl_nosnap = 0; 1402 return; 1403 #endif 1404 1405 case DLT_AX25_KISS: 1406 /* 1407 * Currently, only raw "link[N:M]" filtering is supported. 1408 */ 1409 off_linktype = -1; /* variable, min 15, max 71 steps of 7 */ 1410 off_macpl = -1; 1411 off_nl = -1; /* variable, min 16, max 71 steps of 7 */ 1412 off_nl_nosnap = -1; /* no 802.2 LLC */ 1413 off_mac = 1; /* step over the kiss length byte */ 1414 return; 1415 1416 case DLT_IPNET: 1417 off_linktype = 1; 1418 off_macpl = 24; /* ipnet header length */ 1419 off_nl = 0; 1420 off_nl_nosnap = -1; 1421 return; 1422 1423 case DLT_NETANALYZER: 1424 off_mac = 4; /* MAC header is past 4-byte pseudo-header */ 1425 off_linktype = 16; /* includes 4-byte pseudo-header */ 1426 off_macpl = 18; /* pseudo-header+Ethernet header length */ 1427 off_nl = 0; /* Ethernet II */ 1428 off_nl_nosnap = 3; /* 802.3+802.2 */ 1429 return; 1430 1431 case DLT_NETANALYZER_TRANSPARENT: 1432 off_mac = 12; /* MAC header is past 4-byte pseudo-header, preamble, and SFD */ 1433 off_linktype = 24; /* includes 4-byte pseudo-header+preamble+SFD */ 1434 off_macpl = 26; /* pseudo-header+preamble+SFD+Ethernet header length */ 1435 off_nl = 0; /* Ethernet II */ 1436 off_nl_nosnap = 3; /* 802.3+802.2 */ 1437 return; 1438 1439 default: 1440 /* 1441 * For values in the range in which we've assigned new 1442 * DLT_ values, only raw "link[N:M]" filtering is supported. 1443 */ 1444 if (linktype >= DLT_MATCHING_MIN && 1445 linktype <= DLT_MATCHING_MAX) { 1446 off_linktype = -1; 1447 off_macpl = -1; 1448 off_nl = -1; 1449 off_nl_nosnap = -1; 1450 return; 1451 } 1452 1453 } 1454 bpf_error("unknown data link type %d", linktype); 1455 /* NOTREACHED */ 1456 } 1457 1458 /* 1459 * Load a value relative to the beginning of the link-layer header. 1460 * The link-layer header doesn't necessarily begin at the beginning 1461 * of the packet data; there might be a variable-length prefix containing 1462 * radio information. 1463 */ 1464 static struct slist * 1465 gen_load_llrel(offset, size) 1466 u_int offset, size; 1467 { 1468 struct slist *s, *s2; 1469 1470 s = gen_llprefixlen(); 1471 1472 /* 1473 * If "s" is non-null, it has code to arrange that the X register 1474 * contains the length of the prefix preceding the link-layer 1475 * header. 1476 * 1477 * Otherwise, the length of the prefix preceding the link-layer 1478 * header is "off_ll". 1479 */ 1480 if (s != NULL) { 1481 /* 1482 * There's a variable-length prefix preceding the 1483 * link-layer header. "s" points to a list of statements 1484 * that put the length of that prefix into the X register. 1485 * do an indirect load, to use the X register as an offset. 1486 */ 1487 s2 = new_stmt(BPF_LD|BPF_IND|size); 1488 s2->s.k = offset; 1489 sappend(s, s2); 1490 } else { 1491 /* 1492 * There is no variable-length header preceding the 1493 * link-layer header; add in off_ll, which, if there's 1494 * a fixed-length header preceding the link-layer header, 1495 * is the length of that header. 1496 */ 1497 s = new_stmt(BPF_LD|BPF_ABS|size); 1498 s->s.k = offset + off_ll; 1499 } 1500 return s; 1501 } 1502 1503 /* 1504 * Load a value relative to the beginning of the MAC-layer payload. 1505 */ 1506 static struct slist * 1507 gen_load_macplrel(offset, size) 1508 u_int offset, size; 1509 { 1510 struct slist *s, *s2; 1511 1512 s = gen_off_macpl(); 1513 1514 /* 1515 * If s is non-null, the offset of the MAC-layer payload is 1516 * variable, and s points to a list of instructions that 1517 * arrange that the X register contains that offset. 1518 * 1519 * Otherwise, the offset of the MAC-layer payload is constant, 1520 * and is in off_macpl. 1521 */ 1522 if (s != NULL) { 1523 /* 1524 * The offset of the MAC-layer payload is in the X 1525 * register. Do an indirect load, to use the X register 1526 * as an offset. 1527 */ 1528 s2 = new_stmt(BPF_LD|BPF_IND|size); 1529 s2->s.k = offset; 1530 sappend(s, s2); 1531 } else { 1532 /* 1533 * The offset of the MAC-layer payload is constant, 1534 * and is in off_macpl; load the value at that offset 1535 * plus the specified offset. 1536 */ 1537 s = new_stmt(BPF_LD|BPF_ABS|size); 1538 s->s.k = off_macpl + offset; 1539 } 1540 return s; 1541 } 1542 1543 /* 1544 * Load a value relative to the beginning of the specified header. 1545 */ 1546 static struct slist * 1547 gen_load_a(offrel, offset, size) 1548 enum e_offrel offrel; 1549 u_int offset, size; 1550 { 1551 struct slist *s, *s2; 1552 1553 switch (offrel) { 1554 1555 case OR_PACKET: 1556 s = new_stmt(BPF_LD|BPF_ABS|size); 1557 s->s.k = offset; 1558 break; 1559 1560 case OR_LINK: 1561 s = gen_load_llrel(offset, size); 1562 break; 1563 1564 case OR_MACPL: 1565 s = gen_load_macplrel(offset, size); 1566 break; 1567 1568 case OR_NET: 1569 s = gen_load_macplrel(off_nl + offset, size); 1570 break; 1571 1572 case OR_NET_NOSNAP: 1573 s = gen_load_macplrel(off_nl_nosnap + offset, size); 1574 break; 1575 1576 case OR_TRAN_IPV4: 1577 /* 1578 * Load the X register with the length of the IPv4 header 1579 * (plus the offset of the link-layer header, if it's 1580 * preceded by a variable-length header such as a radio 1581 * header), in bytes. 1582 */ 1583 s = gen_loadx_iphdrlen(); 1584 1585 /* 1586 * Load the item at {offset of the MAC-layer payload} + 1587 * {offset, relative to the start of the MAC-layer 1588 * paylod, of the IPv4 header} + {length of the IPv4 header} + 1589 * {specified offset}. 1590 * 1591 * (If the offset of the MAC-layer payload is variable, 1592 * it's included in the value in the X register, and 1593 * off_macpl is 0.) 1594 */ 1595 s2 = new_stmt(BPF_LD|BPF_IND|size); 1596 s2->s.k = off_macpl + off_nl + offset; 1597 sappend(s, s2); 1598 break; 1599 1600 case OR_TRAN_IPV6: 1601 s = gen_load_macplrel(off_nl + 40 + offset, size); 1602 break; 1603 1604 default: 1605 abort(); 1606 return NULL; 1607 } 1608 return s; 1609 } 1610 1611 /* 1612 * Generate code to load into the X register the sum of the length of 1613 * the IPv4 header and any variable-length header preceding the link-layer 1614 * header. 1615 */ 1616 static struct slist * 1617 gen_loadx_iphdrlen() 1618 { 1619 struct slist *s, *s2; 1620 1621 s = gen_off_macpl(); 1622 if (s != NULL) { 1623 /* 1624 * There's a variable-length prefix preceding the 1625 * link-layer header, or the link-layer header is itself 1626 * variable-length. "s" points to a list of statements 1627 * that put the offset of the MAC-layer payload into 1628 * the X register. 1629 * 1630 * The 4*([k]&0xf) addressing mode can't be used, as we 1631 * don't have a constant offset, so we have to load the 1632 * value in question into the A register and add to it 1633 * the value from the X register. 1634 */ 1635 s2 = new_stmt(BPF_LD|BPF_IND|BPF_B); 1636 s2->s.k = off_nl; 1637 sappend(s, s2); 1638 s2 = new_stmt(BPF_ALU|BPF_AND|BPF_K); 1639 s2->s.k = 0xf; 1640 sappend(s, s2); 1641 s2 = new_stmt(BPF_ALU|BPF_LSH|BPF_K); 1642 s2->s.k = 2; 1643 sappend(s, s2); 1644 1645 /* 1646 * The A register now contains the length of the 1647 * IP header. We need to add to it the offset of 1648 * the MAC-layer payload, which is still in the X 1649 * register, and move the result into the X register. 1650 */ 1651 sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X)); 1652 sappend(s, new_stmt(BPF_MISC|BPF_TAX)); 1653 } else { 1654 /* 1655 * There is no variable-length header preceding the 1656 * link-layer header, and the link-layer header is 1657 * fixed-length; load the length of the IPv4 header, 1658 * which is at an offset of off_nl from the beginning 1659 * of the MAC-layer payload, and thus at an offset 1660 * of off_mac_pl + off_nl from the beginning of the 1661 * raw packet data. 1662 */ 1663 s = new_stmt(BPF_LDX|BPF_MSH|BPF_B); 1664 s->s.k = off_macpl + off_nl; 1665 } 1666 return s; 1667 } 1668 1669 static struct block * 1670 gen_uncond(rsense) 1671 int rsense; 1672 { 1673 struct block *b; 1674 struct slist *s; 1675 1676 s = new_stmt(BPF_LD|BPF_IMM); 1677 s->s.k = !rsense; 1678 b = new_block(JMP(BPF_JEQ)); 1679 b->stmts = s; 1680 1681 return b; 1682 } 1683 1684 static inline struct block * 1685 gen_true() 1686 { 1687 return gen_uncond(1); 1688 } 1689 1690 static inline struct block * 1691 gen_false() 1692 { 1693 return gen_uncond(0); 1694 } 1695 1696 /* 1697 * Byte-swap a 32-bit number. 1698 * ("htonl()" or "ntohl()" won't work - we want to byte-swap even on 1699 * big-endian platforms.) 1700 */ 1701 #define SWAPLONG(y) \ 1702 ((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff)) 1703 1704 /* 1705 * Generate code to match a particular packet type. 1706 * 1707 * "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP 1708 * value, if <= ETHERMTU. We use that to determine whether to 1709 * match the type/length field or to check the type/length field for 1710 * a value <= ETHERMTU to see whether it's a type field and then do 1711 * the appropriate test. 1712 */ 1713 static struct block * 1714 gen_ether_linktype(proto) 1715 register int proto; 1716 { 1717 struct block *b0, *b1; 1718 1719 switch (proto) { 1720 1721 case LLCSAP_ISONS: 1722 case LLCSAP_IP: 1723 case LLCSAP_NETBEUI: 1724 /* 1725 * OSI protocols and NetBEUI always use 802.2 encapsulation, 1726 * so we check the DSAP and SSAP. 1727 * 1728 * LLCSAP_IP checks for IP-over-802.2, rather 1729 * than IP-over-Ethernet or IP-over-SNAP. 1730 * 1731 * XXX - should we check both the DSAP and the 1732 * SSAP, like this, or should we check just the 1733 * DSAP, as we do for other types <= ETHERMTU 1734 * (i.e., other SAP values)? 1735 */ 1736 b0 = gen_cmp_gt(OR_LINK, off_linktype, BPF_H, ETHERMTU); 1737 gen_not(b0); 1738 b1 = gen_cmp(OR_MACPL, 0, BPF_H, (bpf_int32) 1739 ((proto << 8) | proto)); 1740 gen_and(b0, b1); 1741 return b1; 1742 1743 case LLCSAP_IPX: 1744 /* 1745 * Check for; 1746 * 1747 * Ethernet_II frames, which are Ethernet 1748 * frames with a frame type of ETHERTYPE_IPX; 1749 * 1750 * Ethernet_802.3 frames, which are 802.3 1751 * frames (i.e., the type/length field is 1752 * a length field, <= ETHERMTU, rather than 1753 * a type field) with the first two bytes 1754 * after the Ethernet/802.3 header being 1755 * 0xFFFF; 1756 * 1757 * Ethernet_802.2 frames, which are 802.3 1758 * frames with an 802.2 LLC header and 1759 * with the IPX LSAP as the DSAP in the LLC 1760 * header; 1761 * 1762 * Ethernet_SNAP frames, which are 802.3 1763 * frames with an LLC header and a SNAP 1764 * header and with an OUI of 0x000000 1765 * (encapsulated Ethernet) and a protocol 1766 * ID of ETHERTYPE_IPX in the SNAP header. 1767 * 1768 * XXX - should we generate the same code both 1769 * for tests for LLCSAP_IPX and for ETHERTYPE_IPX? 1770 */ 1771 1772 /* 1773 * This generates code to check both for the 1774 * IPX LSAP (Ethernet_802.2) and for Ethernet_802.3. 1775 */ 1776 b0 = gen_cmp(OR_MACPL, 0, BPF_B, (bpf_int32)LLCSAP_IPX); 1777 b1 = gen_cmp(OR_MACPL, 0, BPF_H, (bpf_int32)0xFFFF); 1778 gen_or(b0, b1); 1779 1780 /* 1781 * Now we add code to check for SNAP frames with 1782 * ETHERTYPE_IPX, i.e. Ethernet_SNAP. 1783 */ 1784 b0 = gen_snap(0x000000, ETHERTYPE_IPX); 1785 gen_or(b0, b1); 1786 1787 /* 1788 * Now we generate code to check for 802.3 1789 * frames in general. 1790 */ 1791 b0 = gen_cmp_gt(OR_LINK, off_linktype, BPF_H, ETHERMTU); 1792 gen_not(b0); 1793 1794 /* 1795 * Now add the check for 802.3 frames before the 1796 * check for Ethernet_802.2 and Ethernet_802.3, 1797 * as those checks should only be done on 802.3 1798 * frames, not on Ethernet frames. 1799 */ 1800 gen_and(b0, b1); 1801 1802 /* 1803 * Now add the check for Ethernet_II frames, and 1804 * do that before checking for the other frame 1805 * types. 1806 */ 1807 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, 1808 (bpf_int32)ETHERTYPE_IPX); 1809 gen_or(b0, b1); 1810 return b1; 1811 1812 case ETHERTYPE_ATALK: 1813 case ETHERTYPE_AARP: 1814 /* 1815 * EtherTalk (AppleTalk protocols on Ethernet link 1816 * layer) may use 802.2 encapsulation. 1817 */ 1818 1819 /* 1820 * Check for 802.2 encapsulation (EtherTalk phase 2?); 1821 * we check for an Ethernet type field less than 1822 * 1500, which means it's an 802.3 length field. 1823 */ 1824 b0 = gen_cmp_gt(OR_LINK, off_linktype, BPF_H, ETHERMTU); 1825 gen_not(b0); 1826 1827 /* 1828 * 802.2-encapsulated ETHERTYPE_ATALK packets are 1829 * SNAP packets with an organization code of 1830 * 0x080007 (Apple, for Appletalk) and a protocol 1831 * type of ETHERTYPE_ATALK (Appletalk). 1832 * 1833 * 802.2-encapsulated ETHERTYPE_AARP packets are 1834 * SNAP packets with an organization code of 1835 * 0x000000 (encapsulated Ethernet) and a protocol 1836 * type of ETHERTYPE_AARP (Appletalk ARP). 1837 */ 1838 if (proto == ETHERTYPE_ATALK) 1839 b1 = gen_snap(0x080007, ETHERTYPE_ATALK); 1840 else /* proto == ETHERTYPE_AARP */ 1841 b1 = gen_snap(0x000000, ETHERTYPE_AARP); 1842 gen_and(b0, b1); 1843 1844 /* 1845 * Check for Ethernet encapsulation (Ethertalk 1846 * phase 1?); we just check for the Ethernet 1847 * protocol type. 1848 */ 1849 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, (bpf_int32)proto); 1850 1851 gen_or(b0, b1); 1852 return b1; 1853 1854 default: 1855 if (proto <= ETHERMTU) { 1856 /* 1857 * This is an LLC SAP value, so the frames 1858 * that match would be 802.2 frames. 1859 * Check that the frame is an 802.2 frame 1860 * (i.e., that the length/type field is 1861 * a length field, <= ETHERMTU) and 1862 * then check the DSAP. 1863 */ 1864 b0 = gen_cmp_gt(OR_LINK, off_linktype, BPF_H, ETHERMTU); 1865 gen_not(b0); 1866 b1 = gen_cmp(OR_LINK, off_linktype + 2, BPF_B, 1867 (bpf_int32)proto); 1868 gen_and(b0, b1); 1869 return b1; 1870 } else { 1871 /* 1872 * This is an Ethernet type, so compare 1873 * the length/type field with it (if 1874 * the frame is an 802.2 frame, the length 1875 * field will be <= ETHERMTU, and, as 1876 * "proto" is > ETHERMTU, this test 1877 * will fail and the frame won't match, 1878 * which is what we want). 1879 */ 1880 return gen_cmp(OR_LINK, off_linktype, BPF_H, 1881 (bpf_int32)proto); 1882 } 1883 } 1884 } 1885 1886 /* 1887 * "proto" is an Ethernet type value and for IPNET, if it is not IPv4 1888 * or IPv6 then we have an error. 1889 */ 1890 static struct block * 1891 gen_ipnet_linktype(proto) 1892 register int proto; 1893 { 1894 switch (proto) { 1895 1896 case ETHERTYPE_IP: 1897 return gen_cmp(OR_LINK, off_linktype, BPF_B, 1898 (bpf_int32)IPH_AF_INET); 1899 /* NOTREACHED */ 1900 1901 case ETHERTYPE_IPV6: 1902 return gen_cmp(OR_LINK, off_linktype, BPF_B, 1903 (bpf_int32)IPH_AF_INET6); 1904 /* NOTREACHED */ 1905 1906 default: 1907 break; 1908 } 1909 1910 return gen_false(); 1911 } 1912 1913 /* 1914 * Generate code to match a particular packet type. 1915 * 1916 * "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP 1917 * value, if <= ETHERMTU. We use that to determine whether to 1918 * match the type field or to check the type field for the special 1919 * LINUX_SLL_P_802_2 value and then do the appropriate test. 1920 */ 1921 static struct block * 1922 gen_linux_sll_linktype(proto) 1923 register int proto; 1924 { 1925 struct block *b0, *b1; 1926 1927 switch (proto) { 1928 1929 case LLCSAP_ISONS: 1930 case LLCSAP_IP: 1931 case LLCSAP_NETBEUI: 1932 /* 1933 * OSI protocols and NetBEUI always use 802.2 encapsulation, 1934 * so we check the DSAP and SSAP. 1935 * 1936 * LLCSAP_IP checks for IP-over-802.2, rather 1937 * than IP-over-Ethernet or IP-over-SNAP. 1938 * 1939 * XXX - should we check both the DSAP and the 1940 * SSAP, like this, or should we check just the 1941 * DSAP, as we do for other types <= ETHERMTU 1942 * (i.e., other SAP values)? 1943 */ 1944 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, LINUX_SLL_P_802_2); 1945 b1 = gen_cmp(OR_MACPL, 0, BPF_H, (bpf_int32) 1946 ((proto << 8) | proto)); 1947 gen_and(b0, b1); 1948 return b1; 1949 1950 case LLCSAP_IPX: 1951 /* 1952 * Ethernet_II frames, which are Ethernet 1953 * frames with a frame type of ETHERTYPE_IPX; 1954 * 1955 * Ethernet_802.3 frames, which have a frame 1956 * type of LINUX_SLL_P_802_3; 1957 * 1958 * Ethernet_802.2 frames, which are 802.3 1959 * frames with an 802.2 LLC header (i.e, have 1960 * a frame type of LINUX_SLL_P_802_2) and 1961 * with the IPX LSAP as the DSAP in the LLC 1962 * header; 1963 * 1964 * Ethernet_SNAP frames, which are 802.3 1965 * frames with an LLC header and a SNAP 1966 * header and with an OUI of 0x000000 1967 * (encapsulated Ethernet) and a protocol 1968 * ID of ETHERTYPE_IPX in the SNAP header. 1969 * 1970 * First, do the checks on LINUX_SLL_P_802_2 1971 * frames; generate the check for either 1972 * Ethernet_802.2 or Ethernet_SNAP frames, and 1973 * then put a check for LINUX_SLL_P_802_2 frames 1974 * before it. 1975 */ 1976 b0 = gen_cmp(OR_MACPL, 0, BPF_B, (bpf_int32)LLCSAP_IPX); 1977 b1 = gen_snap(0x000000, ETHERTYPE_IPX); 1978 gen_or(b0, b1); 1979 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, LINUX_SLL_P_802_2); 1980 gen_and(b0, b1); 1981 1982 /* 1983 * Now check for 802.3 frames and OR that with 1984 * the previous test. 1985 */ 1986 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, LINUX_SLL_P_802_3); 1987 gen_or(b0, b1); 1988 1989 /* 1990 * Now add the check for Ethernet_II frames, and 1991 * do that before checking for the other frame 1992 * types. 1993 */ 1994 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, 1995 (bpf_int32)ETHERTYPE_IPX); 1996 gen_or(b0, b1); 1997 return b1; 1998 1999 case ETHERTYPE_ATALK: 2000 case ETHERTYPE_AARP: 2001 /* 2002 * EtherTalk (AppleTalk protocols on Ethernet link 2003 * layer) may use 802.2 encapsulation. 2004 */ 2005 2006 /* 2007 * Check for 802.2 encapsulation (EtherTalk phase 2?); 2008 * we check for the 802.2 protocol type in the 2009 * "Ethernet type" field. 2010 */ 2011 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, LINUX_SLL_P_802_2); 2012 2013 /* 2014 * 802.2-encapsulated ETHERTYPE_ATALK packets are 2015 * SNAP packets with an organization code of 2016 * 0x080007 (Apple, for Appletalk) and a protocol 2017 * type of ETHERTYPE_ATALK (Appletalk). 2018 * 2019 * 802.2-encapsulated ETHERTYPE_AARP packets are 2020 * SNAP packets with an organization code of 2021 * 0x000000 (encapsulated Ethernet) and a protocol 2022 * type of ETHERTYPE_AARP (Appletalk ARP). 2023 */ 2024 if (proto == ETHERTYPE_ATALK) 2025 b1 = gen_snap(0x080007, ETHERTYPE_ATALK); 2026 else /* proto == ETHERTYPE_AARP */ 2027 b1 = gen_snap(0x000000, ETHERTYPE_AARP); 2028 gen_and(b0, b1); 2029 2030 /* 2031 * Check for Ethernet encapsulation (Ethertalk 2032 * phase 1?); we just check for the Ethernet 2033 * protocol type. 2034 */ 2035 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, (bpf_int32)proto); 2036 2037 gen_or(b0, b1); 2038 return b1; 2039 2040 default: 2041 if (proto <= ETHERMTU) { 2042 /* 2043 * This is an LLC SAP value, so the frames 2044 * that match would be 802.2 frames. 2045 * Check for the 802.2 protocol type 2046 * in the "Ethernet type" field, and 2047 * then check the DSAP. 2048 */ 2049 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, 2050 LINUX_SLL_P_802_2); 2051 b1 = gen_cmp(OR_LINK, off_macpl, BPF_B, 2052 (bpf_int32)proto); 2053 gen_and(b0, b1); 2054 return b1; 2055 } else { 2056 /* 2057 * This is an Ethernet type, so compare 2058 * the length/type field with it (if 2059 * the frame is an 802.2 frame, the length 2060 * field will be <= ETHERMTU, and, as 2061 * "proto" is > ETHERMTU, this test 2062 * will fail and the frame won't match, 2063 * which is what we want). 2064 */ 2065 return gen_cmp(OR_LINK, off_linktype, BPF_H, 2066 (bpf_int32)proto); 2067 } 2068 } 2069 } 2070 2071 static struct slist * 2072 gen_load_prism_llprefixlen() 2073 { 2074 struct slist *s1, *s2; 2075 struct slist *sjeq_avs_cookie; 2076 struct slist *sjcommon; 2077 2078 /* 2079 * This code is not compatible with the optimizer, as 2080 * we are generating jmp instructions within a normal 2081 * slist of instructions 2082 */ 2083 no_optimize = 1; 2084 2085 /* 2086 * Generate code to load the length of the radio header into 2087 * the register assigned to hold that length, if one has been 2088 * assigned. (If one hasn't been assigned, no code we've 2089 * generated uses that prefix, so we don't need to generate any 2090 * code to load it.) 2091 * 2092 * Some Linux drivers use ARPHRD_IEEE80211_PRISM but sometimes 2093 * or always use the AVS header rather than the Prism header. 2094 * We load a 4-byte big-endian value at the beginning of the 2095 * raw packet data, and see whether, when masked with 0xFFFFF000, 2096 * it's equal to 0x80211000. If so, that indicates that it's 2097 * an AVS header (the masked-out bits are the version number). 2098 * Otherwise, it's a Prism header. 2099 * 2100 * XXX - the Prism header is also, in theory, variable-length, 2101 * but no known software generates headers that aren't 144 2102 * bytes long. 2103 */ 2104 if (reg_off_ll != -1) { 2105 /* 2106 * Load the cookie. 2107 */ 2108 s1 = new_stmt(BPF_LD|BPF_W|BPF_ABS); 2109 s1->s.k = 0; 2110 2111 /* 2112 * AND it with 0xFFFFF000. 2113 */ 2114 s2 = new_stmt(BPF_ALU|BPF_AND|BPF_K); 2115 s2->s.k = 0xFFFFF000; 2116 sappend(s1, s2); 2117 2118 /* 2119 * Compare with 0x80211000. 2120 */ 2121 sjeq_avs_cookie = new_stmt(JMP(BPF_JEQ)); 2122 sjeq_avs_cookie->s.k = 0x80211000; 2123 sappend(s1, sjeq_avs_cookie); 2124 2125 /* 2126 * If it's AVS: 2127 * 2128 * The 4 bytes at an offset of 4 from the beginning of 2129 * the AVS header are the length of the AVS header. 2130 * That field is big-endian. 2131 */ 2132 s2 = new_stmt(BPF_LD|BPF_W|BPF_ABS); 2133 s2->s.k = 4; 2134 sappend(s1, s2); 2135 sjeq_avs_cookie->s.jt = s2; 2136 2137 /* 2138 * Now jump to the code to allocate a register 2139 * into which to save the header length and 2140 * store the length there. (The "jump always" 2141 * instruction needs to have the k field set; 2142 * it's added to the PC, so, as we're jumping 2143 * over a single instruction, it should be 1.) 2144 */ 2145 sjcommon = new_stmt(JMP(BPF_JA)); 2146 sjcommon->s.k = 1; 2147 sappend(s1, sjcommon); 2148 2149 /* 2150 * Now for the code that handles the Prism header. 2151 * Just load the length of the Prism header (144) 2152 * into the A register. Have the test for an AVS 2153 * header branch here if we don't have an AVS header. 2154 */ 2155 s2 = new_stmt(BPF_LD|BPF_W|BPF_IMM); 2156 s2->s.k = 144; 2157 sappend(s1, s2); 2158 sjeq_avs_cookie->s.jf = s2; 2159 2160 /* 2161 * Now allocate a register to hold that value and store 2162 * it. The code for the AVS header will jump here after 2163 * loading the length of the AVS header. 2164 */ 2165 s2 = new_stmt(BPF_ST); 2166 s2->s.k = reg_off_ll; 2167 sappend(s1, s2); 2168 sjcommon->s.jf = s2; 2169 2170 /* 2171 * Now move it into the X register. 2172 */ 2173 s2 = new_stmt(BPF_MISC|BPF_TAX); 2174 sappend(s1, s2); 2175 2176 return (s1); 2177 } else 2178 return (NULL); 2179 } 2180 2181 static struct slist * 2182 gen_load_avs_llprefixlen() 2183 { 2184 struct slist *s1, *s2; 2185 2186 /* 2187 * Generate code to load the length of the AVS header into 2188 * the register assigned to hold that length, if one has been 2189 * assigned. (If one hasn't been assigned, no code we've 2190 * generated uses that prefix, so we don't need to generate any 2191 * code to load it.) 2192 */ 2193 if (reg_off_ll != -1) { 2194 /* 2195 * The 4 bytes at an offset of 4 from the beginning of 2196 * the AVS header are the length of the AVS header. 2197 * That field is big-endian. 2198 */ 2199 s1 = new_stmt(BPF_LD|BPF_W|BPF_ABS); 2200 s1->s.k = 4; 2201 2202 /* 2203 * Now allocate a register to hold that value and store 2204 * it. 2205 */ 2206 s2 = new_stmt(BPF_ST); 2207 s2->s.k = reg_off_ll; 2208 sappend(s1, s2); 2209 2210 /* 2211 * Now move it into the X register. 2212 */ 2213 s2 = new_stmt(BPF_MISC|BPF_TAX); 2214 sappend(s1, s2); 2215 2216 return (s1); 2217 } else 2218 return (NULL); 2219 } 2220 2221 static struct slist * 2222 gen_load_radiotap_llprefixlen() 2223 { 2224 struct slist *s1, *s2; 2225 2226 /* 2227 * Generate code to load the length of the radiotap header into 2228 * the register assigned to hold that length, if one has been 2229 * assigned. (If one hasn't been assigned, no code we've 2230 * generated uses that prefix, so we don't need to generate any 2231 * code to load it.) 2232 */ 2233 if (reg_off_ll != -1) { 2234 /* 2235 * The 2 bytes at offsets of 2 and 3 from the beginning 2236 * of the radiotap header are the length of the radiotap 2237 * header; unfortunately, it's little-endian, so we have 2238 * to load it a byte at a time and construct the value. 2239 */ 2240 2241 /* 2242 * Load the high-order byte, at an offset of 3, shift it 2243 * left a byte, and put the result in the X register. 2244 */ 2245 s1 = new_stmt(BPF_LD|BPF_B|BPF_ABS); 2246 s1->s.k = 3; 2247 s2 = new_stmt(BPF_ALU|BPF_LSH|BPF_K); 2248 sappend(s1, s2); 2249 s2->s.k = 8; 2250 s2 = new_stmt(BPF_MISC|BPF_TAX); 2251 sappend(s1, s2); 2252 2253 /* 2254 * Load the next byte, at an offset of 2, and OR the 2255 * value from the X register into it. 2256 */ 2257 s2 = new_stmt(BPF_LD|BPF_B|BPF_ABS); 2258 sappend(s1, s2); 2259 s2->s.k = 2; 2260 s2 = new_stmt(BPF_ALU|BPF_OR|BPF_X); 2261 sappend(s1, s2); 2262 2263 /* 2264 * Now allocate a register to hold that value and store 2265 * it. 2266 */ 2267 s2 = new_stmt(BPF_ST); 2268 s2->s.k = reg_off_ll; 2269 sappend(s1, s2); 2270 2271 /* 2272 * Now move it into the X register. 2273 */ 2274 s2 = new_stmt(BPF_MISC|BPF_TAX); 2275 sappend(s1, s2); 2276 2277 return (s1); 2278 } else 2279 return (NULL); 2280 } 2281 2282 /* 2283 * At the moment we treat PPI as normal Radiotap encoded 2284 * packets. The difference is in the function that generates 2285 * the code at the beginning to compute the header length. 2286 * Since this code generator of PPI supports bare 802.11 2287 * encapsulation only (i.e. the encapsulated DLT should be 2288 * DLT_IEEE802_11) we generate code to check for this too; 2289 * that's done in finish_parse(). 2290 */ 2291 static struct slist * 2292 gen_load_ppi_llprefixlen() 2293 { 2294 struct slist *s1, *s2; 2295 2296 /* 2297 * Generate code to load the length of the radiotap header 2298 * into the register assigned to hold that length, if one has 2299 * been assigned. 2300 */ 2301 if (reg_off_ll != -1) { 2302 /* 2303 * The 2 bytes at offsets of 2 and 3 from the beginning 2304 * of the radiotap header are the length of the radiotap 2305 * header; unfortunately, it's little-endian, so we have 2306 * to load it a byte at a time and construct the value. 2307 */ 2308 2309 /* 2310 * Load the high-order byte, at an offset of 3, shift it 2311 * left a byte, and put the result in the X register. 2312 */ 2313 s1 = new_stmt(BPF_LD|BPF_B|BPF_ABS); 2314 s1->s.k = 3; 2315 s2 = new_stmt(BPF_ALU|BPF_LSH|BPF_K); 2316 sappend(s1, s2); 2317 s2->s.k = 8; 2318 s2 = new_stmt(BPF_MISC|BPF_TAX); 2319 sappend(s1, s2); 2320 2321 /* 2322 * Load the next byte, at an offset of 2, and OR the 2323 * value from the X register into it. 2324 */ 2325 s2 = new_stmt(BPF_LD|BPF_B|BPF_ABS); 2326 sappend(s1, s2); 2327 s2->s.k = 2; 2328 s2 = new_stmt(BPF_ALU|BPF_OR|BPF_X); 2329 sappend(s1, s2); 2330 2331 /* 2332 * Now allocate a register to hold that value and store 2333 * it. 2334 */ 2335 s2 = new_stmt(BPF_ST); 2336 s2->s.k = reg_off_ll; 2337 sappend(s1, s2); 2338 2339 /* 2340 * Now move it into the X register. 2341 */ 2342 s2 = new_stmt(BPF_MISC|BPF_TAX); 2343 sappend(s1, s2); 2344 2345 return (s1); 2346 } else 2347 return (NULL); 2348 } 2349 2350 /* 2351 * Load a value relative to the beginning of the link-layer header after the 802.11 2352 * header, i.e. LLC_SNAP. 2353 * The link-layer header doesn't necessarily begin at the beginning 2354 * of the packet data; there might be a variable-length prefix containing 2355 * radio information. 2356 */ 2357 static struct slist * 2358 gen_load_802_11_header_len(struct slist *s, struct slist *snext) 2359 { 2360 struct slist *s2; 2361 struct slist *sjset_data_frame_1; 2362 struct slist *sjset_data_frame_2; 2363 struct slist *sjset_qos; 2364 struct slist *sjset_radiotap_flags; 2365 struct slist *sjset_radiotap_tsft; 2366 struct slist *sjset_tsft_datapad, *sjset_notsft_datapad; 2367 struct slist *s_roundup; 2368 2369 if (reg_off_macpl == -1) { 2370 /* 2371 * No register has been assigned to the offset of 2372 * the MAC-layer payload, which means nobody needs 2373 * it; don't bother computing it - just return 2374 * what we already have. 2375 */ 2376 return (s); 2377 } 2378 2379 /* 2380 * This code is not compatible with the optimizer, as 2381 * we are generating jmp instructions within a normal 2382 * slist of instructions 2383 */ 2384 no_optimize = 1; 2385 2386 /* 2387 * If "s" is non-null, it has code to arrange that the X register 2388 * contains the length of the prefix preceding the link-layer 2389 * header. 2390 * 2391 * Otherwise, the length of the prefix preceding the link-layer 2392 * header is "off_ll". 2393 */ 2394 if (s == NULL) { 2395 /* 2396 * There is no variable-length header preceding the 2397 * link-layer header. 2398 * 2399 * Load the length of the fixed-length prefix preceding 2400 * the link-layer header (if any) into the X register, 2401 * and store it in the reg_off_macpl register. 2402 * That length is off_ll. 2403 */ 2404 s = new_stmt(BPF_LDX|BPF_IMM); 2405 s->s.k = off_ll; 2406 } 2407 2408 /* 2409 * The X register contains the offset of the beginning of the 2410 * link-layer header; add 24, which is the minimum length 2411 * of the MAC header for a data frame, to that, and store it 2412 * in reg_off_macpl, and then load the Frame Control field, 2413 * which is at the offset in the X register, with an indexed load. 2414 */ 2415 s2 = new_stmt(BPF_MISC|BPF_TXA); 2416 sappend(s, s2); 2417 s2 = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 2418 s2->s.k = 24; 2419 sappend(s, s2); 2420 s2 = new_stmt(BPF_ST); 2421 s2->s.k = reg_off_macpl; 2422 sappend(s, s2); 2423 2424 s2 = new_stmt(BPF_LD|BPF_IND|BPF_B); 2425 s2->s.k = 0; 2426 sappend(s, s2); 2427 2428 /* 2429 * Check the Frame Control field to see if this is a data frame; 2430 * a data frame has the 0x08 bit (b3) in that field set and the 2431 * 0x04 bit (b2) clear. 2432 */ 2433 sjset_data_frame_1 = new_stmt(JMP(BPF_JSET)); 2434 sjset_data_frame_1->s.k = 0x08; 2435 sappend(s, sjset_data_frame_1); 2436 2437 /* 2438 * If b3 is set, test b2, otherwise go to the first statement of 2439 * the rest of the program. 2440 */ 2441 sjset_data_frame_1->s.jt = sjset_data_frame_2 = new_stmt(JMP(BPF_JSET)); 2442 sjset_data_frame_2->s.k = 0x04; 2443 sappend(s, sjset_data_frame_2); 2444 sjset_data_frame_1->s.jf = snext; 2445 2446 /* 2447 * If b2 is not set, this is a data frame; test the QoS bit. 2448 * Otherwise, go to the first statement of the rest of the 2449 * program. 2450 */ 2451 sjset_data_frame_2->s.jt = snext; 2452 sjset_data_frame_2->s.jf = sjset_qos = new_stmt(JMP(BPF_JSET)); 2453 sjset_qos->s.k = 0x80; /* QoS bit */ 2454 sappend(s, sjset_qos); 2455 2456 /* 2457 * If it's set, add 2 to reg_off_macpl, to skip the QoS 2458 * field. 2459 * Otherwise, go to the first statement of the rest of the 2460 * program. 2461 */ 2462 sjset_qos->s.jt = s2 = new_stmt(BPF_LD|BPF_MEM); 2463 s2->s.k = reg_off_macpl; 2464 sappend(s, s2); 2465 s2 = new_stmt(BPF_ALU|BPF_ADD|BPF_IMM); 2466 s2->s.k = 2; 2467 sappend(s, s2); 2468 s2 = new_stmt(BPF_ST); 2469 s2->s.k = reg_off_macpl; 2470 sappend(s, s2); 2471 2472 /* 2473 * If we have a radiotap header, look at it to see whether 2474 * there's Atheros padding between the MAC-layer header 2475 * and the payload. 2476 * 2477 * Note: all of the fields in the radiotap header are 2478 * little-endian, so we byte-swap all of the values 2479 * we test against, as they will be loaded as big-endian 2480 * values. 2481 */ 2482 if (linktype == DLT_IEEE802_11_RADIO) { 2483 /* 2484 * Is the IEEE80211_RADIOTAP_FLAGS bit (0x0000002) set 2485 * in the presence flag? 2486 */ 2487 sjset_qos->s.jf = s2 = new_stmt(BPF_LD|BPF_ABS|BPF_W); 2488 s2->s.k = 4; 2489 sappend(s, s2); 2490 2491 sjset_radiotap_flags = new_stmt(JMP(BPF_JSET)); 2492 sjset_radiotap_flags->s.k = SWAPLONG(0x00000002); 2493 sappend(s, sjset_radiotap_flags); 2494 2495 /* 2496 * If not, skip all of this. 2497 */ 2498 sjset_radiotap_flags->s.jf = snext; 2499 2500 /* 2501 * Otherwise, is the IEEE80211_RADIOTAP_TSFT bit set? 2502 */ 2503 sjset_radiotap_tsft = sjset_radiotap_flags->s.jt = 2504 new_stmt(JMP(BPF_JSET)); 2505 sjset_radiotap_tsft->s.k = SWAPLONG(0x00000001); 2506 sappend(s, sjset_radiotap_tsft); 2507 2508 /* 2509 * If IEEE80211_RADIOTAP_TSFT is set, the flags field is 2510 * at an offset of 16 from the beginning of the raw packet 2511 * data (8 bytes for the radiotap header and 8 bytes for 2512 * the TSFT field). 2513 * 2514 * Test whether the IEEE80211_RADIOTAP_F_DATAPAD bit (0x20) 2515 * is set. 2516 */ 2517 sjset_radiotap_tsft->s.jt = s2 = new_stmt(BPF_LD|BPF_ABS|BPF_B); 2518 s2->s.k = 16; 2519 sappend(s, s2); 2520 2521 sjset_tsft_datapad = new_stmt(JMP(BPF_JSET)); 2522 sjset_tsft_datapad->s.k = 0x20; 2523 sappend(s, sjset_tsft_datapad); 2524 2525 /* 2526 * If IEEE80211_RADIOTAP_TSFT is not set, the flags field is 2527 * at an offset of 8 from the beginning of the raw packet 2528 * data (8 bytes for the radiotap header). 2529 * 2530 * Test whether the IEEE80211_RADIOTAP_F_DATAPAD bit (0x20) 2531 * is set. 2532 */ 2533 sjset_radiotap_tsft->s.jf = s2 = new_stmt(BPF_LD|BPF_ABS|BPF_B); 2534 s2->s.k = 8; 2535 sappend(s, s2); 2536 2537 sjset_notsft_datapad = new_stmt(JMP(BPF_JSET)); 2538 sjset_notsft_datapad->s.k = 0x20; 2539 sappend(s, sjset_notsft_datapad); 2540 2541 /* 2542 * In either case, if IEEE80211_RADIOTAP_F_DATAPAD is 2543 * set, round the length of the 802.11 header to 2544 * a multiple of 4. Do that by adding 3 and then 2545 * dividing by and multiplying by 4, which we do by 2546 * ANDing with ~3. 2547 */ 2548 s_roundup = new_stmt(BPF_LD|BPF_MEM); 2549 s_roundup->s.k = reg_off_macpl; 2550 sappend(s, s_roundup); 2551 s2 = new_stmt(BPF_ALU|BPF_ADD|BPF_IMM); 2552 s2->s.k = 3; 2553 sappend(s, s2); 2554 s2 = new_stmt(BPF_ALU|BPF_AND|BPF_IMM); 2555 s2->s.k = ~3; 2556 sappend(s, s2); 2557 s2 = new_stmt(BPF_ST); 2558 s2->s.k = reg_off_macpl; 2559 sappend(s, s2); 2560 2561 sjset_tsft_datapad->s.jt = s_roundup; 2562 sjset_tsft_datapad->s.jf = snext; 2563 sjset_notsft_datapad->s.jt = s_roundup; 2564 sjset_notsft_datapad->s.jf = snext; 2565 } else 2566 sjset_qos->s.jf = snext; 2567 2568 return s; 2569 } 2570 2571 static void 2572 insert_compute_vloffsets(b) 2573 struct block *b; 2574 { 2575 struct slist *s; 2576 2577 /* 2578 * For link-layer types that have a variable-length header 2579 * preceding the link-layer header, generate code to load 2580 * the offset of the link-layer header into the register 2581 * assigned to that offset, if any. 2582 */ 2583 switch (linktype) { 2584 2585 case DLT_PRISM_HEADER: 2586 s = gen_load_prism_llprefixlen(); 2587 break; 2588 2589 case DLT_IEEE802_11_RADIO_AVS: 2590 s = gen_load_avs_llprefixlen(); 2591 break; 2592 2593 case DLT_IEEE802_11_RADIO: 2594 s = gen_load_radiotap_llprefixlen(); 2595 break; 2596 2597 case DLT_PPI: 2598 s = gen_load_ppi_llprefixlen(); 2599 break; 2600 2601 default: 2602 s = NULL; 2603 break; 2604 } 2605 2606 /* 2607 * For link-layer types that have a variable-length link-layer 2608 * header, generate code to load the offset of the MAC-layer 2609 * payload into the register assigned to that offset, if any. 2610 */ 2611 switch (linktype) { 2612 2613 case DLT_IEEE802_11: 2614 case DLT_PRISM_HEADER: 2615 case DLT_IEEE802_11_RADIO_AVS: 2616 case DLT_IEEE802_11_RADIO: 2617 case DLT_PPI: 2618 s = gen_load_802_11_header_len(s, b->stmts); 2619 break; 2620 } 2621 2622 /* 2623 * If we have any offset-loading code, append all the 2624 * existing statements in the block to those statements, 2625 * and make the resulting list the list of statements 2626 * for the block. 2627 */ 2628 if (s != NULL) { 2629 sappend(s, b->stmts); 2630 b->stmts = s; 2631 } 2632 } 2633 2634 static struct block * 2635 gen_ppi_dlt_check(void) 2636 { 2637 struct slist *s_load_dlt; 2638 struct block *b; 2639 2640 if (linktype == DLT_PPI) 2641 { 2642 /* Create the statements that check for the DLT 2643 */ 2644 s_load_dlt = new_stmt(BPF_LD|BPF_W|BPF_ABS); 2645 s_load_dlt->s.k = 4; 2646 2647 b = new_block(JMP(BPF_JEQ)); 2648 2649 b->stmts = s_load_dlt; 2650 b->s.k = SWAPLONG(DLT_IEEE802_11); 2651 } 2652 else 2653 { 2654 b = NULL; 2655 } 2656 2657 return b; 2658 } 2659 2660 static struct slist * 2661 gen_prism_llprefixlen(void) 2662 { 2663 struct slist *s; 2664 2665 if (reg_off_ll == -1) { 2666 /* 2667 * We haven't yet assigned a register for the length 2668 * of the radio header; allocate one. 2669 */ 2670 reg_off_ll = alloc_reg(); 2671 } 2672 2673 /* 2674 * Load the register containing the radio length 2675 * into the X register. 2676 */ 2677 s = new_stmt(BPF_LDX|BPF_MEM); 2678 s->s.k = reg_off_ll; 2679 return s; 2680 } 2681 2682 static struct slist * 2683 gen_avs_llprefixlen(void) 2684 { 2685 struct slist *s; 2686 2687 if (reg_off_ll == -1) { 2688 /* 2689 * We haven't yet assigned a register for the length 2690 * of the AVS header; allocate one. 2691 */ 2692 reg_off_ll = alloc_reg(); 2693 } 2694 2695 /* 2696 * Load the register containing the AVS length 2697 * into the X register. 2698 */ 2699 s = new_stmt(BPF_LDX|BPF_MEM); 2700 s->s.k = reg_off_ll; 2701 return s; 2702 } 2703 2704 static struct slist * 2705 gen_radiotap_llprefixlen(void) 2706 { 2707 struct slist *s; 2708 2709 if (reg_off_ll == -1) { 2710 /* 2711 * We haven't yet assigned a register for the length 2712 * of the radiotap header; allocate one. 2713 */ 2714 reg_off_ll = alloc_reg(); 2715 } 2716 2717 /* 2718 * Load the register containing the radiotap length 2719 * into the X register. 2720 */ 2721 s = new_stmt(BPF_LDX|BPF_MEM); 2722 s->s.k = reg_off_ll; 2723 return s; 2724 } 2725 2726 /* 2727 * At the moment we treat PPI as normal Radiotap encoded 2728 * packets. The difference is in the function that generates 2729 * the code at the beginning to compute the header length. 2730 * Since this code generator of PPI supports bare 802.11 2731 * encapsulation only (i.e. the encapsulated DLT should be 2732 * DLT_IEEE802_11) we generate code to check for this too. 2733 */ 2734 static struct slist * 2735 gen_ppi_llprefixlen(void) 2736 { 2737 struct slist *s; 2738 2739 if (reg_off_ll == -1) { 2740 /* 2741 * We haven't yet assigned a register for the length 2742 * of the radiotap header; allocate one. 2743 */ 2744 reg_off_ll = alloc_reg(); 2745 } 2746 2747 /* 2748 * Load the register containing the PPI length 2749 * into the X register. 2750 */ 2751 s = new_stmt(BPF_LDX|BPF_MEM); 2752 s->s.k = reg_off_ll; 2753 return s; 2754 } 2755 2756 /* 2757 * Generate code to compute the link-layer header length, if necessary, 2758 * putting it into the X register, and to return either a pointer to a 2759 * "struct slist" for the list of statements in that code, or NULL if 2760 * no code is necessary. 2761 */ 2762 static struct slist * 2763 gen_llprefixlen(void) 2764 { 2765 switch (linktype) { 2766 2767 case DLT_PRISM_HEADER: 2768 return gen_prism_llprefixlen(); 2769 2770 case DLT_IEEE802_11_RADIO_AVS: 2771 return gen_avs_llprefixlen(); 2772 2773 case DLT_IEEE802_11_RADIO: 2774 return gen_radiotap_llprefixlen(); 2775 2776 case DLT_PPI: 2777 return gen_ppi_llprefixlen(); 2778 2779 default: 2780 return NULL; 2781 } 2782 } 2783 2784 /* 2785 * Generate code to load the register containing the offset of the 2786 * MAC-layer payload into the X register; if no register for that offset 2787 * has been allocated, allocate it first. 2788 */ 2789 static struct slist * 2790 gen_off_macpl(void) 2791 { 2792 struct slist *s; 2793 2794 if (off_macpl_is_variable) { 2795 if (reg_off_macpl == -1) { 2796 /* 2797 * We haven't yet assigned a register for the offset 2798 * of the MAC-layer payload; allocate one. 2799 */ 2800 reg_off_macpl = alloc_reg(); 2801 } 2802 2803 /* 2804 * Load the register containing the offset of the MAC-layer 2805 * payload into the X register. 2806 */ 2807 s = new_stmt(BPF_LDX|BPF_MEM); 2808 s->s.k = reg_off_macpl; 2809 return s; 2810 } else { 2811 /* 2812 * That offset isn't variable, so we don't need to 2813 * generate any code. 2814 */ 2815 return NULL; 2816 } 2817 } 2818 2819 /* 2820 * Map an Ethernet type to the equivalent PPP type. 2821 */ 2822 static int 2823 ethertype_to_ppptype(proto) 2824 int proto; 2825 { 2826 switch (proto) { 2827 2828 case ETHERTYPE_IP: 2829 proto = PPP_IP; 2830 break; 2831 2832 #ifdef INET6 2833 case ETHERTYPE_IPV6: 2834 proto = PPP_IPV6; 2835 break; 2836 #endif 2837 2838 case ETHERTYPE_DN: 2839 proto = PPP_DECNET; 2840 break; 2841 2842 case ETHERTYPE_ATALK: 2843 proto = PPP_APPLE; 2844 break; 2845 2846 case ETHERTYPE_NS: 2847 proto = PPP_NS; 2848 break; 2849 2850 case LLCSAP_ISONS: 2851 proto = PPP_OSI; 2852 break; 2853 2854 case LLCSAP_8021D: 2855 /* 2856 * I'm assuming the "Bridging PDU"s that go 2857 * over PPP are Spanning Tree Protocol 2858 * Bridging PDUs. 2859 */ 2860 proto = PPP_BRPDU; 2861 break; 2862 2863 case LLCSAP_IPX: 2864 proto = PPP_IPX; 2865 break; 2866 } 2867 return (proto); 2868 } 2869 2870 /* 2871 * Generate code to match a particular packet type by matching the 2872 * link-layer type field or fields in the 802.2 LLC header. 2873 * 2874 * "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP 2875 * value, if <= ETHERMTU. 2876 */ 2877 static struct block * 2878 gen_linktype(proto) 2879 register int proto; 2880 { 2881 struct block *b0, *b1, *b2; 2882 2883 /* are we checking MPLS-encapsulated packets? */ 2884 if (label_stack_depth > 0) { 2885 switch (proto) { 2886 case ETHERTYPE_IP: 2887 case PPP_IP: 2888 /* FIXME add other L3 proto IDs */ 2889 return gen_mpls_linktype(Q_IP); 2890 2891 case ETHERTYPE_IPV6: 2892 case PPP_IPV6: 2893 /* FIXME add other L3 proto IDs */ 2894 return gen_mpls_linktype(Q_IPV6); 2895 2896 default: 2897 bpf_error("unsupported protocol over mpls"); 2898 /* NOTREACHED */ 2899 } 2900 } 2901 2902 /* 2903 * Are we testing PPPoE packets? 2904 */ 2905 if (is_pppoes) { 2906 /* 2907 * The PPPoE session header is part of the 2908 * MAC-layer payload, so all references 2909 * should be relative to the beginning of 2910 * that payload. 2911 */ 2912 2913 /* 2914 * We use Ethernet protocol types inside libpcap; 2915 * map them to the corresponding PPP protocol types. 2916 */ 2917 proto = ethertype_to_ppptype(proto); 2918 return gen_cmp(OR_MACPL, off_linktype, BPF_H, (bpf_int32)proto); 2919 } 2920 2921 switch (linktype) { 2922 2923 case DLT_EN10MB: 2924 case DLT_NETANALYZER: 2925 case DLT_NETANALYZER_TRANSPARENT: 2926 return gen_ether_linktype(proto); 2927 /*NOTREACHED*/ 2928 break; 2929 2930 case DLT_C_HDLC: 2931 switch (proto) { 2932 2933 case LLCSAP_ISONS: 2934 proto = (proto << 8 | LLCSAP_ISONS); 2935 /* fall through */ 2936 2937 default: 2938 return gen_cmp(OR_LINK, off_linktype, BPF_H, 2939 (bpf_int32)proto); 2940 /*NOTREACHED*/ 2941 break; 2942 } 2943 break; 2944 2945 case DLT_IEEE802_11: 2946 case DLT_PRISM_HEADER: 2947 case DLT_IEEE802_11_RADIO_AVS: 2948 case DLT_IEEE802_11_RADIO: 2949 case DLT_PPI: 2950 /* 2951 * Check that we have a data frame. 2952 */ 2953 b0 = gen_check_802_11_data_frame(); 2954 2955 /* 2956 * Now check for the specified link-layer type. 2957 */ 2958 b1 = gen_llc_linktype(proto); 2959 gen_and(b0, b1); 2960 return b1; 2961 /*NOTREACHED*/ 2962 break; 2963 2964 case DLT_FDDI: 2965 /* 2966 * XXX - check for asynchronous frames, as per RFC 1103. 2967 */ 2968 return gen_llc_linktype(proto); 2969 /*NOTREACHED*/ 2970 break; 2971 2972 case DLT_IEEE802: 2973 /* 2974 * XXX - check for LLC PDUs, as per IEEE 802.5. 2975 */ 2976 return gen_llc_linktype(proto); 2977 /*NOTREACHED*/ 2978 break; 2979 2980 case DLT_ATM_RFC1483: 2981 case DLT_ATM_CLIP: 2982 case DLT_IP_OVER_FC: 2983 return gen_llc_linktype(proto); 2984 /*NOTREACHED*/ 2985 break; 2986 2987 case DLT_SUNATM: 2988 /* 2989 * If "is_lane" is set, check for a LANE-encapsulated 2990 * version of this protocol, otherwise check for an 2991 * LLC-encapsulated version of this protocol. 2992 * 2993 * We assume LANE means Ethernet, not Token Ring. 2994 */ 2995 if (is_lane) { 2996 /* 2997 * Check that the packet doesn't begin with an 2998 * LE Control marker. (We've already generated 2999 * a test for LANE.) 3000 */ 3001 b0 = gen_cmp(OR_LINK, SUNATM_PKT_BEGIN_POS, BPF_H, 3002 0xFF00); 3003 gen_not(b0); 3004 3005 /* 3006 * Now generate an Ethernet test. 3007 */ 3008 b1 = gen_ether_linktype(proto); 3009 gen_and(b0, b1); 3010 return b1; 3011 } else { 3012 /* 3013 * Check for LLC encapsulation and then check the 3014 * protocol. 3015 */ 3016 b0 = gen_atmfield_code(A_PROTOTYPE, PT_LLC, BPF_JEQ, 0); 3017 b1 = gen_llc_linktype(proto); 3018 gen_and(b0, b1); 3019 return b1; 3020 } 3021 /*NOTREACHED*/ 3022 break; 3023 3024 case DLT_LINUX_SLL: 3025 return gen_linux_sll_linktype(proto); 3026 /*NOTREACHED*/ 3027 break; 3028 3029 case DLT_SLIP: 3030 case DLT_SLIP_BSDOS: 3031 case DLT_RAW: 3032 /* 3033 * These types don't provide any type field; packets 3034 * are always IPv4 or IPv6. 3035 * 3036 * XXX - for IPv4, check for a version number of 4, and, 3037 * for IPv6, check for a version number of 6? 3038 */ 3039 switch (proto) { 3040 3041 case ETHERTYPE_IP: 3042 /* Check for a version number of 4. */ 3043 return gen_mcmp(OR_LINK, 0, BPF_B, 0x40, 0xF0); 3044 #ifdef INET6 3045 case ETHERTYPE_IPV6: 3046 /* Check for a version number of 6. */ 3047 return gen_mcmp(OR_LINK, 0, BPF_B, 0x60, 0xF0); 3048 #endif 3049 3050 default: 3051 return gen_false(); /* always false */ 3052 } 3053 /*NOTREACHED*/ 3054 break; 3055 3056 case DLT_IPV4: 3057 /* 3058 * Raw IPv4, so no type field. 3059 */ 3060 if (proto == ETHERTYPE_IP) 3061 return gen_true(); /* always true */ 3062 3063 /* Checking for something other than IPv4; always false */ 3064 return gen_false(); 3065 /*NOTREACHED*/ 3066 break; 3067 3068 case DLT_IPV6: 3069 /* 3070 * Raw IPv6, so no type field. 3071 */ 3072 #ifdef INET6 3073 if (proto == ETHERTYPE_IPV6) 3074 return gen_true(); /* always true */ 3075 #endif 3076 3077 /* Checking for something other than IPv6; always false */ 3078 return gen_false(); 3079 /*NOTREACHED*/ 3080 break; 3081 3082 case DLT_PPP: 3083 case DLT_PPP_PPPD: 3084 case DLT_PPP_SERIAL: 3085 case DLT_PPP_ETHER: 3086 /* 3087 * We use Ethernet protocol types inside libpcap; 3088 * map them to the corresponding PPP protocol types. 3089 */ 3090 proto = ethertype_to_ppptype(proto); 3091 return gen_cmp(OR_LINK, off_linktype, BPF_H, (bpf_int32)proto); 3092 /*NOTREACHED*/ 3093 break; 3094 3095 case DLT_PPP_BSDOS: 3096 /* 3097 * We use Ethernet protocol types inside libpcap; 3098 * map them to the corresponding PPP protocol types. 3099 */ 3100 switch (proto) { 3101 3102 case ETHERTYPE_IP: 3103 /* 3104 * Also check for Van Jacobson-compressed IP. 3105 * XXX - do this for other forms of PPP? 3106 */ 3107 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, PPP_IP); 3108 b1 = gen_cmp(OR_LINK, off_linktype, BPF_H, PPP_VJC); 3109 gen_or(b0, b1); 3110 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, PPP_VJNC); 3111 gen_or(b1, b0); 3112 return b0; 3113 3114 default: 3115 proto = ethertype_to_ppptype(proto); 3116 return gen_cmp(OR_LINK, off_linktype, BPF_H, 3117 (bpf_int32)proto); 3118 } 3119 /*NOTREACHED*/ 3120 break; 3121 3122 case DLT_NULL: 3123 case DLT_LOOP: 3124 case DLT_ENC: 3125 /* 3126 * For DLT_NULL, the link-layer header is a 32-bit 3127 * word containing an AF_ value in *host* byte order, 3128 * and for DLT_ENC, the link-layer header begins 3129 * with a 32-bit work containing an AF_ value in 3130 * host byte order. 3131 * 3132 * In addition, if we're reading a saved capture file, 3133 * the host byte order in the capture may not be the 3134 * same as the host byte order on this machine. 3135 * 3136 * For DLT_LOOP, the link-layer header is a 32-bit 3137 * word containing an AF_ value in *network* byte order. 3138 * 3139 * XXX - AF_ values may, unfortunately, be platform- 3140 * dependent; for example, FreeBSD's AF_INET6 is 24 3141 * whilst NetBSD's and OpenBSD's is 26. 3142 * 3143 * This means that, when reading a capture file, just 3144 * checking for our AF_INET6 value won't work if the 3145 * capture file came from another OS. 3146 */ 3147 switch (proto) { 3148 3149 case ETHERTYPE_IP: 3150 proto = AF_INET; 3151 break; 3152 3153 #ifdef INET6 3154 case ETHERTYPE_IPV6: 3155 proto = AF_INET6; 3156 break; 3157 #endif 3158 3159 default: 3160 /* 3161 * Not a type on which we support filtering. 3162 * XXX - support those that have AF_ values 3163 * #defined on this platform, at least? 3164 */ 3165 return gen_false(); 3166 } 3167 3168 if (linktype == DLT_NULL || linktype == DLT_ENC) { 3169 /* 3170 * The AF_ value is in host byte order, but 3171 * the BPF interpreter will convert it to 3172 * network byte order. 3173 * 3174 * If this is a save file, and it's from a 3175 * machine with the opposite byte order to 3176 * ours, we byte-swap the AF_ value. 3177 * 3178 * Then we run it through "htonl()", and 3179 * generate code to compare against the result. 3180 */ 3181 if (bpf_pcap->sf.rfile != NULL && 3182 bpf_pcap->sf.swapped) 3183 proto = SWAPLONG(proto); 3184 proto = htonl(proto); 3185 } 3186 return (gen_cmp(OR_LINK, 0, BPF_W, (bpf_int32)proto)); 3187 3188 #ifdef HAVE_NET_PFVAR_H 3189 case DLT_PFLOG: 3190 /* 3191 * af field is host byte order in contrast to the rest of 3192 * the packet. 3193 */ 3194 if (proto == ETHERTYPE_IP) 3195 return (gen_cmp(OR_LINK, offsetof(struct pfloghdr, af), 3196 BPF_B, (bpf_int32)AF_INET)); 3197 #ifdef INET6 3198 else if (proto == ETHERTYPE_IPV6) 3199 return (gen_cmp(OR_LINK, offsetof(struct pfloghdr, af), 3200 BPF_B, (bpf_int32)AF_INET6)); 3201 #endif /* INET6 */ 3202 else 3203 return gen_false(); 3204 /*NOTREACHED*/ 3205 break; 3206 #endif /* HAVE_NET_PFVAR_H */ 3207 3208 case DLT_ARCNET: 3209 case DLT_ARCNET_LINUX: 3210 /* 3211 * XXX should we check for first fragment if the protocol 3212 * uses PHDS? 3213 */ 3214 switch (proto) { 3215 3216 default: 3217 return gen_false(); 3218 3219 #ifdef INET6 3220 case ETHERTYPE_IPV6: 3221 return (gen_cmp(OR_LINK, off_linktype, BPF_B, 3222 (bpf_int32)ARCTYPE_INET6)); 3223 #endif /* INET6 */ 3224 3225 case ETHERTYPE_IP: 3226 b0 = gen_cmp(OR_LINK, off_linktype, BPF_B, 3227 (bpf_int32)ARCTYPE_IP); 3228 b1 = gen_cmp(OR_LINK, off_linktype, BPF_B, 3229 (bpf_int32)ARCTYPE_IP_OLD); 3230 gen_or(b0, b1); 3231 return (b1); 3232 3233 case ETHERTYPE_ARP: 3234 b0 = gen_cmp(OR_LINK, off_linktype, BPF_B, 3235 (bpf_int32)ARCTYPE_ARP); 3236 b1 = gen_cmp(OR_LINK, off_linktype, BPF_B, 3237 (bpf_int32)ARCTYPE_ARP_OLD); 3238 gen_or(b0, b1); 3239 return (b1); 3240 3241 case ETHERTYPE_REVARP: 3242 return (gen_cmp(OR_LINK, off_linktype, BPF_B, 3243 (bpf_int32)ARCTYPE_REVARP)); 3244 3245 case ETHERTYPE_ATALK: 3246 return (gen_cmp(OR_LINK, off_linktype, BPF_B, 3247 (bpf_int32)ARCTYPE_ATALK)); 3248 } 3249 /*NOTREACHED*/ 3250 break; 3251 3252 case DLT_LTALK: 3253 switch (proto) { 3254 case ETHERTYPE_ATALK: 3255 return gen_true(); 3256 default: 3257 return gen_false(); 3258 } 3259 /*NOTREACHED*/ 3260 break; 3261 3262 case DLT_FRELAY: 3263 /* 3264 * XXX - assumes a 2-byte Frame Relay header with 3265 * DLCI and flags. What if the address is longer? 3266 */ 3267 switch (proto) { 3268 3269 case ETHERTYPE_IP: 3270 /* 3271 * Check for the special NLPID for IP. 3272 */ 3273 return gen_cmp(OR_LINK, 2, BPF_H, (0x03<<8) | 0xcc); 3274 3275 #ifdef INET6 3276 case ETHERTYPE_IPV6: 3277 /* 3278 * Check for the special NLPID for IPv6. 3279 */ 3280 return gen_cmp(OR_LINK, 2, BPF_H, (0x03<<8) | 0x8e); 3281 #endif 3282 3283 case LLCSAP_ISONS: 3284 /* 3285 * Check for several OSI protocols. 3286 * 3287 * Frame Relay packets typically have an OSI 3288 * NLPID at the beginning; we check for each 3289 * of them. 3290 * 3291 * What we check for is the NLPID and a frame 3292 * control field of UI, i.e. 0x03 followed 3293 * by the NLPID. 3294 */ 3295 b0 = gen_cmp(OR_LINK, 2, BPF_H, (0x03<<8) | ISO8473_CLNP); 3296 b1 = gen_cmp(OR_LINK, 2, BPF_H, (0x03<<8) | ISO9542_ESIS); 3297 b2 = gen_cmp(OR_LINK, 2, BPF_H, (0x03<<8) | ISO10589_ISIS); 3298 gen_or(b1, b2); 3299 gen_or(b0, b2); 3300 return b2; 3301 3302 default: 3303 return gen_false(); 3304 } 3305 /*NOTREACHED*/ 3306 break; 3307 3308 case DLT_MFR: 3309 bpf_error("Multi-link Frame Relay link-layer type filtering not implemented"); 3310 3311 case DLT_JUNIPER_MFR: 3312 case DLT_JUNIPER_MLFR: 3313 case DLT_JUNIPER_MLPPP: 3314 case DLT_JUNIPER_ATM1: 3315 case DLT_JUNIPER_ATM2: 3316 case DLT_JUNIPER_PPPOE: 3317 case DLT_JUNIPER_PPPOE_ATM: 3318 case DLT_JUNIPER_GGSN: 3319 case DLT_JUNIPER_ES: 3320 case DLT_JUNIPER_MONITOR: 3321 case DLT_JUNIPER_SERVICES: 3322 case DLT_JUNIPER_ETHER: 3323 case DLT_JUNIPER_PPP: 3324 case DLT_JUNIPER_FRELAY: 3325 case DLT_JUNIPER_CHDLC: 3326 case DLT_JUNIPER_VP: 3327 case DLT_JUNIPER_ST: 3328 case DLT_JUNIPER_ISM: 3329 case DLT_JUNIPER_VS: 3330 case DLT_JUNIPER_SRX_E2E: 3331 case DLT_JUNIPER_FIBRECHANNEL: 3332 case DLT_JUNIPER_ATM_CEMIC: 3333 3334 /* just lets verify the magic number for now - 3335 * on ATM we may have up to 6 different encapsulations on the wire 3336 * and need a lot of heuristics to figure out that the payload 3337 * might be; 3338 * 3339 * FIXME encapsulation specific BPF_ filters 3340 */ 3341 return gen_mcmp(OR_LINK, 0, BPF_W, 0x4d474300, 0xffffff00); /* compare the magic number */ 3342 3343 case DLT_IPNET: 3344 return gen_ipnet_linktype(proto); 3345 3346 case DLT_LINUX_IRDA: 3347 bpf_error("IrDA link-layer type filtering not implemented"); 3348 3349 case DLT_DOCSIS: 3350 bpf_error("DOCSIS link-layer type filtering not implemented"); 3351 3352 case DLT_MTP2: 3353 case DLT_MTP2_WITH_PHDR: 3354 bpf_error("MTP2 link-layer type filtering not implemented"); 3355 3356 case DLT_ERF: 3357 bpf_error("ERF link-layer type filtering not implemented"); 3358 3359 #ifdef DLT_PFSYNC 3360 case DLT_PFSYNC: 3361 bpf_error("PFSYNC link-layer type filtering not implemented"); 3362 #endif 3363 3364 case DLT_LINUX_LAPD: 3365 bpf_error("LAPD link-layer type filtering not implemented"); 3366 3367 case DLT_USB: 3368 case DLT_USB_LINUX: 3369 case DLT_USB_LINUX_MMAPPED: 3370 bpf_error("USB link-layer type filtering not implemented"); 3371 3372 case DLT_BLUETOOTH_HCI_H4: 3373 case DLT_BLUETOOTH_HCI_H4_WITH_PHDR: 3374 bpf_error("Bluetooth link-layer type filtering not implemented"); 3375 3376 case DLT_CAN20B: 3377 case DLT_CAN_SOCKETCAN: 3378 bpf_error("CAN link-layer type filtering not implemented"); 3379 3380 case DLT_IEEE802_15_4: 3381 case DLT_IEEE802_15_4_LINUX: 3382 case DLT_IEEE802_15_4_NONASK_PHY: 3383 case DLT_IEEE802_15_4_NOFCS: 3384 bpf_error("IEEE 802.15.4 link-layer type filtering not implemented"); 3385 3386 case DLT_IEEE802_16_MAC_CPS_RADIO: 3387 bpf_error("IEEE 802.16 link-layer type filtering not implemented"); 3388 3389 case DLT_SITA: 3390 bpf_error("SITA link-layer type filtering not implemented"); 3391 3392 case DLT_RAIF1: 3393 bpf_error("RAIF1 link-layer type filtering not implemented"); 3394 3395 case DLT_IPMB: 3396 bpf_error("IPMB link-layer type filtering not implemented"); 3397 3398 case DLT_AX25_KISS: 3399 bpf_error("AX.25 link-layer type filtering not implemented"); 3400 } 3401 3402 /* 3403 * All the types that have no encapsulation should either be 3404 * handled as DLT_SLIP, DLT_SLIP_BSDOS, and DLT_RAW are, if 3405 * all packets are IP packets, or should be handled in some 3406 * special case, if none of them are (if some are and some 3407 * aren't, the lack of encapsulation is a problem, as we'd 3408 * have to find some other way of determining the packet type). 3409 * 3410 * Therefore, if "off_linktype" is -1, there's an error. 3411 */ 3412 if (off_linktype == (u_int)-1) 3413 abort(); 3414 3415 /* 3416 * Any type not handled above should always have an Ethernet 3417 * type at an offset of "off_linktype". 3418 */ 3419 return gen_cmp(OR_LINK, off_linktype, BPF_H, (bpf_int32)proto); 3420 } 3421 3422 /* 3423 * Check for an LLC SNAP packet with a given organization code and 3424 * protocol type; we check the entire contents of the 802.2 LLC and 3425 * snap headers, checking for DSAP and SSAP of SNAP and a control 3426 * field of 0x03 in the LLC header, and for the specified organization 3427 * code and protocol type in the SNAP header. 3428 */ 3429 static struct block * 3430 gen_snap(orgcode, ptype) 3431 bpf_u_int32 orgcode; 3432 bpf_u_int32 ptype; 3433 { 3434 u_char snapblock[8]; 3435 3436 snapblock[0] = LLCSAP_SNAP; /* DSAP = SNAP */ 3437 snapblock[1] = LLCSAP_SNAP; /* SSAP = SNAP */ 3438 snapblock[2] = 0x03; /* control = UI */ 3439 snapblock[3] = (orgcode >> 16); /* upper 8 bits of organization code */ 3440 snapblock[4] = (orgcode >> 8); /* middle 8 bits of organization code */ 3441 snapblock[5] = (orgcode >> 0); /* lower 8 bits of organization code */ 3442 snapblock[6] = (ptype >> 8); /* upper 8 bits of protocol type */ 3443 snapblock[7] = (ptype >> 0); /* lower 8 bits of protocol type */ 3444 return gen_bcmp(OR_MACPL, 0, 8, snapblock); 3445 } 3446 3447 /* 3448 * Generate code to match a particular packet type, for link-layer types 3449 * using 802.2 LLC headers. 3450 * 3451 * This is *NOT* used for Ethernet; "gen_ether_linktype()" is used 3452 * for that - it handles the D/I/X Ethernet vs. 802.3+802.2 issues. 3453 * 3454 * "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP 3455 * value, if <= ETHERMTU. We use that to determine whether to 3456 * match the DSAP or both DSAP and LSAP or to check the OUI and 3457 * protocol ID in a SNAP header. 3458 */ 3459 static struct block * 3460 gen_llc_linktype(proto) 3461 int proto; 3462 { 3463 /* 3464 * XXX - handle token-ring variable-length header. 3465 */ 3466 switch (proto) { 3467 3468 case LLCSAP_IP: 3469 case LLCSAP_ISONS: 3470 case LLCSAP_NETBEUI: 3471 /* 3472 * XXX - should we check both the DSAP and the 3473 * SSAP, like this, or should we check just the 3474 * DSAP, as we do for other types <= ETHERMTU 3475 * (i.e., other SAP values)? 3476 */ 3477 return gen_cmp(OR_MACPL, 0, BPF_H, (bpf_u_int32) 3478 ((proto << 8) | proto)); 3479 3480 case LLCSAP_IPX: 3481 /* 3482 * XXX - are there ever SNAP frames for IPX on 3483 * non-Ethernet 802.x networks? 3484 */ 3485 return gen_cmp(OR_MACPL, 0, BPF_B, 3486 (bpf_int32)LLCSAP_IPX); 3487 3488 case ETHERTYPE_ATALK: 3489 /* 3490 * 802.2-encapsulated ETHERTYPE_ATALK packets are 3491 * SNAP packets with an organization code of 3492 * 0x080007 (Apple, for Appletalk) and a protocol 3493 * type of ETHERTYPE_ATALK (Appletalk). 3494 * 3495 * XXX - check for an organization code of 3496 * encapsulated Ethernet as well? 3497 */ 3498 return gen_snap(0x080007, ETHERTYPE_ATALK); 3499 3500 default: 3501 /* 3502 * XXX - we don't have to check for IPX 802.3 3503 * here, but should we check for the IPX Ethertype? 3504 */ 3505 if (proto <= ETHERMTU) { 3506 /* 3507 * This is an LLC SAP value, so check 3508 * the DSAP. 3509 */ 3510 return gen_cmp(OR_MACPL, 0, BPF_B, (bpf_int32)proto); 3511 } else { 3512 /* 3513 * This is an Ethernet type; we assume that it's 3514 * unlikely that it'll appear in the right place 3515 * at random, and therefore check only the 3516 * location that would hold the Ethernet type 3517 * in a SNAP frame with an organization code of 3518 * 0x000000 (encapsulated Ethernet). 3519 * 3520 * XXX - if we were to check for the SNAP DSAP and 3521 * LSAP, as per XXX, and were also to check for an 3522 * organization code of 0x000000 (encapsulated 3523 * Ethernet), we'd do 3524 * 3525 * return gen_snap(0x000000, proto); 3526 * 3527 * here; for now, we don't, as per the above. 3528 * I don't know whether it's worth the extra CPU 3529 * time to do the right check or not. 3530 */ 3531 return gen_cmp(OR_MACPL, 6, BPF_H, (bpf_int32)proto); 3532 } 3533 } 3534 } 3535 3536 static struct block * 3537 gen_hostop(addr, mask, dir, proto, src_off, dst_off) 3538 bpf_u_int32 addr; 3539 bpf_u_int32 mask; 3540 int dir, proto; 3541 u_int src_off, dst_off; 3542 { 3543 struct block *b0, *b1; 3544 u_int offset; 3545 3546 switch (dir) { 3547 3548 case Q_SRC: 3549 offset = src_off; 3550 break; 3551 3552 case Q_DST: 3553 offset = dst_off; 3554 break; 3555 3556 case Q_AND: 3557 b0 = gen_hostop(addr, mask, Q_SRC, proto, src_off, dst_off); 3558 b1 = gen_hostop(addr, mask, Q_DST, proto, src_off, dst_off); 3559 gen_and(b0, b1); 3560 return b1; 3561 3562 case Q_OR: 3563 case Q_DEFAULT: 3564 b0 = gen_hostop(addr, mask, Q_SRC, proto, src_off, dst_off); 3565 b1 = gen_hostop(addr, mask, Q_DST, proto, src_off, dst_off); 3566 gen_or(b0, b1); 3567 return b1; 3568 3569 default: 3570 abort(); 3571 } 3572 b0 = gen_linktype(proto); 3573 b1 = gen_mcmp(OR_NET, offset, BPF_W, (bpf_int32)addr, mask); 3574 gen_and(b0, b1); 3575 return b1; 3576 } 3577 3578 #ifdef INET6 3579 static struct block * 3580 gen_hostop6(addr, mask, dir, proto, src_off, dst_off) 3581 struct in6_addr *addr; 3582 struct in6_addr *mask; 3583 int dir, proto; 3584 u_int src_off, dst_off; 3585 { 3586 struct block *b0, *b1; 3587 u_int offset; 3588 u_int32_t *a, *m; 3589 3590 switch (dir) { 3591 3592 case Q_SRC: 3593 offset = src_off; 3594 break; 3595 3596 case Q_DST: 3597 offset = dst_off; 3598 break; 3599 3600 case Q_AND: 3601 b0 = gen_hostop6(addr, mask, Q_SRC, proto, src_off, dst_off); 3602 b1 = gen_hostop6(addr, mask, Q_DST, proto, src_off, dst_off); 3603 gen_and(b0, b1); 3604 return b1; 3605 3606 case Q_OR: 3607 case Q_DEFAULT: 3608 b0 = gen_hostop6(addr, mask, Q_SRC, proto, src_off, dst_off); 3609 b1 = gen_hostop6(addr, mask, Q_DST, proto, src_off, dst_off); 3610 gen_or(b0, b1); 3611 return b1; 3612 3613 default: 3614 abort(); 3615 } 3616 /* this order is important */ 3617 a = (u_int32_t *)addr; 3618 m = (u_int32_t *)mask; 3619 b1 = gen_mcmp(OR_NET, offset + 12, BPF_W, ntohl(a[3]), ntohl(m[3])); 3620 b0 = gen_mcmp(OR_NET, offset + 8, BPF_W, ntohl(a[2]), ntohl(m[2])); 3621 gen_and(b0, b1); 3622 b0 = gen_mcmp(OR_NET, offset + 4, BPF_W, ntohl(a[1]), ntohl(m[1])); 3623 gen_and(b0, b1); 3624 b0 = gen_mcmp(OR_NET, offset + 0, BPF_W, ntohl(a[0]), ntohl(m[0])); 3625 gen_and(b0, b1); 3626 b0 = gen_linktype(proto); 3627 gen_and(b0, b1); 3628 return b1; 3629 } 3630 #endif /*INET6*/ 3631 3632 static struct block * 3633 gen_ehostop(eaddr, dir) 3634 register const u_char *eaddr; 3635 register int dir; 3636 { 3637 register struct block *b0, *b1; 3638 3639 switch (dir) { 3640 case Q_SRC: 3641 return gen_bcmp(OR_LINK, off_mac + 6, 6, eaddr); 3642 3643 case Q_DST: 3644 return gen_bcmp(OR_LINK, off_mac + 0, 6, eaddr); 3645 3646 case Q_AND: 3647 b0 = gen_ehostop(eaddr, Q_SRC); 3648 b1 = gen_ehostop(eaddr, Q_DST); 3649 gen_and(b0, b1); 3650 return b1; 3651 3652 case Q_DEFAULT: 3653 case Q_OR: 3654 b0 = gen_ehostop(eaddr, Q_SRC); 3655 b1 = gen_ehostop(eaddr, Q_DST); 3656 gen_or(b0, b1); 3657 return b1; 3658 3659 case Q_ADDR1: 3660 bpf_error("'addr1' is only supported on 802.11 with 802.11 headers"); 3661 break; 3662 3663 case Q_ADDR2: 3664 bpf_error("'addr2' is only supported on 802.11 with 802.11 headers"); 3665 break; 3666 3667 case Q_ADDR3: 3668 bpf_error("'addr3' is only supported on 802.11 with 802.11 headers"); 3669 break; 3670 3671 case Q_ADDR4: 3672 bpf_error("'addr4' is only supported on 802.11 with 802.11 headers"); 3673 break; 3674 3675 case Q_RA: 3676 bpf_error("'ra' is only supported on 802.11 with 802.11 headers"); 3677 break; 3678 3679 case Q_TA: 3680 bpf_error("'ta' is only supported on 802.11 with 802.11 headers"); 3681 break; 3682 } 3683 abort(); 3684 /* NOTREACHED */ 3685 } 3686 3687 /* 3688 * Like gen_ehostop, but for DLT_FDDI 3689 */ 3690 static struct block * 3691 gen_fhostop(eaddr, dir) 3692 register const u_char *eaddr; 3693 register int dir; 3694 { 3695 struct block *b0, *b1; 3696 3697 switch (dir) { 3698 case Q_SRC: 3699 #ifdef PCAP_FDDIPAD 3700 return gen_bcmp(OR_LINK, 6 + 1 + pcap_fddipad, 6, eaddr); 3701 #else 3702 return gen_bcmp(OR_LINK, 6 + 1, 6, eaddr); 3703 #endif 3704 3705 case Q_DST: 3706 #ifdef PCAP_FDDIPAD 3707 return gen_bcmp(OR_LINK, 0 + 1 + pcap_fddipad, 6, eaddr); 3708 #else 3709 return gen_bcmp(OR_LINK, 0 + 1, 6, eaddr); 3710 #endif 3711 3712 case Q_AND: 3713 b0 = gen_fhostop(eaddr, Q_SRC); 3714 b1 = gen_fhostop(eaddr, Q_DST); 3715 gen_and(b0, b1); 3716 return b1; 3717 3718 case Q_DEFAULT: 3719 case Q_OR: 3720 b0 = gen_fhostop(eaddr, Q_SRC); 3721 b1 = gen_fhostop(eaddr, Q_DST); 3722 gen_or(b0, b1); 3723 return b1; 3724 3725 case Q_ADDR1: 3726 bpf_error("'addr1' is only supported on 802.11"); 3727 break; 3728 3729 case Q_ADDR2: 3730 bpf_error("'addr2' is only supported on 802.11"); 3731 break; 3732 3733 case Q_ADDR3: 3734 bpf_error("'addr3' is only supported on 802.11"); 3735 break; 3736 3737 case Q_ADDR4: 3738 bpf_error("'addr4' is only supported on 802.11"); 3739 break; 3740 3741 case Q_RA: 3742 bpf_error("'ra' is only supported on 802.11"); 3743 break; 3744 3745 case Q_TA: 3746 bpf_error("'ta' is only supported on 802.11"); 3747 break; 3748 } 3749 abort(); 3750 /* NOTREACHED */ 3751 } 3752 3753 /* 3754 * Like gen_ehostop, but for DLT_IEEE802 (Token Ring) 3755 */ 3756 static struct block * 3757 gen_thostop(eaddr, dir) 3758 register const u_char *eaddr; 3759 register int dir; 3760 { 3761 register struct block *b0, *b1; 3762 3763 switch (dir) { 3764 case Q_SRC: 3765 return gen_bcmp(OR_LINK, 8, 6, eaddr); 3766 3767 case Q_DST: 3768 return gen_bcmp(OR_LINK, 2, 6, eaddr); 3769 3770 case Q_AND: 3771 b0 = gen_thostop(eaddr, Q_SRC); 3772 b1 = gen_thostop(eaddr, Q_DST); 3773 gen_and(b0, b1); 3774 return b1; 3775 3776 case Q_DEFAULT: 3777 case Q_OR: 3778 b0 = gen_thostop(eaddr, Q_SRC); 3779 b1 = gen_thostop(eaddr, Q_DST); 3780 gen_or(b0, b1); 3781 return b1; 3782 3783 case Q_ADDR1: 3784 bpf_error("'addr1' is only supported on 802.11"); 3785 break; 3786 3787 case Q_ADDR2: 3788 bpf_error("'addr2' is only supported on 802.11"); 3789 break; 3790 3791 case Q_ADDR3: 3792 bpf_error("'addr3' is only supported on 802.11"); 3793 break; 3794 3795 case Q_ADDR4: 3796 bpf_error("'addr4' is only supported on 802.11"); 3797 break; 3798 3799 case Q_RA: 3800 bpf_error("'ra' is only supported on 802.11"); 3801 break; 3802 3803 case Q_TA: 3804 bpf_error("'ta' is only supported on 802.11"); 3805 break; 3806 } 3807 abort(); 3808 /* NOTREACHED */ 3809 } 3810 3811 /* 3812 * Like gen_ehostop, but for DLT_IEEE802_11 (802.11 wireless LAN) and 3813 * various 802.11 + radio headers. 3814 */ 3815 static struct block * 3816 gen_wlanhostop(eaddr, dir) 3817 register const u_char *eaddr; 3818 register int dir; 3819 { 3820 register struct block *b0, *b1, *b2; 3821 register struct slist *s; 3822 3823 #ifdef ENABLE_WLAN_FILTERING_PATCH 3824 /* 3825 * TODO GV 20070613 3826 * We need to disable the optimizer because the optimizer is buggy 3827 * and wipes out some LD instructions generated by the below 3828 * code to validate the Frame Control bits 3829 */ 3830 no_optimize = 1; 3831 #endif /* ENABLE_WLAN_FILTERING_PATCH */ 3832 3833 switch (dir) { 3834 case Q_SRC: 3835 /* 3836 * Oh, yuk. 3837 * 3838 * For control frames, there is no SA. 3839 * 3840 * For management frames, SA is at an 3841 * offset of 10 from the beginning of 3842 * the packet. 3843 * 3844 * For data frames, SA is at an offset 3845 * of 10 from the beginning of the packet 3846 * if From DS is clear, at an offset of 3847 * 16 from the beginning of the packet 3848 * if From DS is set and To DS is clear, 3849 * and an offset of 24 from the beginning 3850 * of the packet if From DS is set and To DS 3851 * is set. 3852 */ 3853 3854 /* 3855 * Generate the tests to be done for data frames 3856 * with From DS set. 3857 * 3858 * First, check for To DS set, i.e. check "link[1] & 0x01". 3859 */ 3860 s = gen_load_a(OR_LINK, 1, BPF_B); 3861 b1 = new_block(JMP(BPF_JSET)); 3862 b1->s.k = 0x01; /* To DS */ 3863 b1->stmts = s; 3864 3865 /* 3866 * If To DS is set, the SA is at 24. 3867 */ 3868 b0 = gen_bcmp(OR_LINK, 24, 6, eaddr); 3869 gen_and(b1, b0); 3870 3871 /* 3872 * Now, check for To DS not set, i.e. check 3873 * "!(link[1] & 0x01)". 3874 */ 3875 s = gen_load_a(OR_LINK, 1, BPF_B); 3876 b2 = new_block(JMP(BPF_JSET)); 3877 b2->s.k = 0x01; /* To DS */ 3878 b2->stmts = s; 3879 gen_not(b2); 3880 3881 /* 3882 * If To DS is not set, the SA is at 16. 3883 */ 3884 b1 = gen_bcmp(OR_LINK, 16, 6, eaddr); 3885 gen_and(b2, b1); 3886 3887 /* 3888 * Now OR together the last two checks. That gives 3889 * the complete set of checks for data frames with 3890 * From DS set. 3891 */ 3892 gen_or(b1, b0); 3893 3894 /* 3895 * Now check for From DS being set, and AND that with 3896 * the ORed-together checks. 3897 */ 3898 s = gen_load_a(OR_LINK, 1, BPF_B); 3899 b1 = new_block(JMP(BPF_JSET)); 3900 b1->s.k = 0x02; /* From DS */ 3901 b1->stmts = s; 3902 gen_and(b1, b0); 3903 3904 /* 3905 * Now check for data frames with From DS not set. 3906 */ 3907 s = gen_load_a(OR_LINK, 1, BPF_B); 3908 b2 = new_block(JMP(BPF_JSET)); 3909 b2->s.k = 0x02; /* From DS */ 3910 b2->stmts = s; 3911 gen_not(b2); 3912 3913 /* 3914 * If From DS isn't set, the SA is at 10. 3915 */ 3916 b1 = gen_bcmp(OR_LINK, 10, 6, eaddr); 3917 gen_and(b2, b1); 3918 3919 /* 3920 * Now OR together the checks for data frames with 3921 * From DS not set and for data frames with From DS 3922 * set; that gives the checks done for data frames. 3923 */ 3924 gen_or(b1, b0); 3925 3926 /* 3927 * Now check for a data frame. 3928 * I.e, check "link[0] & 0x08". 3929 */ 3930 s = gen_load_a(OR_LINK, 0, BPF_B); 3931 b1 = new_block(JMP(BPF_JSET)); 3932 b1->s.k = 0x08; 3933 b1->stmts = s; 3934 3935 /* 3936 * AND that with the checks done for data frames. 3937 */ 3938 gen_and(b1, b0); 3939 3940 /* 3941 * If the high-order bit of the type value is 0, this 3942 * is a management frame. 3943 * I.e, check "!(link[0] & 0x08)". 3944 */ 3945 s = gen_load_a(OR_LINK, 0, BPF_B); 3946 b2 = new_block(JMP(BPF_JSET)); 3947 b2->s.k = 0x08; 3948 b2->stmts = s; 3949 gen_not(b2); 3950 3951 /* 3952 * For management frames, the SA is at 10. 3953 */ 3954 b1 = gen_bcmp(OR_LINK, 10, 6, eaddr); 3955 gen_and(b2, b1); 3956 3957 /* 3958 * OR that with the checks done for data frames. 3959 * That gives the checks done for management and 3960 * data frames. 3961 */ 3962 gen_or(b1, b0); 3963 3964 /* 3965 * If the low-order bit of the type value is 1, 3966 * this is either a control frame or a frame 3967 * with a reserved type, and thus not a 3968 * frame with an SA. 3969 * 3970 * I.e., check "!(link[0] & 0x04)". 3971 */ 3972 s = gen_load_a(OR_LINK, 0, BPF_B); 3973 b1 = new_block(JMP(BPF_JSET)); 3974 b1->s.k = 0x04; 3975 b1->stmts = s; 3976 gen_not(b1); 3977 3978 /* 3979 * AND that with the checks for data and management 3980 * frames. 3981 */ 3982 gen_and(b1, b0); 3983 return b0; 3984 3985 case Q_DST: 3986 /* 3987 * Oh, yuk. 3988 * 3989 * For control frames, there is no DA. 3990 * 3991 * For management frames, DA is at an 3992 * offset of 4 from the beginning of 3993 * the packet. 3994 * 3995 * For data frames, DA is at an offset 3996 * of 4 from the beginning of the packet 3997 * if To DS is clear and at an offset of 3998 * 16 from the beginning of the packet 3999 * if To DS is set. 4000 */ 4001 4002 /* 4003 * Generate the tests to be done for data frames. 4004 * 4005 * First, check for To DS set, i.e. "link[1] & 0x01". 4006 */ 4007 s = gen_load_a(OR_LINK, 1, BPF_B); 4008 b1 = new_block(JMP(BPF_JSET)); 4009 b1->s.k = 0x01; /* To DS */ 4010 b1->stmts = s; 4011 4012 /* 4013 * If To DS is set, the DA is at 16. 4014 */ 4015 b0 = gen_bcmp(OR_LINK, 16, 6, eaddr); 4016 gen_and(b1, b0); 4017 4018 /* 4019 * Now, check for To DS not set, i.e. check 4020 * "!(link[1] & 0x01)". 4021 */ 4022 s = gen_load_a(OR_LINK, 1, BPF_B); 4023 b2 = new_block(JMP(BPF_JSET)); 4024 b2->s.k = 0x01; /* To DS */ 4025 b2->stmts = s; 4026 gen_not(b2); 4027 4028 /* 4029 * If To DS is not set, the DA is at 4. 4030 */ 4031 b1 = gen_bcmp(OR_LINK, 4, 6, eaddr); 4032 gen_and(b2, b1); 4033 4034 /* 4035 * Now OR together the last two checks. That gives 4036 * the complete set of checks for data frames. 4037 */ 4038 gen_or(b1, b0); 4039 4040 /* 4041 * Now check for a data frame. 4042 * I.e, check "link[0] & 0x08". 4043 */ 4044 s = gen_load_a(OR_LINK, 0, BPF_B); 4045 b1 = new_block(JMP(BPF_JSET)); 4046 b1->s.k = 0x08; 4047 b1->stmts = s; 4048 4049 /* 4050 * AND that with the checks done for data frames. 4051 */ 4052 gen_and(b1, b0); 4053 4054 /* 4055 * If the high-order bit of the type value is 0, this 4056 * is a management frame. 4057 * I.e, check "!(link[0] & 0x08)". 4058 */ 4059 s = gen_load_a(OR_LINK, 0, BPF_B); 4060 b2 = new_block(JMP(BPF_JSET)); 4061 b2->s.k = 0x08; 4062 b2->stmts = s; 4063 gen_not(b2); 4064 4065 /* 4066 * For management frames, the DA is at 4. 4067 */ 4068 b1 = gen_bcmp(OR_LINK, 4, 6, eaddr); 4069 gen_and(b2, b1); 4070 4071 /* 4072 * OR that with the checks done for data frames. 4073 * That gives the checks done for management and 4074 * data frames. 4075 */ 4076 gen_or(b1, b0); 4077 4078 /* 4079 * If the low-order bit of the type value is 1, 4080 * this is either a control frame or a frame 4081 * with a reserved type, and thus not a 4082 * frame with an SA. 4083 * 4084 * I.e., check "!(link[0] & 0x04)". 4085 */ 4086 s = gen_load_a(OR_LINK, 0, BPF_B); 4087 b1 = new_block(JMP(BPF_JSET)); 4088 b1->s.k = 0x04; 4089 b1->stmts = s; 4090 gen_not(b1); 4091 4092 /* 4093 * AND that with the checks for data and management 4094 * frames. 4095 */ 4096 gen_and(b1, b0); 4097 return b0; 4098 4099 case Q_RA: 4100 /* 4101 * Not present in management frames; addr1 in other 4102 * frames. 4103 */ 4104 4105 /* 4106 * If the high-order bit of the type value is 0, this 4107 * is a management frame. 4108 * I.e, check "(link[0] & 0x08)". 4109 */ 4110 s = gen_load_a(OR_LINK, 0, BPF_B); 4111 b1 = new_block(JMP(BPF_JSET)); 4112 b1->s.k = 0x08; 4113 b1->stmts = s; 4114 4115 /* 4116 * Check addr1. 4117 */ 4118 b0 = gen_bcmp(OR_LINK, 4, 6, eaddr); 4119 4120 /* 4121 * AND that with the check of addr1. 4122 */ 4123 gen_and(b1, b0); 4124 return (b0); 4125 4126 case Q_TA: 4127 /* 4128 * Not present in management frames; addr2, if present, 4129 * in other frames. 4130 */ 4131 4132 /* 4133 * Not present in CTS or ACK control frames. 4134 */ 4135 b0 = gen_mcmp(OR_LINK, 0, BPF_B, IEEE80211_FC0_TYPE_CTL, 4136 IEEE80211_FC0_TYPE_MASK); 4137 gen_not(b0); 4138 b1 = gen_mcmp(OR_LINK, 0, BPF_B, IEEE80211_FC0_SUBTYPE_CTS, 4139 IEEE80211_FC0_SUBTYPE_MASK); 4140 gen_not(b1); 4141 b2 = gen_mcmp(OR_LINK, 0, BPF_B, IEEE80211_FC0_SUBTYPE_ACK, 4142 IEEE80211_FC0_SUBTYPE_MASK); 4143 gen_not(b2); 4144 gen_and(b1, b2); 4145 gen_or(b0, b2); 4146 4147 /* 4148 * If the high-order bit of the type value is 0, this 4149 * is a management frame. 4150 * I.e, check "(link[0] & 0x08)". 4151 */ 4152 s = gen_load_a(OR_LINK, 0, BPF_B); 4153 b1 = new_block(JMP(BPF_JSET)); 4154 b1->s.k = 0x08; 4155 b1->stmts = s; 4156 4157 /* 4158 * AND that with the check for frames other than 4159 * CTS and ACK frames. 4160 */ 4161 gen_and(b1, b2); 4162 4163 /* 4164 * Check addr2. 4165 */ 4166 b1 = gen_bcmp(OR_LINK, 10, 6, eaddr); 4167 gen_and(b2, b1); 4168 return b1; 4169 4170 /* 4171 * XXX - add BSSID keyword? 4172 */ 4173 case Q_ADDR1: 4174 return (gen_bcmp(OR_LINK, 4, 6, eaddr)); 4175 4176 case Q_ADDR2: 4177 /* 4178 * Not present in CTS or ACK control frames. 4179 */ 4180 b0 = gen_mcmp(OR_LINK, 0, BPF_B, IEEE80211_FC0_TYPE_CTL, 4181 IEEE80211_FC0_TYPE_MASK); 4182 gen_not(b0); 4183 b1 = gen_mcmp(OR_LINK, 0, BPF_B, IEEE80211_FC0_SUBTYPE_CTS, 4184 IEEE80211_FC0_SUBTYPE_MASK); 4185 gen_not(b1); 4186 b2 = gen_mcmp(OR_LINK, 0, BPF_B, IEEE80211_FC0_SUBTYPE_ACK, 4187 IEEE80211_FC0_SUBTYPE_MASK); 4188 gen_not(b2); 4189 gen_and(b1, b2); 4190 gen_or(b0, b2); 4191 b1 = gen_bcmp(OR_LINK, 10, 6, eaddr); 4192 gen_and(b2, b1); 4193 return b1; 4194 4195 case Q_ADDR3: 4196 /* 4197 * Not present in control frames. 4198 */ 4199 b0 = gen_mcmp(OR_LINK, 0, BPF_B, IEEE80211_FC0_TYPE_CTL, 4200 IEEE80211_FC0_TYPE_MASK); 4201 gen_not(b0); 4202 b1 = gen_bcmp(OR_LINK, 16, 6, eaddr); 4203 gen_and(b0, b1); 4204 return b1; 4205 4206 case Q_ADDR4: 4207 /* 4208 * Present only if the direction mask has both "From DS" 4209 * and "To DS" set. Neither control frames nor management 4210 * frames should have both of those set, so we don't 4211 * check the frame type. 4212 */ 4213 b0 = gen_mcmp(OR_LINK, 1, BPF_B, 4214 IEEE80211_FC1_DIR_DSTODS, IEEE80211_FC1_DIR_MASK); 4215 b1 = gen_bcmp(OR_LINK, 24, 6, eaddr); 4216 gen_and(b0, b1); 4217 return b1; 4218 4219 case Q_AND: 4220 b0 = gen_wlanhostop(eaddr, Q_SRC); 4221 b1 = gen_wlanhostop(eaddr, Q_DST); 4222 gen_and(b0, b1); 4223 return b1; 4224 4225 case Q_DEFAULT: 4226 case Q_OR: 4227 b0 = gen_wlanhostop(eaddr, Q_SRC); 4228 b1 = gen_wlanhostop(eaddr, Q_DST); 4229 gen_or(b0, b1); 4230 return b1; 4231 } 4232 abort(); 4233 /* NOTREACHED */ 4234 } 4235 4236 /* 4237 * Like gen_ehostop, but for RFC 2625 IP-over-Fibre-Channel. 4238 * (We assume that the addresses are IEEE 48-bit MAC addresses, 4239 * as the RFC states.) 4240 */ 4241 static struct block * 4242 gen_ipfchostop(eaddr, dir) 4243 register const u_char *eaddr; 4244 register int dir; 4245 { 4246 register struct block *b0, *b1; 4247 4248 switch (dir) { 4249 case Q_SRC: 4250 return gen_bcmp(OR_LINK, 10, 6, eaddr); 4251 4252 case Q_DST: 4253 return gen_bcmp(OR_LINK, 2, 6, eaddr); 4254 4255 case Q_AND: 4256 b0 = gen_ipfchostop(eaddr, Q_SRC); 4257 b1 = gen_ipfchostop(eaddr, Q_DST); 4258 gen_and(b0, b1); 4259 return b1; 4260 4261 case Q_DEFAULT: 4262 case Q_OR: 4263 b0 = gen_ipfchostop(eaddr, Q_SRC); 4264 b1 = gen_ipfchostop(eaddr, Q_DST); 4265 gen_or(b0, b1); 4266 return b1; 4267 4268 case Q_ADDR1: 4269 bpf_error("'addr1' is only supported on 802.11"); 4270 break; 4271 4272 case Q_ADDR2: 4273 bpf_error("'addr2' is only supported on 802.11"); 4274 break; 4275 4276 case Q_ADDR3: 4277 bpf_error("'addr3' is only supported on 802.11"); 4278 break; 4279 4280 case Q_ADDR4: 4281 bpf_error("'addr4' is only supported on 802.11"); 4282 break; 4283 4284 case Q_RA: 4285 bpf_error("'ra' is only supported on 802.11"); 4286 break; 4287 4288 case Q_TA: 4289 bpf_error("'ta' is only supported on 802.11"); 4290 break; 4291 } 4292 abort(); 4293 /* NOTREACHED */ 4294 } 4295 4296 /* 4297 * This is quite tricky because there may be pad bytes in front of the 4298 * DECNET header, and then there are two possible data packet formats that 4299 * carry both src and dst addresses, plus 5 packet types in a format that 4300 * carries only the src node, plus 2 types that use a different format and 4301 * also carry just the src node. 4302 * 4303 * Yuck. 4304 * 4305 * Instead of doing those all right, we just look for data packets with 4306 * 0 or 1 bytes of padding. If you want to look at other packets, that 4307 * will require a lot more hacking. 4308 * 4309 * To add support for filtering on DECNET "areas" (network numbers) 4310 * one would want to add a "mask" argument to this routine. That would 4311 * make the filter even more inefficient, although one could be clever 4312 * and not generate masking instructions if the mask is 0xFFFF. 4313 */ 4314 static struct block * 4315 gen_dnhostop(addr, dir) 4316 bpf_u_int32 addr; 4317 int dir; 4318 { 4319 struct block *b0, *b1, *b2, *tmp; 4320 u_int offset_lh; /* offset if long header is received */ 4321 u_int offset_sh; /* offset if short header is received */ 4322 4323 switch (dir) { 4324 4325 case Q_DST: 4326 offset_sh = 1; /* follows flags */ 4327 offset_lh = 7; /* flgs,darea,dsubarea,HIORD */ 4328 break; 4329 4330 case Q_SRC: 4331 offset_sh = 3; /* follows flags, dstnode */ 4332 offset_lh = 15; /* flgs,darea,dsubarea,did,sarea,ssub,HIORD */ 4333 break; 4334 4335 case Q_AND: 4336 /* Inefficient because we do our Calvinball dance twice */ 4337 b0 = gen_dnhostop(addr, Q_SRC); 4338 b1 = gen_dnhostop(addr, Q_DST); 4339 gen_and(b0, b1); 4340 return b1; 4341 4342 case Q_OR: 4343 case Q_DEFAULT: 4344 /* Inefficient because we do our Calvinball dance twice */ 4345 b0 = gen_dnhostop(addr, Q_SRC); 4346 b1 = gen_dnhostop(addr, Q_DST); 4347 gen_or(b0, b1); 4348 return b1; 4349 4350 case Q_ISO: 4351 bpf_error("ISO host filtering not implemented"); 4352 4353 default: 4354 abort(); 4355 } 4356 b0 = gen_linktype(ETHERTYPE_DN); 4357 /* Check for pad = 1, long header case */ 4358 tmp = gen_mcmp(OR_NET, 2, BPF_H, 4359 (bpf_int32)ntohs(0x0681), (bpf_int32)ntohs(0x07FF)); 4360 b1 = gen_cmp(OR_NET, 2 + 1 + offset_lh, 4361 BPF_H, (bpf_int32)ntohs((u_short)addr)); 4362 gen_and(tmp, b1); 4363 /* Check for pad = 0, long header case */ 4364 tmp = gen_mcmp(OR_NET, 2, BPF_B, (bpf_int32)0x06, (bpf_int32)0x7); 4365 b2 = gen_cmp(OR_NET, 2 + offset_lh, BPF_H, (bpf_int32)ntohs((u_short)addr)); 4366 gen_and(tmp, b2); 4367 gen_or(b2, b1); 4368 /* Check for pad = 1, short header case */ 4369 tmp = gen_mcmp(OR_NET, 2, BPF_H, 4370 (bpf_int32)ntohs(0x0281), (bpf_int32)ntohs(0x07FF)); 4371 b2 = gen_cmp(OR_NET, 2 + 1 + offset_sh, BPF_H, (bpf_int32)ntohs((u_short)addr)); 4372 gen_and(tmp, b2); 4373 gen_or(b2, b1); 4374 /* Check for pad = 0, short header case */ 4375 tmp = gen_mcmp(OR_NET, 2, BPF_B, (bpf_int32)0x02, (bpf_int32)0x7); 4376 b2 = gen_cmp(OR_NET, 2 + offset_sh, BPF_H, (bpf_int32)ntohs((u_short)addr)); 4377 gen_and(tmp, b2); 4378 gen_or(b2, b1); 4379 4380 /* Combine with test for linktype */ 4381 gen_and(b0, b1); 4382 return b1; 4383 } 4384 4385 /* 4386 * Generate a check for IPv4 or IPv6 for MPLS-encapsulated packets; 4387 * test the bottom-of-stack bit, and then check the version number 4388 * field in the IP header. 4389 */ 4390 static struct block * 4391 gen_mpls_linktype(proto) 4392 int proto; 4393 { 4394 struct block *b0, *b1; 4395 4396 switch (proto) { 4397 4398 case Q_IP: 4399 /* match the bottom-of-stack bit */ 4400 b0 = gen_mcmp(OR_NET, -2, BPF_B, 0x01, 0x01); 4401 /* match the IPv4 version number */ 4402 b1 = gen_mcmp(OR_NET, 0, BPF_B, 0x40, 0xf0); 4403 gen_and(b0, b1); 4404 return b1; 4405 4406 case Q_IPV6: 4407 /* match the bottom-of-stack bit */ 4408 b0 = gen_mcmp(OR_NET, -2, BPF_B, 0x01, 0x01); 4409 /* match the IPv4 version number */ 4410 b1 = gen_mcmp(OR_NET, 0, BPF_B, 0x60, 0xf0); 4411 gen_and(b0, b1); 4412 return b1; 4413 4414 default: 4415 abort(); 4416 } 4417 } 4418 4419 static struct block * 4420 gen_host(addr, mask, proto, dir, type) 4421 bpf_u_int32 addr; 4422 bpf_u_int32 mask; 4423 int proto; 4424 int dir; 4425 int type; 4426 { 4427 struct block *b0, *b1; 4428 const char *typestr; 4429 4430 if (type == Q_NET) 4431 typestr = "net"; 4432 else 4433 typestr = "host"; 4434 4435 switch (proto) { 4436 4437 case Q_DEFAULT: 4438 b0 = gen_host(addr, mask, Q_IP, dir, type); 4439 /* 4440 * Only check for non-IPv4 addresses if we're not 4441 * checking MPLS-encapsulated packets. 4442 */ 4443 if (label_stack_depth == 0) { 4444 b1 = gen_host(addr, mask, Q_ARP, dir, type); 4445 gen_or(b0, b1); 4446 b0 = gen_host(addr, mask, Q_RARP, dir, type); 4447 gen_or(b1, b0); 4448 } 4449 return b0; 4450 4451 case Q_IP: 4452 return gen_hostop(addr, mask, dir, ETHERTYPE_IP, 12, 16); 4453 4454 case Q_RARP: 4455 return gen_hostop(addr, mask, dir, ETHERTYPE_REVARP, 14, 24); 4456 4457 case Q_ARP: 4458 return gen_hostop(addr, mask, dir, ETHERTYPE_ARP, 14, 24); 4459 4460 case Q_TCP: 4461 bpf_error("'tcp' modifier applied to %s", typestr); 4462 4463 case Q_SCTP: 4464 bpf_error("'sctp' modifier applied to %s", typestr); 4465 4466 case Q_UDP: 4467 bpf_error("'udp' modifier applied to %s", typestr); 4468 4469 case Q_ICMP: 4470 bpf_error("'icmp' modifier applied to %s", typestr); 4471 4472 case Q_IGMP: 4473 bpf_error("'igmp' modifier applied to %s", typestr); 4474 4475 case Q_IGRP: 4476 bpf_error("'igrp' modifier applied to %s", typestr); 4477 4478 case Q_PIM: 4479 bpf_error("'pim' modifier applied to %s", typestr); 4480 4481 case Q_VRRP: 4482 bpf_error("'vrrp' modifier applied to %s", typestr); 4483 4484 case Q_CARP: 4485 bpf_error("'carp' modifier applied to %s", typestr); 4486 4487 case Q_ATALK: 4488 bpf_error("ATALK host filtering not implemented"); 4489 4490 case Q_AARP: 4491 bpf_error("AARP host filtering not implemented"); 4492 4493 case Q_DECNET: 4494 return gen_dnhostop(addr, dir); 4495 4496 case Q_SCA: 4497 bpf_error("SCA host filtering not implemented"); 4498 4499 case Q_LAT: 4500 bpf_error("LAT host filtering not implemented"); 4501 4502 case Q_MOPDL: 4503 bpf_error("MOPDL host filtering not implemented"); 4504 4505 case Q_MOPRC: 4506 bpf_error("MOPRC host filtering not implemented"); 4507 4508 #ifdef INET6 4509 case Q_IPV6: 4510 bpf_error("'ip6' modifier applied to ip host"); 4511 4512 case Q_ICMPV6: 4513 bpf_error("'icmp6' modifier applied to %s", typestr); 4514 #endif /* INET6 */ 4515 4516 case Q_AH: 4517 bpf_error("'ah' modifier applied to %s", typestr); 4518 4519 case Q_ESP: 4520 bpf_error("'esp' modifier applied to %s", typestr); 4521 4522 case Q_ISO: 4523 bpf_error("ISO host filtering not implemented"); 4524 4525 case Q_ESIS: 4526 bpf_error("'esis' modifier applied to %s", typestr); 4527 4528 case Q_ISIS: 4529 bpf_error("'isis' modifier applied to %s", typestr); 4530 4531 case Q_CLNP: 4532 bpf_error("'clnp' modifier applied to %s", typestr); 4533 4534 case Q_STP: 4535 bpf_error("'stp' modifier applied to %s", typestr); 4536 4537 case Q_IPX: 4538 bpf_error("IPX host filtering not implemented"); 4539 4540 case Q_NETBEUI: 4541 bpf_error("'netbeui' modifier applied to %s", typestr); 4542 4543 case Q_RADIO: 4544 bpf_error("'radio' modifier applied to %s", typestr); 4545 4546 default: 4547 abort(); 4548 } 4549 /* NOTREACHED */ 4550 } 4551 4552 #ifdef INET6 4553 static struct block * 4554 gen_host6(addr, mask, proto, dir, type) 4555 struct in6_addr *addr; 4556 struct in6_addr *mask; 4557 int proto; 4558 int dir; 4559 int type; 4560 { 4561 const char *typestr; 4562 4563 if (type == Q_NET) 4564 typestr = "net"; 4565 else 4566 typestr = "host"; 4567 4568 switch (proto) { 4569 4570 case Q_DEFAULT: 4571 return gen_host6(addr, mask, Q_IPV6, dir, type); 4572 4573 case Q_IP: 4574 bpf_error("'ip' modifier applied to ip6 %s", typestr); 4575 4576 case Q_RARP: 4577 bpf_error("'rarp' modifier applied to ip6 %s", typestr); 4578 4579 case Q_ARP: 4580 bpf_error("'arp' modifier applied to ip6 %s", typestr); 4581 4582 case Q_SCTP: 4583 bpf_error("'sctp' modifier applied to %s", typestr); 4584 4585 case Q_TCP: 4586 bpf_error("'tcp' modifier applied to %s", typestr); 4587 4588 case Q_UDP: 4589 bpf_error("'udp' modifier applied to %s", typestr); 4590 4591 case Q_ICMP: 4592 bpf_error("'icmp' modifier applied to %s", typestr); 4593 4594 case Q_IGMP: 4595 bpf_error("'igmp' modifier applied to %s", typestr); 4596 4597 case Q_IGRP: 4598 bpf_error("'igrp' modifier applied to %s", typestr); 4599 4600 case Q_PIM: 4601 bpf_error("'pim' modifier applied to %s", typestr); 4602 4603 case Q_VRRP: 4604 bpf_error("'vrrp' modifier applied to %s", typestr); 4605 4606 case Q_CARP: 4607 bpf_error("'carp' modifier applied to %s", typestr); 4608 4609 case Q_ATALK: 4610 bpf_error("ATALK host filtering not implemented"); 4611 4612 case Q_AARP: 4613 bpf_error("AARP host filtering not implemented"); 4614 4615 case Q_DECNET: 4616 bpf_error("'decnet' modifier applied to ip6 %s", typestr); 4617 4618 case Q_SCA: 4619 bpf_error("SCA host filtering not implemented"); 4620 4621 case Q_LAT: 4622 bpf_error("LAT host filtering not implemented"); 4623 4624 case Q_MOPDL: 4625 bpf_error("MOPDL host filtering not implemented"); 4626 4627 case Q_MOPRC: 4628 bpf_error("MOPRC host filtering not implemented"); 4629 4630 case Q_IPV6: 4631 return gen_hostop6(addr, mask, dir, ETHERTYPE_IPV6, 8, 24); 4632 4633 case Q_ICMPV6: 4634 bpf_error("'icmp6' modifier applied to %s", typestr); 4635 4636 case Q_AH: 4637 bpf_error("'ah' modifier applied to %s", typestr); 4638 4639 case Q_ESP: 4640 bpf_error("'esp' modifier applied to %s", typestr); 4641 4642 case Q_ISO: 4643 bpf_error("ISO host filtering not implemented"); 4644 4645 case Q_ESIS: 4646 bpf_error("'esis' modifier applied to %s", typestr); 4647 4648 case Q_ISIS: 4649 bpf_error("'isis' modifier applied to %s", typestr); 4650 4651 case Q_CLNP: 4652 bpf_error("'clnp' modifier applied to %s", typestr); 4653 4654 case Q_STP: 4655 bpf_error("'stp' modifier applied to %s", typestr); 4656 4657 case Q_IPX: 4658 bpf_error("IPX host filtering not implemented"); 4659 4660 case Q_NETBEUI: 4661 bpf_error("'netbeui' modifier applied to %s", typestr); 4662 4663 case Q_RADIO: 4664 bpf_error("'radio' modifier applied to %s", typestr); 4665 4666 default: 4667 abort(); 4668 } 4669 /* NOTREACHED */ 4670 } 4671 #endif /*INET6*/ 4672 4673 #ifndef INET6 4674 static struct block * 4675 gen_gateway(eaddr, alist, proto, dir) 4676 const u_char *eaddr; 4677 bpf_u_int32 **alist; 4678 int proto; 4679 int dir; 4680 { 4681 struct block *b0, *b1, *tmp; 4682 4683 if (dir != 0) 4684 bpf_error("direction applied to 'gateway'"); 4685 4686 switch (proto) { 4687 case Q_DEFAULT: 4688 case Q_IP: 4689 case Q_ARP: 4690 case Q_RARP: 4691 switch (linktype) { 4692 case DLT_EN10MB: 4693 case DLT_NETANALYZER: 4694 case DLT_NETANALYZER_TRANSPARENT: 4695 b0 = gen_ehostop(eaddr, Q_OR); 4696 break; 4697 case DLT_FDDI: 4698 b0 = gen_fhostop(eaddr, Q_OR); 4699 break; 4700 case DLT_IEEE802: 4701 b0 = gen_thostop(eaddr, Q_OR); 4702 break; 4703 case DLT_IEEE802_11: 4704 case DLT_PRISM_HEADER: 4705 case DLT_IEEE802_11_RADIO_AVS: 4706 case DLT_IEEE802_11_RADIO: 4707 case DLT_PPI: 4708 b0 = gen_wlanhostop(eaddr, Q_OR); 4709 break; 4710 case DLT_SUNATM: 4711 if (!is_lane) 4712 bpf_error( 4713 "'gateway' supported only on ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel"); 4714 /* 4715 * Check that the packet doesn't begin with an 4716 * LE Control marker. (We've already generated 4717 * a test for LANE.) 4718 */ 4719 b1 = gen_cmp(OR_LINK, SUNATM_PKT_BEGIN_POS, 4720 BPF_H, 0xFF00); 4721 gen_not(b1); 4722 4723 /* 4724 * Now check the MAC address. 4725 */ 4726 b0 = gen_ehostop(eaddr, Q_OR); 4727 gen_and(b1, b0); 4728 break; 4729 case DLT_IP_OVER_FC: 4730 b0 = gen_ipfchostop(eaddr, Q_OR); 4731 break; 4732 default: 4733 bpf_error( 4734 "'gateway' supported only on ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel"); 4735 } 4736 b1 = gen_host(**alist++, 0xffffffff, proto, Q_OR, Q_HOST); 4737 while (*alist) { 4738 tmp = gen_host(**alist++, 0xffffffff, proto, Q_OR, 4739 Q_HOST); 4740 gen_or(b1, tmp); 4741 b1 = tmp; 4742 } 4743 gen_not(b1); 4744 gen_and(b0, b1); 4745 return b1; 4746 } 4747 bpf_error("illegal modifier of 'gateway'"); 4748 /* NOTREACHED */ 4749 } 4750 #endif 4751 4752 struct block * 4753 gen_proto_abbrev(proto) 4754 int proto; 4755 { 4756 struct block *b0; 4757 struct block *b1; 4758 4759 switch (proto) { 4760 4761 case Q_SCTP: 4762 b1 = gen_proto(IPPROTO_SCTP, Q_IP, Q_DEFAULT); 4763 #ifdef INET6 4764 b0 = gen_proto(IPPROTO_SCTP, Q_IPV6, Q_DEFAULT); 4765 gen_or(b0, b1); 4766 #endif 4767 break; 4768 4769 case Q_TCP: 4770 b1 = gen_proto(IPPROTO_TCP, Q_IP, Q_DEFAULT); 4771 #ifdef INET6 4772 b0 = gen_proto(IPPROTO_TCP, Q_IPV6, Q_DEFAULT); 4773 gen_or(b0, b1); 4774 #endif 4775 break; 4776 4777 case Q_UDP: 4778 b1 = gen_proto(IPPROTO_UDP, Q_IP, Q_DEFAULT); 4779 #ifdef INET6 4780 b0 = gen_proto(IPPROTO_UDP, Q_IPV6, Q_DEFAULT); 4781 gen_or(b0, b1); 4782 #endif 4783 break; 4784 4785 case Q_ICMP: 4786 b1 = gen_proto(IPPROTO_ICMP, Q_IP, Q_DEFAULT); 4787 break; 4788 4789 #ifndef IPPROTO_IGMP 4790 #define IPPROTO_IGMP 2 4791 #endif 4792 4793 case Q_IGMP: 4794 b1 = gen_proto(IPPROTO_IGMP, Q_IP, Q_DEFAULT); 4795 break; 4796 4797 #ifndef IPPROTO_IGRP 4798 #define IPPROTO_IGRP 9 4799 #endif 4800 case Q_IGRP: 4801 b1 = gen_proto(IPPROTO_IGRP, Q_IP, Q_DEFAULT); 4802 break; 4803 4804 #ifndef IPPROTO_PIM 4805 #define IPPROTO_PIM 103 4806 #endif 4807 4808 case Q_PIM: 4809 b1 = gen_proto(IPPROTO_PIM, Q_IP, Q_DEFAULT); 4810 #ifdef INET6 4811 b0 = gen_proto(IPPROTO_PIM, Q_IPV6, Q_DEFAULT); 4812 gen_or(b0, b1); 4813 #endif 4814 break; 4815 4816 #ifndef IPPROTO_VRRP 4817 #define IPPROTO_VRRP 112 4818 #endif 4819 4820 case Q_VRRP: 4821 b1 = gen_proto(IPPROTO_VRRP, Q_IP, Q_DEFAULT); 4822 break; 4823 4824 #ifndef IPPROTO_CARP 4825 #define IPPROTO_CARP 112 4826 #endif 4827 4828 case Q_CARP: 4829 b1 = gen_proto(IPPROTO_CARP, Q_IP, Q_DEFAULT); 4830 break; 4831 4832 case Q_IP: 4833 b1 = gen_linktype(ETHERTYPE_IP); 4834 break; 4835 4836 case Q_ARP: 4837 b1 = gen_linktype(ETHERTYPE_ARP); 4838 break; 4839 4840 case Q_RARP: 4841 b1 = gen_linktype(ETHERTYPE_REVARP); 4842 break; 4843 4844 case Q_LINK: 4845 bpf_error("link layer applied in wrong context"); 4846 4847 case Q_ATALK: 4848 b1 = gen_linktype(ETHERTYPE_ATALK); 4849 break; 4850 4851 case Q_AARP: 4852 b1 = gen_linktype(ETHERTYPE_AARP); 4853 break; 4854 4855 case Q_DECNET: 4856 b1 = gen_linktype(ETHERTYPE_DN); 4857 break; 4858 4859 case Q_SCA: 4860 b1 = gen_linktype(ETHERTYPE_SCA); 4861 break; 4862 4863 case Q_LAT: 4864 b1 = gen_linktype(ETHERTYPE_LAT); 4865 break; 4866 4867 case Q_MOPDL: 4868 b1 = gen_linktype(ETHERTYPE_MOPDL); 4869 break; 4870 4871 case Q_MOPRC: 4872 b1 = gen_linktype(ETHERTYPE_MOPRC); 4873 break; 4874 4875 #ifdef INET6 4876 case Q_IPV6: 4877 b1 = gen_linktype(ETHERTYPE_IPV6); 4878 break; 4879 4880 #ifndef IPPROTO_ICMPV6 4881 #define IPPROTO_ICMPV6 58 4882 #endif 4883 case Q_ICMPV6: 4884 b1 = gen_proto(IPPROTO_ICMPV6, Q_IPV6, Q_DEFAULT); 4885 break; 4886 #endif /* INET6 */ 4887 4888 #ifndef IPPROTO_AH 4889 #define IPPROTO_AH 51 4890 #endif 4891 case Q_AH: 4892 b1 = gen_proto(IPPROTO_AH, Q_IP, Q_DEFAULT); 4893 #ifdef INET6 4894 b0 = gen_proto(IPPROTO_AH, Q_IPV6, Q_DEFAULT); 4895 gen_or(b0, b1); 4896 #endif 4897 break; 4898 4899 #ifndef IPPROTO_ESP 4900 #define IPPROTO_ESP 50 4901 #endif 4902 case Q_ESP: 4903 b1 = gen_proto(IPPROTO_ESP, Q_IP, Q_DEFAULT); 4904 #ifdef INET6 4905 b0 = gen_proto(IPPROTO_ESP, Q_IPV6, Q_DEFAULT); 4906 gen_or(b0, b1); 4907 #endif 4908 break; 4909 4910 case Q_ISO: 4911 b1 = gen_linktype(LLCSAP_ISONS); 4912 break; 4913 4914 case Q_ESIS: 4915 b1 = gen_proto(ISO9542_ESIS, Q_ISO, Q_DEFAULT); 4916 break; 4917 4918 case Q_ISIS: 4919 b1 = gen_proto(ISO10589_ISIS, Q_ISO, Q_DEFAULT); 4920 break; 4921 4922 case Q_ISIS_L1: /* all IS-IS Level1 PDU-Types */ 4923 b0 = gen_proto(ISIS_L1_LAN_IIH, Q_ISIS, Q_DEFAULT); 4924 b1 = gen_proto(ISIS_PTP_IIH, Q_ISIS, Q_DEFAULT); /* FIXME extract the circuit-type bits */ 4925 gen_or(b0, b1); 4926 b0 = gen_proto(ISIS_L1_LSP, Q_ISIS, Q_DEFAULT); 4927 gen_or(b0, b1); 4928 b0 = gen_proto(ISIS_L1_CSNP, Q_ISIS, Q_DEFAULT); 4929 gen_or(b0, b1); 4930 b0 = gen_proto(ISIS_L1_PSNP, Q_ISIS, Q_DEFAULT); 4931 gen_or(b0, b1); 4932 break; 4933 4934 case Q_ISIS_L2: /* all IS-IS Level2 PDU-Types */ 4935 b0 = gen_proto(ISIS_L2_LAN_IIH, Q_ISIS, Q_DEFAULT); 4936 b1 = gen_proto(ISIS_PTP_IIH, Q_ISIS, Q_DEFAULT); /* FIXME extract the circuit-type bits */ 4937 gen_or(b0, b1); 4938 b0 = gen_proto(ISIS_L2_LSP, Q_ISIS, Q_DEFAULT); 4939 gen_or(b0, b1); 4940 b0 = gen_proto(ISIS_L2_CSNP, Q_ISIS, Q_DEFAULT); 4941 gen_or(b0, b1); 4942 b0 = gen_proto(ISIS_L2_PSNP, Q_ISIS, Q_DEFAULT); 4943 gen_or(b0, b1); 4944 break; 4945 4946 case Q_ISIS_IIH: /* all IS-IS Hello PDU-Types */ 4947 b0 = gen_proto(ISIS_L1_LAN_IIH, Q_ISIS, Q_DEFAULT); 4948 b1 = gen_proto(ISIS_L2_LAN_IIH, Q_ISIS, Q_DEFAULT); 4949 gen_or(b0, b1); 4950 b0 = gen_proto(ISIS_PTP_IIH, Q_ISIS, Q_DEFAULT); 4951 gen_or(b0, b1); 4952 break; 4953 4954 case Q_ISIS_LSP: 4955 b0 = gen_proto(ISIS_L1_LSP, Q_ISIS, Q_DEFAULT); 4956 b1 = gen_proto(ISIS_L2_LSP, Q_ISIS, Q_DEFAULT); 4957 gen_or(b0, b1); 4958 break; 4959 4960 case Q_ISIS_SNP: 4961 b0 = gen_proto(ISIS_L1_CSNP, Q_ISIS, Q_DEFAULT); 4962 b1 = gen_proto(ISIS_L2_CSNP, Q_ISIS, Q_DEFAULT); 4963 gen_or(b0, b1); 4964 b0 = gen_proto(ISIS_L1_PSNP, Q_ISIS, Q_DEFAULT); 4965 gen_or(b0, b1); 4966 b0 = gen_proto(ISIS_L2_PSNP, Q_ISIS, Q_DEFAULT); 4967 gen_or(b0, b1); 4968 break; 4969 4970 case Q_ISIS_CSNP: 4971 b0 = gen_proto(ISIS_L1_CSNP, Q_ISIS, Q_DEFAULT); 4972 b1 = gen_proto(ISIS_L2_CSNP, Q_ISIS, Q_DEFAULT); 4973 gen_or(b0, b1); 4974 break; 4975 4976 case Q_ISIS_PSNP: 4977 b0 = gen_proto(ISIS_L1_PSNP, Q_ISIS, Q_DEFAULT); 4978 b1 = gen_proto(ISIS_L2_PSNP, Q_ISIS, Q_DEFAULT); 4979 gen_or(b0, b1); 4980 break; 4981 4982 case Q_CLNP: 4983 b1 = gen_proto(ISO8473_CLNP, Q_ISO, Q_DEFAULT); 4984 break; 4985 4986 case Q_STP: 4987 b1 = gen_linktype(LLCSAP_8021D); 4988 break; 4989 4990 case Q_IPX: 4991 b1 = gen_linktype(LLCSAP_IPX); 4992 break; 4993 4994 case Q_NETBEUI: 4995 b1 = gen_linktype(LLCSAP_NETBEUI); 4996 break; 4997 4998 case Q_RADIO: 4999 bpf_error("'radio' is not a valid protocol type"); 5000 5001 default: 5002 abort(); 5003 } 5004 return b1; 5005 } 5006 5007 static struct block * 5008 gen_ipfrag() 5009 { 5010 struct slist *s; 5011 struct block *b; 5012 5013 /* not IPv4 frag other than the first frag */ 5014 s = gen_load_a(OR_NET, 6, BPF_H); 5015 b = new_block(JMP(BPF_JSET)); 5016 b->s.k = 0x1fff; 5017 b->stmts = s; 5018 gen_not(b); 5019 5020 return b; 5021 } 5022 5023 /* 5024 * Generate a comparison to a port value in the transport-layer header 5025 * at the specified offset from the beginning of that header. 5026 * 5027 * XXX - this handles a variable-length prefix preceding the link-layer 5028 * header, such as the radiotap or AVS radio prefix, but doesn't handle 5029 * variable-length link-layer headers (such as Token Ring or 802.11 5030 * headers). 5031 */ 5032 static struct block * 5033 gen_portatom(off, v) 5034 int off; 5035 bpf_int32 v; 5036 { 5037 return gen_cmp(OR_TRAN_IPV4, off, BPF_H, v); 5038 } 5039 5040 #ifdef INET6 5041 static struct block * 5042 gen_portatom6(off, v) 5043 int off; 5044 bpf_int32 v; 5045 { 5046 return gen_cmp(OR_TRAN_IPV6, off, BPF_H, v); 5047 } 5048 #endif/*INET6*/ 5049 5050 struct block * 5051 gen_portop(port, proto, dir) 5052 int port, proto, dir; 5053 { 5054 struct block *b0, *b1, *tmp; 5055 5056 /* ip proto 'proto' and not a fragment other than the first fragment */ 5057 tmp = gen_cmp(OR_NET, 9, BPF_B, (bpf_int32)proto); 5058 b0 = gen_ipfrag(); 5059 gen_and(tmp, b0); 5060 5061 switch (dir) { 5062 case Q_SRC: 5063 b1 = gen_portatom(0, (bpf_int32)port); 5064 break; 5065 5066 case Q_DST: 5067 b1 = gen_portatom(2, (bpf_int32)port); 5068 break; 5069 5070 case Q_OR: 5071 case Q_DEFAULT: 5072 tmp = gen_portatom(0, (bpf_int32)port); 5073 b1 = gen_portatom(2, (bpf_int32)port); 5074 gen_or(tmp, b1); 5075 break; 5076 5077 case Q_AND: 5078 tmp = gen_portatom(0, (bpf_int32)port); 5079 b1 = gen_portatom(2, (bpf_int32)port); 5080 gen_and(tmp, b1); 5081 break; 5082 5083 default: 5084 abort(); 5085 } 5086 gen_and(b0, b1); 5087 5088 return b1; 5089 } 5090 5091 static struct block * 5092 gen_port(port, ip_proto, dir) 5093 int port; 5094 int ip_proto; 5095 int dir; 5096 { 5097 struct block *b0, *b1, *tmp; 5098 5099 /* 5100 * ether proto ip 5101 * 5102 * For FDDI, RFC 1188 says that SNAP encapsulation is used, 5103 * not LLC encapsulation with LLCSAP_IP. 5104 * 5105 * For IEEE 802 networks - which includes 802.5 token ring 5106 * (which is what DLT_IEEE802 means) and 802.11 - RFC 1042 5107 * says that SNAP encapsulation is used, not LLC encapsulation 5108 * with LLCSAP_IP. 5109 * 5110 * For LLC-encapsulated ATM/"Classical IP", RFC 1483 and 5111 * RFC 2225 say that SNAP encapsulation is used, not LLC 5112 * encapsulation with LLCSAP_IP. 5113 * 5114 * So we always check for ETHERTYPE_IP. 5115 */ 5116 b0 = gen_linktype(ETHERTYPE_IP); 5117 5118 switch (ip_proto) { 5119 case IPPROTO_UDP: 5120 case IPPROTO_TCP: 5121 case IPPROTO_SCTP: 5122 b1 = gen_portop(port, ip_proto, dir); 5123 break; 5124 5125 case PROTO_UNDEF: 5126 tmp = gen_portop(port, IPPROTO_TCP, dir); 5127 b1 = gen_portop(port, IPPROTO_UDP, dir); 5128 gen_or(tmp, b1); 5129 tmp = gen_portop(port, IPPROTO_SCTP, dir); 5130 gen_or(tmp, b1); 5131 break; 5132 5133 default: 5134 abort(); 5135 } 5136 gen_and(b0, b1); 5137 return b1; 5138 } 5139 5140 #ifdef INET6 5141 struct block * 5142 gen_portop6(port, proto, dir) 5143 int port, proto, dir; 5144 { 5145 struct block *b0, *b1, *tmp; 5146 5147 /* ip6 proto 'proto' */ 5148 /* XXX - catch the first fragment of a fragmented packet? */ 5149 b0 = gen_cmp(OR_NET, 6, BPF_B, (bpf_int32)proto); 5150 5151 switch (dir) { 5152 case Q_SRC: 5153 b1 = gen_portatom6(0, (bpf_int32)port); 5154 break; 5155 5156 case Q_DST: 5157 b1 = gen_portatom6(2, (bpf_int32)port); 5158 break; 5159 5160 case Q_OR: 5161 case Q_DEFAULT: 5162 tmp = gen_portatom6(0, (bpf_int32)port); 5163 b1 = gen_portatom6(2, (bpf_int32)port); 5164 gen_or(tmp, b1); 5165 break; 5166 5167 case Q_AND: 5168 tmp = gen_portatom6(0, (bpf_int32)port); 5169 b1 = gen_portatom6(2, (bpf_int32)port); 5170 gen_and(tmp, b1); 5171 break; 5172 5173 default: 5174 abort(); 5175 } 5176 gen_and(b0, b1); 5177 5178 return b1; 5179 } 5180 5181 static struct block * 5182 gen_port6(port, ip_proto, dir) 5183 int port; 5184 int ip_proto; 5185 int dir; 5186 { 5187 struct block *b0, *b1, *tmp; 5188 5189 /* link proto ip6 */ 5190 b0 = gen_linktype(ETHERTYPE_IPV6); 5191 5192 switch (ip_proto) { 5193 case IPPROTO_UDP: 5194 case IPPROTO_TCP: 5195 case IPPROTO_SCTP: 5196 b1 = gen_portop6(port, ip_proto, dir); 5197 break; 5198 5199 case PROTO_UNDEF: 5200 tmp = gen_portop6(port, IPPROTO_TCP, dir); 5201 b1 = gen_portop6(port, IPPROTO_UDP, dir); 5202 gen_or(tmp, b1); 5203 tmp = gen_portop6(port, IPPROTO_SCTP, dir); 5204 gen_or(tmp, b1); 5205 break; 5206 5207 default: 5208 abort(); 5209 } 5210 gen_and(b0, b1); 5211 return b1; 5212 } 5213 #endif /* INET6 */ 5214 5215 /* gen_portrange code */ 5216 static struct block * 5217 gen_portrangeatom(off, v1, v2) 5218 int off; 5219 bpf_int32 v1, v2; 5220 { 5221 struct block *b1, *b2; 5222 5223 if (v1 > v2) { 5224 /* 5225 * Reverse the order of the ports, so v1 is the lower one. 5226 */ 5227 bpf_int32 vtemp; 5228 5229 vtemp = v1; 5230 v1 = v2; 5231 v2 = vtemp; 5232 } 5233 5234 b1 = gen_cmp_ge(OR_TRAN_IPV4, off, BPF_H, v1); 5235 b2 = gen_cmp_le(OR_TRAN_IPV4, off, BPF_H, v2); 5236 5237 gen_and(b1, b2); 5238 5239 return b2; 5240 } 5241 5242 struct block * 5243 gen_portrangeop(port1, port2, proto, dir) 5244 int port1, port2; 5245 int proto; 5246 int dir; 5247 { 5248 struct block *b0, *b1, *tmp; 5249 5250 /* ip proto 'proto' and not a fragment other than the first fragment */ 5251 tmp = gen_cmp(OR_NET, 9, BPF_B, (bpf_int32)proto); 5252 b0 = gen_ipfrag(); 5253 gen_and(tmp, b0); 5254 5255 switch (dir) { 5256 case Q_SRC: 5257 b1 = gen_portrangeatom(0, (bpf_int32)port1, (bpf_int32)port2); 5258 break; 5259 5260 case Q_DST: 5261 b1 = gen_portrangeatom(2, (bpf_int32)port1, (bpf_int32)port2); 5262 break; 5263 5264 case Q_OR: 5265 case Q_DEFAULT: 5266 tmp = gen_portrangeatom(0, (bpf_int32)port1, (bpf_int32)port2); 5267 b1 = gen_portrangeatom(2, (bpf_int32)port1, (bpf_int32)port2); 5268 gen_or(tmp, b1); 5269 break; 5270 5271 case Q_AND: 5272 tmp = gen_portrangeatom(0, (bpf_int32)port1, (bpf_int32)port2); 5273 b1 = gen_portrangeatom(2, (bpf_int32)port1, (bpf_int32)port2); 5274 gen_and(tmp, b1); 5275 break; 5276 5277 default: 5278 abort(); 5279 } 5280 gen_and(b0, b1); 5281 5282 return b1; 5283 } 5284 5285 static struct block * 5286 gen_portrange(port1, port2, ip_proto, dir) 5287 int port1, port2; 5288 int ip_proto; 5289 int dir; 5290 { 5291 struct block *b0, *b1, *tmp; 5292 5293 /* link proto ip */ 5294 b0 = gen_linktype(ETHERTYPE_IP); 5295 5296 switch (ip_proto) { 5297 case IPPROTO_UDP: 5298 case IPPROTO_TCP: 5299 case IPPROTO_SCTP: 5300 b1 = gen_portrangeop(port1, port2, ip_proto, dir); 5301 break; 5302 5303 case PROTO_UNDEF: 5304 tmp = gen_portrangeop(port1, port2, IPPROTO_TCP, dir); 5305 b1 = gen_portrangeop(port1, port2, IPPROTO_UDP, dir); 5306 gen_or(tmp, b1); 5307 tmp = gen_portrangeop(port1, port2, IPPROTO_SCTP, dir); 5308 gen_or(tmp, b1); 5309 break; 5310 5311 default: 5312 abort(); 5313 } 5314 gen_and(b0, b1); 5315 return b1; 5316 } 5317 5318 #ifdef INET6 5319 static struct block * 5320 gen_portrangeatom6(off, v1, v2) 5321 int off; 5322 bpf_int32 v1, v2; 5323 { 5324 struct block *b1, *b2; 5325 5326 if (v1 > v2) { 5327 /* 5328 * Reverse the order of the ports, so v1 is the lower one. 5329 */ 5330 bpf_int32 vtemp; 5331 5332 vtemp = v1; 5333 v1 = v2; 5334 v2 = vtemp; 5335 } 5336 5337 b1 = gen_cmp_ge(OR_TRAN_IPV6, off, BPF_H, v1); 5338 b2 = gen_cmp_le(OR_TRAN_IPV6, off, BPF_H, v2); 5339 5340 gen_and(b1, b2); 5341 5342 return b2; 5343 } 5344 5345 struct block * 5346 gen_portrangeop6(port1, port2, proto, dir) 5347 int port1, port2; 5348 int proto; 5349 int dir; 5350 { 5351 struct block *b0, *b1, *tmp; 5352 5353 /* ip6 proto 'proto' */ 5354 /* XXX - catch the first fragment of a fragmented packet? */ 5355 b0 = gen_cmp(OR_NET, 6, BPF_B, (bpf_int32)proto); 5356 5357 switch (dir) { 5358 case Q_SRC: 5359 b1 = gen_portrangeatom6(0, (bpf_int32)port1, (bpf_int32)port2); 5360 break; 5361 5362 case Q_DST: 5363 b1 = gen_portrangeatom6(2, (bpf_int32)port1, (bpf_int32)port2); 5364 break; 5365 5366 case Q_OR: 5367 case Q_DEFAULT: 5368 tmp = gen_portrangeatom6(0, (bpf_int32)port1, (bpf_int32)port2); 5369 b1 = gen_portrangeatom6(2, (bpf_int32)port1, (bpf_int32)port2); 5370 gen_or(tmp, b1); 5371 break; 5372 5373 case Q_AND: 5374 tmp = gen_portrangeatom6(0, (bpf_int32)port1, (bpf_int32)port2); 5375 b1 = gen_portrangeatom6(2, (bpf_int32)port1, (bpf_int32)port2); 5376 gen_and(tmp, b1); 5377 break; 5378 5379 default: 5380 abort(); 5381 } 5382 gen_and(b0, b1); 5383 5384 return b1; 5385 } 5386 5387 static struct block * 5388 gen_portrange6(port1, port2, ip_proto, dir) 5389 int port1, port2; 5390 int ip_proto; 5391 int dir; 5392 { 5393 struct block *b0, *b1, *tmp; 5394 5395 /* link proto ip6 */ 5396 b0 = gen_linktype(ETHERTYPE_IPV6); 5397 5398 switch (ip_proto) { 5399 case IPPROTO_UDP: 5400 case IPPROTO_TCP: 5401 case IPPROTO_SCTP: 5402 b1 = gen_portrangeop6(port1, port2, ip_proto, dir); 5403 break; 5404 5405 case PROTO_UNDEF: 5406 tmp = gen_portrangeop6(port1, port2, IPPROTO_TCP, dir); 5407 b1 = gen_portrangeop6(port1, port2, IPPROTO_UDP, dir); 5408 gen_or(tmp, b1); 5409 tmp = gen_portrangeop6(port1, port2, IPPROTO_SCTP, dir); 5410 gen_or(tmp, b1); 5411 break; 5412 5413 default: 5414 abort(); 5415 } 5416 gen_and(b0, b1); 5417 return b1; 5418 } 5419 #endif /* INET6 */ 5420 5421 static int 5422 lookup_proto(name, proto) 5423 register const char *name; 5424 register int proto; 5425 { 5426 register int v; 5427 5428 switch (proto) { 5429 5430 case Q_DEFAULT: 5431 case Q_IP: 5432 case Q_IPV6: 5433 v = pcap_nametoproto(name); 5434 if (v == PROTO_UNDEF) 5435 bpf_error("unknown ip proto '%s'", name); 5436 break; 5437 5438 case Q_LINK: 5439 /* XXX should look up h/w protocol type based on linktype */ 5440 v = pcap_nametoeproto(name); 5441 if (v == PROTO_UNDEF) { 5442 v = pcap_nametollc(name); 5443 if (v == PROTO_UNDEF) 5444 bpf_error("unknown ether proto '%s'", name); 5445 } 5446 break; 5447 5448 case Q_ISO: 5449 if (strcmp(name, "esis") == 0) 5450 v = ISO9542_ESIS; 5451 else if (strcmp(name, "isis") == 0) 5452 v = ISO10589_ISIS; 5453 else if (strcmp(name, "clnp") == 0) 5454 v = ISO8473_CLNP; 5455 else 5456 bpf_error("unknown osi proto '%s'", name); 5457 break; 5458 5459 default: 5460 v = PROTO_UNDEF; 5461 break; 5462 } 5463 return v; 5464 } 5465 5466 #if 0 5467 struct stmt * 5468 gen_joinsp(s, n) 5469 struct stmt **s; 5470 int n; 5471 { 5472 return NULL; 5473 } 5474 #endif 5475 5476 static struct block * 5477 gen_protochain(v, proto, dir) 5478 int v; 5479 int proto; 5480 int dir; 5481 { 5482 #ifdef NO_PROTOCHAIN 5483 return gen_proto(v, proto, dir); 5484 #else 5485 struct block *b0, *b; 5486 struct slist *s[100]; 5487 int fix2, fix3, fix4, fix5; 5488 int ahcheck, again, end; 5489 int i, max; 5490 int reg2 = alloc_reg(); 5491 5492 memset(s, 0, sizeof(s)); 5493 fix2 = fix3 = fix4 = fix5 = 0; 5494 5495 switch (proto) { 5496 case Q_IP: 5497 case Q_IPV6: 5498 break; 5499 case Q_DEFAULT: 5500 b0 = gen_protochain(v, Q_IP, dir); 5501 b = gen_protochain(v, Q_IPV6, dir); 5502 gen_or(b0, b); 5503 return b; 5504 default: 5505 bpf_error("bad protocol applied for 'protochain'"); 5506 /*NOTREACHED*/ 5507 } 5508 5509 /* 5510 * We don't handle variable-length prefixes before the link-layer 5511 * header, or variable-length link-layer headers, here yet. 5512 * We might want to add BPF instructions to do the protochain 5513 * work, to simplify that and, on platforms that have a BPF 5514 * interpreter with the new instructions, let the filtering 5515 * be done in the kernel. (We already require a modified BPF 5516 * engine to do the protochain stuff, to support backward 5517 * branches, and backward branch support is unlikely to appear 5518 * in kernel BPF engines.) 5519 */ 5520 switch (linktype) { 5521 5522 case DLT_IEEE802_11: 5523 case DLT_PRISM_HEADER: 5524 case DLT_IEEE802_11_RADIO_AVS: 5525 case DLT_IEEE802_11_RADIO: 5526 case DLT_PPI: 5527 bpf_error("'protochain' not supported with 802.11"); 5528 } 5529 5530 no_optimize = 1; /*this code is not compatible with optimzer yet */ 5531 5532 /* 5533 * s[0] is a dummy entry to protect other BPF insn from damage 5534 * by s[fix] = foo with uninitialized variable "fix". It is somewhat 5535 * hard to find interdependency made by jump table fixup. 5536 */ 5537 i = 0; 5538 s[i] = new_stmt(0); /*dummy*/ 5539 i++; 5540 5541 switch (proto) { 5542 case Q_IP: 5543 b0 = gen_linktype(ETHERTYPE_IP); 5544 5545 /* A = ip->ip_p */ 5546 s[i] = new_stmt(BPF_LD|BPF_ABS|BPF_B); 5547 s[i]->s.k = off_macpl + off_nl + 9; 5548 i++; 5549 /* X = ip->ip_hl << 2 */ 5550 s[i] = new_stmt(BPF_LDX|BPF_MSH|BPF_B); 5551 s[i]->s.k = off_macpl + off_nl; 5552 i++; 5553 break; 5554 #ifdef INET6 5555 case Q_IPV6: 5556 b0 = gen_linktype(ETHERTYPE_IPV6); 5557 5558 /* A = ip6->ip_nxt */ 5559 s[i] = new_stmt(BPF_LD|BPF_ABS|BPF_B); 5560 s[i]->s.k = off_macpl + off_nl + 6; 5561 i++; 5562 /* X = sizeof(struct ip6_hdr) */ 5563 s[i] = new_stmt(BPF_LDX|BPF_IMM); 5564 s[i]->s.k = 40; 5565 i++; 5566 break; 5567 #endif 5568 default: 5569 bpf_error("unsupported proto to gen_protochain"); 5570 /*NOTREACHED*/ 5571 } 5572 5573 /* again: if (A == v) goto end; else fall through; */ 5574 again = i; 5575 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 5576 s[i]->s.k = v; 5577 s[i]->s.jt = NULL; /*later*/ 5578 s[i]->s.jf = NULL; /*update in next stmt*/ 5579 fix5 = i; 5580 i++; 5581 5582 #ifndef IPPROTO_NONE 5583 #define IPPROTO_NONE 59 5584 #endif 5585 /* if (A == IPPROTO_NONE) goto end */ 5586 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 5587 s[i]->s.jt = NULL; /*later*/ 5588 s[i]->s.jf = NULL; /*update in next stmt*/ 5589 s[i]->s.k = IPPROTO_NONE; 5590 s[fix5]->s.jf = s[i]; 5591 fix2 = i; 5592 i++; 5593 5594 #ifdef INET6 5595 if (proto == Q_IPV6) { 5596 int v6start, v6end, v6advance, j; 5597 5598 v6start = i; 5599 /* if (A == IPPROTO_HOPOPTS) goto v6advance */ 5600 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 5601 s[i]->s.jt = NULL; /*later*/ 5602 s[i]->s.jf = NULL; /*update in next stmt*/ 5603 s[i]->s.k = IPPROTO_HOPOPTS; 5604 s[fix2]->s.jf = s[i]; 5605 i++; 5606 /* if (A == IPPROTO_DSTOPTS) goto v6advance */ 5607 s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 5608 s[i]->s.jt = NULL; /*later*/ 5609 s[i]->s.jf = NULL; /*update in next stmt*/ 5610 s[i]->s.k = IPPROTO_DSTOPTS; 5611 i++; 5612 /* if (A == IPPROTO_ROUTING) goto v6advance */ 5613 s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 5614 s[i]->s.jt = NULL; /*later*/ 5615 s[i]->s.jf = NULL; /*update in next stmt*/ 5616 s[i]->s.k = IPPROTO_ROUTING; 5617 i++; 5618 /* if (A == IPPROTO_FRAGMENT) goto v6advance; else goto ahcheck; */ 5619 s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 5620 s[i]->s.jt = NULL; /*later*/ 5621 s[i]->s.jf = NULL; /*later*/ 5622 s[i]->s.k = IPPROTO_FRAGMENT; 5623 fix3 = i; 5624 v6end = i; 5625 i++; 5626 5627 /* v6advance: */ 5628 v6advance = i; 5629 5630 /* 5631 * in short, 5632 * A = P[X + packet head]; 5633 * X = X + (P[X + packet head + 1] + 1) * 8; 5634 */ 5635 /* A = P[X + packet head] */ 5636 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B); 5637 s[i]->s.k = off_macpl + off_nl; 5638 i++; 5639 /* MEM[reg2] = A */ 5640 s[i] = new_stmt(BPF_ST); 5641 s[i]->s.k = reg2; 5642 i++; 5643 /* A = P[X + packet head + 1]; */ 5644 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B); 5645 s[i]->s.k = off_macpl + off_nl + 1; 5646 i++; 5647 /* A += 1 */ 5648 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 5649 s[i]->s.k = 1; 5650 i++; 5651 /* A *= 8 */ 5652 s[i] = new_stmt(BPF_ALU|BPF_MUL|BPF_K); 5653 s[i]->s.k = 8; 5654 i++; 5655 /* A += X */ 5656 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_X); 5657 s[i]->s.k = 0; 5658 i++; 5659 /* X = A; */ 5660 s[i] = new_stmt(BPF_MISC|BPF_TAX); 5661 i++; 5662 /* A = MEM[reg2] */ 5663 s[i] = new_stmt(BPF_LD|BPF_MEM); 5664 s[i]->s.k = reg2; 5665 i++; 5666 5667 /* goto again; (must use BPF_JA for backward jump) */ 5668 s[i] = new_stmt(BPF_JMP|BPF_JA); 5669 s[i]->s.k = again - i - 1; 5670 s[i - 1]->s.jf = s[i]; 5671 i++; 5672 5673 /* fixup */ 5674 for (j = v6start; j <= v6end; j++) 5675 s[j]->s.jt = s[v6advance]; 5676 } else 5677 #endif 5678 { 5679 /* nop */ 5680 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 5681 s[i]->s.k = 0; 5682 s[fix2]->s.jf = s[i]; 5683 i++; 5684 } 5685 5686 /* ahcheck: */ 5687 ahcheck = i; 5688 /* if (A == IPPROTO_AH) then fall through; else goto end; */ 5689 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 5690 s[i]->s.jt = NULL; /*later*/ 5691 s[i]->s.jf = NULL; /*later*/ 5692 s[i]->s.k = IPPROTO_AH; 5693 if (fix3) 5694 s[fix3]->s.jf = s[ahcheck]; 5695 fix4 = i; 5696 i++; 5697 5698 /* 5699 * in short, 5700 * A = P[X]; 5701 * X = X + (P[X + 1] + 2) * 4; 5702 */ 5703 /* A = X */ 5704 s[i - 1]->s.jt = s[i] = new_stmt(BPF_MISC|BPF_TXA); 5705 i++; 5706 /* A = P[X + packet head]; */ 5707 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B); 5708 s[i]->s.k = off_macpl + off_nl; 5709 i++; 5710 /* MEM[reg2] = A */ 5711 s[i] = new_stmt(BPF_ST); 5712 s[i]->s.k = reg2; 5713 i++; 5714 /* A = X */ 5715 s[i - 1]->s.jt = s[i] = new_stmt(BPF_MISC|BPF_TXA); 5716 i++; 5717 /* A += 1 */ 5718 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 5719 s[i]->s.k = 1; 5720 i++; 5721 /* X = A */ 5722 s[i] = new_stmt(BPF_MISC|BPF_TAX); 5723 i++; 5724 /* A = P[X + packet head] */ 5725 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B); 5726 s[i]->s.k = off_macpl + off_nl; 5727 i++; 5728 /* A += 2 */ 5729 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 5730 s[i]->s.k = 2; 5731 i++; 5732 /* A *= 4 */ 5733 s[i] = new_stmt(BPF_ALU|BPF_MUL|BPF_K); 5734 s[i]->s.k = 4; 5735 i++; 5736 /* X = A; */ 5737 s[i] = new_stmt(BPF_MISC|BPF_TAX); 5738 i++; 5739 /* A = MEM[reg2] */ 5740 s[i] = new_stmt(BPF_LD|BPF_MEM); 5741 s[i]->s.k = reg2; 5742 i++; 5743 5744 /* goto again; (must use BPF_JA for backward jump) */ 5745 s[i] = new_stmt(BPF_JMP|BPF_JA); 5746 s[i]->s.k = again - i - 1; 5747 i++; 5748 5749 /* end: nop */ 5750 end = i; 5751 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 5752 s[i]->s.k = 0; 5753 s[fix2]->s.jt = s[end]; 5754 s[fix4]->s.jf = s[end]; 5755 s[fix5]->s.jt = s[end]; 5756 i++; 5757 5758 /* 5759 * make slist chain 5760 */ 5761 max = i; 5762 for (i = 0; i < max - 1; i++) 5763 s[i]->next = s[i + 1]; 5764 s[max - 1]->next = NULL; 5765 5766 /* 5767 * emit final check 5768 */ 5769 b = new_block(JMP(BPF_JEQ)); 5770 b->stmts = s[1]; /*remember, s[0] is dummy*/ 5771 b->s.k = v; 5772 5773 free_reg(reg2); 5774 5775 gen_and(b0, b); 5776 return b; 5777 #endif 5778 } 5779 5780 static struct block * 5781 gen_check_802_11_data_frame() 5782 { 5783 struct slist *s; 5784 struct block *b0, *b1; 5785 5786 /* 5787 * A data frame has the 0x08 bit (b3) in the frame control field set 5788 * and the 0x04 bit (b2) clear. 5789 */ 5790 s = gen_load_a(OR_LINK, 0, BPF_B); 5791 b0 = new_block(JMP(BPF_JSET)); 5792 b0->s.k = 0x08; 5793 b0->stmts = s; 5794 5795 s = gen_load_a(OR_LINK, 0, BPF_B); 5796 b1 = new_block(JMP(BPF_JSET)); 5797 b1->s.k = 0x04; 5798 b1->stmts = s; 5799 gen_not(b1); 5800 5801 gen_and(b1, b0); 5802 5803 return b0; 5804 } 5805 5806 /* 5807 * Generate code that checks whether the packet is a packet for protocol 5808 * <proto> and whether the type field in that protocol's header has 5809 * the value <v>, e.g. if <proto> is Q_IP, it checks whether it's an 5810 * IP packet and checks the protocol number in the IP header against <v>. 5811 * 5812 * If <proto> is Q_DEFAULT, i.e. just "proto" was specified, it checks 5813 * against Q_IP and Q_IPV6. 5814 */ 5815 static struct block * 5816 gen_proto(v, proto, dir) 5817 int v; 5818 int proto; 5819 int dir; 5820 { 5821 struct block *b0, *b1; 5822 5823 if (dir != Q_DEFAULT) 5824 bpf_error("direction applied to 'proto'"); 5825 5826 switch (proto) { 5827 case Q_DEFAULT: 5828 #ifdef INET6 5829 b0 = gen_proto(v, Q_IP, dir); 5830 b1 = gen_proto(v, Q_IPV6, dir); 5831 gen_or(b0, b1); 5832 return b1; 5833 #else 5834 /*FALLTHROUGH*/ 5835 #endif 5836 case Q_IP: 5837 /* 5838 * For FDDI, RFC 1188 says that SNAP encapsulation is used, 5839 * not LLC encapsulation with LLCSAP_IP. 5840 * 5841 * For IEEE 802 networks - which includes 802.5 token ring 5842 * (which is what DLT_IEEE802 means) and 802.11 - RFC 1042 5843 * says that SNAP encapsulation is used, not LLC encapsulation 5844 * with LLCSAP_IP. 5845 * 5846 * For LLC-encapsulated ATM/"Classical IP", RFC 1483 and 5847 * RFC 2225 say that SNAP encapsulation is used, not LLC 5848 * encapsulation with LLCSAP_IP. 5849 * 5850 * So we always check for ETHERTYPE_IP. 5851 */ 5852 b0 = gen_linktype(ETHERTYPE_IP); 5853 #ifndef CHASE_CHAIN 5854 b1 = gen_cmp(OR_NET, 9, BPF_B, (bpf_int32)v); 5855 #else 5856 b1 = gen_protochain(v, Q_IP); 5857 #endif 5858 gen_and(b0, b1); 5859 return b1; 5860 5861 case Q_ISO: 5862 switch (linktype) { 5863 5864 case DLT_FRELAY: 5865 /* 5866 * Frame Relay packets typically have an OSI 5867 * NLPID at the beginning; "gen_linktype(LLCSAP_ISONS)" 5868 * generates code to check for all the OSI 5869 * NLPIDs, so calling it and then adding a check 5870 * for the particular NLPID for which we're 5871 * looking is bogus, as we can just check for 5872 * the NLPID. 5873 * 5874 * What we check for is the NLPID and a frame 5875 * control field value of UI, i.e. 0x03 followed 5876 * by the NLPID. 5877 * 5878 * XXX - assumes a 2-byte Frame Relay header with 5879 * DLCI and flags. What if the address is longer? 5880 * 5881 * XXX - what about SNAP-encapsulated frames? 5882 */ 5883 return gen_cmp(OR_LINK, 2, BPF_H, (0x03<<8) | v); 5884 /*NOTREACHED*/ 5885 break; 5886 5887 case DLT_C_HDLC: 5888 /* 5889 * Cisco uses an Ethertype lookalike - for OSI, 5890 * it's 0xfefe. 5891 */ 5892 b0 = gen_linktype(LLCSAP_ISONS<<8 | LLCSAP_ISONS); 5893 /* OSI in C-HDLC is stuffed with a fudge byte */ 5894 b1 = gen_cmp(OR_NET_NOSNAP, 1, BPF_B, (long)v); 5895 gen_and(b0, b1); 5896 return b1; 5897 5898 default: 5899 b0 = gen_linktype(LLCSAP_ISONS); 5900 b1 = gen_cmp(OR_NET_NOSNAP, 0, BPF_B, (long)v); 5901 gen_and(b0, b1); 5902 return b1; 5903 } 5904 5905 case Q_ISIS: 5906 b0 = gen_proto(ISO10589_ISIS, Q_ISO, Q_DEFAULT); 5907 /* 5908 * 4 is the offset of the PDU type relative to the IS-IS 5909 * header. 5910 */ 5911 b1 = gen_cmp(OR_NET_NOSNAP, 4, BPF_B, (long)v); 5912 gen_and(b0, b1); 5913 return b1; 5914 5915 case Q_ARP: 5916 bpf_error("arp does not encapsulate another protocol"); 5917 /* NOTREACHED */ 5918 5919 case Q_RARP: 5920 bpf_error("rarp does not encapsulate another protocol"); 5921 /* NOTREACHED */ 5922 5923 case Q_ATALK: 5924 bpf_error("atalk encapsulation is not specifiable"); 5925 /* NOTREACHED */ 5926 5927 case Q_DECNET: 5928 bpf_error("decnet encapsulation is not specifiable"); 5929 /* NOTREACHED */ 5930 5931 case Q_SCA: 5932 bpf_error("sca does not encapsulate another protocol"); 5933 /* NOTREACHED */ 5934 5935 case Q_LAT: 5936 bpf_error("lat does not encapsulate another protocol"); 5937 /* NOTREACHED */ 5938 5939 case Q_MOPRC: 5940 bpf_error("moprc does not encapsulate another protocol"); 5941 /* NOTREACHED */ 5942 5943 case Q_MOPDL: 5944 bpf_error("mopdl does not encapsulate another protocol"); 5945 /* NOTREACHED */ 5946 5947 case Q_LINK: 5948 return gen_linktype(v); 5949 5950 case Q_UDP: 5951 bpf_error("'udp proto' is bogus"); 5952 /* NOTREACHED */ 5953 5954 case Q_TCP: 5955 bpf_error("'tcp proto' is bogus"); 5956 /* NOTREACHED */ 5957 5958 case Q_SCTP: 5959 bpf_error("'sctp proto' is bogus"); 5960 /* NOTREACHED */ 5961 5962 case Q_ICMP: 5963 bpf_error("'icmp proto' is bogus"); 5964 /* NOTREACHED */ 5965 5966 case Q_IGMP: 5967 bpf_error("'igmp proto' is bogus"); 5968 /* NOTREACHED */ 5969 5970 case Q_IGRP: 5971 bpf_error("'igrp proto' is bogus"); 5972 /* NOTREACHED */ 5973 5974 case Q_PIM: 5975 bpf_error("'pim proto' is bogus"); 5976 /* NOTREACHED */ 5977 5978 case Q_VRRP: 5979 bpf_error("'vrrp proto' is bogus"); 5980 /* NOTREACHED */ 5981 5982 case Q_CARP: 5983 bpf_error("'carp proto' is bogus"); 5984 /* NOTREACHED */ 5985 5986 #ifdef INET6 5987 case Q_IPV6: 5988 b0 = gen_linktype(ETHERTYPE_IPV6); 5989 #ifndef CHASE_CHAIN 5990 b1 = gen_cmp(OR_NET, 6, BPF_B, (bpf_int32)v); 5991 #else 5992 b1 = gen_protochain(v, Q_IPV6); 5993 #endif 5994 gen_and(b0, b1); 5995 return b1; 5996 5997 case Q_ICMPV6: 5998 bpf_error("'icmp6 proto' is bogus"); 5999 #endif /* INET6 */ 6000 6001 case Q_AH: 6002 bpf_error("'ah proto' is bogus"); 6003 6004 case Q_ESP: 6005 bpf_error("'ah proto' is bogus"); 6006 6007 case Q_STP: 6008 bpf_error("'stp proto' is bogus"); 6009 6010 case Q_IPX: 6011 bpf_error("'ipx proto' is bogus"); 6012 6013 case Q_NETBEUI: 6014 bpf_error("'netbeui proto' is bogus"); 6015 6016 case Q_RADIO: 6017 bpf_error("'radio proto' is bogus"); 6018 6019 default: 6020 abort(); 6021 /* NOTREACHED */ 6022 } 6023 /* NOTREACHED */ 6024 } 6025 6026 struct block * 6027 gen_scode(name, q) 6028 register const char *name; 6029 struct qual q; 6030 { 6031 int proto = q.proto; 6032 int dir = q.dir; 6033 int tproto; 6034 u_char *eaddr; 6035 bpf_u_int32 mask, addr; 6036 #ifndef INET6 6037 bpf_u_int32 **alist; 6038 #else 6039 int tproto6; 6040 struct sockaddr_in *sin4; 6041 struct sockaddr_in6 *sin6; 6042 struct addrinfo *res, *res0; 6043 struct in6_addr mask128; 6044 #endif /*INET6*/ 6045 struct block *b, *tmp; 6046 int port, real_proto; 6047 int port1, port2; 6048 6049 switch (q.addr) { 6050 6051 case Q_NET: 6052 addr = pcap_nametonetaddr(name); 6053 if (addr == 0) 6054 bpf_error("unknown network '%s'", name); 6055 /* Left justify network addr and calculate its network mask */ 6056 mask = 0xffffffff; 6057 while (addr && (addr & 0xff000000) == 0) { 6058 addr <<= 8; 6059 mask <<= 8; 6060 } 6061 return gen_host(addr, mask, proto, dir, q.addr); 6062 6063 case Q_DEFAULT: 6064 case Q_HOST: 6065 if (proto == Q_LINK) { 6066 switch (linktype) { 6067 6068 case DLT_EN10MB: 6069 case DLT_NETANALYZER: 6070 case DLT_NETANALYZER_TRANSPARENT: 6071 eaddr = pcap_ether_hostton(name); 6072 if (eaddr == NULL) 6073 bpf_error( 6074 "unknown ether host '%s'", name); 6075 b = gen_ehostop(eaddr, dir); 6076 free(eaddr); 6077 return b; 6078 6079 case DLT_FDDI: 6080 eaddr = pcap_ether_hostton(name); 6081 if (eaddr == NULL) 6082 bpf_error( 6083 "unknown FDDI host '%s'", name); 6084 b = gen_fhostop(eaddr, dir); 6085 free(eaddr); 6086 return b; 6087 6088 case DLT_IEEE802: 6089 eaddr = pcap_ether_hostton(name); 6090 if (eaddr == NULL) 6091 bpf_error( 6092 "unknown token ring host '%s'", name); 6093 b = gen_thostop(eaddr, dir); 6094 free(eaddr); 6095 return b; 6096 6097 case DLT_IEEE802_11: 6098 case DLT_PRISM_HEADER: 6099 case DLT_IEEE802_11_RADIO_AVS: 6100 case DLT_IEEE802_11_RADIO: 6101 case DLT_PPI: 6102 eaddr = pcap_ether_hostton(name); 6103 if (eaddr == NULL) 6104 bpf_error( 6105 "unknown 802.11 host '%s'", name); 6106 b = gen_wlanhostop(eaddr, dir); 6107 free(eaddr); 6108 return b; 6109 6110 case DLT_IP_OVER_FC: 6111 eaddr = pcap_ether_hostton(name); 6112 if (eaddr == NULL) 6113 bpf_error( 6114 "unknown Fibre Channel host '%s'", name); 6115 b = gen_ipfchostop(eaddr, dir); 6116 free(eaddr); 6117 return b; 6118 6119 case DLT_SUNATM: 6120 if (!is_lane) 6121 break; 6122 6123 /* 6124 * Check that the packet doesn't begin 6125 * with an LE Control marker. (We've 6126 * already generated a test for LANE.) 6127 */ 6128 tmp = gen_cmp(OR_LINK, SUNATM_PKT_BEGIN_POS, 6129 BPF_H, 0xFF00); 6130 gen_not(tmp); 6131 6132 eaddr = pcap_ether_hostton(name); 6133 if (eaddr == NULL) 6134 bpf_error( 6135 "unknown ether host '%s'", name); 6136 b = gen_ehostop(eaddr, dir); 6137 gen_and(tmp, b); 6138 free(eaddr); 6139 return b; 6140 } 6141 6142 bpf_error("only ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel supports link-level host name"); 6143 } else if (proto == Q_DECNET) { 6144 unsigned short dn_addr = __pcap_nametodnaddr(name); 6145 /* 6146 * I don't think DECNET hosts can be multihomed, so 6147 * there is no need to build up a list of addresses 6148 */ 6149 return (gen_host(dn_addr, 0, proto, dir, q.addr)); 6150 } else { 6151 #ifndef INET6 6152 alist = pcap_nametoaddr(name); 6153 if (alist == NULL || *alist == NULL) 6154 bpf_error("unknown host '%s'", name); 6155 tproto = proto; 6156 if (off_linktype == (u_int)-1 && tproto == Q_DEFAULT) 6157 tproto = Q_IP; 6158 b = gen_host(**alist++, 0xffffffff, tproto, dir, q.addr); 6159 while (*alist) { 6160 tmp = gen_host(**alist++, 0xffffffff, 6161 tproto, dir, q.addr); 6162 gen_or(b, tmp); 6163 b = tmp; 6164 } 6165 return b; 6166 #else 6167 memset(&mask128, 0xff, sizeof(mask128)); 6168 res0 = res = pcap_nametoaddrinfo(name); 6169 if (res == NULL) 6170 bpf_error("unknown host '%s'", name); 6171 ai = res; 6172 b = tmp = NULL; 6173 tproto = tproto6 = proto; 6174 if (off_linktype == -1 && tproto == Q_DEFAULT) { 6175 tproto = Q_IP; 6176 tproto6 = Q_IPV6; 6177 } 6178 for (res = res0; res; res = res->ai_next) { 6179 switch (res->ai_family) { 6180 case AF_INET: 6181 if (tproto == Q_IPV6) 6182 continue; 6183 6184 sin4 = (struct sockaddr_in *) 6185 res->ai_addr; 6186 tmp = gen_host(ntohl(sin4->sin_addr.s_addr), 6187 0xffffffff, tproto, dir, q.addr); 6188 break; 6189 case AF_INET6: 6190 if (tproto6 == Q_IP) 6191 continue; 6192 6193 sin6 = (struct sockaddr_in6 *) 6194 res->ai_addr; 6195 tmp = gen_host6(&sin6->sin6_addr, 6196 &mask128, tproto6, dir, q.addr); 6197 break; 6198 default: 6199 continue; 6200 } 6201 if (b) 6202 gen_or(b, tmp); 6203 b = tmp; 6204 } 6205 ai = NULL; 6206 freeaddrinfo(res0); 6207 if (b == NULL) { 6208 bpf_error("unknown host '%s'%s", name, 6209 (proto == Q_DEFAULT) 6210 ? "" 6211 : " for specified address family"); 6212 } 6213 return b; 6214 #endif /*INET6*/ 6215 } 6216 6217 case Q_PORT: 6218 if (proto != Q_DEFAULT && 6219 proto != Q_UDP && proto != Q_TCP && proto != Q_SCTP) 6220 bpf_error("illegal qualifier of 'port'"); 6221 if (pcap_nametoport(name, &port, &real_proto) == 0) 6222 bpf_error("unknown port '%s'", name); 6223 if (proto == Q_UDP) { 6224 if (real_proto == IPPROTO_TCP) 6225 bpf_error("port '%s' is tcp", name); 6226 else if (real_proto == IPPROTO_SCTP) 6227 bpf_error("port '%s' is sctp", name); 6228 else 6229 /* override PROTO_UNDEF */ 6230 real_proto = IPPROTO_UDP; 6231 } 6232 if (proto == Q_TCP) { 6233 if (real_proto == IPPROTO_UDP) 6234 bpf_error("port '%s' is udp", name); 6235 6236 else if (real_proto == IPPROTO_SCTP) 6237 bpf_error("port '%s' is sctp", name); 6238 else 6239 /* override PROTO_UNDEF */ 6240 real_proto = IPPROTO_TCP; 6241 } 6242 if (proto == Q_SCTP) { 6243 if (real_proto == IPPROTO_UDP) 6244 bpf_error("port '%s' is udp", name); 6245 6246 else if (real_proto == IPPROTO_TCP) 6247 bpf_error("port '%s' is tcp", name); 6248 else 6249 /* override PROTO_UNDEF */ 6250 real_proto = IPPROTO_SCTP; 6251 } 6252 if (port < 0) 6253 bpf_error("illegal port number %d < 0", port); 6254 if (port > 65535) 6255 bpf_error("illegal port number %d > 65535", port); 6256 #ifndef INET6 6257 return gen_port(port, real_proto, dir); 6258 #else 6259 b = gen_port(port, real_proto, dir); 6260 gen_or(gen_port6(port, real_proto, dir), b); 6261 return b; 6262 #endif /* INET6 */ 6263 6264 case Q_PORTRANGE: 6265 if (proto != Q_DEFAULT && 6266 proto != Q_UDP && proto != Q_TCP && proto != Q_SCTP) 6267 bpf_error("illegal qualifier of 'portrange'"); 6268 if (pcap_nametoportrange(name, &port1, &port2, &real_proto) == 0) 6269 bpf_error("unknown port in range '%s'", name); 6270 if (proto == Q_UDP) { 6271 if (real_proto == IPPROTO_TCP) 6272 bpf_error("port in range '%s' is tcp", name); 6273 else if (real_proto == IPPROTO_SCTP) 6274 bpf_error("port in range '%s' is sctp", name); 6275 else 6276 /* override PROTO_UNDEF */ 6277 real_proto = IPPROTO_UDP; 6278 } 6279 if (proto == Q_TCP) { 6280 if (real_proto == IPPROTO_UDP) 6281 bpf_error("port in range '%s' is udp", name); 6282 else if (real_proto == IPPROTO_SCTP) 6283 bpf_error("port in range '%s' is sctp", name); 6284 else 6285 /* override PROTO_UNDEF */ 6286 real_proto = IPPROTO_TCP; 6287 } 6288 if (proto == Q_SCTP) { 6289 if (real_proto == IPPROTO_UDP) 6290 bpf_error("port in range '%s' is udp", name); 6291 else if (real_proto == IPPROTO_TCP) 6292 bpf_error("port in range '%s' is tcp", name); 6293 else 6294 /* override PROTO_UNDEF */ 6295 real_proto = IPPROTO_SCTP; 6296 } 6297 if (port1 < 0) 6298 bpf_error("illegal port number %d < 0", port1); 6299 if (port1 > 65535) 6300 bpf_error("illegal port number %d > 65535", port1); 6301 if (port2 < 0) 6302 bpf_error("illegal port number %d < 0", port2); 6303 if (port2 > 65535) 6304 bpf_error("illegal port number %d > 65535", port2); 6305 6306 #ifndef INET6 6307 return gen_portrange(port1, port2, real_proto, dir); 6308 #else 6309 b = gen_portrange(port1, port2, real_proto, dir); 6310 gen_or(gen_portrange6(port1, port2, real_proto, dir), b); 6311 return b; 6312 #endif /* INET6 */ 6313 6314 case Q_GATEWAY: 6315 #ifndef INET6 6316 eaddr = pcap_ether_hostton(name); 6317 if (eaddr == NULL) 6318 bpf_error("unknown ether host: %s", name); 6319 6320 alist = pcap_nametoaddr(name); 6321 if (alist == NULL || *alist == NULL) 6322 bpf_error("unknown host '%s'", name); 6323 b = gen_gateway(eaddr, alist, proto, dir); 6324 free(eaddr); 6325 return b; 6326 #else 6327 bpf_error("'gateway' not supported in this configuration"); 6328 #endif /*INET6*/ 6329 6330 case Q_PROTO: 6331 real_proto = lookup_proto(name, proto); 6332 if (real_proto >= 0) 6333 return gen_proto(real_proto, proto, dir); 6334 else 6335 bpf_error("unknown protocol: %s", name); 6336 6337 case Q_PROTOCHAIN: 6338 real_proto = lookup_proto(name, proto); 6339 if (real_proto >= 0) 6340 return gen_protochain(real_proto, proto, dir); 6341 else 6342 bpf_error("unknown protocol: %s", name); 6343 6344 case Q_UNDEF: 6345 syntax(); 6346 /* NOTREACHED */ 6347 } 6348 abort(); 6349 /* NOTREACHED */ 6350 } 6351 6352 struct block * 6353 gen_mcode(s1, s2, masklen, q) 6354 register const char *s1, *s2; 6355 register int masklen; 6356 struct qual q; 6357 { 6358 register int nlen, mlen; 6359 bpf_u_int32 n, m; 6360 6361 nlen = __pcap_atoin(s1, &n); 6362 /* Promote short ipaddr */ 6363 n <<= 32 - nlen; 6364 6365 if (s2 != NULL) { 6366 mlen = __pcap_atoin(s2, &m); 6367 /* Promote short ipaddr */ 6368 m <<= 32 - mlen; 6369 if ((n & ~m) != 0) 6370 bpf_error("non-network bits set in \"%s mask %s\"", 6371 s1, s2); 6372 } else { 6373 /* Convert mask len to mask */ 6374 if (masklen > 32) 6375 bpf_error("mask length must be <= 32"); 6376 if (masklen == 0) { 6377 /* 6378 * X << 32 is not guaranteed by C to be 0; it's 6379 * undefined. 6380 */ 6381 m = 0; 6382 } else 6383 m = 0xffffffff << (32 - masklen); 6384 if ((n & ~m) != 0) 6385 bpf_error("non-network bits set in \"%s/%d\"", 6386 s1, masklen); 6387 } 6388 6389 switch (q.addr) { 6390 6391 case Q_NET: 6392 return gen_host(n, m, q.proto, q.dir, q.addr); 6393 6394 default: 6395 bpf_error("Mask syntax for networks only"); 6396 /* NOTREACHED */ 6397 } 6398 /* NOTREACHED */ 6399 return NULL; 6400 } 6401 6402 struct block * 6403 gen_ncode(s, v, q) 6404 register const char *s; 6405 bpf_u_int32 v; 6406 struct qual q; 6407 { 6408 bpf_u_int32 mask; 6409 int proto = q.proto; 6410 int dir = q.dir; 6411 register int vlen; 6412 6413 if (s == NULL) 6414 vlen = 32; 6415 else if (q.proto == Q_DECNET) 6416 vlen = __pcap_atodn(s, &v); 6417 else 6418 vlen = __pcap_atoin(s, &v); 6419 6420 switch (q.addr) { 6421 6422 case Q_DEFAULT: 6423 case Q_HOST: 6424 case Q_NET: 6425 if (proto == Q_DECNET) 6426 return gen_host(v, 0, proto, dir, q.addr); 6427 else if (proto == Q_LINK) { 6428 bpf_error("illegal link layer address"); 6429 } else { 6430 mask = 0xffffffff; 6431 if (s == NULL && q.addr == Q_NET) { 6432 /* Promote short net number */ 6433 while (v && (v & 0xff000000) == 0) { 6434 v <<= 8; 6435 mask <<= 8; 6436 } 6437 } else { 6438 /* Promote short ipaddr */ 6439 v <<= 32 - vlen; 6440 mask <<= 32 - vlen; 6441 } 6442 return gen_host(v, mask, proto, dir, q.addr); 6443 } 6444 6445 case Q_PORT: 6446 if (proto == Q_UDP) 6447 proto = IPPROTO_UDP; 6448 else if (proto == Q_TCP) 6449 proto = IPPROTO_TCP; 6450 else if (proto == Q_SCTP) 6451 proto = IPPROTO_SCTP; 6452 else if (proto == Q_DEFAULT) 6453 proto = PROTO_UNDEF; 6454 else 6455 bpf_error("illegal qualifier of 'port'"); 6456 6457 if (v > 65535) 6458 bpf_error("illegal port number %u > 65535", v); 6459 6460 #ifndef INET6 6461 return gen_port((int)v, proto, dir); 6462 #else 6463 { 6464 struct block *b; 6465 b = gen_port((int)v, proto, dir); 6466 gen_or(gen_port6((int)v, proto, dir), b); 6467 return b; 6468 } 6469 #endif /* INET6 */ 6470 6471 case Q_PORTRANGE: 6472 if (proto == Q_UDP) 6473 proto = IPPROTO_UDP; 6474 else if (proto == Q_TCP) 6475 proto = IPPROTO_TCP; 6476 else if (proto == Q_SCTP) 6477 proto = IPPROTO_SCTP; 6478 else if (proto == Q_DEFAULT) 6479 proto = PROTO_UNDEF; 6480 else 6481 bpf_error("illegal qualifier of 'portrange'"); 6482 6483 if (v > 65535) 6484 bpf_error("illegal port number %u > 65535", v); 6485 6486 #ifndef INET6 6487 return gen_portrange((int)v, (int)v, proto, dir); 6488 #else 6489 { 6490 struct block *b; 6491 b = gen_portrange((int)v, (int)v, proto, dir); 6492 gen_or(gen_portrange6((int)v, (int)v, proto, dir), b); 6493 return b; 6494 } 6495 #endif /* INET6 */ 6496 6497 case Q_GATEWAY: 6498 bpf_error("'gateway' requires a name"); 6499 /* NOTREACHED */ 6500 6501 case Q_PROTO: 6502 return gen_proto((int)v, proto, dir); 6503 6504 case Q_PROTOCHAIN: 6505 return gen_protochain((int)v, proto, dir); 6506 6507 case Q_UNDEF: 6508 syntax(); 6509 /* NOTREACHED */ 6510 6511 default: 6512 abort(); 6513 /* NOTREACHED */ 6514 } 6515 /* NOTREACHED */ 6516 } 6517 6518 #ifdef INET6 6519 struct block * 6520 gen_mcode6(s1, s2, masklen, q) 6521 register const char *s1, *s2; 6522 register int masklen; 6523 struct qual q; 6524 { 6525 struct addrinfo *res; 6526 struct in6_addr *addr; 6527 struct in6_addr mask; 6528 struct block *b; 6529 u_int32_t *a, *m; 6530 6531 if (s2) 6532 bpf_error("no mask %s supported", s2); 6533 6534 res = pcap_nametoaddrinfo(s1); 6535 if (!res) 6536 bpf_error("invalid ip6 address %s", s1); 6537 ai = res; 6538 if (res->ai_next) 6539 bpf_error("%s resolved to multiple address", s1); 6540 addr = &((struct sockaddr_in6 *)res->ai_addr)->sin6_addr; 6541 6542 if (sizeof(mask) * 8 < masklen) 6543 bpf_error("mask length must be <= %u", (unsigned int)(sizeof(mask) * 8)); 6544 memset(&mask, 0, sizeof(mask)); 6545 memset(&mask, 0xff, masklen / 8); 6546 if (masklen % 8) { 6547 mask.s6_addr[masklen / 8] = 6548 (0xff << (8 - masklen % 8)) & 0xff; 6549 } 6550 6551 a = (u_int32_t *)addr; 6552 m = (u_int32_t *)&mask; 6553 if ((a[0] & ~m[0]) || (a[1] & ~m[1]) 6554 || (a[2] & ~m[2]) || (a[3] & ~m[3])) { 6555 bpf_error("non-network bits set in \"%s/%d\"", s1, masklen); 6556 } 6557 6558 switch (q.addr) { 6559 6560 case Q_DEFAULT: 6561 case Q_HOST: 6562 if (masklen != 128) 6563 bpf_error("Mask syntax for networks only"); 6564 /* FALLTHROUGH */ 6565 6566 case Q_NET: 6567 b = gen_host6(addr, &mask, q.proto, q.dir, q.addr); 6568 ai = NULL; 6569 freeaddrinfo(res); 6570 return b; 6571 6572 default: 6573 bpf_error("invalid qualifier against IPv6 address"); 6574 /* NOTREACHED */ 6575 } 6576 return NULL; 6577 } 6578 #endif /*INET6*/ 6579 6580 struct block * 6581 gen_ecode(eaddr, q) 6582 register const u_char *eaddr; 6583 struct qual q; 6584 { 6585 struct block *b, *tmp; 6586 6587 if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) && q.proto == Q_LINK) { 6588 switch (linktype) { 6589 case DLT_EN10MB: 6590 case DLT_NETANALYZER: 6591 case DLT_NETANALYZER_TRANSPARENT: 6592 return gen_ehostop(eaddr, (int)q.dir); 6593 case DLT_FDDI: 6594 return gen_fhostop(eaddr, (int)q.dir); 6595 case DLT_IEEE802: 6596 return gen_thostop(eaddr, (int)q.dir); 6597 case DLT_IEEE802_11: 6598 case DLT_PRISM_HEADER: 6599 case DLT_IEEE802_11_RADIO_AVS: 6600 case DLT_IEEE802_11_RADIO: 6601 case DLT_PPI: 6602 return gen_wlanhostop(eaddr, (int)q.dir); 6603 case DLT_SUNATM: 6604 if (is_lane) { 6605 /* 6606 * Check that the packet doesn't begin with an 6607 * LE Control marker. (We've already generated 6608 * a test for LANE.) 6609 */ 6610 tmp = gen_cmp(OR_LINK, SUNATM_PKT_BEGIN_POS, BPF_H, 6611 0xFF00); 6612 gen_not(tmp); 6613 6614 /* 6615 * Now check the MAC address. 6616 */ 6617 b = gen_ehostop(eaddr, (int)q.dir); 6618 gen_and(tmp, b); 6619 return b; 6620 } 6621 break; 6622 case DLT_IP_OVER_FC: 6623 return gen_ipfchostop(eaddr, (int)q.dir); 6624 default: 6625 bpf_error("ethernet addresses supported only on ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel"); 6626 break; 6627 } 6628 } 6629 bpf_error("ethernet address used in non-ether expression"); 6630 /* NOTREACHED */ 6631 return NULL; 6632 } 6633 6634 void 6635 sappend(s0, s1) 6636 struct slist *s0, *s1; 6637 { 6638 /* 6639 * This is definitely not the best way to do this, but the 6640 * lists will rarely get long. 6641 */ 6642 while (s0->next) 6643 s0 = s0->next; 6644 s0->next = s1; 6645 } 6646 6647 static struct slist * 6648 xfer_to_x(a) 6649 struct arth *a; 6650 { 6651 struct slist *s; 6652 6653 s = new_stmt(BPF_LDX|BPF_MEM); 6654 s->s.k = a->regno; 6655 return s; 6656 } 6657 6658 static struct slist * 6659 xfer_to_a(a) 6660 struct arth *a; 6661 { 6662 struct slist *s; 6663 6664 s = new_stmt(BPF_LD|BPF_MEM); 6665 s->s.k = a->regno; 6666 return s; 6667 } 6668 6669 /* 6670 * Modify "index" to use the value stored into its register as an 6671 * offset relative to the beginning of the header for the protocol 6672 * "proto", and allocate a register and put an item "size" bytes long 6673 * (1, 2, or 4) at that offset into that register, making it the register 6674 * for "index". 6675 */ 6676 struct arth * 6677 gen_load(proto, inst, size) 6678 int proto; 6679 struct arth *inst; 6680 int size; 6681 { 6682 struct slist *s, *tmp; 6683 struct block *b; 6684 int regno = alloc_reg(); 6685 6686 free_reg(inst->regno); 6687 switch (size) { 6688 6689 default: 6690 bpf_error("data size must be 1, 2, or 4"); 6691 6692 case 1: 6693 size = BPF_B; 6694 break; 6695 6696 case 2: 6697 size = BPF_H; 6698 break; 6699 6700 case 4: 6701 size = BPF_W; 6702 break; 6703 } 6704 switch (proto) { 6705 default: 6706 bpf_error("unsupported index operation"); 6707 6708 case Q_RADIO: 6709 /* 6710 * The offset is relative to the beginning of the packet 6711 * data, if we have a radio header. (If we don't, this 6712 * is an error.) 6713 */ 6714 if (linktype != DLT_IEEE802_11_RADIO_AVS && 6715 linktype != DLT_IEEE802_11_RADIO && 6716 linktype != DLT_PRISM_HEADER) 6717 bpf_error("radio information not present in capture"); 6718 6719 /* 6720 * Load into the X register the offset computed into the 6721 * register specified by "index". 6722 */ 6723 s = xfer_to_x(inst); 6724 6725 /* 6726 * Load the item at that offset. 6727 */ 6728 tmp = new_stmt(BPF_LD|BPF_IND|size); 6729 sappend(s, tmp); 6730 sappend(inst->s, s); 6731 break; 6732 6733 case Q_LINK: 6734 /* 6735 * The offset is relative to the beginning of 6736 * the link-layer header. 6737 * 6738 * XXX - what about ATM LANE? Should the index be 6739 * relative to the beginning of the AAL5 frame, so 6740 * that 0 refers to the beginning of the LE Control 6741 * field, or relative to the beginning of the LAN 6742 * frame, so that 0 refers, for Ethernet LANE, to 6743 * the beginning of the destination address? 6744 */ 6745 s = gen_llprefixlen(); 6746 6747 /* 6748 * If "s" is non-null, it has code to arrange that the 6749 * X register contains the length of the prefix preceding 6750 * the link-layer header. Add to it the offset computed 6751 * into the register specified by "index", and move that 6752 * into the X register. Otherwise, just load into the X 6753 * register the offset computed into the register specified 6754 * by "index". 6755 */ 6756 if (s != NULL) { 6757 sappend(s, xfer_to_a(inst)); 6758 sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X)); 6759 sappend(s, new_stmt(BPF_MISC|BPF_TAX)); 6760 } else 6761 s = xfer_to_x(inst); 6762 6763 /* 6764 * Load the item at the sum of the offset we've put in the 6765 * X register and the offset of the start of the link 6766 * layer header (which is 0 if the radio header is 6767 * variable-length; that header length is what we put 6768 * into the X register and then added to the index). 6769 */ 6770 tmp = new_stmt(BPF_LD|BPF_IND|size); 6771 tmp->s.k = off_ll; 6772 sappend(s, tmp); 6773 sappend(inst->s, s); 6774 break; 6775 6776 case Q_IP: 6777 case Q_ARP: 6778 case Q_RARP: 6779 case Q_ATALK: 6780 case Q_DECNET: 6781 case Q_SCA: 6782 case Q_LAT: 6783 case Q_MOPRC: 6784 case Q_MOPDL: 6785 #ifdef INET6 6786 case Q_IPV6: 6787 #endif 6788 /* 6789 * The offset is relative to the beginning of 6790 * the network-layer header. 6791 * XXX - are there any cases where we want 6792 * off_nl_nosnap? 6793 */ 6794 s = gen_off_macpl(); 6795 6796 /* 6797 * If "s" is non-null, it has code to arrange that the 6798 * X register contains the offset of the MAC-layer 6799 * payload. Add to it the offset computed into the 6800 * register specified by "index", and move that into 6801 * the X register. Otherwise, just load into the X 6802 * register the offset computed into the register specified 6803 * by "index". 6804 */ 6805 if (s != NULL) { 6806 sappend(s, xfer_to_a(inst)); 6807 sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X)); 6808 sappend(s, new_stmt(BPF_MISC|BPF_TAX)); 6809 } else 6810 s = xfer_to_x(inst); 6811 6812 /* 6813 * Load the item at the sum of the offset we've put in the 6814 * X register, the offset of the start of the network 6815 * layer header from the beginning of the MAC-layer 6816 * payload, and the purported offset of the start of the 6817 * MAC-layer payload (which might be 0 if there's a 6818 * variable-length prefix before the link-layer header 6819 * or the link-layer header itself is variable-length; 6820 * the variable-length offset of the start of the 6821 * MAC-layer payload is what we put into the X register 6822 * and then added to the index). 6823 */ 6824 tmp = new_stmt(BPF_LD|BPF_IND|size); 6825 tmp->s.k = off_macpl + off_nl; 6826 sappend(s, tmp); 6827 sappend(inst->s, s); 6828 6829 /* 6830 * Do the computation only if the packet contains 6831 * the protocol in question. 6832 */ 6833 b = gen_proto_abbrev(proto); 6834 if (inst->b) 6835 gen_and(inst->b, b); 6836 inst->b = b; 6837 break; 6838 6839 case Q_SCTP: 6840 case Q_TCP: 6841 case Q_UDP: 6842 case Q_ICMP: 6843 case Q_IGMP: 6844 case Q_IGRP: 6845 case Q_PIM: 6846 case Q_VRRP: 6847 case Q_CARP: 6848 /* 6849 * The offset is relative to the beginning of 6850 * the transport-layer header. 6851 * 6852 * Load the X register with the length of the IPv4 header 6853 * (plus the offset of the link-layer header, if it's 6854 * a variable-length header), in bytes. 6855 * 6856 * XXX - are there any cases where we want 6857 * off_nl_nosnap? 6858 * XXX - we should, if we're built with 6859 * IPv6 support, generate code to load either 6860 * IPv4, IPv6, or both, as appropriate. 6861 */ 6862 s = gen_loadx_iphdrlen(); 6863 6864 /* 6865 * The X register now contains the sum of the length 6866 * of any variable-length header preceding the link-layer 6867 * header, any variable-length link-layer header, and the 6868 * length of the network-layer header. 6869 * 6870 * Load into the A register the offset relative to 6871 * the beginning of the transport layer header, 6872 * add the X register to that, move that to the 6873 * X register, and load with an offset from the 6874 * X register equal to the offset of the network 6875 * layer header relative to the beginning of 6876 * the MAC-layer payload plus the fixed-length 6877 * portion of the offset of the MAC-layer payload 6878 * from the beginning of the raw packet data. 6879 */ 6880 sappend(s, xfer_to_a(inst)); 6881 sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X)); 6882 sappend(s, new_stmt(BPF_MISC|BPF_TAX)); 6883 sappend(s, tmp = new_stmt(BPF_LD|BPF_IND|size)); 6884 tmp->s.k = off_macpl + off_nl; 6885 sappend(inst->s, s); 6886 6887 /* 6888 * Do the computation only if the packet contains 6889 * the protocol in question - which is true only 6890 * if this is an IP datagram and is the first or 6891 * only fragment of that datagram. 6892 */ 6893 gen_and(gen_proto_abbrev(proto), b = gen_ipfrag()); 6894 if (inst->b) 6895 gen_and(inst->b, b); 6896 #ifdef INET6 6897 gen_and(gen_proto_abbrev(Q_IP), b); 6898 #endif 6899 inst->b = b; 6900 break; 6901 #ifdef INET6 6902 case Q_ICMPV6: 6903 bpf_error("IPv6 upper-layer protocol is not supported by proto[x]"); 6904 /*NOTREACHED*/ 6905 #endif 6906 } 6907 inst->regno = regno; 6908 s = new_stmt(BPF_ST); 6909 s->s.k = regno; 6910 sappend(inst->s, s); 6911 6912 return inst; 6913 } 6914 6915 struct block * 6916 gen_relation(code, a0, a1, reversed) 6917 int code; 6918 struct arth *a0, *a1; 6919 int reversed; 6920 { 6921 struct slist *s0, *s1, *s2; 6922 struct block *b, *tmp; 6923 6924 s0 = xfer_to_x(a1); 6925 s1 = xfer_to_a(a0); 6926 if (code == BPF_JEQ) { 6927 s2 = new_stmt(BPF_ALU|BPF_SUB|BPF_X); 6928 b = new_block(JMP(code)); 6929 sappend(s1, s2); 6930 } 6931 else 6932 b = new_block(BPF_JMP|code|BPF_X); 6933 if (reversed) 6934 gen_not(b); 6935 6936 sappend(s0, s1); 6937 sappend(a1->s, s0); 6938 sappend(a0->s, a1->s); 6939 6940 b->stmts = a0->s; 6941 6942 free_reg(a0->regno); 6943 free_reg(a1->regno); 6944 6945 /* 'and' together protocol checks */ 6946 if (a0->b) { 6947 if (a1->b) { 6948 gen_and(a0->b, tmp = a1->b); 6949 } 6950 else 6951 tmp = a0->b; 6952 } else 6953 tmp = a1->b; 6954 6955 if (tmp) 6956 gen_and(tmp, b); 6957 6958 return b; 6959 } 6960 6961 struct arth * 6962 gen_loadlen() 6963 { 6964 int regno = alloc_reg(); 6965 struct arth *a = (struct arth *)newchunk(sizeof(*a)); 6966 struct slist *s; 6967 6968 s = new_stmt(BPF_LD|BPF_LEN); 6969 s->next = new_stmt(BPF_ST); 6970 s->next->s.k = regno; 6971 a->s = s; 6972 a->regno = regno; 6973 6974 return a; 6975 } 6976 6977 struct arth * 6978 gen_loadi(val) 6979 int val; 6980 { 6981 struct arth *a; 6982 struct slist *s; 6983 int reg; 6984 6985 a = (struct arth *)newchunk(sizeof(*a)); 6986 6987 reg = alloc_reg(); 6988 6989 s = new_stmt(BPF_LD|BPF_IMM); 6990 s->s.k = val; 6991 s->next = new_stmt(BPF_ST); 6992 s->next->s.k = reg; 6993 a->s = s; 6994 a->regno = reg; 6995 6996 return a; 6997 } 6998 6999 struct arth * 7000 gen_neg(a) 7001 struct arth *a; 7002 { 7003 struct slist *s; 7004 7005 s = xfer_to_a(a); 7006 sappend(a->s, s); 7007 s = new_stmt(BPF_ALU|BPF_NEG); 7008 s->s.k = 0; 7009 sappend(a->s, s); 7010 s = new_stmt(BPF_ST); 7011 s->s.k = a->regno; 7012 sappend(a->s, s); 7013 7014 return a; 7015 } 7016 7017 struct arth * 7018 gen_arth(code, a0, a1) 7019 int code; 7020 struct arth *a0, *a1; 7021 { 7022 struct slist *s0, *s1, *s2; 7023 7024 s0 = xfer_to_x(a1); 7025 s1 = xfer_to_a(a0); 7026 s2 = new_stmt(BPF_ALU|BPF_X|code); 7027 7028 sappend(s1, s2); 7029 sappend(s0, s1); 7030 sappend(a1->s, s0); 7031 sappend(a0->s, a1->s); 7032 7033 free_reg(a0->regno); 7034 free_reg(a1->regno); 7035 7036 s0 = new_stmt(BPF_ST); 7037 a0->regno = s0->s.k = alloc_reg(); 7038 sappend(a0->s, s0); 7039 7040 return a0; 7041 } 7042 7043 /* 7044 * Here we handle simple allocation of the scratch registers. 7045 * If too many registers are alloc'd, the allocator punts. 7046 */ 7047 static int regused[BPF_MEMWORDS]; 7048 static int curreg; 7049 7050 /* 7051 * Initialize the table of used registers and the current register. 7052 */ 7053 static void 7054 init_regs() 7055 { 7056 curreg = 0; 7057 memset(regused, 0, sizeof regused); 7058 } 7059 7060 /* 7061 * Return the next free register. 7062 */ 7063 static int 7064 alloc_reg() 7065 { 7066 int n = BPF_MEMWORDS; 7067 7068 while (--n >= 0) { 7069 if (regused[curreg]) 7070 curreg = (curreg + 1) % BPF_MEMWORDS; 7071 else { 7072 regused[curreg] = 1; 7073 return curreg; 7074 } 7075 } 7076 bpf_error("too many registers needed to evaluate expression"); 7077 /* NOTREACHED */ 7078 return 0; 7079 } 7080 7081 /* 7082 * Return a register to the table so it can 7083 * be used later. 7084 */ 7085 static void 7086 free_reg(n) 7087 int n; 7088 { 7089 regused[n] = 0; 7090 } 7091 7092 static struct block * 7093 gen_len(jmp, n) 7094 int jmp, n; 7095 { 7096 struct slist *s; 7097 struct block *b; 7098 7099 s = new_stmt(BPF_LD|BPF_LEN); 7100 b = new_block(JMP(jmp)); 7101 b->stmts = s; 7102 b->s.k = n; 7103 7104 return b; 7105 } 7106 7107 struct block * 7108 gen_greater(n) 7109 int n; 7110 { 7111 return gen_len(BPF_JGE, n); 7112 } 7113 7114 /* 7115 * Actually, this is less than or equal. 7116 */ 7117 struct block * 7118 gen_less(n) 7119 int n; 7120 { 7121 struct block *b; 7122 7123 b = gen_len(BPF_JGT, n); 7124 gen_not(b); 7125 7126 return b; 7127 } 7128 7129 /* 7130 * This is for "byte {idx} {op} {val}"; "idx" is treated as relative to 7131 * the beginning of the link-layer header. 7132 * XXX - that means you can't test values in the radiotap header, but 7133 * as that header is difficult if not impossible to parse generally 7134 * without a loop, that might not be a severe problem. A new keyword 7135 * "radio" could be added for that, although what you'd really want 7136 * would be a way of testing particular radio header values, which 7137 * would generate code appropriate to the radio header in question. 7138 */ 7139 struct block * 7140 gen_byteop(op, idx, val) 7141 int op, idx, val; 7142 { 7143 struct block *b; 7144 struct slist *s; 7145 7146 switch (op) { 7147 default: 7148 abort(); 7149 7150 case '=': 7151 return gen_cmp(OR_LINK, (u_int)idx, BPF_B, (bpf_int32)val); 7152 7153 case '<': 7154 b = gen_cmp_lt(OR_LINK, (u_int)idx, BPF_B, (bpf_int32)val); 7155 return b; 7156 7157 case '>': 7158 b = gen_cmp_gt(OR_LINK, (u_int)idx, BPF_B, (bpf_int32)val); 7159 return b; 7160 7161 case '|': 7162 s = new_stmt(BPF_ALU|BPF_OR|BPF_K); 7163 break; 7164 7165 case '&': 7166 s = new_stmt(BPF_ALU|BPF_AND|BPF_K); 7167 break; 7168 } 7169 s->s.k = val; 7170 b = new_block(JMP(BPF_JEQ)); 7171 b->stmts = s; 7172 gen_not(b); 7173 7174 return b; 7175 } 7176 7177 static u_char abroadcast[] = { 0x0 }; 7178 7179 struct block * 7180 gen_broadcast(proto) 7181 int proto; 7182 { 7183 bpf_u_int32 hostmask; 7184 struct block *b0, *b1, *b2; 7185 static u_char ebroadcast[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; 7186 7187 switch (proto) { 7188 7189 case Q_DEFAULT: 7190 case Q_LINK: 7191 switch (linktype) { 7192 case DLT_ARCNET: 7193 case DLT_ARCNET_LINUX: 7194 return gen_ahostop(abroadcast, Q_DST); 7195 case DLT_EN10MB: 7196 case DLT_NETANALYZER: 7197 case DLT_NETANALYZER_TRANSPARENT: 7198 return gen_ehostop(ebroadcast, Q_DST); 7199 case DLT_FDDI: 7200 return gen_fhostop(ebroadcast, Q_DST); 7201 case DLT_IEEE802: 7202 return gen_thostop(ebroadcast, Q_DST); 7203 case DLT_IEEE802_11: 7204 case DLT_PRISM_HEADER: 7205 case DLT_IEEE802_11_RADIO_AVS: 7206 case DLT_IEEE802_11_RADIO: 7207 case DLT_PPI: 7208 return gen_wlanhostop(ebroadcast, Q_DST); 7209 case DLT_IP_OVER_FC: 7210 return gen_ipfchostop(ebroadcast, Q_DST); 7211 case DLT_SUNATM: 7212 if (is_lane) { 7213 /* 7214 * Check that the packet doesn't begin with an 7215 * LE Control marker. (We've already generated 7216 * a test for LANE.) 7217 */ 7218 b1 = gen_cmp(OR_LINK, SUNATM_PKT_BEGIN_POS, 7219 BPF_H, 0xFF00); 7220 gen_not(b1); 7221 7222 /* 7223 * Now check the MAC address. 7224 */ 7225 b0 = gen_ehostop(ebroadcast, Q_DST); 7226 gen_and(b1, b0); 7227 return b0; 7228 } 7229 break; 7230 default: 7231 bpf_error("not a broadcast link"); 7232 } 7233 break; 7234 7235 case Q_IP: 7236 /* 7237 * We treat a netmask of PCAP_NETMASK_UNKNOWN (0xffffffff) 7238 * as an indication that we don't know the netmask, and fail 7239 * in that case. 7240 */ 7241 if (netmask == PCAP_NETMASK_UNKNOWN) 7242 bpf_error("netmask not known, so 'ip broadcast' not supported"); 7243 b0 = gen_linktype(ETHERTYPE_IP); 7244 hostmask = ~netmask; 7245 b1 = gen_mcmp(OR_NET, 16, BPF_W, (bpf_int32)0, hostmask); 7246 b2 = gen_mcmp(OR_NET, 16, BPF_W, 7247 (bpf_int32)(~0 & hostmask), hostmask); 7248 gen_or(b1, b2); 7249 gen_and(b0, b2); 7250 return b2; 7251 } 7252 bpf_error("only link-layer/IP broadcast filters supported"); 7253 /* NOTREACHED */ 7254 return NULL; 7255 } 7256 7257 /* 7258 * Generate code to test the low-order bit of a MAC address (that's 7259 * the bottom bit of the *first* byte). 7260 */ 7261 static struct block * 7262 gen_mac_multicast(offset) 7263 int offset; 7264 { 7265 register struct block *b0; 7266 register struct slist *s; 7267 7268 /* link[offset] & 1 != 0 */ 7269 s = gen_load_a(OR_LINK, offset, BPF_B); 7270 b0 = new_block(JMP(BPF_JSET)); 7271 b0->s.k = 1; 7272 b0->stmts = s; 7273 return b0; 7274 } 7275 7276 struct block * 7277 gen_multicast(proto) 7278 int proto; 7279 { 7280 register struct block *b0, *b1, *b2; 7281 register struct slist *s; 7282 7283 switch (proto) { 7284 7285 case Q_DEFAULT: 7286 case Q_LINK: 7287 switch (linktype) { 7288 case DLT_ARCNET: 7289 case DLT_ARCNET_LINUX: 7290 /* all ARCnet multicasts use the same address */ 7291 return gen_ahostop(abroadcast, Q_DST); 7292 case DLT_EN10MB: 7293 case DLT_NETANALYZER: 7294 case DLT_NETANALYZER_TRANSPARENT: 7295 /* ether[0] & 1 != 0 */ 7296 return gen_mac_multicast(0); 7297 case DLT_FDDI: 7298 /* 7299 * XXX TEST THIS: MIGHT NOT PORT PROPERLY XXX 7300 * 7301 * XXX - was that referring to bit-order issues? 7302 */ 7303 /* fddi[1] & 1 != 0 */ 7304 return gen_mac_multicast(1); 7305 case DLT_IEEE802: 7306 /* tr[2] & 1 != 0 */ 7307 return gen_mac_multicast(2); 7308 case DLT_IEEE802_11: 7309 case DLT_PRISM_HEADER: 7310 case DLT_IEEE802_11_RADIO_AVS: 7311 case DLT_IEEE802_11_RADIO: 7312 case DLT_PPI: 7313 /* 7314 * Oh, yuk. 7315 * 7316 * For control frames, there is no DA. 7317 * 7318 * For management frames, DA is at an 7319 * offset of 4 from the beginning of 7320 * the packet. 7321 * 7322 * For data frames, DA is at an offset 7323 * of 4 from the beginning of the packet 7324 * if To DS is clear and at an offset of 7325 * 16 from the beginning of the packet 7326 * if To DS is set. 7327 */ 7328 7329 /* 7330 * Generate the tests to be done for data frames. 7331 * 7332 * First, check for To DS set, i.e. "link[1] & 0x01". 7333 */ 7334 s = gen_load_a(OR_LINK, 1, BPF_B); 7335 b1 = new_block(JMP(BPF_JSET)); 7336 b1->s.k = 0x01; /* To DS */ 7337 b1->stmts = s; 7338 7339 /* 7340 * If To DS is set, the DA is at 16. 7341 */ 7342 b0 = gen_mac_multicast(16); 7343 gen_and(b1, b0); 7344 7345 /* 7346 * Now, check for To DS not set, i.e. check 7347 * "!(link[1] & 0x01)". 7348 */ 7349 s = gen_load_a(OR_LINK, 1, BPF_B); 7350 b2 = new_block(JMP(BPF_JSET)); 7351 b2->s.k = 0x01; /* To DS */ 7352 b2->stmts = s; 7353 gen_not(b2); 7354 7355 /* 7356 * If To DS is not set, the DA is at 4. 7357 */ 7358 b1 = gen_mac_multicast(4); 7359 gen_and(b2, b1); 7360 7361 /* 7362 * Now OR together the last two checks. That gives 7363 * the complete set of checks for data frames. 7364 */ 7365 gen_or(b1, b0); 7366 7367 /* 7368 * Now check for a data frame. 7369 * I.e, check "link[0] & 0x08". 7370 */ 7371 s = gen_load_a(OR_LINK, 0, BPF_B); 7372 b1 = new_block(JMP(BPF_JSET)); 7373 b1->s.k = 0x08; 7374 b1->stmts = s; 7375 7376 /* 7377 * AND that with the checks done for data frames. 7378 */ 7379 gen_and(b1, b0); 7380 7381 /* 7382 * If the high-order bit of the type value is 0, this 7383 * is a management frame. 7384 * I.e, check "!(link[0] & 0x08)". 7385 */ 7386 s = gen_load_a(OR_LINK, 0, BPF_B); 7387 b2 = new_block(JMP(BPF_JSET)); 7388 b2->s.k = 0x08; 7389 b2->stmts = s; 7390 gen_not(b2); 7391 7392 /* 7393 * For management frames, the DA is at 4. 7394 */ 7395 b1 = gen_mac_multicast(4); 7396 gen_and(b2, b1); 7397 7398 /* 7399 * OR that with the checks done for data frames. 7400 * That gives the checks done for management and 7401 * data frames. 7402 */ 7403 gen_or(b1, b0); 7404 7405 /* 7406 * If the low-order bit of the type value is 1, 7407 * this is either a control frame or a frame 7408 * with a reserved type, and thus not a 7409 * frame with an SA. 7410 * 7411 * I.e., check "!(link[0] & 0x04)". 7412 */ 7413 s = gen_load_a(OR_LINK, 0, BPF_B); 7414 b1 = new_block(JMP(BPF_JSET)); 7415 b1->s.k = 0x04; 7416 b1->stmts = s; 7417 gen_not(b1); 7418 7419 /* 7420 * AND that with the checks for data and management 7421 * frames. 7422 */ 7423 gen_and(b1, b0); 7424 return b0; 7425 case DLT_IP_OVER_FC: 7426 b0 = gen_mac_multicast(2); 7427 return b0; 7428 case DLT_SUNATM: 7429 if (is_lane) { 7430 /* 7431 * Check that the packet doesn't begin with an 7432 * LE Control marker. (We've already generated 7433 * a test for LANE.) 7434 */ 7435 b1 = gen_cmp(OR_LINK, SUNATM_PKT_BEGIN_POS, 7436 BPF_H, 0xFF00); 7437 gen_not(b1); 7438 7439 /* ether[off_mac] & 1 != 0 */ 7440 b0 = gen_mac_multicast(off_mac); 7441 gen_and(b1, b0); 7442 return b0; 7443 } 7444 break; 7445 default: 7446 break; 7447 } 7448 /* Link not known to support multicasts */ 7449 break; 7450 7451 case Q_IP: 7452 b0 = gen_linktype(ETHERTYPE_IP); 7453 b1 = gen_cmp_ge(OR_NET, 16, BPF_B, (bpf_int32)224); 7454 gen_and(b0, b1); 7455 return b1; 7456 7457 #ifdef INET6 7458 case Q_IPV6: 7459 b0 = gen_linktype(ETHERTYPE_IPV6); 7460 b1 = gen_cmp(OR_NET, 24, BPF_B, (bpf_int32)255); 7461 gen_and(b0, b1); 7462 return b1; 7463 #endif /* INET6 */ 7464 } 7465 bpf_error("link-layer multicast filters supported only on ethernet/FDDI/token ring/ARCNET/802.11/ATM LANE/Fibre Channel"); 7466 /* NOTREACHED */ 7467 return NULL; 7468 } 7469 7470 /* 7471 * generate command for inbound/outbound. It's here so we can 7472 * make it link-type specific. 'dir' = 0 implies "inbound", 7473 * = 1 implies "outbound". 7474 */ 7475 struct block * 7476 gen_inbound(dir) 7477 int dir; 7478 { 7479 register struct block *b0; 7480 7481 /* 7482 * Only some data link types support inbound/outbound qualifiers. 7483 */ 7484 switch (linktype) { 7485 case DLT_SLIP: 7486 b0 = gen_relation(BPF_JEQ, 7487 gen_load(Q_LINK, gen_loadi(0), 1), 7488 gen_loadi(0), 7489 dir); 7490 break; 7491 7492 case DLT_IPNET: 7493 if (dir) { 7494 /* match outgoing packets */ 7495 b0 = gen_cmp(OR_LINK, 2, BPF_H, IPNET_OUTBOUND); 7496 } else { 7497 /* match incoming packets */ 7498 b0 = gen_cmp(OR_LINK, 2, BPF_H, IPNET_INBOUND); 7499 } 7500 break; 7501 7502 case DLT_LINUX_SLL: 7503 if (dir) { 7504 /* 7505 * Match packets sent by this machine. 7506 */ 7507 b0 = gen_cmp(OR_LINK, 0, BPF_H, LINUX_SLL_OUTGOING); 7508 } else { 7509 /* 7510 * Match packets sent to this machine. 7511 * (No broadcast or multicast packets, or 7512 * packets sent to some other machine and 7513 * received promiscuously.) 7514 * 7515 * XXX - packets sent to other machines probably 7516 * shouldn't be matched, but what about broadcast 7517 * or multicast packets we received? 7518 */ 7519 b0 = gen_cmp(OR_LINK, 0, BPF_H, LINUX_SLL_HOST); 7520 } 7521 break; 7522 7523 #ifdef HAVE_NET_PFVAR_H 7524 case DLT_PFLOG: 7525 b0 = gen_cmp(OR_LINK, offsetof(struct pfloghdr, dir), BPF_B, 7526 (bpf_int32)((dir == 0) ? PF_IN : PF_OUT)); 7527 break; 7528 #endif 7529 7530 case DLT_PPP_PPPD: 7531 if (dir) { 7532 /* match outgoing packets */ 7533 b0 = gen_cmp(OR_LINK, 0, BPF_B, PPP_PPPD_OUT); 7534 } else { 7535 /* match incoming packets */ 7536 b0 = gen_cmp(OR_LINK, 0, BPF_B, PPP_PPPD_IN); 7537 } 7538 break; 7539 7540 case DLT_JUNIPER_MFR: 7541 case DLT_JUNIPER_MLFR: 7542 case DLT_JUNIPER_MLPPP: 7543 case DLT_JUNIPER_ATM1: 7544 case DLT_JUNIPER_ATM2: 7545 case DLT_JUNIPER_PPPOE: 7546 case DLT_JUNIPER_PPPOE_ATM: 7547 case DLT_JUNIPER_GGSN: 7548 case DLT_JUNIPER_ES: 7549 case DLT_JUNIPER_MONITOR: 7550 case DLT_JUNIPER_SERVICES: 7551 case DLT_JUNIPER_ETHER: 7552 case DLT_JUNIPER_PPP: 7553 case DLT_JUNIPER_FRELAY: 7554 case DLT_JUNIPER_CHDLC: 7555 case DLT_JUNIPER_VP: 7556 case DLT_JUNIPER_ST: 7557 case DLT_JUNIPER_ISM: 7558 case DLT_JUNIPER_VS: 7559 case DLT_JUNIPER_SRX_E2E: 7560 case DLT_JUNIPER_FIBRECHANNEL: 7561 case DLT_JUNIPER_ATM_CEMIC: 7562 7563 /* juniper flags (including direction) are stored 7564 * the byte after the 3-byte magic number */ 7565 if (dir) { 7566 /* match outgoing packets */ 7567 b0 = gen_mcmp(OR_LINK, 3, BPF_B, 0, 0x01); 7568 } else { 7569 /* match incoming packets */ 7570 b0 = gen_mcmp(OR_LINK, 3, BPF_B, 1, 0x01); 7571 } 7572 break; 7573 7574 default: 7575 bpf_error("inbound/outbound not supported on linktype %d", 7576 linktype); 7577 b0 = NULL; 7578 /* NOTREACHED */ 7579 } 7580 return (b0); 7581 } 7582 7583 #ifdef HAVE_NET_PFVAR_H 7584 /* PF firewall log matched interface */ 7585 struct block * 7586 gen_pf_ifname(const char *ifname) 7587 { 7588 struct block *b0; 7589 u_int len, off; 7590 7591 if (linktype != DLT_PFLOG) { 7592 bpf_error("ifname supported only on PF linktype"); 7593 /* NOTREACHED */ 7594 } 7595 len = sizeof(((struct pfloghdr *)0)->ifname); 7596 off = offsetof(struct pfloghdr, ifname); 7597 if (strlen(ifname) >= len) { 7598 bpf_error("ifname interface names can only be %d characters", 7599 len-1); 7600 /* NOTREACHED */ 7601 } 7602 b0 = gen_bcmp(OR_LINK, off, strlen(ifname), (const u_char *)ifname); 7603 return (b0); 7604 } 7605 7606 /* PF firewall log ruleset name */ 7607 struct block * 7608 gen_pf_ruleset(char *ruleset) 7609 { 7610 struct block *b0; 7611 7612 if (linktype != DLT_PFLOG) { 7613 bpf_error("ruleset supported only on PF linktype"); 7614 /* NOTREACHED */ 7615 } 7616 7617 if (strlen(ruleset) >= sizeof(((struct pfloghdr *)0)->ruleset)) { 7618 bpf_error("ruleset names can only be %ld characters", 7619 (long)(sizeof(((struct pfloghdr *)0)->ruleset) - 1)); 7620 /* NOTREACHED */ 7621 } 7622 7623 b0 = gen_bcmp(OR_LINK, offsetof(struct pfloghdr, ruleset), 7624 strlen(ruleset), (const u_char *)ruleset); 7625 return (b0); 7626 } 7627 7628 /* PF firewall log rule number */ 7629 struct block * 7630 gen_pf_rnr(int rnr) 7631 { 7632 struct block *b0; 7633 7634 if (linktype != DLT_PFLOG) { 7635 bpf_error("rnr supported only on PF linktype"); 7636 /* NOTREACHED */ 7637 } 7638 7639 b0 = gen_cmp(OR_LINK, offsetof(struct pfloghdr, rulenr), BPF_W, 7640 (bpf_int32)rnr); 7641 return (b0); 7642 } 7643 7644 /* PF firewall log sub-rule number */ 7645 struct block * 7646 gen_pf_srnr(int srnr) 7647 { 7648 struct block *b0; 7649 7650 if (linktype != DLT_PFLOG) { 7651 bpf_error("srnr supported only on PF linktype"); 7652 /* NOTREACHED */ 7653 } 7654 7655 b0 = gen_cmp(OR_LINK, offsetof(struct pfloghdr, subrulenr), BPF_W, 7656 (bpf_int32)srnr); 7657 return (b0); 7658 } 7659 7660 /* PF firewall log reason code */ 7661 struct block * 7662 gen_pf_reason(int reason) 7663 { 7664 struct block *b0; 7665 7666 if (linktype != DLT_PFLOG) { 7667 bpf_error("reason supported only on PF linktype"); 7668 /* NOTREACHED */ 7669 } 7670 7671 b0 = gen_cmp(OR_LINK, offsetof(struct pfloghdr, reason), BPF_B, 7672 (bpf_int32)reason); 7673 return (b0); 7674 } 7675 7676 /* PF firewall log action */ 7677 struct block * 7678 gen_pf_action(int action) 7679 { 7680 struct block *b0; 7681 7682 if (linktype != DLT_PFLOG) { 7683 bpf_error("action supported only on PF linktype"); 7684 /* NOTREACHED */ 7685 } 7686 7687 b0 = gen_cmp(OR_LINK, offsetof(struct pfloghdr, action), BPF_B, 7688 (bpf_int32)action); 7689 return (b0); 7690 } 7691 #else /* !HAVE_NET_PFVAR_H */ 7692 struct block * 7693 gen_pf_ifname(const char *ifname) 7694 { 7695 bpf_error("libpcap was compiled without pf support"); 7696 /* NOTREACHED */ 7697 return (NULL); 7698 } 7699 7700 struct block * 7701 gen_pf_ruleset(char *ruleset) 7702 { 7703 bpf_error("libpcap was compiled on a machine without pf support"); 7704 /* NOTREACHED */ 7705 return (NULL); 7706 } 7707 7708 struct block * 7709 gen_pf_rnr(int rnr) 7710 { 7711 bpf_error("libpcap was compiled on a machine without pf support"); 7712 /* NOTREACHED */ 7713 return (NULL); 7714 } 7715 7716 struct block * 7717 gen_pf_srnr(int srnr) 7718 { 7719 bpf_error("libpcap was compiled on a machine without pf support"); 7720 /* NOTREACHED */ 7721 return (NULL); 7722 } 7723 7724 struct block * 7725 gen_pf_reason(int reason) 7726 { 7727 bpf_error("libpcap was compiled on a machine without pf support"); 7728 /* NOTREACHED */ 7729 return (NULL); 7730 } 7731 7732 struct block * 7733 gen_pf_action(int action) 7734 { 7735 bpf_error("libpcap was compiled on a machine without pf support"); 7736 /* NOTREACHED */ 7737 return (NULL); 7738 } 7739 #endif /* HAVE_NET_PFVAR_H */ 7740 7741 /* IEEE 802.11 wireless header */ 7742 struct block * 7743 gen_p80211_type(int type, int mask) 7744 { 7745 struct block *b0; 7746 7747 switch (linktype) { 7748 7749 case DLT_IEEE802_11: 7750 case DLT_PRISM_HEADER: 7751 case DLT_IEEE802_11_RADIO_AVS: 7752 case DLT_IEEE802_11_RADIO: 7753 b0 = gen_mcmp(OR_LINK, 0, BPF_B, (bpf_int32)type, 7754 (bpf_int32)mask); 7755 break; 7756 7757 default: 7758 bpf_error("802.11 link-layer types supported only on 802.11"); 7759 /* NOTREACHED */ 7760 } 7761 7762 return (b0); 7763 } 7764 7765 struct block * 7766 gen_p80211_fcdir(int fcdir) 7767 { 7768 struct block *b0; 7769 7770 switch (linktype) { 7771 7772 case DLT_IEEE802_11: 7773 case DLT_PRISM_HEADER: 7774 case DLT_IEEE802_11_RADIO_AVS: 7775 case DLT_IEEE802_11_RADIO: 7776 break; 7777 7778 default: 7779 bpf_error("frame direction supported only with 802.11 headers"); 7780 /* NOTREACHED */ 7781 } 7782 7783 b0 = gen_mcmp(OR_LINK, 1, BPF_B, (bpf_int32)fcdir, 7784 (bpf_u_int32)IEEE80211_FC1_DIR_MASK); 7785 7786 return (b0); 7787 } 7788 7789 struct block * 7790 gen_acode(eaddr, q) 7791 register const u_char *eaddr; 7792 struct qual q; 7793 { 7794 switch (linktype) { 7795 7796 case DLT_ARCNET: 7797 case DLT_ARCNET_LINUX: 7798 if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) && 7799 q.proto == Q_LINK) 7800 return (gen_ahostop(eaddr, (int)q.dir)); 7801 else { 7802 bpf_error("ARCnet address used in non-arc expression"); 7803 /* NOTREACHED */ 7804 } 7805 break; 7806 7807 default: 7808 bpf_error("aid supported only on ARCnet"); 7809 /* NOTREACHED */ 7810 } 7811 bpf_error("ARCnet address used in non-arc expression"); 7812 /* NOTREACHED */ 7813 return NULL; 7814 } 7815 7816 static struct block * 7817 gen_ahostop(eaddr, dir) 7818 register const u_char *eaddr; 7819 register int dir; 7820 { 7821 register struct block *b0, *b1; 7822 7823 switch (dir) { 7824 /* src comes first, different from Ethernet */ 7825 case Q_SRC: 7826 return gen_bcmp(OR_LINK, 0, 1, eaddr); 7827 7828 case Q_DST: 7829 return gen_bcmp(OR_LINK, 1, 1, eaddr); 7830 7831 case Q_AND: 7832 b0 = gen_ahostop(eaddr, Q_SRC); 7833 b1 = gen_ahostop(eaddr, Q_DST); 7834 gen_and(b0, b1); 7835 return b1; 7836 7837 case Q_DEFAULT: 7838 case Q_OR: 7839 b0 = gen_ahostop(eaddr, Q_SRC); 7840 b1 = gen_ahostop(eaddr, Q_DST); 7841 gen_or(b0, b1); 7842 return b1; 7843 7844 case Q_ADDR1: 7845 bpf_error("'addr1' is only supported on 802.11"); 7846 break; 7847 7848 case Q_ADDR2: 7849 bpf_error("'addr2' is only supported on 802.11"); 7850 break; 7851 7852 case Q_ADDR3: 7853 bpf_error("'addr3' is only supported on 802.11"); 7854 break; 7855 7856 case Q_ADDR4: 7857 bpf_error("'addr4' is only supported on 802.11"); 7858 break; 7859 7860 case Q_RA: 7861 bpf_error("'ra' is only supported on 802.11"); 7862 break; 7863 7864 case Q_TA: 7865 bpf_error("'ta' is only supported on 802.11"); 7866 break; 7867 } 7868 abort(); 7869 /* NOTREACHED */ 7870 } 7871 7872 /* 7873 * support IEEE 802.1Q VLAN trunk over ethernet 7874 */ 7875 struct block * 7876 gen_vlan(vlan_num) 7877 int vlan_num; 7878 { 7879 struct block *b0, *b1; 7880 7881 /* can't check for VLAN-encapsulated packets inside MPLS */ 7882 if (label_stack_depth > 0) 7883 bpf_error("no VLAN match after MPLS"); 7884 7885 /* 7886 * Check for a VLAN packet, and then change the offsets to point 7887 * to the type and data fields within the VLAN packet. Just 7888 * increment the offsets, so that we can support a hierarchy, e.g. 7889 * "vlan 300 && vlan 200" to capture VLAN 200 encapsulated within 7890 * VLAN 100. 7891 * 7892 * XXX - this is a bit of a kludge. If we were to split the 7893 * compiler into a parser that parses an expression and 7894 * generates an expression tree, and a code generator that 7895 * takes an expression tree (which could come from our 7896 * parser or from some other parser) and generates BPF code, 7897 * we could perhaps make the offsets parameters of routines 7898 * and, in the handler for an "AND" node, pass to subnodes 7899 * other than the VLAN node the adjusted offsets. 7900 * 7901 * This would mean that "vlan" would, instead of changing the 7902 * behavior of *all* tests after it, change only the behavior 7903 * of tests ANDed with it. That would change the documented 7904 * semantics of "vlan", which might break some expressions. 7905 * However, it would mean that "(vlan and ip) or ip" would check 7906 * both for VLAN-encapsulated IP and IP-over-Ethernet, rather than 7907 * checking only for VLAN-encapsulated IP, so that could still 7908 * be considered worth doing; it wouldn't break expressions 7909 * that are of the form "vlan and ..." or "vlan N and ...", 7910 * which I suspect are the most common expressions involving 7911 * "vlan". "vlan or ..." doesn't necessarily do what the user 7912 * would really want, now, as all the "or ..." tests would 7913 * be done assuming a VLAN, even though the "or" could be viewed 7914 * as meaning "or, if this isn't a VLAN packet...". 7915 */ 7916 orig_nl = off_nl; 7917 7918 switch (linktype) { 7919 7920 case DLT_EN10MB: 7921 case DLT_NETANALYZER: 7922 case DLT_NETANALYZER_TRANSPARENT: 7923 /* check for VLAN, including QinQ */ 7924 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, 7925 (bpf_int32)ETHERTYPE_8021Q); 7926 b1 = gen_cmp(OR_LINK, off_linktype, BPF_H, 7927 (bpf_int32)ETHERTYPE_8021QINQ); 7928 gen_or(b0,b1); 7929 b0 = b1; 7930 7931 /* If a specific VLAN is requested, check VLAN id */ 7932 if (vlan_num >= 0) { 7933 b1 = gen_mcmp(OR_MACPL, 0, BPF_H, 7934 (bpf_int32)vlan_num, 0x0fff); 7935 gen_and(b0, b1); 7936 b0 = b1; 7937 } 7938 7939 off_macpl += 4; 7940 off_linktype += 4; 7941 #if 0 7942 off_nl_nosnap += 4; 7943 off_nl += 4; 7944 #endif 7945 break; 7946 7947 default: 7948 bpf_error("no VLAN support for data link type %d", 7949 linktype); 7950 /*NOTREACHED*/ 7951 } 7952 7953 return (b0); 7954 } 7955 7956 /* 7957 * support for MPLS 7958 */ 7959 struct block * 7960 gen_mpls(label_num) 7961 int label_num; 7962 { 7963 struct block *b0,*b1; 7964 7965 /* 7966 * Change the offsets to point to the type and data fields within 7967 * the MPLS packet. Just increment the offsets, so that we 7968 * can support a hierarchy, e.g. "mpls 100000 && mpls 1024" to 7969 * capture packets with an outer label of 100000 and an inner 7970 * label of 1024. 7971 * 7972 * XXX - this is a bit of a kludge. See comments in gen_vlan(). 7973 */ 7974 orig_nl = off_nl; 7975 7976 if (label_stack_depth > 0) { 7977 /* just match the bottom-of-stack bit clear */ 7978 b0 = gen_mcmp(OR_MACPL, orig_nl-2, BPF_B, 0, 0x01); 7979 } else { 7980 /* 7981 * Indicate that we're checking MPLS-encapsulated headers, 7982 * to make sure higher level code generators don't try to 7983 * match against IP-related protocols such as Q_ARP, Q_RARP 7984 * etc. 7985 */ 7986 switch (linktype) { 7987 7988 case DLT_C_HDLC: /* fall through */ 7989 case DLT_EN10MB: 7990 case DLT_NETANALYZER: 7991 case DLT_NETANALYZER_TRANSPARENT: 7992 b0 = gen_linktype(ETHERTYPE_MPLS); 7993 break; 7994 7995 case DLT_PPP: 7996 b0 = gen_linktype(PPP_MPLS_UCAST); 7997 break; 7998 7999 /* FIXME add other DLT_s ... 8000 * for Frame-Relay/and ATM this may get messy due to SNAP headers 8001 * leave it for now */ 8002 8003 default: 8004 bpf_error("no MPLS support for data link type %d", 8005 linktype); 8006 b0 = NULL; 8007 /*NOTREACHED*/ 8008 break; 8009 } 8010 } 8011 8012 /* If a specific MPLS label is requested, check it */ 8013 if (label_num >= 0) { 8014 label_num = label_num << 12; /* label is shifted 12 bits on the wire */ 8015 b1 = gen_mcmp(OR_MACPL, orig_nl, BPF_W, (bpf_int32)label_num, 8016 0xfffff000); /* only compare the first 20 bits */ 8017 gen_and(b0, b1); 8018 b0 = b1; 8019 } 8020 8021 off_nl_nosnap += 4; 8022 off_nl += 4; 8023 label_stack_depth++; 8024 return (b0); 8025 } 8026 8027 /* 8028 * Support PPPOE discovery and session. 8029 */ 8030 struct block * 8031 gen_pppoed() 8032 { 8033 /* check for PPPoE discovery */ 8034 return gen_linktype((bpf_int32)ETHERTYPE_PPPOED); 8035 } 8036 8037 struct block * 8038 gen_pppoes() 8039 { 8040 struct block *b0; 8041 8042 /* 8043 * Test against the PPPoE session link-layer type. 8044 */ 8045 b0 = gen_linktype((bpf_int32)ETHERTYPE_PPPOES); 8046 8047 /* 8048 * Change the offsets to point to the type and data fields within 8049 * the PPP packet, and note that this is PPPoE rather than 8050 * raw PPP. 8051 * 8052 * XXX - this is a bit of a kludge. If we were to split the 8053 * compiler into a parser that parses an expression and 8054 * generates an expression tree, and a code generator that 8055 * takes an expression tree (which could come from our 8056 * parser or from some other parser) and generates BPF code, 8057 * we could perhaps make the offsets parameters of routines 8058 * and, in the handler for an "AND" node, pass to subnodes 8059 * other than the PPPoE node the adjusted offsets. 8060 * 8061 * This would mean that "pppoes" would, instead of changing the 8062 * behavior of *all* tests after it, change only the behavior 8063 * of tests ANDed with it. That would change the documented 8064 * semantics of "pppoes", which might break some expressions. 8065 * However, it would mean that "(pppoes and ip) or ip" would check 8066 * both for VLAN-encapsulated IP and IP-over-Ethernet, rather than 8067 * checking only for VLAN-encapsulated IP, so that could still 8068 * be considered worth doing; it wouldn't break expressions 8069 * that are of the form "pppoes and ..." which I suspect are the 8070 * most common expressions involving "pppoes". "pppoes or ..." 8071 * doesn't necessarily do what the user would really want, now, 8072 * as all the "or ..." tests would be done assuming PPPoE, even 8073 * though the "or" could be viewed as meaning "or, if this isn't 8074 * a PPPoE packet...". 8075 */ 8076 orig_linktype = off_linktype; /* save original values */ 8077 orig_nl = off_nl; 8078 is_pppoes = 1; 8079 8080 /* 8081 * The "network-layer" protocol is PPPoE, which has a 6-byte 8082 * PPPoE header, followed by a PPP packet. 8083 * 8084 * There is no HDLC encapsulation for the PPP packet (it's 8085 * encapsulated in PPPoES instead), so the link-layer type 8086 * starts at the first byte of the PPP packet. For PPPoE, 8087 * that offset is relative to the beginning of the total 8088 * link-layer payload, including any 802.2 LLC header, so 8089 * it's 6 bytes past off_nl. 8090 */ 8091 off_linktype = off_nl + 6; 8092 8093 /* 8094 * The network-layer offsets are relative to the beginning 8095 * of the MAC-layer payload; that's past the 6-byte 8096 * PPPoE header and the 2-byte PPP header. 8097 */ 8098 off_nl = 6+2; 8099 off_nl_nosnap = 6+2; 8100 8101 return b0; 8102 } 8103 8104 struct block * 8105 gen_atmfield_code(atmfield, jvalue, jtype, reverse) 8106 int atmfield; 8107 bpf_int32 jvalue; 8108 bpf_u_int32 jtype; 8109 int reverse; 8110 { 8111 struct block *b0; 8112 8113 switch (atmfield) { 8114 8115 case A_VPI: 8116 if (!is_atm) 8117 bpf_error("'vpi' supported only on raw ATM"); 8118 if (off_vpi == (u_int)-1) 8119 abort(); 8120 b0 = gen_ncmp(OR_LINK, off_vpi, BPF_B, 0xffffffff, jtype, 8121 reverse, jvalue); 8122 break; 8123 8124 case A_VCI: 8125 if (!is_atm) 8126 bpf_error("'vci' supported only on raw ATM"); 8127 if (off_vci == (u_int)-1) 8128 abort(); 8129 b0 = gen_ncmp(OR_LINK, off_vci, BPF_H, 0xffffffff, jtype, 8130 reverse, jvalue); 8131 break; 8132 8133 case A_PROTOTYPE: 8134 if (off_proto == (u_int)-1) 8135 abort(); /* XXX - this isn't on FreeBSD */ 8136 b0 = gen_ncmp(OR_LINK, off_proto, BPF_B, 0x0f, jtype, 8137 reverse, jvalue); 8138 break; 8139 8140 case A_MSGTYPE: 8141 if (off_payload == (u_int)-1) 8142 abort(); 8143 b0 = gen_ncmp(OR_LINK, off_payload + MSG_TYPE_POS, BPF_B, 8144 0xffffffff, jtype, reverse, jvalue); 8145 break; 8146 8147 case A_CALLREFTYPE: 8148 if (!is_atm) 8149 bpf_error("'callref' supported only on raw ATM"); 8150 if (off_proto == (u_int)-1) 8151 abort(); 8152 b0 = gen_ncmp(OR_LINK, off_proto, BPF_B, 0xffffffff, 8153 jtype, reverse, jvalue); 8154 break; 8155 8156 default: 8157 abort(); 8158 } 8159 return b0; 8160 } 8161 8162 struct block * 8163 gen_atmtype_abbrev(type) 8164 int type; 8165 { 8166 struct block *b0, *b1; 8167 8168 switch (type) { 8169 8170 case A_METAC: 8171 /* Get all packets in Meta signalling Circuit */ 8172 if (!is_atm) 8173 bpf_error("'metac' supported only on raw ATM"); 8174 b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0); 8175 b1 = gen_atmfield_code(A_VCI, 1, BPF_JEQ, 0); 8176 gen_and(b0, b1); 8177 break; 8178 8179 case A_BCC: 8180 /* Get all packets in Broadcast Circuit*/ 8181 if (!is_atm) 8182 bpf_error("'bcc' supported only on raw ATM"); 8183 b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0); 8184 b1 = gen_atmfield_code(A_VCI, 2, BPF_JEQ, 0); 8185 gen_and(b0, b1); 8186 break; 8187 8188 case A_OAMF4SC: 8189 /* Get all cells in Segment OAM F4 circuit*/ 8190 if (!is_atm) 8191 bpf_error("'oam4sc' supported only on raw ATM"); 8192 b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0); 8193 b1 = gen_atmfield_code(A_VCI, 3, BPF_JEQ, 0); 8194 gen_and(b0, b1); 8195 break; 8196 8197 case A_OAMF4EC: 8198 /* Get all cells in End-to-End OAM F4 Circuit*/ 8199 if (!is_atm) 8200 bpf_error("'oam4ec' supported only on raw ATM"); 8201 b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0); 8202 b1 = gen_atmfield_code(A_VCI, 4, BPF_JEQ, 0); 8203 gen_and(b0, b1); 8204 break; 8205 8206 case A_SC: 8207 /* Get all packets in connection Signalling Circuit */ 8208 if (!is_atm) 8209 bpf_error("'sc' supported only on raw ATM"); 8210 b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0); 8211 b1 = gen_atmfield_code(A_VCI, 5, BPF_JEQ, 0); 8212 gen_and(b0, b1); 8213 break; 8214 8215 case A_ILMIC: 8216 /* Get all packets in ILMI Circuit */ 8217 if (!is_atm) 8218 bpf_error("'ilmic' supported only on raw ATM"); 8219 b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0); 8220 b1 = gen_atmfield_code(A_VCI, 16, BPF_JEQ, 0); 8221 gen_and(b0, b1); 8222 break; 8223 8224 case A_LANE: 8225 /* Get all LANE packets */ 8226 if (!is_atm) 8227 bpf_error("'lane' supported only on raw ATM"); 8228 b1 = gen_atmfield_code(A_PROTOTYPE, PT_LANE, BPF_JEQ, 0); 8229 8230 /* 8231 * Arrange that all subsequent tests assume LANE 8232 * rather than LLC-encapsulated packets, and set 8233 * the offsets appropriately for LANE-encapsulated 8234 * Ethernet. 8235 * 8236 * "off_mac" is the offset of the Ethernet header, 8237 * which is 2 bytes past the ATM pseudo-header 8238 * (skipping the pseudo-header and 2-byte LE Client 8239 * field). The other offsets are Ethernet offsets 8240 * relative to "off_mac". 8241 */ 8242 is_lane = 1; 8243 off_mac = off_payload + 2; /* MAC header */ 8244 off_linktype = off_mac + 12; 8245 off_macpl = off_mac + 14; /* Ethernet */ 8246 off_nl = 0; /* Ethernet II */ 8247 off_nl_nosnap = 3; /* 802.3+802.2 */ 8248 break; 8249 8250 case A_LLC: 8251 /* Get all LLC-encapsulated packets */ 8252 if (!is_atm) 8253 bpf_error("'llc' supported only on raw ATM"); 8254 b1 = gen_atmfield_code(A_PROTOTYPE, PT_LLC, BPF_JEQ, 0); 8255 is_lane = 0; 8256 break; 8257 8258 default: 8259 abort(); 8260 } 8261 return b1; 8262 } 8263 8264 /* 8265 * Filtering for MTP2 messages based on li value 8266 * FISU, length is null 8267 * LSSU, length is 1 or 2 8268 * MSU, length is 3 or more 8269 */ 8270 struct block * 8271 gen_mtp2type_abbrev(type) 8272 int type; 8273 { 8274 struct block *b0, *b1; 8275 8276 switch (type) { 8277 8278 case M_FISU: 8279 if ( (linktype != DLT_MTP2) && 8280 (linktype != DLT_ERF) && 8281 (linktype != DLT_MTP2_WITH_PHDR) ) 8282 bpf_error("'fisu' supported only on MTP2"); 8283 /* gen_ncmp(offrel, offset, size, mask, jtype, reverse, value) */ 8284 b0 = gen_ncmp(OR_PACKET, off_li, BPF_B, 0x3f, BPF_JEQ, 0, 0); 8285 break; 8286 8287 case M_LSSU: 8288 if ( (linktype != DLT_MTP2) && 8289 (linktype != DLT_ERF) && 8290 (linktype != DLT_MTP2_WITH_PHDR) ) 8291 bpf_error("'lssu' supported only on MTP2"); 8292 b0 = gen_ncmp(OR_PACKET, off_li, BPF_B, 0x3f, BPF_JGT, 1, 2); 8293 b1 = gen_ncmp(OR_PACKET, off_li, BPF_B, 0x3f, BPF_JGT, 0, 0); 8294 gen_and(b1, b0); 8295 break; 8296 8297 case M_MSU: 8298 if ( (linktype != DLT_MTP2) && 8299 (linktype != DLT_ERF) && 8300 (linktype != DLT_MTP2_WITH_PHDR) ) 8301 bpf_error("'msu' supported only on MTP2"); 8302 b0 = gen_ncmp(OR_PACKET, off_li, BPF_B, 0x3f, BPF_JGT, 0, 2); 8303 break; 8304 8305 default: 8306 abort(); 8307 } 8308 return b0; 8309 } 8310 8311 struct block * 8312 gen_mtp3field_code(mtp3field, jvalue, jtype, reverse) 8313 int mtp3field; 8314 bpf_u_int32 jvalue; 8315 bpf_u_int32 jtype; 8316 int reverse; 8317 { 8318 struct block *b0; 8319 bpf_u_int32 val1 , val2 , val3; 8320 8321 switch (mtp3field) { 8322 8323 case M_SIO: 8324 if (off_sio == (u_int)-1) 8325 bpf_error("'sio' supported only on SS7"); 8326 /* sio coded on 1 byte so max value 255 */ 8327 if(jvalue > 255) 8328 bpf_error("sio value %u too big; max value = 255", 8329 jvalue); 8330 b0 = gen_ncmp(OR_PACKET, off_sio, BPF_B, 0xffffffff, 8331 (u_int)jtype, reverse, (u_int)jvalue); 8332 break; 8333 8334 case M_OPC: 8335 if (off_opc == (u_int)-1) 8336 bpf_error("'opc' supported only on SS7"); 8337 /* opc coded on 14 bits so max value 16383 */ 8338 if (jvalue > 16383) 8339 bpf_error("opc value %u too big; max value = 16383", 8340 jvalue); 8341 /* the following instructions are made to convert jvalue 8342 * to the form used to write opc in an ss7 message*/ 8343 val1 = jvalue & 0x00003c00; 8344 val1 = val1 >>10; 8345 val2 = jvalue & 0x000003fc; 8346 val2 = val2 <<6; 8347 val3 = jvalue & 0x00000003; 8348 val3 = val3 <<22; 8349 jvalue = val1 + val2 + val3; 8350 b0 = gen_ncmp(OR_PACKET, off_opc, BPF_W, 0x00c0ff0f, 8351 (u_int)jtype, reverse, (u_int)jvalue); 8352 break; 8353 8354 case M_DPC: 8355 if (off_dpc == (u_int)-1) 8356 bpf_error("'dpc' supported only on SS7"); 8357 /* dpc coded on 14 bits so max value 16383 */ 8358 if (jvalue > 16383) 8359 bpf_error("dpc value %u too big; max value = 16383", 8360 jvalue); 8361 /* the following instructions are made to convert jvalue 8362 * to the forme used to write dpc in an ss7 message*/ 8363 val1 = jvalue & 0x000000ff; 8364 val1 = val1 << 24; 8365 val2 = jvalue & 0x00003f00; 8366 val2 = val2 << 8; 8367 jvalue = val1 + val2; 8368 b0 = gen_ncmp(OR_PACKET, off_dpc, BPF_W, 0xff3f0000, 8369 (u_int)jtype, reverse, (u_int)jvalue); 8370 break; 8371 8372 case M_SLS: 8373 if (off_sls == (u_int)-1) 8374 bpf_error("'sls' supported only on SS7"); 8375 /* sls coded on 4 bits so max value 15 */ 8376 if (jvalue > 15) 8377 bpf_error("sls value %u too big; max value = 15", 8378 jvalue); 8379 /* the following instruction is made to convert jvalue 8380 * to the forme used to write sls in an ss7 message*/ 8381 jvalue = jvalue << 4; 8382 b0 = gen_ncmp(OR_PACKET, off_sls, BPF_B, 0xf0, 8383 (u_int)jtype,reverse, (u_int)jvalue); 8384 break; 8385 8386 default: 8387 abort(); 8388 } 8389 return b0; 8390 } 8391 8392 static struct block * 8393 gen_msg_abbrev(type) 8394 int type; 8395 { 8396 struct block *b1; 8397 8398 /* 8399 * Q.2931 signalling protocol messages for handling virtual circuits 8400 * establishment and teardown 8401 */ 8402 switch (type) { 8403 8404 case A_SETUP: 8405 b1 = gen_atmfield_code(A_MSGTYPE, SETUP, BPF_JEQ, 0); 8406 break; 8407 8408 case A_CALLPROCEED: 8409 b1 = gen_atmfield_code(A_MSGTYPE, CALL_PROCEED, BPF_JEQ, 0); 8410 break; 8411 8412 case A_CONNECT: 8413 b1 = gen_atmfield_code(A_MSGTYPE, CONNECT, BPF_JEQ, 0); 8414 break; 8415 8416 case A_CONNECTACK: 8417 b1 = gen_atmfield_code(A_MSGTYPE, CONNECT_ACK, BPF_JEQ, 0); 8418 break; 8419 8420 case A_RELEASE: 8421 b1 = gen_atmfield_code(A_MSGTYPE, RELEASE, BPF_JEQ, 0); 8422 break; 8423 8424 case A_RELEASE_DONE: 8425 b1 = gen_atmfield_code(A_MSGTYPE, RELEASE_DONE, BPF_JEQ, 0); 8426 break; 8427 8428 default: 8429 abort(); 8430 } 8431 return b1; 8432 } 8433 8434 struct block * 8435 gen_atmmulti_abbrev(type) 8436 int type; 8437 { 8438 struct block *b0, *b1; 8439 8440 switch (type) { 8441 8442 case A_OAM: 8443 if (!is_atm) 8444 bpf_error("'oam' supported only on raw ATM"); 8445 b1 = gen_atmmulti_abbrev(A_OAMF4); 8446 break; 8447 8448 case A_OAMF4: 8449 if (!is_atm) 8450 bpf_error("'oamf4' supported only on raw ATM"); 8451 /* OAM F4 type */ 8452 b0 = gen_atmfield_code(A_VCI, 3, BPF_JEQ, 0); 8453 b1 = gen_atmfield_code(A_VCI, 4, BPF_JEQ, 0); 8454 gen_or(b0, b1); 8455 b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0); 8456 gen_and(b0, b1); 8457 break; 8458 8459 case A_CONNECTMSG: 8460 /* 8461 * Get Q.2931 signalling messages for switched 8462 * virtual connection 8463 */ 8464 if (!is_atm) 8465 bpf_error("'connectmsg' supported only on raw ATM"); 8466 b0 = gen_msg_abbrev(A_SETUP); 8467 b1 = gen_msg_abbrev(A_CALLPROCEED); 8468 gen_or(b0, b1); 8469 b0 = gen_msg_abbrev(A_CONNECT); 8470 gen_or(b0, b1); 8471 b0 = gen_msg_abbrev(A_CONNECTACK); 8472 gen_or(b0, b1); 8473 b0 = gen_msg_abbrev(A_RELEASE); 8474 gen_or(b0, b1); 8475 b0 = gen_msg_abbrev(A_RELEASE_DONE); 8476 gen_or(b0, b1); 8477 b0 = gen_atmtype_abbrev(A_SC); 8478 gen_and(b0, b1); 8479 break; 8480 8481 case A_METACONNECT: 8482 if (!is_atm) 8483 bpf_error("'metaconnect' supported only on raw ATM"); 8484 b0 = gen_msg_abbrev(A_SETUP); 8485 b1 = gen_msg_abbrev(A_CALLPROCEED); 8486 gen_or(b0, b1); 8487 b0 = gen_msg_abbrev(A_CONNECT); 8488 gen_or(b0, b1); 8489 b0 = gen_msg_abbrev(A_RELEASE); 8490 gen_or(b0, b1); 8491 b0 = gen_msg_abbrev(A_RELEASE_DONE); 8492 gen_or(b0, b1); 8493 b0 = gen_atmtype_abbrev(A_METAC); 8494 gen_and(b0, b1); 8495 break; 8496 8497 default: 8498 abort(); 8499 } 8500 return b1; 8501 } 8502