1 /* $OpenBSD: gencode.c,v 1.29 2007/11/06 10:22:29 chl Exp $ */ 2 3 /* 4 * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that: (1) source code distributions 9 * retain the above copyright notice and this paragraph in its entirety, (2) 10 * distributions including binary code include the above copyright notice and 11 * this paragraph in its entirety in the documentation or other materials 12 * provided with the distribution, and (3) all advertising materials mentioning 13 * features or use of this software display the following acknowledgement: 14 * ``This product includes software developed by the University of California, 15 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of 16 * the University nor the names of its contributors may be used to endorse 17 * or promote products derived from this software without specific prior 18 * written permission. 19 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED 20 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF 21 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 22 */ 23 24 #include <sys/types.h> 25 #include <sys/socket.h> 26 #include <sys/time.h> 27 28 struct mbuf; 29 struct rtentry; 30 31 #include <net/if.h> 32 33 #include <netinet/in.h> 34 #include <netinet/if_ether.h> 35 36 #include <net/if_pflog.h> 37 #include <net/pfvar.h> 38 39 #include <net80211/ieee80211.h> 40 #include <net80211/ieee80211_radiotap.h> 41 42 #include <stdlib.h> 43 #include <stddef.h> 44 #include <memory.h> 45 #include <setjmp.h> 46 #include <stdarg.h> 47 48 #include "pcap-int.h" 49 50 #include "ethertype.h" 51 #include "llc.h" 52 #include "gencode.h" 53 #include "ppp.h" 54 #include <pcap-namedb.h> 55 #ifdef INET6 56 #include <netdb.h> 57 #include <sys/socket.h> 58 #endif /*INET6*/ 59 60 #ifdef HAVE_OS_PROTO_H 61 #include "os-proto.h" 62 #endif 63 64 #define JMP(c) ((c)|BPF_JMP|BPF_K) 65 66 /* Locals */ 67 static jmp_buf top_ctx; 68 static pcap_t *bpf_pcap; 69 70 /* XXX */ 71 #ifdef PCAP_FDDIPAD 72 int pcap_fddipad = PCAP_FDDIPAD; 73 #else 74 int pcap_fddipad; 75 #endif 76 77 /* VARARGS */ 78 __dead void 79 bpf_error(const char *fmt, ...) 80 { 81 va_list ap; 82 83 va_start(ap, fmt); 84 if (bpf_pcap != NULL) 85 (void)vsnprintf(pcap_geterr(bpf_pcap), PCAP_ERRBUF_SIZE, 86 fmt, ap); 87 va_end(ap); 88 longjmp(top_ctx, 1); 89 /* NOTREACHED */ 90 } 91 92 static void init_linktype(int); 93 94 static int alloc_reg(void); 95 static void free_reg(int); 96 97 static struct block *root; 98 99 /* 100 * We divy out chunks of memory rather than call malloc each time so 101 * we don't have to worry about leaking memory. It's probably 102 * not a big deal if all this memory was wasted but it this ever 103 * goes into a library that would probably not be a good idea. 104 */ 105 #define NCHUNKS 16 106 #define CHUNK0SIZE 1024 107 struct chunk { 108 u_int n_left; 109 void *m; 110 }; 111 112 static struct chunk chunks[NCHUNKS]; 113 static int cur_chunk; 114 115 static void *newchunk(u_int); 116 static void freechunks(void); 117 static __inline struct block *new_block(int); 118 static __inline struct slist *new_stmt(int); 119 static struct block *gen_retblk(int); 120 static __inline void syntax(void); 121 122 static void backpatch(struct block *, struct block *); 123 static void merge(struct block *, struct block *); 124 static struct block *gen_cmp(u_int, u_int, bpf_int32); 125 static struct block *gen_cmp_gt(u_int, u_int, bpf_int32); 126 static struct block *gen_mcmp(u_int, u_int, bpf_int32, bpf_u_int32); 127 static struct block *gen_bcmp(u_int, u_int, const u_char *); 128 static struct block *gen_uncond(int); 129 static __inline struct block *gen_true(void); 130 static __inline struct block *gen_false(void); 131 static struct block *gen_linktype(int); 132 static struct block *gen_hostop(bpf_u_int32, bpf_u_int32, int, int, u_int, u_int); 133 #ifdef INET6 134 static struct block *gen_hostop6(struct in6_addr *, struct in6_addr *, int, int, u_int, u_int); 135 #endif 136 static struct block *gen_ehostop(const u_char *, int); 137 static struct block *gen_fhostop(const u_char *, int); 138 static struct block *gen_dnhostop(bpf_u_int32, int, u_int); 139 static struct block *gen_p80211_hostop(const u_char *, int); 140 static struct block *gen_p80211_addr(int, u_int, const u_char *); 141 static struct block *gen_host(bpf_u_int32, bpf_u_int32, int, int); 142 #ifdef INET6 143 static struct block *gen_host6(struct in6_addr *, struct in6_addr *, int, int); 144 #endif 145 #ifndef INET6 146 static struct block *gen_gateway(const u_char *, bpf_u_int32 **, int, int); 147 #endif 148 static struct block *gen_ipfrag(void); 149 static struct block *gen_portatom(int, bpf_int32); 150 #ifdef INET6 151 static struct block *gen_portatom6(int, bpf_int32); 152 #endif 153 struct block *gen_portop(int, int, int); 154 static struct block *gen_port(int, int, int); 155 #ifdef INET6 156 struct block *gen_portop6(int, int, int); 157 static struct block *gen_port6(int, int, int); 158 #endif 159 static int lookup_proto(const char *, int); 160 static struct block *gen_protochain(int, int, int); 161 static struct block *gen_proto(int, int, int); 162 static struct slist *xfer_to_x(struct arth *); 163 static struct slist *xfer_to_a(struct arth *); 164 static struct block *gen_len(int, int); 165 166 static void * 167 newchunk(n) 168 u_int n; 169 { 170 struct chunk *cp; 171 int k, size; 172 173 /* XXX Round to structure boundary. */ 174 n = ALIGN(n); 175 176 cp = &chunks[cur_chunk]; 177 if (n > cp->n_left) { 178 ++cp, k = ++cur_chunk; 179 if (k >= NCHUNKS) 180 bpf_error("out of memory"); 181 size = CHUNK0SIZE << k; 182 cp->m = (void *)malloc(size); 183 if (cp->m == NULL) 184 bpf_error("out of memory"); 185 186 memset((char *)cp->m, 0, size); 187 cp->n_left = size; 188 if (n > size) 189 bpf_error("out of memory"); 190 } 191 cp->n_left -= n; 192 return (void *)((char *)cp->m + cp->n_left); 193 } 194 195 static void 196 freechunks() 197 { 198 int i; 199 200 cur_chunk = 0; 201 for (i = 0; i < NCHUNKS; ++i) 202 if (chunks[i].m != NULL) { 203 free(chunks[i].m); 204 chunks[i].m = NULL; 205 } 206 } 207 208 /* 209 * A strdup whose allocations are freed after code generation is over. 210 */ 211 char * 212 sdup(s) 213 register const char *s; 214 { 215 int n = strlen(s) + 1; 216 char *cp = newchunk(n); 217 218 strlcpy(cp, s, n); 219 return (cp); 220 } 221 222 static __inline struct block * 223 new_block(code) 224 int code; 225 { 226 struct block *p; 227 228 p = (struct block *)newchunk(sizeof(*p)); 229 p->s.code = code; 230 p->head = p; 231 232 return p; 233 } 234 235 static __inline struct slist * 236 new_stmt(code) 237 int code; 238 { 239 struct slist *p; 240 241 p = (struct slist *)newchunk(sizeof(*p)); 242 p->s.code = code; 243 244 return p; 245 } 246 247 static struct block * 248 gen_retblk(v) 249 int v; 250 { 251 struct block *b = new_block(BPF_RET|BPF_K); 252 253 b->s.k = v; 254 return b; 255 } 256 257 static __inline void 258 syntax() 259 { 260 bpf_error("syntax error in filter expression"); 261 } 262 263 static bpf_u_int32 netmask; 264 static int snaplen; 265 int no_optimize; 266 267 int 268 pcap_compile(pcap_t *p, struct bpf_program *program, 269 char *buf, int optimize, bpf_u_int32 mask) 270 { 271 extern int n_errors; 272 int len; 273 274 no_optimize = 0; 275 n_errors = 0; 276 root = NULL; 277 bpf_pcap = p; 278 if (setjmp(top_ctx)) { 279 freechunks(); 280 return (-1); 281 } 282 283 netmask = mask; 284 snaplen = pcap_snapshot(p); 285 286 lex_init(buf ? buf : ""); 287 init_linktype(pcap_datalink(p)); 288 (void)pcap_parse(); 289 290 if (n_errors) 291 syntax(); 292 293 if (root == NULL) 294 root = gen_retblk(snaplen); 295 296 if (optimize && !no_optimize) { 297 bpf_optimize(&root); 298 if (root == NULL || 299 (root->s.code == (BPF_RET|BPF_K) && root->s.k == 0)) 300 bpf_error("expression rejects all packets"); 301 } 302 program->bf_insns = icode_to_fcode(root, &len); 303 program->bf_len = len; 304 305 freechunks(); 306 return (0); 307 } 308 309 /* 310 * entry point for using the compiler with no pcap open 311 * pass in all the stuff that is needed explicitly instead. 312 */ 313 int 314 pcap_compile_nopcap(int snaplen_arg, int linktype_arg, 315 struct bpf_program *program, 316 char *buf, int optimize, bpf_u_int32 mask) 317 { 318 extern int n_errors; 319 int len; 320 321 n_errors = 0; 322 root = NULL; 323 bpf_pcap = NULL; 324 if (setjmp(top_ctx)) { 325 freechunks(); 326 return (-1); 327 } 328 329 netmask = mask; 330 331 /* XXX needed? I don't grok the use of globals here. */ 332 snaplen = snaplen_arg; 333 334 lex_init(buf ? buf : ""); 335 init_linktype(linktype_arg); 336 (void)pcap_parse(); 337 338 if (n_errors) 339 syntax(); 340 341 if (root == NULL) 342 root = gen_retblk(snaplen_arg); 343 344 if (optimize) { 345 bpf_optimize(&root); 346 if (root == NULL || 347 (root->s.code == (BPF_RET|BPF_K) && root->s.k == 0)) 348 bpf_error("expression rejects all packets"); 349 } 350 program->bf_insns = icode_to_fcode(root, &len); 351 program->bf_len = len; 352 353 freechunks(); 354 return (0); 355 } 356 357 /* 358 * Clean up a "struct bpf_program" by freeing all the memory allocated 359 * in it. 360 */ 361 void 362 pcap_freecode(struct bpf_program *program) 363 { 364 program->bf_len = 0; 365 if (program->bf_insns != NULL) { 366 free((char *)program->bf_insns); 367 program->bf_insns = NULL; 368 } 369 } 370 371 /* 372 * Backpatch the blocks in 'list' to 'target'. The 'sense' field indicates 373 * which of the jt and jf fields has been resolved and which is a pointer 374 * back to another unresolved block (or nil). At least one of the fields 375 * in each block is already resolved. 376 */ 377 static void 378 backpatch(list, target) 379 struct block *list, *target; 380 { 381 struct block *next; 382 383 while (list) { 384 if (!list->sense) { 385 next = JT(list); 386 JT(list) = target; 387 } else { 388 next = JF(list); 389 JF(list) = target; 390 } 391 list = next; 392 } 393 } 394 395 /* 396 * Merge the lists in b0 and b1, using the 'sense' field to indicate 397 * which of jt and jf is the link. 398 */ 399 static void 400 merge(b0, b1) 401 struct block *b0, *b1; 402 { 403 register struct block **p = &b0; 404 405 /* Find end of list. */ 406 while (*p) 407 p = !((*p)->sense) ? &JT(*p) : &JF(*p); 408 409 /* Concatenate the lists. */ 410 *p = b1; 411 } 412 413 void 414 finish_parse(p) 415 struct block *p; 416 { 417 backpatch(p, gen_retblk(snaplen)); 418 p->sense = !p->sense; 419 backpatch(p, gen_retblk(0)); 420 root = p->head; 421 } 422 423 void 424 gen_and(b0, b1) 425 struct block *b0, *b1; 426 { 427 backpatch(b0, b1->head); 428 b0->sense = !b0->sense; 429 b1->sense = !b1->sense; 430 merge(b1, b0); 431 b1->sense = !b1->sense; 432 b1->head = b0->head; 433 } 434 435 void 436 gen_or(b0, b1) 437 struct block *b0, *b1; 438 { 439 b0->sense = !b0->sense; 440 backpatch(b0, b1->head); 441 b0->sense = !b0->sense; 442 merge(b1, b0); 443 b1->head = b0->head; 444 } 445 446 void 447 gen_not(b) 448 struct block *b; 449 { 450 b->sense = !b->sense; 451 } 452 453 static struct block * 454 gen_cmp(offset, size, v) 455 u_int offset, size; 456 bpf_int32 v; 457 { 458 struct slist *s; 459 struct block *b; 460 461 s = new_stmt(BPF_LD|BPF_ABS|size); 462 s->s.k = offset; 463 464 b = new_block(JMP(BPF_JEQ)); 465 b->stmts = s; 466 b->s.k = v; 467 468 return b; 469 } 470 471 static struct block * 472 gen_cmp_gt(offset, size, v) 473 u_int offset, size; 474 bpf_int32 v; 475 { 476 struct slist *s; 477 struct block *b; 478 479 s = new_stmt(BPF_LD|BPF_ABS|size); 480 s->s.k = offset; 481 482 b = new_block(JMP(BPF_JGT)); 483 b->stmts = s; 484 b->s.k = v; 485 486 return b; 487 } 488 489 static struct block * 490 gen_mcmp(offset, size, v, mask) 491 u_int offset, size; 492 bpf_int32 v; 493 bpf_u_int32 mask; 494 { 495 struct block *b = gen_cmp(offset, size, v); 496 struct slist *s; 497 498 if (mask != 0xffffffff) { 499 s = new_stmt(BPF_ALU|BPF_AND|BPF_K); 500 s->s.k = mask; 501 b->stmts->next = s; 502 } 503 return b; 504 } 505 506 static struct block * 507 gen_bcmp(offset, size, v) 508 register u_int offset, size; 509 register const u_char *v; 510 { 511 register struct block *b, *tmp; 512 513 b = NULL; 514 while (size >= 4) { 515 register const u_char *p = &v[size - 4]; 516 bpf_int32 w = ((bpf_int32)p[0] << 24) | 517 ((bpf_int32)p[1] << 16) | ((bpf_int32)p[2] << 8) | p[3]; 518 519 tmp = gen_cmp(offset + size - 4, BPF_W, w); 520 if (b != NULL) 521 gen_and(b, tmp); 522 b = tmp; 523 size -= 4; 524 } 525 while (size >= 2) { 526 register const u_char *p = &v[size - 2]; 527 bpf_int32 w = ((bpf_int32)p[0] << 8) | p[1]; 528 529 tmp = gen_cmp(offset + size - 2, BPF_H, w); 530 if (b != NULL) 531 gen_and(b, tmp); 532 b = tmp; 533 size -= 2; 534 } 535 if (size > 0) { 536 tmp = gen_cmp(offset, BPF_B, (bpf_int32)v[0]); 537 if (b != NULL) 538 gen_and(b, tmp); 539 b = tmp; 540 } 541 return b; 542 } 543 544 /* 545 * Various code constructs need to know the layout of the data link 546 * layer. These variables give the necessary offsets. off_linktype 547 * is set to -1 for no encapsulation, in which case, IP is assumed. 548 */ 549 static u_int off_linktype; 550 static u_int off_nl; 551 static int linktype; 552 553 static void 554 init_linktype(type) 555 int type; 556 { 557 linktype = type; 558 559 switch (type) { 560 561 case DLT_EN10MB: 562 off_linktype = 12; 563 off_nl = 14; 564 return; 565 566 case DLT_SLIP: 567 /* 568 * SLIP doesn't have a link level type. The 16 byte 569 * header is hacked into our SLIP driver. 570 */ 571 off_linktype = -1; 572 off_nl = 16; 573 return; 574 575 case DLT_SLIP_BSDOS: 576 /* XXX this may be the same as the DLT_PPP_BSDOS case */ 577 off_linktype = -1; 578 /* XXX end */ 579 off_nl = 24; 580 return; 581 582 case DLT_NULL: 583 off_linktype = 0; 584 off_nl = 4; 585 return; 586 587 case DLT_PPP: 588 off_linktype = 2; 589 off_nl = 4; 590 return; 591 592 case DLT_PPP_ETHER: 593 /* 594 * This does not include the Ethernet header, and 595 * only covers session state. 596 */ 597 off_linktype = 6; 598 off_nl = 8; 599 return; 600 601 case DLT_PPP_BSDOS: 602 off_linktype = 5; 603 off_nl = 24; 604 return; 605 606 case DLT_FDDI: 607 /* 608 * FDDI doesn't really have a link-level type field. 609 * We assume that SSAP = SNAP is being used and pick 610 * out the encapsulated Ethernet type. 611 */ 612 off_linktype = 19; 613 #ifdef PCAP_FDDIPAD 614 off_linktype += pcap_fddipad; 615 #endif 616 off_nl = 21; 617 #ifdef PCAP_FDDIPAD 618 off_nl += pcap_fddipad; 619 #endif 620 return; 621 622 case DLT_IEEE802: 623 off_linktype = 20; 624 off_nl = 22; 625 return; 626 627 case DLT_IEEE802_11: 628 off_linktype = 30; /* XXX variable */ 629 off_nl = 32; 630 return; 631 632 case DLT_IEEE802_11_RADIO: /* XXX variable */ 633 off_linktype = 30 + IEEE80211_RADIOTAP_HDRLEN; 634 off_nl = 32 + IEEE80211_RADIOTAP_HDRLEN; 635 return; 636 637 case DLT_ATM_RFC1483: 638 /* 639 * assume routed, non-ISO PDUs 640 * (i.e., LLC = 0xAA-AA-03, OUT = 0x00-00-00) 641 */ 642 off_linktype = 6; 643 off_nl = 8; 644 return; 645 646 case DLT_LOOP: 647 off_linktype = -1; 648 off_nl = 4; 649 return; 650 651 case DLT_ENC: 652 off_linktype = -1; 653 off_nl = 12; 654 return; 655 656 case DLT_OLD_PFLOG: 657 off_linktype = 0; 658 off_nl = 28; 659 return; 660 661 case DLT_PFLOG: 662 off_linktype = 0; 663 /* XXX read from header? */ 664 off_nl = PFLOG_HDRLEN; 665 return; 666 667 case DLT_PFSYNC: 668 off_linktype = -1; 669 off_nl = 4; 670 return; 671 672 case DLT_RAW: 673 off_linktype = -1; 674 off_nl = 0; 675 return; 676 } 677 bpf_error("unknown data link type 0x%x", linktype); 678 /* NOTREACHED */ 679 } 680 681 static struct block * 682 gen_uncond(rsense) 683 int rsense; 684 { 685 struct block *b; 686 struct slist *s; 687 688 s = new_stmt(BPF_LD|BPF_IMM); 689 s->s.k = !rsense; 690 b = new_block(JMP(BPF_JEQ)); 691 b->stmts = s; 692 693 return b; 694 } 695 696 static __inline struct block * 697 gen_true() 698 { 699 return gen_uncond(1); 700 } 701 702 static __inline struct block * 703 gen_false() 704 { 705 return gen_uncond(0); 706 } 707 708 static struct block * 709 gen_linktype(proto) 710 register int proto; 711 { 712 struct block *b0, *b1; 713 714 /* If we're not using encapsulation and checking for IP, we're done */ 715 if (off_linktype == -1 && proto == ETHERTYPE_IP) 716 return gen_true(); 717 #ifdef INET6 718 /* this isn't the right thing to do, but sometimes necessary */ 719 if (off_linktype == -1 && proto == ETHERTYPE_IPV6) 720 return gen_true(); 721 #endif 722 723 switch (linktype) { 724 725 case DLT_EN10MB: 726 if (proto <= ETHERMTU) { 727 /* This is an LLC SAP value */ 728 b0 = gen_cmp_gt(off_linktype, BPF_H, ETHERMTU); 729 gen_not(b0); 730 b1 = gen_cmp(off_linktype + 2, BPF_B, (bpf_int32)proto); 731 gen_and(b0, b1); 732 return b1; 733 } else { 734 /* This is an Ethernet type */ 735 return gen_cmp(off_linktype, BPF_H, (bpf_int32)proto); 736 } 737 break; 738 739 case DLT_SLIP: 740 return gen_false(); 741 742 case DLT_PPP: 743 case DLT_PPP_ETHER: 744 if (proto == ETHERTYPE_IP) 745 proto = PPP_IP; /* XXX was 0x21 */ 746 #ifdef INET6 747 else if (proto == ETHERTYPE_IPV6) 748 proto = PPP_IPV6; 749 #endif 750 break; 751 752 case DLT_PPP_BSDOS: 753 switch (proto) { 754 755 case ETHERTYPE_IP: 756 b0 = gen_cmp(off_linktype, BPF_H, PPP_IP); 757 b1 = gen_cmp(off_linktype, BPF_H, PPP_VJC); 758 gen_or(b0, b1); 759 b0 = gen_cmp(off_linktype, BPF_H, PPP_VJNC); 760 gen_or(b1, b0); 761 return b0; 762 763 #ifdef INET6 764 case ETHERTYPE_IPV6: 765 proto = PPP_IPV6; 766 /* more to go? */ 767 break; 768 #endif /* INET6 */ 769 770 case ETHERTYPE_DN: 771 proto = PPP_DECNET; 772 break; 773 774 case ETHERTYPE_ATALK: 775 proto = PPP_APPLE; 776 break; 777 778 case ETHERTYPE_NS: 779 proto = PPP_NS; 780 break; 781 } 782 break; 783 784 case DLT_LOOP: 785 case DLT_ENC: 786 case DLT_NULL: 787 /* XXX */ 788 if (proto == ETHERTYPE_IP) 789 return (gen_cmp(0, BPF_W, (bpf_int32)htonl(AF_INET))); 790 #ifdef INET6 791 else if (proto == ETHERTYPE_IPV6) 792 return (gen_cmp(0, BPF_W, (bpf_int32)htonl(AF_INET6))); 793 #endif /* INET6 */ 794 else 795 return gen_false(); 796 break; 797 case DLT_OLD_PFLOG: 798 if (proto == ETHERTYPE_IP) 799 return (gen_cmp(0, BPF_W, (bpf_int32)AF_INET)); 800 #ifdef INET6 801 else if (proto == ETHERTYPE_IPV6) 802 return (gen_cmp(0, BPF_W, (bpf_int32)AF_INET6)); 803 #endif /* INET6 */ 804 else 805 return gen_false(); 806 break; 807 808 case DLT_PFLOG: 809 if (proto == ETHERTYPE_IP) 810 return (gen_cmp(offsetof(struct pfloghdr, af), BPF_B, 811 (bpf_int32)AF_INET)); 812 #ifdef INET6 813 else if (proto == ETHERTYPE_IPV6) 814 return (gen_cmp(offsetof(struct pfloghdr, af), BPF_B, 815 (bpf_int32)AF_INET6)); 816 #endif /* INET6 */ 817 else 818 return gen_false(); 819 break; 820 821 } 822 return gen_cmp(off_linktype, BPF_H, (bpf_int32)proto); 823 } 824 825 static struct block * 826 gen_hostop(addr, mask, dir, proto, src_off, dst_off) 827 bpf_u_int32 addr; 828 bpf_u_int32 mask; 829 int dir, proto; 830 u_int src_off, dst_off; 831 { 832 struct block *b0, *b1; 833 u_int offset; 834 835 switch (dir) { 836 837 case Q_SRC: 838 offset = src_off; 839 break; 840 841 case Q_DST: 842 offset = dst_off; 843 break; 844 845 case Q_AND: 846 b0 = gen_hostop(addr, mask, Q_SRC, proto, src_off, dst_off); 847 b1 = gen_hostop(addr, mask, Q_DST, proto, src_off, dst_off); 848 gen_and(b0, b1); 849 return b1; 850 851 case Q_OR: 852 case Q_DEFAULT: 853 b0 = gen_hostop(addr, mask, Q_SRC, proto, src_off, dst_off); 854 b1 = gen_hostop(addr, mask, Q_DST, proto, src_off, dst_off); 855 gen_or(b0, b1); 856 return b1; 857 858 default: 859 bpf_error("direction not supported on linktype 0x%x", 860 linktype); 861 } 862 b0 = gen_linktype(proto); 863 b1 = gen_mcmp(offset, BPF_W, (bpf_int32)addr, mask); 864 gen_and(b0, b1); 865 return b1; 866 } 867 868 #ifdef INET6 869 static struct block * 870 gen_hostop6(addr, mask, dir, proto, src_off, dst_off) 871 struct in6_addr *addr; 872 struct in6_addr *mask; 873 int dir, proto; 874 u_int src_off, dst_off; 875 { 876 struct block *b0, *b1; 877 u_int offset; 878 u_int32_t *a, *m; 879 880 switch (dir) { 881 882 case Q_SRC: 883 offset = src_off; 884 break; 885 886 case Q_DST: 887 offset = dst_off; 888 break; 889 890 case Q_AND: 891 b0 = gen_hostop6(addr, mask, Q_SRC, proto, src_off, dst_off); 892 b1 = gen_hostop6(addr, mask, Q_DST, proto, src_off, dst_off); 893 gen_and(b0, b1); 894 return b1; 895 896 case Q_OR: 897 case Q_DEFAULT: 898 b0 = gen_hostop6(addr, mask, Q_SRC, proto, src_off, dst_off); 899 b1 = gen_hostop6(addr, mask, Q_DST, proto, src_off, dst_off); 900 gen_or(b0, b1); 901 return b1; 902 903 default: 904 bpf_error("direction not supported on linktype 0x%x", 905 linktype); 906 } 907 /* this order is important */ 908 a = (u_int32_t *)addr; 909 m = (u_int32_t *)mask; 910 b1 = gen_mcmp(offset + 12, BPF_W, ntohl(a[3]), ntohl(m[3])); 911 b0 = gen_mcmp(offset + 8, BPF_W, ntohl(a[2]), ntohl(m[2])); 912 gen_and(b0, b1); 913 b0 = gen_mcmp(offset + 4, BPF_W, ntohl(a[1]), ntohl(m[1])); 914 gen_and(b0, b1); 915 b0 = gen_mcmp(offset + 0, BPF_W, ntohl(a[0]), ntohl(m[0])); 916 gen_and(b0, b1); 917 b0 = gen_linktype(proto); 918 gen_and(b0, b1); 919 return b1; 920 } 921 #endif /*INET6*/ 922 923 static struct block * 924 gen_ehostop(eaddr, dir) 925 register const u_char *eaddr; 926 register int dir; 927 { 928 struct block *b0, *b1; 929 930 switch (dir) { 931 case Q_SRC: 932 return gen_bcmp(6, 6, eaddr); 933 934 case Q_DST: 935 return gen_bcmp(0, 6, eaddr); 936 937 case Q_AND: 938 b0 = gen_ehostop(eaddr, Q_SRC); 939 b1 = gen_ehostop(eaddr, Q_DST); 940 gen_and(b0, b1); 941 return b1; 942 943 case Q_DEFAULT: 944 case Q_OR: 945 b0 = gen_ehostop(eaddr, Q_SRC); 946 b1 = gen_ehostop(eaddr, Q_DST); 947 gen_or(b0, b1); 948 return b1; 949 default: 950 bpf_error("direction not supported on linktype 0x%x", 951 linktype); 952 } 953 /* NOTREACHED */ 954 } 955 956 /* 957 * Like gen_ehostop, but for DLT_FDDI 958 */ 959 static struct block * 960 gen_fhostop(eaddr, dir) 961 register const u_char *eaddr; 962 register int dir; 963 { 964 struct block *b0, *b1; 965 966 switch (dir) { 967 case Q_SRC: 968 #ifdef PCAP_FDDIPAD 969 return gen_bcmp(6 + 1 + pcap_fddipad, 6, eaddr); 970 #else 971 return gen_bcmp(6 + 1, 6, eaddr); 972 #endif 973 974 case Q_DST: 975 #ifdef PCAP_FDDIPAD 976 return gen_bcmp(0 + 1 + pcap_fddipad, 6, eaddr); 977 #else 978 return gen_bcmp(0 + 1, 6, eaddr); 979 #endif 980 981 case Q_AND: 982 b0 = gen_fhostop(eaddr, Q_SRC); 983 b1 = gen_fhostop(eaddr, Q_DST); 984 gen_and(b0, b1); 985 return b1; 986 987 case Q_DEFAULT: 988 case Q_OR: 989 b0 = gen_fhostop(eaddr, Q_SRC); 990 b1 = gen_fhostop(eaddr, Q_DST); 991 gen_or(b0, b1); 992 return b1; 993 default: 994 bpf_error("direction not supported on linktype 0x%x", 995 linktype); 996 } 997 /* NOTREACHED */ 998 } 999 1000 /* 1001 * This is quite tricky because there may be pad bytes in front of the 1002 * DECNET header, and then there are two possible data packet formats that 1003 * carry both src and dst addresses, plus 5 packet types in a format that 1004 * carries only the src node, plus 2 types that use a different format and 1005 * also carry just the src node. 1006 * 1007 * Yuck. 1008 * 1009 * Instead of doing those all right, we just look for data packets with 1010 * 0 or 1 bytes of padding. If you want to look at other packets, that 1011 * will require a lot more hacking. 1012 * 1013 * To add support for filtering on DECNET "areas" (network numbers) 1014 * one would want to add a "mask" argument to this routine. That would 1015 * make the filter even more inefficient, although one could be clever 1016 * and not generate masking instructions if the mask is 0xFFFF. 1017 */ 1018 static struct block * 1019 gen_dnhostop(addr, dir, base_off) 1020 bpf_u_int32 addr; 1021 int dir; 1022 u_int base_off; 1023 { 1024 struct block *b0, *b1, *b2, *tmp; 1025 u_int offset_lh; /* offset if long header is received */ 1026 u_int offset_sh; /* offset if short header is received */ 1027 1028 switch (dir) { 1029 1030 case Q_DST: 1031 offset_sh = 1; /* follows flags */ 1032 offset_lh = 7; /* flgs,darea,dsubarea,HIORD */ 1033 break; 1034 1035 case Q_SRC: 1036 offset_sh = 3; /* follows flags, dstnode */ 1037 offset_lh = 15; /* flgs,darea,dsubarea,did,sarea,ssub,HIORD */ 1038 break; 1039 1040 case Q_AND: 1041 /* Inefficient because we do our Calvinball dance twice */ 1042 b0 = gen_dnhostop(addr, Q_SRC, base_off); 1043 b1 = gen_dnhostop(addr, Q_DST, base_off); 1044 gen_and(b0, b1); 1045 return b1; 1046 1047 case Q_OR: 1048 case Q_DEFAULT: 1049 /* Inefficient because we do our Calvinball dance twice */ 1050 b0 = gen_dnhostop(addr, Q_SRC, base_off); 1051 b1 = gen_dnhostop(addr, Q_DST, base_off); 1052 gen_or(b0, b1); 1053 return b1; 1054 1055 default: 1056 bpf_error("direction not supported on linktype 0x%x", 1057 linktype); 1058 } 1059 b0 = gen_linktype(ETHERTYPE_DN); 1060 /* Check for pad = 1, long header case */ 1061 tmp = gen_mcmp(base_off + 2, BPF_H, 1062 (bpf_int32)ntohs(0x0681), (bpf_int32)ntohs(0x07FF)); 1063 b1 = gen_cmp(base_off + 2 + 1 + offset_lh, 1064 BPF_H, (bpf_int32)ntohs(addr)); 1065 gen_and(tmp, b1); 1066 /* Check for pad = 0, long header case */ 1067 tmp = gen_mcmp(base_off + 2, BPF_B, (bpf_int32)0x06, (bpf_int32)0x7); 1068 b2 = gen_cmp(base_off + 2 + offset_lh, BPF_H, (bpf_int32)ntohs(addr)); 1069 gen_and(tmp, b2); 1070 gen_or(b2, b1); 1071 /* Check for pad = 1, short header case */ 1072 tmp = gen_mcmp(base_off + 2, BPF_H, 1073 (bpf_int32)ntohs(0x0281), (bpf_int32)ntohs(0x07FF)); 1074 b2 = gen_cmp(base_off + 2 + 1 + offset_sh, 1075 BPF_H, (bpf_int32)ntohs(addr)); 1076 gen_and(tmp, b2); 1077 gen_or(b2, b1); 1078 /* Check for pad = 0, short header case */ 1079 tmp = gen_mcmp(base_off + 2, BPF_B, (bpf_int32)0x02, (bpf_int32)0x7); 1080 b2 = gen_cmp(base_off + 2 + offset_sh, BPF_H, (bpf_int32)ntohs(addr)); 1081 gen_and(tmp, b2); 1082 gen_or(b2, b1); 1083 1084 /* Combine with test for linktype */ 1085 gen_and(b0, b1); 1086 return b1; 1087 } 1088 1089 static struct block * 1090 gen_host(addr, mask, proto, dir) 1091 bpf_u_int32 addr; 1092 bpf_u_int32 mask; 1093 int proto; 1094 int dir; 1095 { 1096 struct block *b0, *b1; 1097 1098 switch (proto) { 1099 1100 case Q_DEFAULT: 1101 b0 = gen_host(addr, mask, Q_IP, dir); 1102 b1 = gen_host(addr, mask, Q_ARP, dir); 1103 gen_or(b0, b1); 1104 b0 = gen_host(addr, mask, Q_RARP, dir); 1105 gen_or(b1, b0); 1106 return b0; 1107 1108 case Q_IP: 1109 return gen_hostop(addr, mask, dir, ETHERTYPE_IP, 1110 off_nl + 12, off_nl + 16); 1111 1112 case Q_RARP: 1113 return gen_hostop(addr, mask, dir, ETHERTYPE_REVARP, 1114 off_nl + 14, off_nl + 24); 1115 1116 case Q_ARP: 1117 return gen_hostop(addr, mask, dir, ETHERTYPE_ARP, 1118 off_nl + 14, off_nl + 24); 1119 1120 case Q_TCP: 1121 bpf_error("'tcp' modifier applied to host"); 1122 1123 case Q_UDP: 1124 bpf_error("'udp' modifier applied to host"); 1125 1126 case Q_ICMP: 1127 bpf_error("'icmp' modifier applied to host"); 1128 1129 case Q_IGMP: 1130 bpf_error("'igmp' modifier applied to host"); 1131 1132 case Q_IGRP: 1133 bpf_error("'igrp' modifier applied to host"); 1134 1135 case Q_PIM: 1136 bpf_error("'pim' modifier applied to host"); 1137 1138 case Q_STP: 1139 bpf_error("'stp' modifier applied to host"); 1140 1141 case Q_ATALK: 1142 bpf_error("ATALK host filtering not implemented"); 1143 1144 case Q_DECNET: 1145 return gen_dnhostop(addr, dir, off_nl); 1146 1147 case Q_SCA: 1148 bpf_error("SCA host filtering not implemented"); 1149 1150 case Q_LAT: 1151 bpf_error("LAT host filtering not implemented"); 1152 1153 case Q_MOPDL: 1154 bpf_error("MOPDL host filtering not implemented"); 1155 1156 case Q_MOPRC: 1157 bpf_error("MOPRC host filtering not implemented"); 1158 1159 #ifdef INET6 1160 case Q_IPV6: 1161 bpf_error("'ip6' modifier applied to ip host"); 1162 1163 case Q_ICMPV6: 1164 bpf_error("'icmp6' modifier applied to host"); 1165 #endif /* INET6 */ 1166 1167 case Q_AH: 1168 bpf_error("'ah' modifier applied to host"); 1169 1170 case Q_ESP: 1171 bpf_error("'esp' modifier applied to host"); 1172 1173 default: 1174 bpf_error("direction not supported on linktype 0x%x", 1175 linktype); 1176 } 1177 /* NOTREACHED */ 1178 } 1179 1180 #ifdef INET6 1181 static struct block * 1182 gen_host6(addr, mask, proto, dir) 1183 struct in6_addr *addr; 1184 struct in6_addr *mask; 1185 int proto; 1186 int dir; 1187 { 1188 switch (proto) { 1189 1190 case Q_DEFAULT: 1191 return gen_host6(addr, mask, Q_IPV6, dir); 1192 1193 case Q_IP: 1194 bpf_error("'ip' modifier applied to ip6 host"); 1195 1196 case Q_RARP: 1197 bpf_error("'rarp' modifier applied to ip6 host"); 1198 1199 case Q_ARP: 1200 bpf_error("'arp' modifier applied to ip6 host"); 1201 1202 case Q_TCP: 1203 bpf_error("'tcp' modifier applied to host"); 1204 1205 case Q_UDP: 1206 bpf_error("'udp' modifier applied to host"); 1207 1208 case Q_ICMP: 1209 bpf_error("'icmp' modifier applied to host"); 1210 1211 case Q_IGMP: 1212 bpf_error("'igmp' modifier applied to host"); 1213 1214 case Q_IGRP: 1215 bpf_error("'igrp' modifier applied to host"); 1216 1217 case Q_PIM: 1218 bpf_error("'pim' modifier applied to host"); 1219 1220 case Q_STP: 1221 bpf_error("'stp' modifier applied to host"); 1222 1223 case Q_ATALK: 1224 bpf_error("ATALK host filtering not implemented"); 1225 1226 case Q_DECNET: 1227 bpf_error("'decnet' modifier applied to ip6 host"); 1228 1229 case Q_SCA: 1230 bpf_error("SCA host filtering not implemented"); 1231 1232 case Q_LAT: 1233 bpf_error("LAT host filtering not implemented"); 1234 1235 case Q_MOPDL: 1236 bpf_error("MOPDL host filtering not implemented"); 1237 1238 case Q_MOPRC: 1239 bpf_error("MOPRC host filtering not implemented"); 1240 1241 case Q_IPV6: 1242 return gen_hostop6(addr, mask, dir, ETHERTYPE_IPV6, 1243 off_nl + 8, off_nl + 24); 1244 1245 case Q_ICMPV6: 1246 bpf_error("'icmp6' modifier applied to host"); 1247 1248 case Q_AH: 1249 bpf_error("'ah' modifier applied to host"); 1250 1251 case Q_ESP: 1252 bpf_error("'esp' modifier applied to host"); 1253 1254 default: 1255 abort(); 1256 } 1257 /* NOTREACHED */ 1258 } 1259 #endif /*INET6*/ 1260 1261 #ifndef INET6 1262 static struct block * 1263 gen_gateway(eaddr, alist, proto, dir) 1264 const u_char *eaddr; 1265 bpf_u_int32 **alist; 1266 int proto; 1267 int dir; 1268 { 1269 struct block *b0, *b1, *tmp; 1270 1271 if (dir != 0) 1272 bpf_error("direction applied to 'gateway'"); 1273 1274 switch (proto) { 1275 case Q_DEFAULT: 1276 case Q_IP: 1277 case Q_ARP: 1278 case Q_RARP: 1279 if (linktype == DLT_EN10MB) 1280 b0 = gen_ehostop(eaddr, Q_OR); 1281 else if (linktype == DLT_FDDI) 1282 b0 = gen_fhostop(eaddr, Q_OR); 1283 else 1284 bpf_error( 1285 "'gateway' supported only on ethernet or FDDI"); 1286 1287 b1 = gen_host(**alist++, 0xffffffff, proto, Q_OR); 1288 while (*alist) { 1289 tmp = gen_host(**alist++, 0xffffffff, proto, Q_OR); 1290 gen_or(b1, tmp); 1291 b1 = tmp; 1292 } 1293 gen_not(b1); 1294 gen_and(b0, b1); 1295 return b1; 1296 } 1297 bpf_error("illegal modifier of 'gateway'"); 1298 /* NOTREACHED */ 1299 } 1300 #endif /*INET6*/ 1301 1302 struct block * 1303 gen_proto_abbrev(proto) 1304 int proto; 1305 { 1306 struct block *b0 = NULL, *b1; 1307 1308 switch (proto) { 1309 1310 case Q_TCP: 1311 b1 = gen_proto(IPPROTO_TCP, Q_IP, Q_DEFAULT); 1312 #ifdef INET6 1313 b0 = gen_proto(IPPROTO_TCP, Q_IPV6, Q_DEFAULT); 1314 gen_or(b0, b1); 1315 #endif 1316 break; 1317 1318 case Q_UDP: 1319 b1 = gen_proto(IPPROTO_UDP, Q_IP, Q_DEFAULT); 1320 #ifdef INET6 1321 b0 = gen_proto(IPPROTO_UDP, Q_IPV6, Q_DEFAULT); 1322 gen_or(b0, b1); 1323 #endif 1324 break; 1325 1326 case Q_ICMP: 1327 b1 = gen_proto(IPPROTO_ICMP, Q_IP, Q_DEFAULT); 1328 break; 1329 1330 #ifndef IPPROTO_IGMP 1331 #define IPPROTO_IGMP 2 1332 #endif 1333 1334 case Q_IGMP: 1335 b1 = gen_proto(IPPROTO_IGMP, Q_IP, Q_DEFAULT); 1336 break; 1337 1338 #ifndef IPPROTO_IGRP 1339 #define IPPROTO_IGRP 9 1340 #endif 1341 case Q_IGRP: 1342 b1 = gen_proto(IPPROTO_IGRP, Q_IP, Q_DEFAULT); 1343 break; 1344 1345 #ifndef IPPROTO_PIM 1346 #define IPPROTO_PIM 103 1347 #endif 1348 1349 case Q_PIM: 1350 b1 = gen_proto(IPPROTO_PIM, Q_IP, Q_DEFAULT); 1351 #ifdef INET6 1352 b0 = gen_proto(IPPROTO_PIM, Q_IPV6, Q_DEFAULT); 1353 gen_or(b0, b1); 1354 #endif 1355 break; 1356 1357 case Q_IP: 1358 b1 = gen_linktype(ETHERTYPE_IP); 1359 break; 1360 1361 case Q_ARP: 1362 b1 = gen_linktype(ETHERTYPE_ARP); 1363 break; 1364 1365 case Q_RARP: 1366 b1 = gen_linktype(ETHERTYPE_REVARP); 1367 break; 1368 1369 case Q_LINK: 1370 bpf_error("link layer applied in wrong context"); 1371 1372 case Q_ATALK: 1373 b1 = gen_linktype(ETHERTYPE_ATALK); 1374 break; 1375 1376 case Q_DECNET: 1377 b1 = gen_linktype(ETHERTYPE_DN); 1378 break; 1379 1380 case Q_SCA: 1381 b1 = gen_linktype(ETHERTYPE_SCA); 1382 break; 1383 1384 case Q_LAT: 1385 b1 = gen_linktype(ETHERTYPE_LAT); 1386 break; 1387 1388 case Q_MOPDL: 1389 b1 = gen_linktype(ETHERTYPE_MOPDL); 1390 break; 1391 1392 case Q_MOPRC: 1393 b1 = gen_linktype(ETHERTYPE_MOPRC); 1394 break; 1395 1396 case Q_STP: 1397 b1 = gen_linktype(LLCSAP_8021D); 1398 break; 1399 1400 #ifdef INET6 1401 case Q_IPV6: 1402 b1 = gen_linktype(ETHERTYPE_IPV6); 1403 break; 1404 1405 #ifndef IPPROTO_ICMPV6 1406 #define IPPROTO_ICMPV6 58 1407 #endif 1408 case Q_ICMPV6: 1409 b1 = gen_proto(IPPROTO_ICMPV6, Q_IPV6, Q_DEFAULT); 1410 break; 1411 #endif /* INET6 */ 1412 1413 #ifndef IPPROTO_AH 1414 #define IPPROTO_AH 51 1415 #endif 1416 case Q_AH: 1417 b1 = gen_proto(IPPROTO_AH, Q_IP, Q_DEFAULT); 1418 #ifdef INET6 1419 b0 = gen_proto(IPPROTO_AH, Q_IPV6, Q_DEFAULT); 1420 gen_or(b0, b1); 1421 #endif 1422 break; 1423 1424 #ifndef IPPROTO_ESP 1425 #define IPPROTO_ESP 50 1426 #endif 1427 case Q_ESP: 1428 b1 = gen_proto(IPPROTO_ESP, Q_IP, Q_DEFAULT); 1429 #ifdef INET6 1430 b0 = gen_proto(IPPROTO_ESP, Q_IPV6, Q_DEFAULT); 1431 gen_or(b0, b1); 1432 #endif 1433 break; 1434 1435 default: 1436 abort(); 1437 } 1438 return b1; 1439 } 1440 1441 static struct block * 1442 gen_ipfrag() 1443 { 1444 struct slist *s; 1445 struct block *b; 1446 1447 /* not ip frag */ 1448 s = new_stmt(BPF_LD|BPF_H|BPF_ABS); 1449 s->s.k = off_nl + 6; 1450 b = new_block(JMP(BPF_JSET)); 1451 b->s.k = 0x1fff; 1452 b->stmts = s; 1453 gen_not(b); 1454 1455 return b; 1456 } 1457 1458 static struct block * 1459 gen_portatom(off, v) 1460 int off; 1461 bpf_int32 v; 1462 { 1463 struct slist *s; 1464 struct block *b; 1465 1466 s = new_stmt(BPF_LDX|BPF_MSH|BPF_B); 1467 s->s.k = off_nl; 1468 1469 s->next = new_stmt(BPF_LD|BPF_IND|BPF_H); 1470 s->next->s.k = off_nl + off; 1471 1472 b = new_block(JMP(BPF_JEQ)); 1473 b->stmts = s; 1474 b->s.k = v; 1475 1476 return b; 1477 } 1478 1479 #ifdef INET6 1480 static struct block * 1481 gen_portatom6(off, v) 1482 int off; 1483 bpf_int32 v; 1484 { 1485 return gen_cmp(off_nl + 40 + off, BPF_H, v); 1486 } 1487 #endif/*INET6*/ 1488 1489 struct block * 1490 gen_portop(port, proto, dir) 1491 int port, proto, dir; 1492 { 1493 struct block *b0, *b1, *tmp; 1494 1495 /* ip proto 'proto' */ 1496 tmp = gen_cmp(off_nl + 9, BPF_B, (bpf_int32)proto); 1497 b0 = gen_ipfrag(); 1498 gen_and(tmp, b0); 1499 1500 switch (dir) { 1501 case Q_SRC: 1502 b1 = gen_portatom(0, (bpf_int32)port); 1503 break; 1504 1505 case Q_DST: 1506 b1 = gen_portatom(2, (bpf_int32)port); 1507 break; 1508 1509 case Q_OR: 1510 case Q_DEFAULT: 1511 tmp = gen_portatom(0, (bpf_int32)port); 1512 b1 = gen_portatom(2, (bpf_int32)port); 1513 gen_or(tmp, b1); 1514 break; 1515 1516 case Q_AND: 1517 tmp = gen_portatom(0, (bpf_int32)port); 1518 b1 = gen_portatom(2, (bpf_int32)port); 1519 gen_and(tmp, b1); 1520 break; 1521 1522 default: 1523 abort(); 1524 } 1525 gen_and(b0, b1); 1526 1527 return b1; 1528 } 1529 1530 static struct block * 1531 gen_port(port, ip_proto, dir) 1532 int port; 1533 int ip_proto; 1534 int dir; 1535 { 1536 struct block *b0, *b1, *tmp; 1537 1538 /* ether proto ip */ 1539 b0 = gen_linktype(ETHERTYPE_IP); 1540 1541 switch (ip_proto) { 1542 case IPPROTO_UDP: 1543 case IPPROTO_TCP: 1544 b1 = gen_portop(port, ip_proto, dir); 1545 break; 1546 1547 case PROTO_UNDEF: 1548 tmp = gen_portop(port, IPPROTO_TCP, dir); 1549 b1 = gen_portop(port, IPPROTO_UDP, dir); 1550 gen_or(tmp, b1); 1551 break; 1552 1553 default: 1554 abort(); 1555 } 1556 gen_and(b0, b1); 1557 return b1; 1558 } 1559 1560 #ifdef INET6 1561 struct block * 1562 gen_portop6(port, proto, dir) 1563 int port, proto, dir; 1564 { 1565 struct block *b0, *b1, *tmp; 1566 1567 /* ip proto 'proto' */ 1568 b0 = gen_cmp(off_nl + 6, BPF_B, (bpf_int32)proto); 1569 1570 switch (dir) { 1571 case Q_SRC: 1572 b1 = gen_portatom6(0, (bpf_int32)port); 1573 break; 1574 1575 case Q_DST: 1576 b1 = gen_portatom6(2, (bpf_int32)port); 1577 break; 1578 1579 case Q_OR: 1580 case Q_DEFAULT: 1581 tmp = gen_portatom6(0, (bpf_int32)port); 1582 b1 = gen_portatom6(2, (bpf_int32)port); 1583 gen_or(tmp, b1); 1584 break; 1585 1586 case Q_AND: 1587 tmp = gen_portatom6(0, (bpf_int32)port); 1588 b1 = gen_portatom6(2, (bpf_int32)port); 1589 gen_and(tmp, b1); 1590 break; 1591 1592 default: 1593 abort(); 1594 } 1595 gen_and(b0, b1); 1596 1597 return b1; 1598 } 1599 1600 static struct block * 1601 gen_port6(port, ip_proto, dir) 1602 int port; 1603 int ip_proto; 1604 int dir; 1605 { 1606 struct block *b0, *b1, *tmp; 1607 1608 /* ether proto ip */ 1609 b0 = gen_linktype(ETHERTYPE_IPV6); 1610 1611 switch (ip_proto) { 1612 case IPPROTO_UDP: 1613 case IPPROTO_TCP: 1614 b1 = gen_portop6(port, ip_proto, dir); 1615 break; 1616 1617 case PROTO_UNDEF: 1618 tmp = gen_portop6(port, IPPROTO_TCP, dir); 1619 b1 = gen_portop6(port, IPPROTO_UDP, dir); 1620 gen_or(tmp, b1); 1621 break; 1622 1623 default: 1624 abort(); 1625 } 1626 gen_and(b0, b1); 1627 return b1; 1628 } 1629 #endif /* INET6 */ 1630 1631 static int 1632 lookup_proto(name, proto) 1633 register const char *name; 1634 register int proto; 1635 { 1636 register int v; 1637 1638 switch (proto) { 1639 1640 case Q_DEFAULT: 1641 case Q_IP: 1642 v = pcap_nametoproto(name); 1643 if (v == PROTO_UNDEF) 1644 bpf_error("unknown ip proto '%s'", name); 1645 break; 1646 1647 case Q_LINK: 1648 /* XXX should look up h/w protocol type based on linktype */ 1649 v = pcap_nametoeproto(name); 1650 if (v == PROTO_UNDEF) { 1651 v = pcap_nametollc(name); 1652 if (v == PROTO_UNDEF) 1653 bpf_error("unknown ether proto '%s'", name); 1654 } 1655 break; 1656 1657 default: 1658 v = PROTO_UNDEF; 1659 break; 1660 } 1661 return v; 1662 } 1663 1664 static struct block * 1665 gen_protochain(v, proto, dir) 1666 int v; 1667 int proto; 1668 int dir; 1669 { 1670 struct block *b0, *b; 1671 struct slist *s[100]; 1672 int fix2, fix3, fix4, fix5; 1673 int ahcheck, again, end; 1674 int i, max; 1675 int reg1 = alloc_reg(); 1676 int reg2 = alloc_reg(); 1677 1678 memset(s, 0, sizeof(s)); 1679 fix2 = fix3 = fix4 = fix5 = 0; 1680 1681 switch (proto) { 1682 case Q_IP: 1683 case Q_IPV6: 1684 break; 1685 case Q_DEFAULT: 1686 b0 = gen_protochain(v, Q_IP, dir); 1687 b = gen_protochain(v, Q_IPV6, dir); 1688 gen_or(b0, b); 1689 return b; 1690 default: 1691 bpf_error("bad protocol applied for 'protochain'"); 1692 /*NOTREACHED*/ 1693 } 1694 1695 no_optimize = 1; /*this code is not compatible with optimzer yet */ 1696 1697 /* 1698 * s[0] is a dummy entry to protect other BPF insn from damaged 1699 * by s[fix] = foo with uninitialized variable "fix". It is somewhat 1700 * hard to find interdependency made by jump table fixup. 1701 */ 1702 i = 0; 1703 s[i] = new_stmt(0); /*dummy*/ 1704 i++; 1705 1706 switch (proto) { 1707 case Q_IP: 1708 b0 = gen_linktype(ETHERTYPE_IP); 1709 1710 /* A = ip->ip_p */ 1711 s[i] = new_stmt(BPF_LD|BPF_ABS|BPF_B); 1712 s[i]->s.k = off_nl + 9; 1713 i++; 1714 /* X = ip->ip_hl << 2 */ 1715 s[i] = new_stmt(BPF_LDX|BPF_MSH|BPF_B); 1716 s[i]->s.k = off_nl; 1717 i++; 1718 break; 1719 case Q_IPV6: 1720 b0 = gen_linktype(ETHERTYPE_IPV6); 1721 1722 /* A = ip6->ip_nxt */ 1723 s[i] = new_stmt(BPF_LD|BPF_ABS|BPF_B); 1724 s[i]->s.k = off_nl + 6; 1725 i++; 1726 /* X = sizeof(struct ip6_hdr) */ 1727 s[i] = new_stmt(BPF_LDX|BPF_IMM); 1728 s[i]->s.k = 40; 1729 i++; 1730 break; 1731 default: 1732 bpf_error("unsupported proto to gen_protochain"); 1733 /*NOTREACHED*/ 1734 } 1735 1736 /* again: if (A == v) goto end; else fall through; */ 1737 again = i; 1738 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1739 s[i]->s.k = v; 1740 s[i]->s.jt = NULL; /*later*/ 1741 s[i]->s.jf = NULL; /*update in next stmt*/ 1742 fix5 = i; 1743 i++; 1744 1745 /* if (A == IPPROTO_NONE) goto end */ 1746 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1747 s[i]->s.jt = NULL; /*later*/ 1748 s[i]->s.jf = NULL; /*update in next stmt*/ 1749 s[i]->s.k = IPPROTO_NONE; 1750 s[fix5]->s.jf = s[i]; 1751 fix2 = i; 1752 i++; 1753 1754 if (proto == Q_IPV6) { 1755 int v6start, v6end, v6advance, j; 1756 1757 v6start = i; 1758 /* if (A == IPPROTO_HOPOPTS) goto v6advance */ 1759 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1760 s[i]->s.jt = NULL; /*later*/ 1761 s[i]->s.jf = NULL; /*update in next stmt*/ 1762 s[i]->s.k = IPPROTO_HOPOPTS; 1763 s[fix2]->s.jf = s[i]; 1764 i++; 1765 /* if (A == IPPROTO_DSTOPTS) goto v6advance */ 1766 s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1767 s[i]->s.jt = NULL; /*later*/ 1768 s[i]->s.jf = NULL; /*update in next stmt*/ 1769 s[i]->s.k = IPPROTO_DSTOPTS; 1770 i++; 1771 /* if (A == IPPROTO_ROUTING) goto v6advance */ 1772 s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1773 s[i]->s.jt = NULL; /*later*/ 1774 s[i]->s.jf = NULL; /*update in next stmt*/ 1775 s[i]->s.k = IPPROTO_ROUTING; 1776 i++; 1777 /* if (A == IPPROTO_FRAGMENT) goto v6advance; else goto ahcheck; */ 1778 s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1779 s[i]->s.jt = NULL; /*later*/ 1780 s[i]->s.jf = NULL; /*later*/ 1781 s[i]->s.k = IPPROTO_FRAGMENT; 1782 fix3 = i; 1783 v6end = i; 1784 i++; 1785 1786 /* v6advance: */ 1787 v6advance = i; 1788 1789 /* 1790 * in short, 1791 * A = P[X + 1]; 1792 * X = X + (P[X] + 1) * 8; 1793 */ 1794 /* A = X */ 1795 s[i] = new_stmt(BPF_MISC|BPF_TXA); 1796 i++; 1797 /* MEM[reg1] = A */ 1798 s[i] = new_stmt(BPF_ST); 1799 s[i]->s.k = reg1; 1800 i++; 1801 /* A += 1 */ 1802 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1803 s[i]->s.k = 1; 1804 i++; 1805 /* X = A */ 1806 s[i] = new_stmt(BPF_MISC|BPF_TAX); 1807 i++; 1808 /* A = P[X + packet head]; */ 1809 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B); 1810 s[i]->s.k = off_nl; 1811 i++; 1812 /* MEM[reg2] = A */ 1813 s[i] = new_stmt(BPF_ST); 1814 s[i]->s.k = reg2; 1815 i++; 1816 /* X = MEM[reg1] */ 1817 s[i] = new_stmt(BPF_LDX|BPF_MEM); 1818 s[i]->s.k = reg1; 1819 i++; 1820 /* A = P[X + packet head] */ 1821 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B); 1822 s[i]->s.k = off_nl; 1823 i++; 1824 /* A += 1 */ 1825 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1826 s[i]->s.k = 1; 1827 i++; 1828 /* A *= 8 */ 1829 s[i] = new_stmt(BPF_ALU|BPF_MUL|BPF_K); 1830 s[i]->s.k = 8; 1831 i++; 1832 /* X = A; */ 1833 s[i] = new_stmt(BPF_MISC|BPF_TAX); 1834 i++; 1835 /* A = MEM[reg2] */ 1836 s[i] = new_stmt(BPF_LD|BPF_MEM); 1837 s[i]->s.k = reg2; 1838 i++; 1839 1840 /* goto again; (must use BPF_JA for backward jump) */ 1841 s[i] = new_stmt(BPF_JMP|BPF_JA); 1842 s[i]->s.k = again - i - 1; 1843 s[i - 1]->s.jf = s[i]; 1844 i++; 1845 1846 /* fixup */ 1847 for (j = v6start; j <= v6end; j++) 1848 s[j]->s.jt = s[v6advance]; 1849 } else { 1850 /* nop */ 1851 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1852 s[i]->s.k = 0; 1853 s[fix2]->s.jf = s[i]; 1854 i++; 1855 } 1856 1857 /* ahcheck: */ 1858 ahcheck = i; 1859 /* if (A == IPPROTO_AH) then fall through; else goto end; */ 1860 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1861 s[i]->s.jt = NULL; /*later*/ 1862 s[i]->s.jf = NULL; /*later*/ 1863 s[i]->s.k = IPPROTO_AH; 1864 if (fix3) 1865 s[fix3]->s.jf = s[ahcheck]; 1866 fix4 = i; 1867 i++; 1868 1869 /* 1870 * in short, 1871 * A = P[X + 1]; 1872 * X = X + (P[X] + 2) * 4; 1873 */ 1874 /* A = X */ 1875 s[i - 1]->s.jt = s[i] = new_stmt(BPF_MISC|BPF_TXA); 1876 i++; 1877 /* MEM[reg1] = A */ 1878 s[i] = new_stmt(BPF_ST); 1879 s[i]->s.k = reg1; 1880 i++; 1881 /* A += 1 */ 1882 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1883 s[i]->s.k = 1; 1884 i++; 1885 /* X = A */ 1886 s[i] = new_stmt(BPF_MISC|BPF_TAX); 1887 i++; 1888 /* A = P[X + packet head]; */ 1889 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B); 1890 s[i]->s.k = off_nl; 1891 i++; 1892 /* MEM[reg2] = A */ 1893 s[i] = new_stmt(BPF_ST); 1894 s[i]->s.k = reg2; 1895 i++; 1896 /* X = MEM[reg1] */ 1897 s[i] = new_stmt(BPF_LDX|BPF_MEM); 1898 s[i]->s.k = reg1; 1899 i++; 1900 /* A = P[X + packet head] */ 1901 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B); 1902 s[i]->s.k = off_nl; 1903 i++; 1904 /* A += 2 */ 1905 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1906 s[i]->s.k = 2; 1907 i++; 1908 /* A *= 4 */ 1909 s[i] = new_stmt(BPF_ALU|BPF_MUL|BPF_K); 1910 s[i]->s.k = 4; 1911 i++; 1912 /* X = A; */ 1913 s[i] = new_stmt(BPF_MISC|BPF_TAX); 1914 i++; 1915 /* A = MEM[reg2] */ 1916 s[i] = new_stmt(BPF_LD|BPF_MEM); 1917 s[i]->s.k = reg2; 1918 i++; 1919 1920 /* goto again; (must use BPF_JA for backward jump) */ 1921 s[i] = new_stmt(BPF_JMP|BPF_JA); 1922 s[i]->s.k = again - i - 1; 1923 i++; 1924 1925 /* end: nop */ 1926 end = i; 1927 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1928 s[i]->s.k = 0; 1929 s[fix2]->s.jt = s[end]; 1930 s[fix4]->s.jf = s[end]; 1931 s[fix5]->s.jt = s[end]; 1932 i++; 1933 1934 /* 1935 * make slist chain 1936 */ 1937 max = i; 1938 for (i = 0; i < max - 1; i++) 1939 s[i]->next = s[i + 1]; 1940 s[max - 1]->next = NULL; 1941 1942 /* 1943 * emit final check 1944 */ 1945 b = new_block(JMP(BPF_JEQ)); 1946 b->stmts = s[1]; /*remember, s[0] is dummy*/ 1947 b->s.k = v; 1948 1949 free_reg(reg1); 1950 free_reg(reg2); 1951 1952 gen_and(b0, b); 1953 return b; 1954 } 1955 1956 static struct block * 1957 gen_proto(v, proto, dir) 1958 int v; 1959 int proto; 1960 int dir; 1961 { 1962 struct block *b0, *b1; 1963 1964 if (dir != Q_DEFAULT) 1965 bpf_error("direction applied to 'proto'"); 1966 1967 switch (proto) { 1968 case Q_DEFAULT: 1969 #ifdef INET6 1970 b0 = gen_proto(v, Q_IP, dir); 1971 b1 = gen_proto(v, Q_IPV6, dir); 1972 gen_or(b0, b1); 1973 return b1; 1974 #else 1975 /*FALLTHROUGH*/ 1976 #endif 1977 case Q_IP: 1978 b0 = gen_linktype(ETHERTYPE_IP); 1979 #ifndef CHASE_CHAIN 1980 b1 = gen_cmp(off_nl + 9, BPF_B, (bpf_int32)v); 1981 #else 1982 b1 = gen_protochain(v, Q_IP); 1983 #endif 1984 gen_and(b0, b1); 1985 return b1; 1986 1987 case Q_ARP: 1988 bpf_error("arp does not encapsulate another protocol"); 1989 /* NOTREACHED */ 1990 1991 case Q_RARP: 1992 bpf_error("rarp does not encapsulate another protocol"); 1993 /* NOTREACHED */ 1994 1995 case Q_ATALK: 1996 bpf_error("atalk encapsulation is not specifiable"); 1997 /* NOTREACHED */ 1998 1999 case Q_DECNET: 2000 bpf_error("decnet encapsulation is not specifiable"); 2001 /* NOTREACHED */ 2002 2003 case Q_SCA: 2004 bpf_error("sca does not encapsulate another protocol"); 2005 /* NOTREACHED */ 2006 2007 case Q_LAT: 2008 bpf_error("lat does not encapsulate another protocol"); 2009 /* NOTREACHED */ 2010 2011 case Q_MOPRC: 2012 bpf_error("moprc does not encapsulate another protocol"); 2013 /* NOTREACHED */ 2014 2015 case Q_MOPDL: 2016 bpf_error("mopdl does not encapsulate another protocol"); 2017 /* NOTREACHED */ 2018 2019 case Q_LINK: 2020 return gen_linktype(v); 2021 2022 case Q_UDP: 2023 bpf_error("'udp proto' is bogus"); 2024 /* NOTREACHED */ 2025 2026 case Q_TCP: 2027 bpf_error("'tcp proto' is bogus"); 2028 /* NOTREACHED */ 2029 2030 case Q_ICMP: 2031 bpf_error("'icmp proto' is bogus"); 2032 /* NOTREACHED */ 2033 2034 case Q_IGMP: 2035 bpf_error("'igmp proto' is bogus"); 2036 /* NOTREACHED */ 2037 2038 case Q_IGRP: 2039 bpf_error("'igrp proto' is bogus"); 2040 /* NOTREACHED */ 2041 2042 case Q_PIM: 2043 bpf_error("'pim proto' is bogus"); 2044 /* NOTREACHED */ 2045 2046 case Q_STP: 2047 bpf_error("'stp proto' is bogus"); 2048 /* NOTREACHED */ 2049 2050 #ifdef INET6 2051 case Q_IPV6: 2052 b0 = gen_linktype(ETHERTYPE_IPV6); 2053 #ifndef CHASE_CHAIN 2054 b1 = gen_cmp(off_nl + 6, BPF_B, (bpf_int32)v); 2055 #else 2056 b1 = gen_protochain(v, Q_IPV6); 2057 #endif 2058 gen_and(b0, b1); 2059 return b1; 2060 2061 case Q_ICMPV6: 2062 bpf_error("'icmp6 proto' is bogus"); 2063 #endif /* INET6 */ 2064 2065 case Q_AH: 2066 bpf_error("'ah proto' is bogus"); 2067 2068 case Q_ESP: 2069 bpf_error("'ah proto' is bogus"); 2070 2071 default: 2072 abort(); 2073 /* NOTREACHED */ 2074 } 2075 /* NOTREACHED */ 2076 } 2077 2078 struct block * 2079 gen_scode(name, q) 2080 register const char *name; 2081 struct qual q; 2082 { 2083 int proto = q.proto; 2084 int dir = q.dir; 2085 int tproto; 2086 u_char *eaddr; 2087 bpf_u_int32 mask, addr; 2088 #ifndef INET6 2089 bpf_u_int32 **alist; 2090 #else 2091 int tproto6; 2092 struct sockaddr_in *sin; 2093 struct sockaddr_in6 *sin6; 2094 struct addrinfo *res, *res0; 2095 struct in6_addr mask128; 2096 #endif /*INET6*/ 2097 struct block *b, *tmp; 2098 int port, real_proto; 2099 2100 switch (q.addr) { 2101 2102 case Q_NET: 2103 addr = pcap_nametonetaddr(name); 2104 if (addr == 0) 2105 bpf_error("unknown network '%s'", name); 2106 /* Left justify network addr and calculate its network mask */ 2107 mask = 0xffffffff; 2108 while (addr && (addr & 0xff000000) == 0) { 2109 addr <<= 8; 2110 mask <<= 8; 2111 } 2112 return gen_host(addr, mask, proto, dir); 2113 2114 case Q_DEFAULT: 2115 case Q_HOST: 2116 if (proto == Q_LINK) { 2117 switch (linktype) { 2118 2119 case DLT_EN10MB: 2120 eaddr = pcap_ether_hostton(name); 2121 if (eaddr == NULL) 2122 bpf_error( 2123 "unknown ether host '%s'", name); 2124 return gen_ehostop(eaddr, dir); 2125 2126 case DLT_FDDI: 2127 eaddr = pcap_ether_hostton(name); 2128 if (eaddr == NULL) 2129 bpf_error( 2130 "unknown FDDI host '%s'", name); 2131 return gen_fhostop(eaddr, dir); 2132 2133 case DLT_IEEE802_11: 2134 case DLT_IEEE802_11_RADIO: 2135 eaddr = pcap_ether_hostton(name); 2136 if (eaddr == NULL) 2137 bpf_error( 2138 "unknown 802.11 host '%s'", name); 2139 2140 return gen_p80211_hostop(eaddr, dir); 2141 2142 default: 2143 bpf_error( 2144 "only ethernet/FDDI supports link-level host name"); 2145 break; 2146 } 2147 } else if (proto == Q_DECNET) { 2148 unsigned short dn_addr = __pcap_nametodnaddr(name); 2149 /* 2150 * I don't think DECNET hosts can be multihomed, so 2151 * there is no need to build up a list of addresses 2152 */ 2153 return (gen_host(dn_addr, 0, proto, dir)); 2154 } else { 2155 #ifndef INET6 2156 alist = pcap_nametoaddr(name); 2157 if (alist == NULL || *alist == NULL) 2158 bpf_error("unknown host '%s'", name); 2159 tproto = proto; 2160 if (off_linktype == -1 && tproto == Q_DEFAULT) 2161 tproto = Q_IP; 2162 b = gen_host(**alist++, 0xffffffff, tproto, dir); 2163 while (*alist) { 2164 tmp = gen_host(**alist++, 0xffffffff, 2165 tproto, dir); 2166 gen_or(b, tmp); 2167 b = tmp; 2168 } 2169 return b; 2170 #else 2171 memset(&mask128, 0xff, sizeof(mask128)); 2172 res0 = res = pcap_nametoaddrinfo(name); 2173 if (res == NULL) 2174 bpf_error("unknown host '%s'", name); 2175 b = tmp = NULL; 2176 tproto = tproto6 = proto; 2177 if (off_linktype == -1 && tproto == Q_DEFAULT) { 2178 tproto = Q_IP; 2179 tproto6 = Q_IPV6; 2180 } 2181 for (res = res0; res; res = res->ai_next) { 2182 switch (res->ai_family) { 2183 case AF_INET: 2184 if (tproto == Q_IPV6) 2185 continue; 2186 2187 sin = (struct sockaddr_in *) 2188 res->ai_addr; 2189 tmp = gen_host(ntohl(sin->sin_addr.s_addr), 2190 0xffffffff, tproto, dir); 2191 break; 2192 case AF_INET6: 2193 if (tproto6 == Q_IP) 2194 continue; 2195 2196 sin6 = (struct sockaddr_in6 *) 2197 res->ai_addr; 2198 tmp = gen_host6(&sin6->sin6_addr, 2199 &mask128, tproto6, dir); 2200 break; 2201 } 2202 if (b) 2203 gen_or(b, tmp); 2204 b = tmp; 2205 } 2206 freeaddrinfo(res0); 2207 if (b == NULL) { 2208 bpf_error("unknown host '%s'%s", name, 2209 (proto == Q_DEFAULT) 2210 ? "" 2211 : " for specified address family"); 2212 } 2213 return b; 2214 #endif /*INET6*/ 2215 } 2216 2217 case Q_PORT: 2218 if (proto != Q_DEFAULT && proto != Q_UDP && proto != Q_TCP) 2219 bpf_error("illegal qualifier of 'port'"); 2220 if (pcap_nametoport(name, &port, &real_proto) == 0) 2221 bpf_error("unknown port '%s'", name); 2222 if (proto == Q_UDP) { 2223 if (real_proto == IPPROTO_TCP) 2224 bpf_error("port '%s' is tcp", name); 2225 else 2226 /* override PROTO_UNDEF */ 2227 real_proto = IPPROTO_UDP; 2228 } 2229 if (proto == Q_TCP) { 2230 if (real_proto == IPPROTO_UDP) 2231 bpf_error("port '%s' is udp", name); 2232 else 2233 /* override PROTO_UNDEF */ 2234 real_proto = IPPROTO_TCP; 2235 } 2236 #ifndef INET6 2237 return gen_port(port, real_proto, dir); 2238 #else 2239 { 2240 struct block *b; 2241 b = gen_port(port, real_proto, dir); 2242 gen_or(gen_port6(port, real_proto, dir), b); 2243 return b; 2244 } 2245 #endif /* INET6 */ 2246 2247 case Q_GATEWAY: 2248 #ifndef INET6 2249 eaddr = pcap_ether_hostton(name); 2250 if (eaddr == NULL) 2251 bpf_error("unknown ether host: %s", name); 2252 2253 alist = pcap_nametoaddr(name); 2254 if (alist == NULL || *alist == NULL) 2255 bpf_error("unknown host '%s'", name); 2256 return gen_gateway(eaddr, alist, proto, dir); 2257 #else 2258 bpf_error("'gateway' not supported in this configuration"); 2259 #endif /*INET6*/ 2260 2261 case Q_PROTO: 2262 real_proto = lookup_proto(name, proto); 2263 if (real_proto >= 0) 2264 return gen_proto(real_proto, proto, dir); 2265 else 2266 bpf_error("unknown protocol: %s", name); 2267 2268 case Q_PROTOCHAIN: 2269 real_proto = lookup_proto(name, proto); 2270 if (real_proto >= 0) 2271 return gen_protochain(real_proto, proto, dir); 2272 else 2273 bpf_error("unknown protocol: %s", name); 2274 2275 2276 case Q_UNDEF: 2277 syntax(); 2278 /* NOTREACHED */ 2279 } 2280 abort(); 2281 /* NOTREACHED */ 2282 } 2283 2284 struct block * 2285 gen_mcode(s1, s2, masklen, q) 2286 register const char *s1, *s2; 2287 register int masklen; 2288 struct qual q; 2289 { 2290 register int nlen, mlen; 2291 bpf_u_int32 n, m; 2292 2293 nlen = __pcap_atoin(s1, &n); 2294 /* Promote short ipaddr */ 2295 n <<= 32 - nlen; 2296 2297 if (s2 != NULL) { 2298 mlen = __pcap_atoin(s2, &m); 2299 /* Promote short ipaddr */ 2300 m <<= 32 - mlen; 2301 if ((n & ~m) != 0) 2302 bpf_error("non-network bits set in \"%s mask %s\"", 2303 s1, s2); 2304 } else { 2305 /* Convert mask len to mask */ 2306 if (masklen > 32) 2307 bpf_error("mask length must be <= 32"); 2308 m = 0xffffffff << (32 - masklen); 2309 if ((n & ~m) != 0) 2310 bpf_error("non-network bits set in \"%s/%d\"", 2311 s1, masklen); 2312 } 2313 2314 switch (q.addr) { 2315 2316 case Q_NET: 2317 return gen_host(n, m, q.proto, q.dir); 2318 2319 default: 2320 bpf_error("Mask syntax for networks only"); 2321 /* NOTREACHED */ 2322 } 2323 } 2324 2325 struct block * 2326 gen_ncode(s, v, q) 2327 register const char *s; 2328 bpf_u_int32 v; 2329 struct qual q; 2330 { 2331 bpf_u_int32 mask; 2332 int proto = q.proto; 2333 int dir = q.dir; 2334 register int vlen; 2335 2336 if (s == NULL) 2337 vlen = 32; 2338 else if (q.proto == Q_DECNET) 2339 vlen = __pcap_atodn(s, &v); 2340 else 2341 vlen = __pcap_atoin(s, &v); 2342 2343 switch (q.addr) { 2344 2345 case Q_DEFAULT: 2346 case Q_HOST: 2347 case Q_NET: 2348 if (proto == Q_DECNET) 2349 return gen_host(v, 0, proto, dir); 2350 else if (proto == Q_LINK) { 2351 bpf_error("illegal link layer address"); 2352 } else { 2353 mask = 0xffffffff; 2354 if (s == NULL && q.addr == Q_NET) { 2355 /* Promote short net number */ 2356 while (v && (v & 0xff000000) == 0) { 2357 v <<= 8; 2358 mask <<= 8; 2359 } 2360 } else { 2361 /* Promote short ipaddr */ 2362 v <<= 32 - vlen; 2363 mask <<= 32 - vlen; 2364 } 2365 return gen_host(v, mask, proto, dir); 2366 } 2367 2368 case Q_PORT: 2369 if (proto == Q_UDP) 2370 proto = IPPROTO_UDP; 2371 else if (proto == Q_TCP) 2372 proto = IPPROTO_TCP; 2373 else if (proto == Q_DEFAULT) 2374 proto = PROTO_UNDEF; 2375 else 2376 bpf_error("illegal qualifier of 'port'"); 2377 2378 #ifndef INET6 2379 return gen_port((int)v, proto, dir); 2380 #else 2381 { 2382 struct block *b; 2383 b = gen_port((int)v, proto, dir); 2384 gen_or(gen_port6((int)v, proto, dir), b); 2385 return b; 2386 } 2387 #endif /* INET6 */ 2388 2389 case Q_GATEWAY: 2390 bpf_error("'gateway' requires a name"); 2391 /* NOTREACHED */ 2392 2393 case Q_PROTO: 2394 return gen_proto((int)v, proto, dir); 2395 2396 case Q_PROTOCHAIN: 2397 return gen_protochain((int)v, proto, dir); 2398 2399 case Q_UNDEF: 2400 syntax(); 2401 /* NOTREACHED */ 2402 2403 default: 2404 abort(); 2405 /* NOTREACHED */ 2406 } 2407 /* NOTREACHED */ 2408 } 2409 2410 #ifdef INET6 2411 struct block * 2412 gen_mcode6(s1, s2, masklen, q) 2413 register const char *s1, *s2; 2414 register int masklen; 2415 struct qual q; 2416 { 2417 struct addrinfo *res; 2418 struct in6_addr *addr; 2419 struct in6_addr mask; 2420 struct block *b; 2421 u_int32_t *a, *m; 2422 2423 if (s2) 2424 bpf_error("no mask %s supported", s2); 2425 2426 res = pcap_nametoaddrinfo(s1); 2427 if (!res) 2428 bpf_error("invalid ip6 address %s", s1); 2429 if (res->ai_next) 2430 bpf_error("%s resolved to multiple address", s1); 2431 addr = &((struct sockaddr_in6 *)res->ai_addr)->sin6_addr; 2432 2433 if (sizeof(mask) * 8 < masklen) 2434 bpf_error("mask length must be <= %u", (unsigned int)(sizeof(mask) * 8)); 2435 memset(&mask, 0xff, masklen / 8); 2436 if (masklen % 8) { 2437 mask.s6_addr[masklen / 8] = 2438 (0xff << (8 - masklen % 8)) & 0xff; 2439 } 2440 2441 a = (u_int32_t *)addr; 2442 m = (u_int32_t *)&mask; 2443 if ((a[0] & ~m[0]) || (a[1] & ~m[1]) 2444 || (a[2] & ~m[2]) || (a[3] & ~m[3])) { 2445 bpf_error("non-network bits set in \"%s/%d\"", s1, masklen); 2446 } 2447 2448 switch (q.addr) { 2449 2450 case Q_DEFAULT: 2451 case Q_HOST: 2452 if (masklen != 128) 2453 bpf_error("Mask syntax for networks only"); 2454 /* FALLTHROUGH */ 2455 2456 case Q_NET: 2457 b = gen_host6(addr, &mask, q.proto, q.dir); 2458 freeaddrinfo(res); 2459 return b; 2460 2461 default: 2462 bpf_error("invalid qualifier against IPv6 address"); 2463 /* NOTREACHED */ 2464 } 2465 } 2466 #endif /*INET6*/ 2467 2468 struct block * 2469 gen_ecode(eaddr, q) 2470 register const u_char *eaddr; 2471 struct qual q; 2472 { 2473 if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) && q.proto == Q_LINK) { 2474 if (linktype == DLT_EN10MB) 2475 return gen_ehostop(eaddr, (int)q.dir); 2476 if (linktype == DLT_FDDI) 2477 return gen_fhostop(eaddr, (int)q.dir); 2478 if (linktype == DLT_IEEE802_11 || 2479 linktype == DLT_IEEE802_11_RADIO) 2480 return gen_p80211_hostop(eaddr, (int)q.dir); 2481 } 2482 bpf_error("ethernet address used in non-ether expression"); 2483 /* NOTREACHED */ 2484 } 2485 2486 void 2487 sappend(s0, s1) 2488 struct slist *s0, *s1; 2489 { 2490 /* 2491 * This is definitely not the best way to do this, but the 2492 * lists will rarely get long. 2493 */ 2494 while (s0->next) 2495 s0 = s0->next; 2496 s0->next = s1; 2497 } 2498 2499 static struct slist * 2500 xfer_to_x(a) 2501 struct arth *a; 2502 { 2503 struct slist *s; 2504 2505 s = new_stmt(BPF_LDX|BPF_MEM); 2506 s->s.k = a->regno; 2507 return s; 2508 } 2509 2510 static struct slist * 2511 xfer_to_a(a) 2512 struct arth *a; 2513 { 2514 struct slist *s; 2515 2516 s = new_stmt(BPF_LD|BPF_MEM); 2517 s->s.k = a->regno; 2518 return s; 2519 } 2520 2521 struct arth * 2522 gen_load(proto, index, size) 2523 int proto; 2524 struct arth *index; 2525 int size; 2526 { 2527 struct slist *s, *tmp; 2528 struct block *b; 2529 int regno = alloc_reg(); 2530 2531 free_reg(index->regno); 2532 switch (size) { 2533 2534 default: 2535 bpf_error("data size must be 1, 2, or 4"); 2536 2537 case 1: 2538 size = BPF_B; 2539 break; 2540 2541 case 2: 2542 size = BPF_H; 2543 break; 2544 2545 case 4: 2546 size = BPF_W; 2547 break; 2548 } 2549 switch (proto) { 2550 default: 2551 bpf_error("unsupported index operation"); 2552 2553 case Q_LINK: 2554 s = xfer_to_x(index); 2555 tmp = new_stmt(BPF_LD|BPF_IND|size); 2556 sappend(s, tmp); 2557 sappend(index->s, s); 2558 break; 2559 2560 case Q_IP: 2561 case Q_ARP: 2562 case Q_RARP: 2563 case Q_ATALK: 2564 case Q_DECNET: 2565 case Q_SCA: 2566 case Q_LAT: 2567 case Q_MOPRC: 2568 case Q_MOPDL: 2569 #ifdef INET6 2570 case Q_IPV6: 2571 #endif 2572 /* XXX Note that we assume a fixed link header here. */ 2573 s = xfer_to_x(index); 2574 tmp = new_stmt(BPF_LD|BPF_IND|size); 2575 tmp->s.k = off_nl; 2576 sappend(s, tmp); 2577 sappend(index->s, s); 2578 2579 b = gen_proto_abbrev(proto); 2580 if (index->b) 2581 gen_and(index->b, b); 2582 index->b = b; 2583 break; 2584 2585 case Q_TCP: 2586 case Q_UDP: 2587 case Q_ICMP: 2588 case Q_IGMP: 2589 case Q_IGRP: 2590 case Q_PIM: 2591 s = new_stmt(BPF_LDX|BPF_MSH|BPF_B); 2592 s->s.k = off_nl; 2593 sappend(s, xfer_to_a(index)); 2594 sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X)); 2595 sappend(s, new_stmt(BPF_MISC|BPF_TAX)); 2596 sappend(s, tmp = new_stmt(BPF_LD|BPF_IND|size)); 2597 tmp->s.k = off_nl; 2598 sappend(index->s, s); 2599 2600 gen_and(gen_proto_abbrev(proto), b = gen_ipfrag()); 2601 if (index->b) 2602 gen_and(index->b, b); 2603 #ifdef INET6 2604 gen_and(gen_proto_abbrev(Q_IP), b); 2605 #endif 2606 index->b = b; 2607 break; 2608 #ifdef INET6 2609 case Q_ICMPV6: 2610 bpf_error("IPv6 upper-layer protocol is not supported by proto[x]"); 2611 /*NOTREACHED*/ 2612 #endif 2613 } 2614 index->regno = regno; 2615 s = new_stmt(BPF_ST); 2616 s->s.k = regno; 2617 sappend(index->s, s); 2618 2619 return index; 2620 } 2621 2622 struct block * 2623 gen_relation(code, a0, a1, reversed) 2624 int code; 2625 struct arth *a0, *a1; 2626 int reversed; 2627 { 2628 struct slist *s0, *s1, *s2; 2629 struct block *b, *tmp; 2630 2631 s0 = xfer_to_x(a1); 2632 s1 = xfer_to_a(a0); 2633 s2 = new_stmt(BPF_ALU|BPF_SUB|BPF_X); 2634 b = new_block(JMP(code)); 2635 if (code == BPF_JGT || code == BPF_JGE) { 2636 reversed = !reversed; 2637 b->s.k = 0x80000000; 2638 } 2639 if (reversed) 2640 gen_not(b); 2641 2642 sappend(s1, s2); 2643 sappend(s0, s1); 2644 sappend(a1->s, s0); 2645 sappend(a0->s, a1->s); 2646 2647 b->stmts = a0->s; 2648 2649 free_reg(a0->regno); 2650 free_reg(a1->regno); 2651 2652 /* 'and' together protocol checks */ 2653 if (a0->b) { 2654 if (a1->b) { 2655 gen_and(a0->b, tmp = a1->b); 2656 } 2657 else 2658 tmp = a0->b; 2659 } else 2660 tmp = a1->b; 2661 2662 if (tmp) 2663 gen_and(tmp, b); 2664 2665 return b; 2666 } 2667 2668 struct arth * 2669 gen_loadlen() 2670 { 2671 int regno = alloc_reg(); 2672 struct arth *a = (struct arth *)newchunk(sizeof(*a)); 2673 struct slist *s; 2674 2675 s = new_stmt(BPF_LD|BPF_LEN); 2676 s->next = new_stmt(BPF_ST); 2677 s->next->s.k = regno; 2678 a->s = s; 2679 a->regno = regno; 2680 2681 return a; 2682 } 2683 2684 struct arth * 2685 gen_loadi(val) 2686 int val; 2687 { 2688 struct arth *a; 2689 struct slist *s; 2690 int reg; 2691 2692 a = (struct arth *)newchunk(sizeof(*a)); 2693 2694 reg = alloc_reg(); 2695 2696 s = new_stmt(BPF_LD|BPF_IMM); 2697 s->s.k = val; 2698 s->next = new_stmt(BPF_ST); 2699 s->next->s.k = reg; 2700 a->s = s; 2701 a->regno = reg; 2702 2703 return a; 2704 } 2705 2706 struct arth * 2707 gen_neg(a) 2708 struct arth *a; 2709 { 2710 struct slist *s; 2711 2712 s = xfer_to_a(a); 2713 sappend(a->s, s); 2714 s = new_stmt(BPF_ALU|BPF_NEG); 2715 s->s.k = 0; 2716 sappend(a->s, s); 2717 s = new_stmt(BPF_ST); 2718 s->s.k = a->regno; 2719 sappend(a->s, s); 2720 2721 return a; 2722 } 2723 2724 struct arth * 2725 gen_arth(code, a0, a1) 2726 int code; 2727 struct arth *a0, *a1; 2728 { 2729 struct slist *s0, *s1, *s2; 2730 2731 s0 = xfer_to_x(a1); 2732 s1 = xfer_to_a(a0); 2733 s2 = new_stmt(BPF_ALU|BPF_X|code); 2734 2735 sappend(s1, s2); 2736 sappend(s0, s1); 2737 sappend(a1->s, s0); 2738 sappend(a0->s, a1->s); 2739 2740 free_reg(a1->regno); 2741 2742 s0 = new_stmt(BPF_ST); 2743 a0->regno = s0->s.k = alloc_reg(); 2744 sappend(a0->s, s0); 2745 2746 return a0; 2747 } 2748 2749 /* 2750 * Here we handle simple allocation of the scratch registers. 2751 * If too many registers are alloc'd, the allocator punts. 2752 */ 2753 static int regused[BPF_MEMWORDS]; 2754 static int curreg; 2755 2756 /* 2757 * Return the next free register. 2758 */ 2759 static int 2760 alloc_reg() 2761 { 2762 int n = BPF_MEMWORDS; 2763 2764 while (--n >= 0) { 2765 if (regused[curreg]) 2766 curreg = (curreg + 1) % BPF_MEMWORDS; 2767 else { 2768 regused[curreg] = 1; 2769 return curreg; 2770 } 2771 } 2772 bpf_error("too many registers needed to evaluate expression"); 2773 /* NOTREACHED */ 2774 } 2775 2776 /* 2777 * Return a register to the table so it can 2778 * be used later. 2779 */ 2780 static void 2781 free_reg(n) 2782 int n; 2783 { 2784 regused[n] = 0; 2785 } 2786 2787 static struct block * 2788 gen_len(jmp, n) 2789 int jmp, n; 2790 { 2791 struct slist *s; 2792 struct block *b; 2793 2794 s = new_stmt(BPF_LD|BPF_LEN); 2795 b = new_block(JMP(jmp)); 2796 b->stmts = s; 2797 b->s.k = n; 2798 2799 return b; 2800 } 2801 2802 struct block * 2803 gen_greater(n) 2804 int n; 2805 { 2806 return gen_len(BPF_JGE, n); 2807 } 2808 2809 struct block * 2810 gen_less(n) 2811 int n; 2812 { 2813 struct block *b; 2814 2815 b = gen_len(BPF_JGT, n); 2816 gen_not(b); 2817 2818 return b; 2819 } 2820 2821 struct block * 2822 gen_byteop(op, idx, val) 2823 int op, idx, val; 2824 { 2825 struct block *b; 2826 struct slist *s; 2827 2828 switch (op) { 2829 default: 2830 abort(); 2831 2832 case '=': 2833 return gen_cmp((u_int)idx, BPF_B, (bpf_int32)val); 2834 2835 case '<': 2836 b = gen_cmp((u_int)idx, BPF_B, (bpf_int32)val); 2837 b->s.code = JMP(BPF_JGE); 2838 gen_not(b); 2839 return b; 2840 2841 case '>': 2842 b = gen_cmp((u_int)idx, BPF_B, (bpf_int32)val); 2843 b->s.code = JMP(BPF_JGT); 2844 return b; 2845 2846 case '|': 2847 s = new_stmt(BPF_ALU|BPF_OR|BPF_K); 2848 break; 2849 2850 case '&': 2851 s = new_stmt(BPF_ALU|BPF_AND|BPF_K); 2852 break; 2853 } 2854 s->s.k = val; 2855 b = new_block(JMP(BPF_JEQ)); 2856 b->stmts = s; 2857 gen_not(b); 2858 2859 return b; 2860 } 2861 2862 struct block * 2863 gen_broadcast(proto) 2864 int proto; 2865 { 2866 bpf_u_int32 hostmask; 2867 struct block *b0, *b1, *b2; 2868 static u_char ebroadcast[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; 2869 2870 switch (proto) { 2871 2872 case Q_DEFAULT: 2873 case Q_LINK: 2874 if (linktype == DLT_EN10MB) 2875 return gen_ehostop(ebroadcast, Q_DST); 2876 if (linktype == DLT_FDDI) 2877 return gen_fhostop(ebroadcast, Q_DST); 2878 if (linktype == DLT_IEEE802_11 || 2879 linktype == DLT_IEEE802_11_RADIO) 2880 return gen_p80211_hostop(ebroadcast, Q_DST); 2881 bpf_error("not a broadcast link"); 2882 break; 2883 2884 case Q_IP: 2885 b0 = gen_linktype(ETHERTYPE_IP); 2886 hostmask = ~netmask; 2887 b1 = gen_mcmp(off_nl + 16, BPF_W, (bpf_int32)0, hostmask); 2888 b2 = gen_mcmp(off_nl + 16, BPF_W, 2889 (bpf_int32)(~0 & hostmask), hostmask); 2890 gen_or(b1, b2); 2891 gen_and(b0, b2); 2892 return b2; 2893 } 2894 bpf_error("only ether/ip broadcast filters supported"); 2895 } 2896 2897 struct block * 2898 gen_multicast(proto) 2899 int proto; 2900 { 2901 register struct block *b0, *b1; 2902 register struct slist *s; 2903 2904 switch (proto) { 2905 2906 case Q_DEFAULT: 2907 case Q_LINK: 2908 if (linktype == DLT_EN10MB) { 2909 /* ether[0] & 1 != 0 */ 2910 s = new_stmt(BPF_LD|BPF_B|BPF_ABS); 2911 s->s.k = 0; 2912 b0 = new_block(JMP(BPF_JSET)); 2913 b0->s.k = 1; 2914 b0->stmts = s; 2915 return b0; 2916 } 2917 2918 if (linktype == DLT_FDDI) { 2919 /* XXX TEST THIS: MIGHT NOT PORT PROPERLY XXX */ 2920 /* fddi[1] & 1 != 0 */ 2921 s = new_stmt(BPF_LD|BPF_B|BPF_ABS); 2922 s->s.k = 1; 2923 b0 = new_block(JMP(BPF_JSET)); 2924 b0->s.k = 1; 2925 b0->stmts = s; 2926 return b0; 2927 } 2928 /* Link not known to support multicasts */ 2929 break; 2930 2931 case Q_IP: 2932 b0 = gen_linktype(ETHERTYPE_IP); 2933 b1 = gen_cmp(off_nl + 16, BPF_B, (bpf_int32)224); 2934 b1->s.code = JMP(BPF_JGE); 2935 gen_and(b0, b1); 2936 return b1; 2937 2938 #ifdef INET6 2939 case Q_IPV6: 2940 b0 = gen_linktype(ETHERTYPE_IPV6); 2941 b1 = gen_cmp(off_nl + 24, BPF_B, (bpf_int32)255); 2942 gen_and(b0, b1); 2943 return b1; 2944 #endif /* INET6 */ 2945 } 2946 bpf_error("only IP multicast filters supported on ethernet/FDDI"); 2947 } 2948 2949 /* 2950 * generate command for inbound/outbound. It's here so we can 2951 * make it link-type specific. 'dir' = 0 implies "inbound", 2952 * = 1 implies "outbound". 2953 */ 2954 struct block * 2955 gen_inbound(dir) 2956 int dir; 2957 { 2958 register struct block *b0; 2959 2960 /* 2961 * Only SLIP and old-style PPP data link types support 2962 * inbound/outbound qualifiers. 2963 */ 2964 switch (linktype) { 2965 case DLT_SLIP: 2966 case DLT_PPP: 2967 b0 = gen_relation(BPF_JEQ, 2968 gen_load(Q_LINK, gen_loadi(0), 1), 2969 gen_loadi(0), 2970 dir); 2971 break; 2972 2973 case DLT_PFLOG: 2974 b0 = gen_cmp(offsetof(struct pfloghdr, dir), BPF_B, 2975 (bpf_int32)((dir == 0) ? PF_IN : PF_OUT)); 2976 break; 2977 2978 case DLT_OLD_PFLOG: 2979 b0 = gen_cmp(offsetof(struct old_pfloghdr, dir), BPF_H, 2980 (bpf_int32)((dir == 0) ? PF_IN : PF_OUT)); 2981 break; 2982 2983 default: 2984 bpf_error("inbound/outbound not supported on linktype 0x%x", 2985 linktype); 2986 /* NOTREACHED */ 2987 } 2988 2989 return (b0); 2990 } 2991 2992 2993 /* PF firewall log matched interface */ 2994 struct block * 2995 gen_pf_ifname(char *ifname) 2996 { 2997 struct block *b0; 2998 u_int len, off; 2999 3000 if (linktype == DLT_PFLOG) { 3001 len = sizeof(((struct pfloghdr *)0)->ifname); 3002 off = offsetof(struct pfloghdr, ifname); 3003 } else if (linktype == DLT_OLD_PFLOG) { 3004 len = sizeof(((struct old_pfloghdr *)0)->ifname); 3005 off = offsetof(struct old_pfloghdr, ifname); 3006 } else { 3007 bpf_error("ifname not supported on linktype 0x%x", linktype); 3008 /* NOTREACHED */ 3009 } 3010 if (strlen(ifname) >= len) { 3011 bpf_error("ifname interface names can only be %d characters", 3012 len - 1); 3013 /* NOTREACHED */ 3014 } 3015 b0 = gen_bcmp(off, strlen(ifname), ifname); 3016 return (b0); 3017 } 3018 3019 3020 /* PF firewall log ruleset name */ 3021 struct block * 3022 gen_pf_ruleset(char *ruleset) 3023 { 3024 struct block *b0; 3025 3026 if (linktype != DLT_PFLOG) { 3027 bpf_error("ruleset not supported on linktype 0x%x", linktype); 3028 /* NOTREACHED */ 3029 } 3030 if (strlen(ruleset) >= sizeof(((struct pfloghdr *)0)->ruleset)) { 3031 bpf_error("ruleset names can only be %zu characters", 3032 sizeof(((struct pfloghdr *)0)->ruleset) - 1); 3033 /* NOTREACHED */ 3034 } 3035 b0 = gen_bcmp(offsetof(struct pfloghdr, ruleset), 3036 strlen(ruleset), ruleset); 3037 return (b0); 3038 } 3039 3040 3041 /* PF firewall log rule number */ 3042 struct block * 3043 gen_pf_rnr(int rnr) 3044 { 3045 struct block *b0; 3046 3047 if (linktype == DLT_PFLOG) { 3048 b0 = gen_cmp(offsetof(struct pfloghdr, rulenr), BPF_W, 3049 (bpf_int32)rnr); 3050 } else if (linktype == DLT_OLD_PFLOG) { 3051 b0 = gen_cmp(offsetof(struct old_pfloghdr, rnr), BPF_H, 3052 (bpf_int32)rnr); 3053 } else { 3054 bpf_error("rnr not supported on linktype 0x%x", linktype); 3055 /* NOTREACHED */ 3056 } 3057 3058 return (b0); 3059 } 3060 3061 3062 /* PF firewall log sub-rule number */ 3063 struct block * 3064 gen_pf_srnr(int srnr) 3065 { 3066 struct block *b0; 3067 3068 if (linktype != DLT_PFLOG) { 3069 bpf_error("srnr not supported on linktype 0x%x", linktype); 3070 /* NOTREACHED */ 3071 } 3072 3073 b0 = gen_cmp(offsetof(struct pfloghdr, subrulenr), BPF_W, 3074 (bpf_int32)srnr); 3075 return (b0); 3076 } 3077 3078 /* PF firewall log reason code */ 3079 struct block * 3080 gen_pf_reason(int reason) 3081 { 3082 struct block *b0; 3083 3084 if (linktype == DLT_PFLOG) { 3085 b0 = gen_cmp(offsetof(struct pfloghdr, reason), BPF_B, 3086 (bpf_int32)reason); 3087 } else if (linktype == DLT_OLD_PFLOG) { 3088 b0 = gen_cmp(offsetof(struct old_pfloghdr, reason), BPF_H, 3089 (bpf_int32)reason); 3090 } else { 3091 bpf_error("reason not supported on linktype 0x%x", linktype); 3092 /* NOTREACHED */ 3093 } 3094 3095 return (b0); 3096 } 3097 3098 /* PF firewall log action */ 3099 struct block * 3100 gen_pf_action(int action) 3101 { 3102 struct block *b0; 3103 3104 if (linktype == DLT_PFLOG) { 3105 b0 = gen_cmp(offsetof(struct pfloghdr, action), BPF_B, 3106 (bpf_int32)action); 3107 } else if (linktype == DLT_OLD_PFLOG) { 3108 b0 = gen_cmp(offsetof(struct old_pfloghdr, action), BPF_H, 3109 (bpf_int32)action); 3110 } else { 3111 bpf_error("action not supported on linktype 0x%x", linktype); 3112 /* NOTREACHED */ 3113 } 3114 3115 return (b0); 3116 } 3117 3118 /* IEEE 802.11 wireless header */ 3119 struct block * 3120 gen_p80211_type(int type, int mask) 3121 { 3122 struct block *b0; 3123 u_int offset; 3124 3125 if (!(linktype == DLT_IEEE802_11 || 3126 linktype == DLT_IEEE802_11_RADIO)) { 3127 bpf_error("type not supported on linktype 0x%x", 3128 linktype); 3129 /* NOTREACHED */ 3130 } 3131 offset = (u_int)offsetof(struct ieee80211_frame, i_fc[0]); 3132 if (linktype == DLT_IEEE802_11_RADIO) 3133 offset += IEEE80211_RADIOTAP_HDRLEN; 3134 3135 b0 = gen_mcmp(offset, BPF_B, (bpf_int32)type, (bpf_u_int32)mask); 3136 3137 return (b0); 3138 } 3139 3140 struct block * 3141 gen_p80211_fcdir(int fcdir) 3142 { 3143 struct block *b0; 3144 u_int offset; 3145 3146 if (!(linktype == DLT_IEEE802_11 || 3147 linktype == DLT_IEEE802_11_RADIO)) { 3148 bpf_error("frame direction not supported on linktype 0x%x", 3149 linktype); 3150 /* NOTREACHED */ 3151 } 3152 offset = (u_int)offsetof(struct ieee80211_frame, i_fc[1]); 3153 if (linktype == DLT_IEEE802_11_RADIO) 3154 offset += IEEE80211_RADIOTAP_HDRLEN; 3155 3156 b0 = gen_mcmp(offset, BPF_B, (bpf_int32)fcdir, 3157 (bpf_u_int32)IEEE80211_FC1_DIR_MASK); 3158 3159 return (b0); 3160 } 3161 3162 static struct block * 3163 gen_p80211_hostop(const u_char *lladdr, int dir) 3164 { 3165 struct block *b0, *b1, *b2, *b3, *b4; 3166 u_int offset = 0; 3167 3168 if (linktype == DLT_IEEE802_11_RADIO) 3169 offset = IEEE80211_RADIOTAP_HDRLEN; 3170 3171 switch (dir) { 3172 case Q_SRC: 3173 b0 = gen_p80211_addr(IEEE80211_FC1_DIR_NODS, offset + 3174 (u_int)offsetof(struct ieee80211_frame, i_addr2), 3175 lladdr); 3176 b1 = gen_p80211_addr(IEEE80211_FC1_DIR_TODS, offset + 3177 (u_int)offsetof(struct ieee80211_frame, i_addr2), 3178 lladdr); 3179 b2 = gen_p80211_addr(IEEE80211_FC1_DIR_FROMDS, offset + 3180 (u_int)offsetof(struct ieee80211_frame, i_addr3), 3181 lladdr); 3182 b3 = gen_p80211_addr(IEEE80211_FC1_DIR_DSTODS, offset + 3183 (u_int)offsetof(struct ieee80211_frame_addr4, i_addr4), 3184 lladdr); 3185 b4 = gen_p80211_addr(IEEE80211_FC1_DIR_DSTODS, offset + 3186 (u_int)offsetof(struct ieee80211_frame_addr4, i_addr2), 3187 lladdr); 3188 3189 gen_or(b0, b1); 3190 gen_or(b1, b2); 3191 gen_or(b2, b3); 3192 gen_or(b3, b4); 3193 return (b4); 3194 3195 case Q_DST: 3196 b0 = gen_p80211_addr(IEEE80211_FC1_DIR_NODS, offset + 3197 (u_int)offsetof(struct ieee80211_frame, i_addr1), 3198 lladdr); 3199 b1 = gen_p80211_addr(IEEE80211_FC1_DIR_TODS, offset + 3200 (u_int)offsetof(struct ieee80211_frame, i_addr3), 3201 lladdr); 3202 b2 = gen_p80211_addr(IEEE80211_FC1_DIR_FROMDS, offset + 3203 (u_int)offsetof(struct ieee80211_frame, i_addr1), 3204 lladdr); 3205 b3 = gen_p80211_addr(IEEE80211_FC1_DIR_DSTODS, offset + 3206 (u_int)offsetof(struct ieee80211_frame_addr4, i_addr3), 3207 lladdr); 3208 b4 = gen_p80211_addr(IEEE80211_FC1_DIR_DSTODS, offset + 3209 (u_int)offsetof(struct ieee80211_frame_addr4, i_addr1), 3210 lladdr); 3211 3212 gen_or(b0, b1); 3213 gen_or(b1, b2); 3214 gen_or(b2, b3); 3215 gen_or(b3, b4); 3216 return (b4); 3217 3218 case Q_ADDR1: 3219 return (gen_bcmp(offset + 3220 (u_int)offsetof(struct ieee80211_frame, 3221 i_addr1), IEEE80211_ADDR_LEN, lladdr)); 3222 3223 case Q_ADDR2: 3224 return (gen_bcmp(offset + 3225 (u_int)offsetof(struct ieee80211_frame, 3226 i_addr2), IEEE80211_ADDR_LEN, lladdr)); 3227 3228 case Q_ADDR3: 3229 return (gen_bcmp(offset + 3230 (u_int)offsetof(struct ieee80211_frame, 3231 i_addr3), IEEE80211_ADDR_LEN, lladdr)); 3232 3233 case Q_ADDR4: 3234 return (gen_p80211_addr(IEEE80211_FC1_DIR_DSTODS, offset + 3235 (u_int)offsetof(struct ieee80211_frame_addr4, i_addr4), 3236 lladdr)); 3237 3238 case Q_AND: 3239 b0 = gen_p80211_hostop(lladdr, Q_SRC); 3240 b1 = gen_p80211_hostop(lladdr, Q_DST); 3241 gen_and(b0, b1); 3242 return (b1); 3243 3244 case Q_DEFAULT: 3245 case Q_OR: 3246 b0 = gen_p80211_hostop(lladdr, Q_ADDR1); 3247 b1 = gen_p80211_hostop(lladdr, Q_ADDR2); 3248 b2 = gen_p80211_hostop(lladdr, Q_ADDR3); 3249 b3 = gen_p80211_hostop(lladdr, Q_ADDR4); 3250 gen_or(b0, b1); 3251 gen_or(b1, b2); 3252 gen_or(b2, b3); 3253 return (b3); 3254 3255 default: 3256 bpf_error("direction not supported on linktype 0x%x", 3257 linktype); 3258 } 3259 /* NOTREACHED */ 3260 } 3261 3262 static struct block * 3263 gen_p80211_addr(int fcdir, u_int offset, const u_char *lladdr) 3264 { 3265 struct block *b0, *b1; 3266 3267 b0 = gen_mcmp(offset, BPF_B, (bpf_int32)fcdir, IEEE80211_FC1_DIR_MASK); 3268 b1 = gen_bcmp(offset, IEEE80211_ADDR_LEN, lladdr); 3269 gen_and(b0, b1); 3270 3271 return (b1); 3272 } 3273