1 /* $OpenBSD: gencode.c,v 1.22 2004/05/21 05:40:37 brad 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 #include <netinet/if_arc.h> 36 37 #include <net/if_pflog.h> 38 #include <net/pfvar.h> 39 40 #include <stdlib.h> 41 #include <stddef.h> 42 #include <memory.h> 43 #include <setjmp.h> 44 #include <stdarg.h> 45 46 #include "pcap-int.h" 47 48 #include "ethertype.h" 49 #include "gencode.h" 50 #include "ppp.h" 51 #include <pcap-namedb.h> 52 #ifdef INET6 53 #include <netdb.h> 54 #include <sys/socket.h> 55 #endif /*INET6*/ 56 57 #ifdef HAVE_OS_PROTO_H 58 #include "os-proto.h" 59 #endif 60 61 #define JMP(c) ((c)|BPF_JMP|BPF_K) 62 63 /* Locals */ 64 static jmp_buf top_ctx; 65 static pcap_t *bpf_pcap; 66 67 /* XXX */ 68 #ifdef PCAP_FDDIPAD 69 int pcap_fddipad = PCAP_FDDIPAD; 70 #else 71 int pcap_fddipad; 72 #endif 73 74 /* VARARGS */ 75 __dead void 76 bpf_error(const char *fmt, ...) 77 { 78 va_list ap; 79 80 va_start(ap, fmt); 81 if (bpf_pcap != NULL) 82 (void)vsnprintf(pcap_geterr(bpf_pcap), PCAP_ERRBUF_SIZE, 83 fmt, ap); 84 va_end(ap); 85 longjmp(top_ctx, 1); 86 /* NOTREACHED */ 87 } 88 89 static void init_linktype(int); 90 91 static int alloc_reg(void); 92 static void free_reg(int); 93 94 static struct block *root; 95 96 /* 97 * We divy out chunks of memory rather than call malloc each time so 98 * we don't have to worry about leaking memory. It's probably 99 * not a big deal if all this memory was wasted but it this ever 100 * goes into a library that would probably not be a good idea. 101 */ 102 #define NCHUNKS 16 103 #define CHUNK0SIZE 1024 104 struct chunk { 105 u_int n_left; 106 void *m; 107 }; 108 109 static struct chunk chunks[NCHUNKS]; 110 static int cur_chunk; 111 112 static void *newchunk(u_int); 113 static void freechunks(void); 114 static __inline struct block *new_block(int); 115 static __inline struct slist *new_stmt(int); 116 static struct block *gen_retblk(int); 117 static __inline void syntax(void); 118 119 static void backpatch(struct block *, struct block *); 120 static void merge(struct block *, struct block *); 121 static struct block *gen_cmp(u_int, u_int, bpf_int32); 122 static struct block *gen_mcmp(u_int, u_int, bpf_int32, bpf_u_int32); 123 static struct block *gen_bcmp(u_int, u_int, const u_char *); 124 static struct block *gen_uncond(int); 125 static __inline struct block *gen_true(void); 126 static __inline struct block *gen_false(void); 127 static struct block *gen_linktype(int); 128 static struct block *gen_hostop(bpf_u_int32, bpf_u_int32, int, int, u_int, u_int); 129 #ifdef INET6 130 static struct block *gen_hostop6(struct in6_addr *, struct in6_addr *, int, int, u_int, u_int); 131 #endif 132 static struct block *gen_ahostop(const u_char *, int); 133 static struct block *gen_ehostop(const u_char *, int); 134 static struct block *gen_fhostop(const u_char *, int); 135 static struct block *gen_dnhostop(bpf_u_int32, int, u_int); 136 static struct block *gen_host(bpf_u_int32, bpf_u_int32, int, int); 137 #ifdef INET6 138 static struct block *gen_host6(struct in6_addr *, struct in6_addr *, int, int); 139 #endif 140 #ifndef INET6 141 static struct block *gen_gateway(const u_char *, bpf_u_int32 **, int, int); 142 #endif 143 static struct block *gen_ipfrag(void); 144 static struct block *gen_portatom(int, bpf_int32); 145 #ifdef INET6 146 static struct block *gen_portatom6(int, bpf_int32); 147 #endif 148 struct block *gen_portop(int, int, int); 149 static struct block *gen_port(int, int, int); 150 #ifdef INET6 151 struct block *gen_portop6(int, int, int); 152 static struct block *gen_port6(int, int, int); 153 #endif 154 static int lookup_proto(const char *, int); 155 static struct block *gen_protochain(int, int, int); 156 static struct block *gen_proto(int, int, int); 157 static struct slist *xfer_to_x(struct arth *); 158 static struct slist *xfer_to_a(struct arth *); 159 static struct block *gen_len(int, int); 160 161 static void * 162 newchunk(n) 163 u_int n; 164 { 165 struct chunk *cp; 166 int k, size; 167 168 /* XXX Round to structure boundary. */ 169 n = ALIGN(n); 170 171 cp = &chunks[cur_chunk]; 172 if (n > cp->n_left) { 173 ++cp, k = ++cur_chunk; 174 if (k >= NCHUNKS) 175 bpf_error("out of memory"); 176 size = CHUNK0SIZE << k; 177 cp->m = (void *)malloc(size); 178 if (cp->m == NULL) 179 bpf_error("out of memory"); 180 181 memset((char *)cp->m, 0, size); 182 cp->n_left = size; 183 if (n > size) 184 bpf_error("out of memory"); 185 } 186 cp->n_left -= n; 187 return (void *)((char *)cp->m + cp->n_left); 188 } 189 190 static void 191 freechunks() 192 { 193 int i; 194 195 cur_chunk = 0; 196 for (i = 0; i < NCHUNKS; ++i) 197 if (chunks[i].m != NULL) { 198 free(chunks[i].m); 199 chunks[i].m = NULL; 200 } 201 } 202 203 /* 204 * A strdup whose allocations are freed after code generation is over. 205 */ 206 char * 207 sdup(s) 208 register const char *s; 209 { 210 int n = strlen(s) + 1; 211 char *cp = newchunk(n); 212 213 strlcpy(cp, s, n); 214 return (cp); 215 } 216 217 static __inline struct block * 218 new_block(code) 219 int code; 220 { 221 struct block *p; 222 223 p = (struct block *)newchunk(sizeof(*p)); 224 p->s.code = code; 225 p->head = p; 226 227 return p; 228 } 229 230 static __inline struct slist * 231 new_stmt(code) 232 int code; 233 { 234 struct slist *p; 235 236 p = (struct slist *)newchunk(sizeof(*p)); 237 p->s.code = code; 238 239 return p; 240 } 241 242 static struct block * 243 gen_retblk(v) 244 int v; 245 { 246 struct block *b = new_block(BPF_RET|BPF_K); 247 248 b->s.k = v; 249 return b; 250 } 251 252 static __inline void 253 syntax() 254 { 255 bpf_error("syntax error in filter expression"); 256 } 257 258 static bpf_u_int32 netmask; 259 static int snaplen; 260 int no_optimize; 261 262 int 263 pcap_compile(pcap_t *p, struct bpf_program *program, 264 char *buf, int optimize, bpf_u_int32 mask) 265 { 266 extern int n_errors; 267 int len; 268 269 no_optimize = 0; 270 n_errors = 0; 271 root = NULL; 272 bpf_pcap = p; 273 if (setjmp(top_ctx)) { 274 freechunks(); 275 return (-1); 276 } 277 278 netmask = mask; 279 snaplen = pcap_snapshot(p); 280 281 lex_init(buf ? buf : ""); 282 init_linktype(pcap_datalink(p)); 283 (void)pcap_parse(); 284 285 if (n_errors) 286 syntax(); 287 288 if (root == NULL) 289 root = gen_retblk(snaplen); 290 291 if (optimize && !no_optimize) { 292 bpf_optimize(&root); 293 if (root == NULL || 294 (root->s.code == (BPF_RET|BPF_K) && root->s.k == 0)) 295 bpf_error("expression rejects all packets"); 296 } 297 program->bf_insns = icode_to_fcode(root, &len); 298 program->bf_len = len; 299 300 freechunks(); 301 return (0); 302 } 303 304 /* 305 * entry point for using the compiler with no pcap open 306 * pass in all the stuff that is needed explicitly instead. 307 */ 308 int 309 pcap_compile_nopcap(int snaplen_arg, int linktype_arg, 310 struct bpf_program *program, 311 char *buf, int optimize, bpf_u_int32 mask) 312 { 313 extern int n_errors; 314 int len; 315 316 n_errors = 0; 317 root = NULL; 318 bpf_pcap = NULL; 319 if (setjmp(top_ctx)) { 320 freechunks(); 321 return (-1); 322 } 323 324 netmask = mask; 325 326 /* XXX needed? I don't grok the use of globals here. */ 327 snaplen = snaplen_arg; 328 329 lex_init(buf ? buf : ""); 330 init_linktype(linktype_arg); 331 (void)pcap_parse(); 332 333 if (n_errors) 334 syntax(); 335 336 if (root == NULL) 337 root = gen_retblk(snaplen_arg); 338 339 if (optimize) { 340 bpf_optimize(&root); 341 if (root == NULL || 342 (root->s.code == (BPF_RET|BPF_K) && root->s.k == 0)) 343 bpf_error("expression rejects all packets"); 344 } 345 program->bf_insns = icode_to_fcode(root, &len); 346 program->bf_len = len; 347 348 freechunks(); 349 return (0); 350 } 351 352 /* 353 * Clean up a "struct bpf_program" by freeing all the memory allocated 354 * in it. 355 */ 356 void 357 pcap_freecode(struct bpf_program *program) 358 { 359 program->bf_len = 0; 360 if (program->bf_insns != NULL) { 361 free((char *)program->bf_insns); 362 program->bf_insns = NULL; 363 } 364 } 365 366 /* 367 * Backpatch the blocks in 'list' to 'target'. The 'sense' field indicates 368 * which of the jt and jf fields has been resolved and which is a pointer 369 * back to another unresolved block (or nil). At least one of the fields 370 * in each block is already resolved. 371 */ 372 static void 373 backpatch(list, target) 374 struct block *list, *target; 375 { 376 struct block *next; 377 378 while (list) { 379 if (!list->sense) { 380 next = JT(list); 381 JT(list) = target; 382 } else { 383 next = JF(list); 384 JF(list) = target; 385 } 386 list = next; 387 } 388 } 389 390 /* 391 * Merge the lists in b0 and b1, using the 'sense' field to indicate 392 * which of jt and jf is the link. 393 */ 394 static void 395 merge(b0, b1) 396 struct block *b0, *b1; 397 { 398 register struct block **p = &b0; 399 400 /* Find end of list. */ 401 while (*p) 402 p = !((*p)->sense) ? &JT(*p) : &JF(*p); 403 404 /* Concatenate the lists. */ 405 *p = b1; 406 } 407 408 void 409 finish_parse(p) 410 struct block *p; 411 { 412 backpatch(p, gen_retblk(snaplen)); 413 p->sense = !p->sense; 414 backpatch(p, gen_retblk(0)); 415 root = p->head; 416 } 417 418 void 419 gen_and(b0, b1) 420 struct block *b0, *b1; 421 { 422 backpatch(b0, b1->head); 423 b0->sense = !b0->sense; 424 b1->sense = !b1->sense; 425 merge(b1, b0); 426 b1->sense = !b1->sense; 427 b1->head = b0->head; 428 } 429 430 void 431 gen_or(b0, b1) 432 struct block *b0, *b1; 433 { 434 b0->sense = !b0->sense; 435 backpatch(b0, b1->head); 436 b0->sense = !b0->sense; 437 merge(b1, b0); 438 b1->head = b0->head; 439 } 440 441 void 442 gen_not(b) 443 struct block *b; 444 { 445 b->sense = !b->sense; 446 } 447 448 static struct block * 449 gen_cmp(offset, size, v) 450 u_int offset, size; 451 bpf_int32 v; 452 { 453 struct slist *s; 454 struct block *b; 455 456 s = new_stmt(BPF_LD|BPF_ABS|size); 457 s->s.k = offset; 458 459 b = new_block(JMP(BPF_JEQ)); 460 b->stmts = s; 461 b->s.k = v; 462 463 return b; 464 } 465 466 static struct block * 467 gen_mcmp(offset, size, v, mask) 468 u_int offset, size; 469 bpf_int32 v; 470 bpf_u_int32 mask; 471 { 472 struct block *b = gen_cmp(offset, size, v); 473 struct slist *s; 474 475 if (mask != 0xffffffff) { 476 s = new_stmt(BPF_ALU|BPF_AND|BPF_K); 477 s->s.k = mask; 478 b->stmts->next = s; 479 } 480 return b; 481 } 482 483 static struct block * 484 gen_bcmp(offset, size, v) 485 register u_int offset, size; 486 register const u_char *v; 487 { 488 register struct block *b, *tmp; 489 490 b = NULL; 491 while (size >= 4) { 492 register const u_char *p = &v[size - 4]; 493 bpf_int32 w = ((bpf_int32)p[0] << 24) | 494 ((bpf_int32)p[1] << 16) | ((bpf_int32)p[2] << 8) | p[3]; 495 496 tmp = gen_cmp(offset + size - 4, BPF_W, w); 497 if (b != NULL) 498 gen_and(b, tmp); 499 b = tmp; 500 size -= 4; 501 } 502 while (size >= 2) { 503 register const u_char *p = &v[size - 2]; 504 bpf_int32 w = ((bpf_int32)p[0] << 8) | p[1]; 505 506 tmp = gen_cmp(offset + size - 2, BPF_H, w); 507 if (b != NULL) 508 gen_and(b, tmp); 509 b = tmp; 510 size -= 2; 511 } 512 if (size > 0) { 513 tmp = gen_cmp(offset, BPF_B, (bpf_int32)v[0]); 514 if (b != NULL) 515 gen_and(b, tmp); 516 b = tmp; 517 } 518 return b; 519 } 520 521 /* 522 * Various code constructs need to know the layout of the data link 523 * layer. These variables give the necessary offsets. off_linktype 524 * is set to -1 for no encapsulation, in which case, IP is assumed. 525 */ 526 static u_int off_linktype; 527 static u_int off_nl; 528 static int linktype; 529 530 static void 531 init_linktype(type) 532 int type; 533 { 534 linktype = type; 535 536 switch (type) { 537 538 case DLT_ARCNET: 539 off_linktype = 2; 540 off_nl = 6; /* XXX in reality, variable! */ 541 return; 542 543 case DLT_EN10MB: 544 off_linktype = 12; 545 off_nl = 14; 546 return; 547 548 case DLT_SLIP: 549 /* 550 * SLIP doesn't have a link level type. The 16 byte 551 * header is hacked into our SLIP driver. 552 */ 553 off_linktype = -1; 554 off_nl = 16; 555 return; 556 557 case DLT_SLIP_BSDOS: 558 /* XXX this may be the same as the DLT_PPP_BSDOS case */ 559 off_linktype = -1; 560 /* XXX end */ 561 off_nl = 24; 562 return; 563 564 case DLT_NULL: 565 off_linktype = 0; 566 off_nl = 4; 567 return; 568 569 case DLT_PPP: 570 off_linktype = 2; 571 off_nl = 4; 572 return; 573 574 case DLT_PPP_ETHER: 575 /* 576 * This does not include the Ethernet header, and 577 * only covers session state. 578 */ 579 off_linktype = 6; 580 off_nl = 8; 581 return; 582 583 case DLT_PPP_BSDOS: 584 off_linktype = 5; 585 off_nl = 24; 586 return; 587 588 case DLT_FDDI: 589 /* 590 * FDDI doesn't really have a link-level type field. 591 * We assume that SSAP = SNAP is being used and pick 592 * out the encapsulated Ethernet type. 593 */ 594 off_linktype = 19; 595 #ifdef PCAP_FDDIPAD 596 off_linktype += pcap_fddipad; 597 #endif 598 off_nl = 21; 599 #ifdef PCAP_FDDIPAD 600 off_nl += pcap_fddipad; 601 #endif 602 return; 603 604 case DLT_IEEE802: 605 off_linktype = 20; 606 off_nl = 22; 607 return; 608 609 case DLT_IEEE802_11: 610 off_linktype = 30; /* XXX variable */ 611 off_nl = 32; 612 return; 613 614 case DLT_ATM_RFC1483: 615 /* 616 * assume routed, non-ISO PDUs 617 * (i.e., LLC = 0xAA-AA-03, OUT = 0x00-00-00) 618 */ 619 off_linktype = 6; 620 off_nl = 8; 621 return; 622 623 case DLT_LOOP: 624 off_linktype = -1; 625 off_nl = 4; 626 return; 627 628 case DLT_ENC: 629 off_linktype = -1; 630 off_nl = 12; 631 return; 632 633 case DLT_OLD_PFLOG: 634 off_linktype = 0; 635 off_nl = 28; 636 return; 637 638 case DLT_PFLOG: 639 off_linktype = 0; 640 /* XXX read from header? */ 641 off_nl = PFLOG_HDRLEN; 642 return; 643 644 case DLT_PFSYNC: 645 off_linktype = -1; 646 off_nl = 4; 647 return; 648 649 case DLT_RAW: 650 off_linktype = -1; 651 off_nl = 0; 652 return; 653 } 654 bpf_error("unknown data link type 0x%x", linktype); 655 /* NOTREACHED */ 656 } 657 658 static struct block * 659 gen_uncond(rsense) 660 int rsense; 661 { 662 struct block *b; 663 struct slist *s; 664 665 s = new_stmt(BPF_LD|BPF_IMM); 666 s->s.k = !rsense; 667 b = new_block(JMP(BPF_JEQ)); 668 b->stmts = s; 669 670 return b; 671 } 672 673 static __inline struct block * 674 gen_true() 675 { 676 return gen_uncond(1); 677 } 678 679 static __inline struct block * 680 gen_false() 681 { 682 return gen_uncond(0); 683 } 684 685 static struct block * 686 gen_linktype(proto) 687 register int proto; 688 { 689 struct block *b0, *b1; 690 691 /* If we're not using encapsulation and checking for IP, we're done */ 692 if (off_linktype == -1 && proto == ETHERTYPE_IP) 693 return gen_true(); 694 #ifdef INET6 695 /* this isn't the right thing to do, but sometimes necessary */ 696 if (off_linktype == -1 && proto == ETHERTYPE_IPV6) 697 return gen_true(); 698 #endif 699 700 switch (linktype) { 701 702 case DLT_SLIP: 703 return gen_false(); 704 705 case DLT_PPP: 706 case DLT_PPP_ETHER: 707 if (proto == ETHERTYPE_IP) 708 proto = PPP_IP; /* XXX was 0x21 */ 709 #ifdef INET6 710 else if (proto == ETHERTYPE_IPV6) 711 proto = PPP_IPV6; 712 #endif 713 break; 714 715 case DLT_PPP_BSDOS: 716 switch (proto) { 717 718 case ETHERTYPE_IP: 719 b0 = gen_cmp(off_linktype, BPF_H, PPP_IP); 720 b1 = gen_cmp(off_linktype, BPF_H, PPP_VJC); 721 gen_or(b0, b1); 722 b0 = gen_cmp(off_linktype, BPF_H, PPP_VJNC); 723 gen_or(b1, b0); 724 return b0; 725 726 #ifdef INET6 727 case ETHERTYPE_IPV6: 728 proto = PPP_IPV6; 729 /* more to go? */ 730 break; 731 #endif /* INET6 */ 732 733 case ETHERTYPE_DN: 734 proto = PPP_DECNET; 735 break; 736 737 case ETHERTYPE_ATALK: 738 proto = PPP_APPLE; 739 break; 740 741 case ETHERTYPE_NS: 742 proto = PPP_NS; 743 break; 744 } 745 break; 746 747 case DLT_LOOP: 748 case DLT_ENC: 749 case DLT_NULL: 750 /* XXX */ 751 if (proto == ETHERTYPE_IP) 752 return (gen_cmp(0, BPF_W, (bpf_int32)htonl(AF_INET))); 753 #ifdef INET6 754 else if (proto == ETHERTYPE_IPV6) 755 return (gen_cmp(0, BPF_W, (bpf_int32)htonl(AF_INET6))); 756 #endif /* INET6 */ 757 else 758 return gen_false(); 759 break; 760 case DLT_OLD_PFLOG: 761 if (proto == ETHERTYPE_IP) 762 return (gen_cmp(0, BPF_W, (bpf_int32)AF_INET)); 763 #ifdef INET6 764 else if (proto == ETHERTYPE_IPV6) 765 return (gen_cmp(0, BPF_W, (bpf_int32)AF_INET6)); 766 #endif /* INET6 */ 767 else 768 return gen_false(); 769 break; 770 771 case DLT_PFLOG: 772 if (proto == ETHERTYPE_IP) 773 return (gen_cmp(offsetof(struct pfloghdr, af), BPF_B, 774 (bpf_int32)AF_INET)); 775 #ifdef INET6 776 else if (proto == ETHERTYPE_IPV6) 777 return (gen_cmp(offsetof(struct pfloghdr, af), BPF_B, 778 (bpf_int32)AF_INET6)); 779 #endif /* INET6 */ 780 else 781 return gen_false(); 782 break; 783 784 case DLT_ARCNET: 785 /* 786 * XXX should we check for first fragment if the protocol 787 * uses PHDS? 788 */ 789 switch(proto) { 790 default: 791 return gen_false(); 792 #ifdef INET6 793 case ETHERTYPE_IPV6: 794 return(gen_cmp(2, BPF_B, 795 (bpf_int32)htonl(ARCTYPE_INET6))); 796 #endif /* INET6 */ 797 case ETHERTYPE_IP: 798 b0 = gen_cmp(2, BPF_B, (bpf_int32)htonl(ARCTYPE_IP)); 799 b1 = gen_cmp(2, BPF_B, 800 (bpf_int32)htonl(ARCTYPE_IP_OLD)); 801 gen_or(b0, b1); 802 return(b1); 803 case ETHERTYPE_ARP: 804 b0 = gen_cmp(2, BPF_B, (bpf_int32)htonl(ARCTYPE_ARP)); 805 b1 = gen_cmp(2, BPF_B, 806 (bpf_int32)htonl(ARCTYPE_ARP_OLD)); 807 gen_or(b0, b1); 808 return(b1); 809 case ETHERTYPE_REVARP: 810 return(gen_cmp(2, BPF_B, 811 (bpf_int32)htonl(ARCTYPE_REVARP))); 812 case ETHERTYPE_ATALK: 813 return(gen_cmp(2, BPF_B, 814 (bpf_int32)htonl(ARCTYPE_ATALK))); 815 } 816 } 817 return gen_cmp(off_linktype, BPF_H, (bpf_int32)proto); 818 } 819 820 static struct block * 821 gen_hostop(addr, mask, dir, proto, src_off, dst_off) 822 bpf_u_int32 addr; 823 bpf_u_int32 mask; 824 int dir, proto; 825 u_int src_off, dst_off; 826 { 827 struct block *b0, *b1; 828 u_int offset; 829 830 switch (dir) { 831 832 case Q_SRC: 833 offset = src_off; 834 break; 835 836 case Q_DST: 837 offset = dst_off; 838 break; 839 840 case Q_AND: 841 b0 = gen_hostop(addr, mask, Q_SRC, proto, src_off, dst_off); 842 b1 = gen_hostop(addr, mask, Q_DST, proto, src_off, dst_off); 843 gen_and(b0, b1); 844 return b1; 845 846 case Q_OR: 847 case Q_DEFAULT: 848 b0 = gen_hostop(addr, mask, Q_SRC, proto, src_off, dst_off); 849 b1 = gen_hostop(addr, mask, Q_DST, proto, src_off, dst_off); 850 gen_or(b0, b1); 851 return b1; 852 853 default: 854 abort(); 855 } 856 b0 = gen_linktype(proto); 857 b1 = gen_mcmp(offset, BPF_W, (bpf_int32)addr, mask); 858 gen_and(b0, b1); 859 return b1; 860 } 861 862 #ifdef INET6 863 static struct block * 864 gen_hostop6(addr, mask, dir, proto, src_off, dst_off) 865 struct in6_addr *addr; 866 struct in6_addr *mask; 867 int dir, proto; 868 u_int src_off, dst_off; 869 { 870 struct block *b0, *b1; 871 u_int offset; 872 u_int32_t *a, *m; 873 874 switch (dir) { 875 876 case Q_SRC: 877 offset = src_off; 878 break; 879 880 case Q_DST: 881 offset = dst_off; 882 break; 883 884 case Q_AND: 885 b0 = gen_hostop6(addr, mask, Q_SRC, proto, src_off, dst_off); 886 b1 = gen_hostop6(addr, mask, Q_DST, proto, src_off, dst_off); 887 gen_and(b0, b1); 888 return b1; 889 890 case Q_OR: 891 case Q_DEFAULT: 892 b0 = gen_hostop6(addr, mask, Q_SRC, proto, src_off, dst_off); 893 b1 = gen_hostop6(addr, mask, Q_DST, proto, src_off, dst_off); 894 gen_or(b0, b1); 895 return b1; 896 897 default: 898 abort(); 899 } 900 /* this order is important */ 901 a = (u_int32_t *)addr; 902 m = (u_int32_t *)mask; 903 b1 = gen_mcmp(offset + 12, BPF_W, ntohl(a[3]), ntohl(m[3])); 904 b0 = gen_mcmp(offset + 8, BPF_W, ntohl(a[2]), ntohl(m[2])); 905 gen_and(b0, b1); 906 b0 = gen_mcmp(offset + 4, BPF_W, ntohl(a[1]), ntohl(m[1])); 907 gen_and(b0, b1); 908 b0 = gen_mcmp(offset + 0, BPF_W, ntohl(a[0]), ntohl(m[0])); 909 gen_and(b0, b1); 910 b0 = gen_linktype(proto); 911 gen_and(b0, b1); 912 return b1; 913 } 914 #endif /*INET6*/ 915 916 static struct block * 917 gen_ehostop(eaddr, dir) 918 register const u_char *eaddr; 919 register int dir; 920 { 921 struct block *b0, *b1; 922 923 switch (dir) { 924 case Q_SRC: 925 return gen_bcmp(6, 6, eaddr); 926 927 case Q_DST: 928 return gen_bcmp(0, 6, eaddr); 929 930 case Q_AND: 931 b0 = gen_ehostop(eaddr, Q_SRC); 932 b1 = gen_ehostop(eaddr, Q_DST); 933 gen_and(b0, b1); 934 return b1; 935 936 case Q_DEFAULT: 937 case Q_OR: 938 b0 = gen_ehostop(eaddr, Q_SRC); 939 b1 = gen_ehostop(eaddr, Q_DST); 940 gen_or(b0, b1); 941 return b1; 942 } 943 abort(); 944 /* NOTREACHED */ 945 } 946 947 /* 948 * Like gen_ehostop, but for DLT_FDDI 949 */ 950 static struct block * 951 gen_fhostop(eaddr, dir) 952 register const u_char *eaddr; 953 register int dir; 954 { 955 struct block *b0, *b1; 956 957 switch (dir) { 958 case Q_SRC: 959 #ifdef PCAP_FDDIPAD 960 return gen_bcmp(6 + 1 + pcap_fddipad, 6, eaddr); 961 #else 962 return gen_bcmp(6 + 1, 6, eaddr); 963 #endif 964 965 case Q_DST: 966 #ifdef PCAP_FDDIPAD 967 return gen_bcmp(0 + 1 + pcap_fddipad, 6, eaddr); 968 #else 969 return gen_bcmp(0 + 1, 6, eaddr); 970 #endif 971 972 case Q_AND: 973 b0 = gen_fhostop(eaddr, Q_SRC); 974 b1 = gen_fhostop(eaddr, Q_DST); 975 gen_and(b0, b1); 976 return b1; 977 978 case Q_DEFAULT: 979 case Q_OR: 980 b0 = gen_fhostop(eaddr, Q_SRC); 981 b1 = gen_fhostop(eaddr, Q_DST); 982 gen_or(b0, b1); 983 return b1; 984 } 985 abort(); 986 /* NOTREACHED */ 987 } 988 989 /* 990 * This is quite tricky because there may be pad bytes in front of the 991 * DECNET header, and then there are two possible data packet formats that 992 * carry both src and dst addresses, plus 5 packet types in a format that 993 * carries only the src node, plus 2 types that use a different format and 994 * also carry just the src node. 995 * 996 * Yuck. 997 * 998 * Instead of doing those all right, we just look for data packets with 999 * 0 or 1 bytes of padding. If you want to look at other packets, that 1000 * will require a lot more hacking. 1001 * 1002 * To add support for filtering on DECNET "areas" (network numbers) 1003 * one would want to add a "mask" argument to this routine. That would 1004 * make the filter even more inefficient, although one could be clever 1005 * and not generate masking instructions if the mask is 0xFFFF. 1006 */ 1007 static struct block * 1008 gen_dnhostop(addr, dir, base_off) 1009 bpf_u_int32 addr; 1010 int dir; 1011 u_int base_off; 1012 { 1013 struct block *b0, *b1, *b2, *tmp; 1014 u_int offset_lh; /* offset if long header is received */ 1015 u_int offset_sh; /* offset if short header is received */ 1016 1017 switch (dir) { 1018 1019 case Q_DST: 1020 offset_sh = 1; /* follows flags */ 1021 offset_lh = 7; /* flgs,darea,dsubarea,HIORD */ 1022 break; 1023 1024 case Q_SRC: 1025 offset_sh = 3; /* follows flags, dstnode */ 1026 offset_lh = 15; /* flgs,darea,dsubarea,did,sarea,ssub,HIORD */ 1027 break; 1028 1029 case Q_AND: 1030 /* Inefficient because we do our Calvinball dance twice */ 1031 b0 = gen_dnhostop(addr, Q_SRC, base_off); 1032 b1 = gen_dnhostop(addr, Q_DST, base_off); 1033 gen_and(b0, b1); 1034 return b1; 1035 1036 case Q_OR: 1037 case Q_DEFAULT: 1038 /* Inefficient because we do our Calvinball dance twice */ 1039 b0 = gen_dnhostop(addr, Q_SRC, base_off); 1040 b1 = gen_dnhostop(addr, Q_DST, base_off); 1041 gen_or(b0, b1); 1042 return b1; 1043 1044 default: 1045 abort(); 1046 } 1047 b0 = gen_linktype(ETHERTYPE_DN); 1048 /* Check for pad = 1, long header case */ 1049 tmp = gen_mcmp(base_off + 2, BPF_H, 1050 (bpf_int32)ntohs(0x0681), (bpf_int32)ntohs(0x07FF)); 1051 b1 = gen_cmp(base_off + 2 + 1 + offset_lh, 1052 BPF_H, (bpf_int32)ntohs(addr)); 1053 gen_and(tmp, b1); 1054 /* Check for pad = 0, long header case */ 1055 tmp = gen_mcmp(base_off + 2, BPF_B, (bpf_int32)0x06, (bpf_int32)0x7); 1056 b2 = gen_cmp(base_off + 2 + offset_lh, BPF_H, (bpf_int32)ntohs(addr)); 1057 gen_and(tmp, b2); 1058 gen_or(b2, b1); 1059 /* Check for pad = 1, short header case */ 1060 tmp = gen_mcmp(base_off + 2, BPF_H, 1061 (bpf_int32)ntohs(0x0281), (bpf_int32)ntohs(0x07FF)); 1062 b2 = gen_cmp(base_off + 2 + 1 + offset_sh, 1063 BPF_H, (bpf_int32)ntohs(addr)); 1064 gen_and(tmp, b2); 1065 gen_or(b2, b1); 1066 /* Check for pad = 0, short header case */ 1067 tmp = gen_mcmp(base_off + 2, BPF_B, (bpf_int32)0x02, (bpf_int32)0x7); 1068 b2 = gen_cmp(base_off + 2 + offset_sh, BPF_H, (bpf_int32)ntohs(addr)); 1069 gen_and(tmp, b2); 1070 gen_or(b2, b1); 1071 1072 /* Combine with test for linktype */ 1073 gen_and(b0, b1); 1074 return b1; 1075 } 1076 1077 static struct block * 1078 gen_host(addr, mask, proto, dir) 1079 bpf_u_int32 addr; 1080 bpf_u_int32 mask; 1081 int proto; 1082 int dir; 1083 { 1084 struct block *b0, *b1; 1085 1086 switch (proto) { 1087 1088 case Q_DEFAULT: 1089 b0 = gen_host(addr, mask, Q_IP, dir); 1090 b1 = gen_host(addr, mask, Q_ARP, dir); 1091 gen_or(b0, b1); 1092 b0 = gen_host(addr, mask, Q_RARP, dir); 1093 gen_or(b1, b0); 1094 return b0; 1095 1096 case Q_IP: 1097 return gen_hostop(addr, mask, dir, ETHERTYPE_IP, 1098 off_nl + 12, off_nl + 16); 1099 1100 case Q_RARP: 1101 return gen_hostop(addr, mask, dir, ETHERTYPE_REVARP, 1102 off_nl + 14, off_nl + 24); 1103 1104 case Q_ARP: 1105 return gen_hostop(addr, mask, dir, ETHERTYPE_ARP, 1106 off_nl + 14, off_nl + 24); 1107 1108 case Q_TCP: 1109 bpf_error("'tcp' modifier applied to host"); 1110 1111 case Q_UDP: 1112 bpf_error("'udp' modifier applied to host"); 1113 1114 case Q_ICMP: 1115 bpf_error("'icmp' modifier applied to host"); 1116 1117 case Q_IGMP: 1118 bpf_error("'igmp' modifier applied to host"); 1119 1120 case Q_IGRP: 1121 bpf_error("'igrp' modifier applied to host"); 1122 1123 case Q_PIM: 1124 bpf_error("'pim' modifier applied to host"); 1125 1126 case Q_ATALK: 1127 bpf_error("ATALK host filtering not implemented"); 1128 1129 case Q_DECNET: 1130 return gen_dnhostop(addr, dir, off_nl); 1131 1132 case Q_SCA: 1133 bpf_error("SCA host filtering not implemented"); 1134 1135 case Q_LAT: 1136 bpf_error("LAT host filtering not implemented"); 1137 1138 case Q_MOPDL: 1139 bpf_error("MOPDL host filtering not implemented"); 1140 1141 case Q_MOPRC: 1142 bpf_error("MOPRC host filtering not implemented"); 1143 1144 #ifdef INET6 1145 case Q_IPV6: 1146 bpf_error("'ip6' modifier applied to ip host"); 1147 1148 case Q_ICMPV6: 1149 bpf_error("'icmp6' modifier applied to host"); 1150 #endif /* INET6 */ 1151 1152 case Q_AH: 1153 bpf_error("'ah' modifier applied to host"); 1154 1155 case Q_ESP: 1156 bpf_error("'esp' modifier applied to host"); 1157 1158 default: 1159 abort(); 1160 } 1161 /* NOTREACHED */ 1162 } 1163 1164 #ifdef INET6 1165 static struct block * 1166 gen_host6(addr, mask, proto, dir) 1167 struct in6_addr *addr; 1168 struct in6_addr *mask; 1169 int proto; 1170 int dir; 1171 { 1172 switch (proto) { 1173 1174 case Q_DEFAULT: 1175 return gen_host6(addr, mask, Q_IPV6, dir); 1176 1177 case Q_IP: 1178 bpf_error("'ip' modifier applied to ip6 host"); 1179 1180 case Q_RARP: 1181 bpf_error("'rarp' modifier applied to ip6 host"); 1182 1183 case Q_ARP: 1184 bpf_error("'arp' modifier applied to ip6 host"); 1185 1186 case Q_TCP: 1187 bpf_error("'tcp' modifier applied to host"); 1188 1189 case Q_UDP: 1190 bpf_error("'udp' modifier applied to host"); 1191 1192 case Q_ICMP: 1193 bpf_error("'icmp' modifier applied to host"); 1194 1195 case Q_IGMP: 1196 bpf_error("'igmp' modifier applied to host"); 1197 1198 case Q_IGRP: 1199 bpf_error("'igrp' modifier applied to host"); 1200 1201 case Q_PIM: 1202 bpf_error("'pim' modifier applied to host"); 1203 1204 case Q_ATALK: 1205 bpf_error("ATALK host filtering not implemented"); 1206 1207 case Q_DECNET: 1208 bpf_error("'decnet' modifier applied to ip6 host"); 1209 1210 case Q_SCA: 1211 bpf_error("SCA host filtering not implemented"); 1212 1213 case Q_LAT: 1214 bpf_error("LAT host filtering not implemented"); 1215 1216 case Q_MOPDL: 1217 bpf_error("MOPDL host filtering not implemented"); 1218 1219 case Q_MOPRC: 1220 bpf_error("MOPRC host filtering not implemented"); 1221 1222 case Q_IPV6: 1223 return gen_hostop6(addr, mask, dir, ETHERTYPE_IPV6, 1224 off_nl + 8, off_nl + 24); 1225 1226 case Q_ICMPV6: 1227 bpf_error("'icmp6' modifier applied to host"); 1228 1229 case Q_AH: 1230 bpf_error("'ah' modifier applied to host"); 1231 1232 case Q_ESP: 1233 bpf_error("'esp' modifier applied to host"); 1234 1235 default: 1236 abort(); 1237 } 1238 /* NOTREACHED */ 1239 } 1240 #endif /*INET6*/ 1241 1242 #ifndef INET6 1243 static struct block * 1244 gen_gateway(eaddr, alist, proto, dir) 1245 const u_char *eaddr; 1246 bpf_u_int32 **alist; 1247 int proto; 1248 int dir; 1249 { 1250 struct block *b0, *b1, *tmp; 1251 1252 if (dir != 0) 1253 bpf_error("direction applied to 'gateway'"); 1254 1255 switch (proto) { 1256 case Q_DEFAULT: 1257 case Q_IP: 1258 case Q_ARP: 1259 case Q_RARP: 1260 if (linktype == DLT_EN10MB) 1261 b0 = gen_ehostop(eaddr, Q_OR); 1262 else if (linktype == DLT_FDDI) 1263 b0 = gen_fhostop(eaddr, Q_OR); 1264 else 1265 bpf_error( 1266 "'gateway' supported only on ethernet or FDDI"); 1267 1268 b1 = gen_host(**alist++, 0xffffffff, proto, Q_OR); 1269 while (*alist) { 1270 tmp = gen_host(**alist++, 0xffffffff, proto, Q_OR); 1271 gen_or(b1, tmp); 1272 b1 = tmp; 1273 } 1274 gen_not(b1); 1275 gen_and(b0, b1); 1276 return b1; 1277 } 1278 bpf_error("illegal modifier of 'gateway'"); 1279 /* NOTREACHED */ 1280 } 1281 #endif /*INET6*/ 1282 1283 struct block * 1284 gen_proto_abbrev(proto) 1285 int proto; 1286 { 1287 struct block *b0 = NULL, *b1; 1288 1289 switch (proto) { 1290 1291 case Q_TCP: 1292 b1 = gen_proto(IPPROTO_TCP, Q_IP, Q_DEFAULT); 1293 #ifdef INET6 1294 b0 = gen_proto(IPPROTO_TCP, Q_IPV6, Q_DEFAULT); 1295 gen_or(b0, b1); 1296 #endif 1297 break; 1298 1299 case Q_UDP: 1300 b1 = gen_proto(IPPROTO_UDP, Q_IP, Q_DEFAULT); 1301 #ifdef INET6 1302 b0 = gen_proto(IPPROTO_UDP, Q_IPV6, Q_DEFAULT); 1303 gen_or(b0, b1); 1304 #endif 1305 break; 1306 1307 case Q_ICMP: 1308 b1 = gen_proto(IPPROTO_ICMP, Q_IP, Q_DEFAULT); 1309 break; 1310 1311 #ifndef IPPROTO_IGMP 1312 #define IPPROTO_IGMP 2 1313 #endif 1314 1315 case Q_IGMP: 1316 b1 = gen_proto(IPPROTO_IGMP, Q_IP, Q_DEFAULT); 1317 break; 1318 1319 #ifndef IPPROTO_IGRP 1320 #define IPPROTO_IGRP 9 1321 #endif 1322 case Q_IGRP: 1323 b1 = gen_proto(IPPROTO_IGRP, Q_IP, Q_DEFAULT); 1324 break; 1325 1326 #ifndef IPPROTO_PIM 1327 #define IPPROTO_PIM 103 1328 #endif 1329 1330 case Q_PIM: 1331 b1 = gen_proto(IPPROTO_PIM, Q_IP, Q_DEFAULT); 1332 #ifdef INET6 1333 b0 = gen_proto(IPPROTO_PIM, Q_IPV6, Q_DEFAULT); 1334 gen_or(b0, b1); 1335 #endif 1336 break; 1337 1338 case Q_IP: 1339 b1 = gen_linktype(ETHERTYPE_IP); 1340 break; 1341 1342 case Q_ARP: 1343 b1 = gen_linktype(ETHERTYPE_ARP); 1344 break; 1345 1346 case Q_RARP: 1347 b1 = gen_linktype(ETHERTYPE_REVARP); 1348 break; 1349 1350 case Q_LINK: 1351 bpf_error("link layer applied in wrong context"); 1352 1353 case Q_ATALK: 1354 b1 = gen_linktype(ETHERTYPE_ATALK); 1355 break; 1356 1357 case Q_DECNET: 1358 b1 = gen_linktype(ETHERTYPE_DN); 1359 break; 1360 1361 case Q_SCA: 1362 b1 = gen_linktype(ETHERTYPE_SCA); 1363 break; 1364 1365 case Q_LAT: 1366 b1 = gen_linktype(ETHERTYPE_LAT); 1367 break; 1368 1369 case Q_MOPDL: 1370 b1 = gen_linktype(ETHERTYPE_MOPDL); 1371 break; 1372 1373 case Q_MOPRC: 1374 b1 = gen_linktype(ETHERTYPE_MOPRC); 1375 break; 1376 1377 #ifdef INET6 1378 case Q_IPV6: 1379 b1 = gen_linktype(ETHERTYPE_IPV6); 1380 break; 1381 1382 #ifndef IPPROTO_ICMPV6 1383 #define IPPROTO_ICMPV6 58 1384 #endif 1385 case Q_ICMPV6: 1386 b1 = gen_proto(IPPROTO_ICMPV6, Q_IPV6, Q_DEFAULT); 1387 break; 1388 #endif /* INET6 */ 1389 1390 #ifndef IPPROTO_AH 1391 #define IPPROTO_AH 51 1392 #endif 1393 case Q_AH: 1394 b1 = gen_proto(IPPROTO_AH, Q_IP, Q_DEFAULT); 1395 #ifdef INET6 1396 b0 = gen_proto(IPPROTO_AH, Q_IPV6, Q_DEFAULT); 1397 gen_or(b0, b1); 1398 #endif 1399 break; 1400 1401 #ifndef IPPROTO_ESP 1402 #define IPPROTO_ESP 50 1403 #endif 1404 case Q_ESP: 1405 b1 = gen_proto(IPPROTO_ESP, Q_IP, Q_DEFAULT); 1406 #ifdef INET6 1407 b0 = gen_proto(IPPROTO_ESP, Q_IPV6, Q_DEFAULT); 1408 gen_or(b0, b1); 1409 #endif 1410 break; 1411 1412 default: 1413 abort(); 1414 } 1415 return b1; 1416 } 1417 1418 static struct block * 1419 gen_ipfrag() 1420 { 1421 struct slist *s; 1422 struct block *b; 1423 1424 /* not ip frag */ 1425 s = new_stmt(BPF_LD|BPF_H|BPF_ABS); 1426 s->s.k = off_nl + 6; 1427 b = new_block(JMP(BPF_JSET)); 1428 b->s.k = 0x1fff; 1429 b->stmts = s; 1430 gen_not(b); 1431 1432 return b; 1433 } 1434 1435 static struct block * 1436 gen_portatom(off, v) 1437 int off; 1438 bpf_int32 v; 1439 { 1440 struct slist *s; 1441 struct block *b; 1442 1443 s = new_stmt(BPF_LDX|BPF_MSH|BPF_B); 1444 s->s.k = off_nl; 1445 1446 s->next = new_stmt(BPF_LD|BPF_IND|BPF_H); 1447 s->next->s.k = off_nl + off; 1448 1449 b = new_block(JMP(BPF_JEQ)); 1450 b->stmts = s; 1451 b->s.k = v; 1452 1453 return b; 1454 } 1455 1456 #ifdef INET6 1457 static struct block * 1458 gen_portatom6(off, v) 1459 int off; 1460 bpf_int32 v; 1461 { 1462 return gen_cmp(off_nl + 40 + off, BPF_H, v); 1463 } 1464 #endif/*INET6*/ 1465 1466 struct block * 1467 gen_portop(port, proto, dir) 1468 int port, proto, dir; 1469 { 1470 struct block *b0, *b1, *tmp; 1471 1472 /* ip proto 'proto' */ 1473 tmp = gen_cmp(off_nl + 9, BPF_B, (bpf_int32)proto); 1474 b0 = gen_ipfrag(); 1475 gen_and(tmp, b0); 1476 1477 switch (dir) { 1478 case Q_SRC: 1479 b1 = gen_portatom(0, (bpf_int32)port); 1480 break; 1481 1482 case Q_DST: 1483 b1 = gen_portatom(2, (bpf_int32)port); 1484 break; 1485 1486 case Q_OR: 1487 case Q_DEFAULT: 1488 tmp = gen_portatom(0, (bpf_int32)port); 1489 b1 = gen_portatom(2, (bpf_int32)port); 1490 gen_or(tmp, b1); 1491 break; 1492 1493 case Q_AND: 1494 tmp = gen_portatom(0, (bpf_int32)port); 1495 b1 = gen_portatom(2, (bpf_int32)port); 1496 gen_and(tmp, b1); 1497 break; 1498 1499 default: 1500 abort(); 1501 } 1502 gen_and(b0, b1); 1503 1504 return b1; 1505 } 1506 1507 static struct block * 1508 gen_port(port, ip_proto, dir) 1509 int port; 1510 int ip_proto; 1511 int dir; 1512 { 1513 struct block *b0, *b1, *tmp; 1514 1515 /* ether proto ip */ 1516 b0 = gen_linktype(ETHERTYPE_IP); 1517 1518 switch (ip_proto) { 1519 case IPPROTO_UDP: 1520 case IPPROTO_TCP: 1521 b1 = gen_portop(port, ip_proto, dir); 1522 break; 1523 1524 case PROTO_UNDEF: 1525 tmp = gen_portop(port, IPPROTO_TCP, dir); 1526 b1 = gen_portop(port, IPPROTO_UDP, dir); 1527 gen_or(tmp, b1); 1528 break; 1529 1530 default: 1531 abort(); 1532 } 1533 gen_and(b0, b1); 1534 return b1; 1535 } 1536 1537 #ifdef INET6 1538 struct block * 1539 gen_portop6(port, proto, dir) 1540 int port, proto, dir; 1541 { 1542 struct block *b0, *b1, *tmp; 1543 1544 /* ip proto 'proto' */ 1545 b0 = gen_cmp(off_nl + 6, BPF_B, (bpf_int32)proto); 1546 1547 switch (dir) { 1548 case Q_SRC: 1549 b1 = gen_portatom6(0, (bpf_int32)port); 1550 break; 1551 1552 case Q_DST: 1553 b1 = gen_portatom6(2, (bpf_int32)port); 1554 break; 1555 1556 case Q_OR: 1557 case Q_DEFAULT: 1558 tmp = gen_portatom6(0, (bpf_int32)port); 1559 b1 = gen_portatom6(2, (bpf_int32)port); 1560 gen_or(tmp, b1); 1561 break; 1562 1563 case Q_AND: 1564 tmp = gen_portatom6(0, (bpf_int32)port); 1565 b1 = gen_portatom6(2, (bpf_int32)port); 1566 gen_and(tmp, b1); 1567 break; 1568 1569 default: 1570 abort(); 1571 } 1572 gen_and(b0, b1); 1573 1574 return b1; 1575 } 1576 1577 static struct block * 1578 gen_port6(port, ip_proto, dir) 1579 int port; 1580 int ip_proto; 1581 int dir; 1582 { 1583 struct block *b0, *b1, *tmp; 1584 1585 /* ether proto ip */ 1586 b0 = gen_linktype(ETHERTYPE_IPV6); 1587 1588 switch (ip_proto) { 1589 case IPPROTO_UDP: 1590 case IPPROTO_TCP: 1591 b1 = gen_portop6(port, ip_proto, dir); 1592 break; 1593 1594 case PROTO_UNDEF: 1595 tmp = gen_portop6(port, IPPROTO_TCP, dir); 1596 b1 = gen_portop6(port, IPPROTO_UDP, dir); 1597 gen_or(tmp, b1); 1598 break; 1599 1600 default: 1601 abort(); 1602 } 1603 gen_and(b0, b1); 1604 return b1; 1605 } 1606 #endif /* INET6 */ 1607 1608 static int 1609 lookup_proto(name, proto) 1610 register const char *name; 1611 register int proto; 1612 { 1613 register int v; 1614 1615 switch (proto) { 1616 1617 case Q_DEFAULT: 1618 case Q_IP: 1619 v = pcap_nametoproto(name); 1620 if (v == PROTO_UNDEF) 1621 bpf_error("unknown ip proto '%s'", name); 1622 break; 1623 1624 case Q_LINK: 1625 /* XXX should look up h/w protocol type based on linktype */ 1626 v = pcap_nametoeproto(name); 1627 if (v == PROTO_UNDEF) 1628 bpf_error("unknown ether proto '%s'", name); 1629 break; 1630 1631 default: 1632 v = PROTO_UNDEF; 1633 break; 1634 } 1635 return v; 1636 } 1637 1638 static struct block * 1639 gen_protochain(v, proto, dir) 1640 int v; 1641 int proto; 1642 int dir; 1643 { 1644 struct block *b0, *b; 1645 struct slist *s[100]; 1646 int fix2, fix3, fix4, fix5; 1647 int ahcheck, again, end; 1648 int i, max; 1649 int reg1 = alloc_reg(); 1650 int reg2 = alloc_reg(); 1651 1652 memset(s, 0, sizeof(s)); 1653 fix2 = fix3 = fix4 = fix5 = 0; 1654 1655 switch (proto) { 1656 case Q_IP: 1657 case Q_IPV6: 1658 break; 1659 case Q_DEFAULT: 1660 b0 = gen_protochain(v, Q_IP, dir); 1661 b = gen_protochain(v, Q_IPV6, dir); 1662 gen_or(b0, b); 1663 return b; 1664 default: 1665 bpf_error("bad protocol applied for 'protochain'"); 1666 /*NOTREACHED*/ 1667 } 1668 1669 no_optimize = 1; /*this code is not compatible with optimzer yet */ 1670 1671 /* 1672 * s[0] is a dummy entry to protect other BPF insn from damaged 1673 * by s[fix] = foo with uninitialized variable "fix". It is somewhat 1674 * hard to find interdependency made by jump table fixup. 1675 */ 1676 i = 0; 1677 s[i] = new_stmt(0); /*dummy*/ 1678 i++; 1679 1680 switch (proto) { 1681 case Q_IP: 1682 b0 = gen_linktype(ETHERTYPE_IP); 1683 1684 /* A = ip->ip_p */ 1685 s[i] = new_stmt(BPF_LD|BPF_ABS|BPF_B); 1686 s[i]->s.k = off_nl + 9; 1687 i++; 1688 /* X = ip->ip_hl << 2 */ 1689 s[i] = new_stmt(BPF_LDX|BPF_MSH|BPF_B); 1690 s[i]->s.k = off_nl; 1691 i++; 1692 break; 1693 case Q_IPV6: 1694 b0 = gen_linktype(ETHERTYPE_IPV6); 1695 1696 /* A = ip6->ip_nxt */ 1697 s[i] = new_stmt(BPF_LD|BPF_ABS|BPF_B); 1698 s[i]->s.k = off_nl + 6; 1699 i++; 1700 /* X = sizeof(struct ip6_hdr) */ 1701 s[i] = new_stmt(BPF_LDX|BPF_IMM); 1702 s[i]->s.k = 40; 1703 i++; 1704 break; 1705 default: 1706 bpf_error("unsupported proto to gen_protochain"); 1707 /*NOTREACHED*/ 1708 } 1709 1710 /* again: if (A == v) goto end; else fall through; */ 1711 again = i; 1712 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1713 s[i]->s.k = v; 1714 s[i]->s.jt = NULL; /*later*/ 1715 s[i]->s.jf = NULL; /*update in next stmt*/ 1716 fix5 = i; 1717 i++; 1718 1719 /* if (A == IPPROTO_NONE) goto end */ 1720 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1721 s[i]->s.jt = NULL; /*later*/ 1722 s[i]->s.jf = NULL; /*update in next stmt*/ 1723 s[i]->s.k = IPPROTO_NONE; 1724 s[fix5]->s.jf = s[i]; 1725 fix2 = i; 1726 i++; 1727 1728 if (proto == Q_IPV6) { 1729 int v6start, v6end, v6advance, j; 1730 1731 v6start = i; 1732 /* if (A == IPPROTO_HOPOPTS) goto v6advance */ 1733 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1734 s[i]->s.jt = NULL; /*later*/ 1735 s[i]->s.jf = NULL; /*update in next stmt*/ 1736 s[i]->s.k = IPPROTO_HOPOPTS; 1737 s[fix2]->s.jf = s[i]; 1738 i++; 1739 /* if (A == IPPROTO_DSTOPTS) goto v6advance */ 1740 s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1741 s[i]->s.jt = NULL; /*later*/ 1742 s[i]->s.jf = NULL; /*update in next stmt*/ 1743 s[i]->s.k = IPPROTO_DSTOPTS; 1744 i++; 1745 /* if (A == IPPROTO_ROUTING) goto v6advance */ 1746 s[i - 1]->s.jf = 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_ROUTING; 1750 i++; 1751 /* if (A == IPPROTO_FRAGMENT) goto v6advance; else goto ahcheck; */ 1752 s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1753 s[i]->s.jt = NULL; /*later*/ 1754 s[i]->s.jf = NULL; /*later*/ 1755 s[i]->s.k = IPPROTO_FRAGMENT; 1756 fix3 = i; 1757 v6end = i; 1758 i++; 1759 1760 /* v6advance: */ 1761 v6advance = i; 1762 1763 /* 1764 * in short, 1765 * A = P[X + 1]; 1766 * X = X + (P[X] + 1) * 8; 1767 */ 1768 /* A = X */ 1769 s[i] = new_stmt(BPF_MISC|BPF_TXA); 1770 i++; 1771 /* MEM[reg1] = A */ 1772 s[i] = new_stmt(BPF_ST); 1773 s[i]->s.k = reg1; 1774 i++; 1775 /* A += 1 */ 1776 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1777 s[i]->s.k = 1; 1778 i++; 1779 /* X = A */ 1780 s[i] = new_stmt(BPF_MISC|BPF_TAX); 1781 i++; 1782 /* A = P[X + packet head]; */ 1783 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B); 1784 s[i]->s.k = off_nl; 1785 i++; 1786 /* MEM[reg2] = A */ 1787 s[i] = new_stmt(BPF_ST); 1788 s[i]->s.k = reg2; 1789 i++; 1790 /* X = MEM[reg1] */ 1791 s[i] = new_stmt(BPF_LDX|BPF_MEM); 1792 s[i]->s.k = reg1; 1793 i++; 1794 /* A = P[X + packet head] */ 1795 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B); 1796 s[i]->s.k = off_nl; 1797 i++; 1798 /* A += 1 */ 1799 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1800 s[i]->s.k = 1; 1801 i++; 1802 /* A *= 8 */ 1803 s[i] = new_stmt(BPF_ALU|BPF_MUL|BPF_K); 1804 s[i]->s.k = 8; 1805 i++; 1806 /* X = A; */ 1807 s[i] = new_stmt(BPF_MISC|BPF_TAX); 1808 i++; 1809 /* A = MEM[reg2] */ 1810 s[i] = new_stmt(BPF_LD|BPF_MEM); 1811 s[i]->s.k = reg2; 1812 i++; 1813 1814 /* goto again; (must use BPF_JA for backward jump) */ 1815 s[i] = new_stmt(BPF_JMP|BPF_JA); 1816 s[i]->s.k = again - i - 1; 1817 s[i - 1]->s.jf = s[i]; 1818 i++; 1819 1820 /* fixup */ 1821 for (j = v6start; j <= v6end; j++) 1822 s[j]->s.jt = s[v6advance]; 1823 } else { 1824 /* nop */ 1825 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1826 s[i]->s.k = 0; 1827 s[fix2]->s.jf = s[i]; 1828 i++; 1829 } 1830 1831 /* ahcheck: */ 1832 ahcheck = i; 1833 /* if (A == IPPROTO_AH) then fall through; else goto end; */ 1834 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1835 s[i]->s.jt = NULL; /*later*/ 1836 s[i]->s.jf = NULL; /*later*/ 1837 s[i]->s.k = IPPROTO_AH; 1838 if (fix3) 1839 s[fix3]->s.jf = s[ahcheck]; 1840 fix4 = i; 1841 i++; 1842 1843 /* 1844 * in short, 1845 * A = P[X + 1]; 1846 * X = X + (P[X] + 2) * 4; 1847 */ 1848 /* A = X */ 1849 s[i - 1]->s.jt = s[i] = new_stmt(BPF_MISC|BPF_TXA); 1850 i++; 1851 /* MEM[reg1] = A */ 1852 s[i] = new_stmt(BPF_ST); 1853 s[i]->s.k = reg1; 1854 i++; 1855 /* A += 1 */ 1856 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1857 s[i]->s.k = 1; 1858 i++; 1859 /* X = A */ 1860 s[i] = new_stmt(BPF_MISC|BPF_TAX); 1861 i++; 1862 /* A = P[X + packet head]; */ 1863 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B); 1864 s[i]->s.k = off_nl; 1865 i++; 1866 /* MEM[reg2] = A */ 1867 s[i] = new_stmt(BPF_ST); 1868 s[i]->s.k = reg2; 1869 i++; 1870 /* X = MEM[reg1] */ 1871 s[i] = new_stmt(BPF_LDX|BPF_MEM); 1872 s[i]->s.k = reg1; 1873 i++; 1874 /* A = P[X + packet head] */ 1875 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B); 1876 s[i]->s.k = off_nl; 1877 i++; 1878 /* A += 2 */ 1879 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1880 s[i]->s.k = 2; 1881 i++; 1882 /* A *= 4 */ 1883 s[i] = new_stmt(BPF_ALU|BPF_MUL|BPF_K); 1884 s[i]->s.k = 4; 1885 i++; 1886 /* X = A; */ 1887 s[i] = new_stmt(BPF_MISC|BPF_TAX); 1888 i++; 1889 /* A = MEM[reg2] */ 1890 s[i] = new_stmt(BPF_LD|BPF_MEM); 1891 s[i]->s.k = reg2; 1892 i++; 1893 1894 /* goto again; (must use BPF_JA for backward jump) */ 1895 s[i] = new_stmt(BPF_JMP|BPF_JA); 1896 s[i]->s.k = again - i - 1; 1897 i++; 1898 1899 /* end: nop */ 1900 end = i; 1901 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1902 s[i]->s.k = 0; 1903 s[fix2]->s.jt = s[end]; 1904 s[fix4]->s.jf = s[end]; 1905 s[fix5]->s.jt = s[end]; 1906 i++; 1907 1908 /* 1909 * make slist chain 1910 */ 1911 max = i; 1912 for (i = 0; i < max - 1; i++) 1913 s[i]->next = s[i + 1]; 1914 s[max - 1]->next = NULL; 1915 1916 /* 1917 * emit final check 1918 */ 1919 b = new_block(JMP(BPF_JEQ)); 1920 b->stmts = s[1]; /*remember, s[0] is dummy*/ 1921 b->s.k = v; 1922 1923 free_reg(reg1); 1924 free_reg(reg2); 1925 1926 gen_and(b0, b); 1927 return b; 1928 } 1929 1930 static struct block * 1931 gen_proto(v, proto, dir) 1932 int v; 1933 int proto; 1934 int dir; 1935 { 1936 struct block *b0, *b1; 1937 1938 if (dir != Q_DEFAULT) 1939 bpf_error("direction applied to 'proto'"); 1940 1941 switch (proto) { 1942 case Q_DEFAULT: 1943 #ifdef INET6 1944 b0 = gen_proto(v, Q_IP, dir); 1945 b1 = gen_proto(v, Q_IPV6, dir); 1946 gen_or(b0, b1); 1947 return b1; 1948 #else 1949 /*FALLTHROUGH*/ 1950 #endif 1951 case Q_IP: 1952 b0 = gen_linktype(ETHERTYPE_IP); 1953 #ifndef CHASE_CHAIN 1954 b1 = gen_cmp(off_nl + 9, BPF_B, (bpf_int32)v); 1955 #else 1956 b1 = gen_protochain(v, Q_IP); 1957 #endif 1958 gen_and(b0, b1); 1959 return b1; 1960 1961 case Q_ARP: 1962 bpf_error("arp does not encapsulate another protocol"); 1963 /* NOTREACHED */ 1964 1965 case Q_RARP: 1966 bpf_error("rarp does not encapsulate another protocol"); 1967 /* NOTREACHED */ 1968 1969 case Q_ATALK: 1970 bpf_error("atalk encapsulation is not specifiable"); 1971 /* NOTREACHED */ 1972 1973 case Q_DECNET: 1974 bpf_error("decnet encapsulation is not specifiable"); 1975 /* NOTREACHED */ 1976 1977 case Q_SCA: 1978 bpf_error("sca does not encapsulate another protocol"); 1979 /* NOTREACHED */ 1980 1981 case Q_LAT: 1982 bpf_error("lat does not encapsulate another protocol"); 1983 /* NOTREACHED */ 1984 1985 case Q_MOPRC: 1986 bpf_error("moprc does not encapsulate another protocol"); 1987 /* NOTREACHED */ 1988 1989 case Q_MOPDL: 1990 bpf_error("mopdl does not encapsulate another protocol"); 1991 /* NOTREACHED */ 1992 1993 case Q_LINK: 1994 return gen_linktype(v); 1995 1996 case Q_UDP: 1997 bpf_error("'udp proto' is bogus"); 1998 /* NOTREACHED */ 1999 2000 case Q_TCP: 2001 bpf_error("'tcp proto' is bogus"); 2002 /* NOTREACHED */ 2003 2004 case Q_ICMP: 2005 bpf_error("'icmp proto' is bogus"); 2006 /* NOTREACHED */ 2007 2008 case Q_IGMP: 2009 bpf_error("'igmp proto' is bogus"); 2010 /* NOTREACHED */ 2011 2012 case Q_IGRP: 2013 bpf_error("'igrp proto' is bogus"); 2014 /* NOTREACHED */ 2015 2016 case Q_PIM: 2017 bpf_error("'pim proto' is bogus"); 2018 /* NOTREACHED */ 2019 2020 #ifdef INET6 2021 case Q_IPV6: 2022 b0 = gen_linktype(ETHERTYPE_IPV6); 2023 #ifndef CHASE_CHAIN 2024 b1 = gen_cmp(off_nl + 6, BPF_B, (bpf_int32)v); 2025 #else 2026 b1 = gen_protochain(v, Q_IPV6); 2027 #endif 2028 gen_and(b0, b1); 2029 return b1; 2030 2031 case Q_ICMPV6: 2032 bpf_error("'icmp6 proto' is bogus"); 2033 #endif /* INET6 */ 2034 2035 case Q_AH: 2036 bpf_error("'ah proto' is bogus"); 2037 2038 case Q_ESP: 2039 bpf_error("'ah proto' is bogus"); 2040 2041 default: 2042 abort(); 2043 /* NOTREACHED */ 2044 } 2045 /* NOTREACHED */ 2046 } 2047 2048 struct block * 2049 gen_scode(name, q) 2050 register const char *name; 2051 struct qual q; 2052 { 2053 int proto = q.proto; 2054 int dir = q.dir; 2055 int tproto; 2056 u_char *eaddr; 2057 bpf_u_int32 mask, addr; 2058 #ifndef INET6 2059 bpf_u_int32 **alist; 2060 #else 2061 int tproto6; 2062 struct sockaddr_in *sin; 2063 struct sockaddr_in6 *sin6; 2064 struct addrinfo *res, *res0; 2065 struct in6_addr mask128; 2066 #endif /*INET6*/ 2067 struct block *b, *tmp; 2068 int port, real_proto; 2069 2070 switch (q.addr) { 2071 2072 case Q_NET: 2073 addr = pcap_nametonetaddr(name); 2074 if (addr == 0) 2075 bpf_error("unknown network '%s'", name); 2076 /* Left justify network addr and calculate its network mask */ 2077 mask = 0xffffffff; 2078 while (addr && (addr & 0xff000000) == 0) { 2079 addr <<= 8; 2080 mask <<= 8; 2081 } 2082 return gen_host(addr, mask, proto, dir); 2083 2084 case Q_DEFAULT: 2085 case Q_HOST: 2086 if (proto == Q_LINK) { 2087 switch (linktype) { 2088 2089 case DLT_EN10MB: 2090 eaddr = pcap_ether_hostton(name); 2091 if (eaddr == NULL) 2092 bpf_error( 2093 "unknown ether host '%s'", name); 2094 return gen_ehostop(eaddr, dir); 2095 2096 case DLT_FDDI: 2097 eaddr = pcap_ether_hostton(name); 2098 if (eaddr == NULL) 2099 bpf_error( 2100 "unknown FDDI host '%s'", name); 2101 return gen_fhostop(eaddr, dir); 2102 2103 default: 2104 bpf_error( 2105 "only ethernet/FDDI supports link-level host name"); 2106 break; 2107 } 2108 } else if (proto == Q_DECNET) { 2109 unsigned short dn_addr = __pcap_nametodnaddr(name); 2110 /* 2111 * I don't think DECNET hosts can be multihomed, so 2112 * there is no need to build up a list of addresses 2113 */ 2114 return (gen_host(dn_addr, 0, proto, dir)); 2115 } else { 2116 #ifndef INET6 2117 alist = pcap_nametoaddr(name); 2118 if (alist == NULL || *alist == NULL) 2119 bpf_error("unknown host '%s'", name); 2120 tproto = proto; 2121 if (off_linktype == -1 && tproto == Q_DEFAULT) 2122 tproto = Q_IP; 2123 b = gen_host(**alist++, 0xffffffff, tproto, dir); 2124 while (*alist) { 2125 tmp = gen_host(**alist++, 0xffffffff, 2126 tproto, dir); 2127 gen_or(b, tmp); 2128 b = tmp; 2129 } 2130 return b; 2131 #else 2132 memset(&mask128, 0xff, sizeof(mask128)); 2133 res0 = res = pcap_nametoaddrinfo(name); 2134 if (res == NULL) 2135 bpf_error("unknown host '%s'", name); 2136 b = tmp = NULL; 2137 tproto = tproto6 = proto; 2138 if (off_linktype == -1 && tproto == Q_DEFAULT) { 2139 tproto = Q_IP; 2140 tproto6 = Q_IPV6; 2141 } 2142 for (res = res0; res; res = res->ai_next) { 2143 switch (res->ai_family) { 2144 case AF_INET: 2145 if (tproto == Q_IPV6) 2146 continue; 2147 2148 sin = (struct sockaddr_in *) 2149 res->ai_addr; 2150 tmp = gen_host(ntohl(sin->sin_addr.s_addr), 2151 0xffffffff, tproto, dir); 2152 break; 2153 case AF_INET6: 2154 if (tproto6 == Q_IP) 2155 continue; 2156 2157 sin6 = (struct sockaddr_in6 *) 2158 res->ai_addr; 2159 tmp = gen_host6(&sin6->sin6_addr, 2160 &mask128, tproto6, dir); 2161 break; 2162 } 2163 if (b) 2164 gen_or(b, tmp); 2165 b = tmp; 2166 } 2167 freeaddrinfo(res0); 2168 if (b == NULL) { 2169 bpf_error("unknown host '%s'%s", name, 2170 (proto == Q_DEFAULT) 2171 ? "" 2172 : " for specified address family"); 2173 } 2174 return b; 2175 #endif /*INET6*/ 2176 } 2177 2178 case Q_PORT: 2179 if (proto != Q_DEFAULT && proto != Q_UDP && proto != Q_TCP) 2180 bpf_error("illegal qualifier of 'port'"); 2181 if (pcap_nametoport(name, &port, &real_proto) == 0) 2182 bpf_error("unknown port '%s'", name); 2183 if (proto == Q_UDP) { 2184 if (real_proto == IPPROTO_TCP) 2185 bpf_error("port '%s' is tcp", name); 2186 else 2187 /* override PROTO_UNDEF */ 2188 real_proto = IPPROTO_UDP; 2189 } 2190 if (proto == Q_TCP) { 2191 if (real_proto == IPPROTO_UDP) 2192 bpf_error("port '%s' is udp", name); 2193 else 2194 /* override PROTO_UNDEF */ 2195 real_proto = IPPROTO_TCP; 2196 } 2197 #ifndef INET6 2198 return gen_port(port, real_proto, dir); 2199 #else 2200 { 2201 struct block *b; 2202 b = gen_port(port, real_proto, dir); 2203 gen_or(gen_port6(port, real_proto, dir), b); 2204 return b; 2205 } 2206 #endif /* INET6 */ 2207 2208 case Q_GATEWAY: 2209 #ifndef INET6 2210 eaddr = pcap_ether_hostton(name); 2211 if (eaddr == NULL) 2212 bpf_error("unknown ether host: %s", name); 2213 2214 alist = pcap_nametoaddr(name); 2215 if (alist == NULL || *alist == NULL) 2216 bpf_error("unknown host '%s'", name); 2217 return gen_gateway(eaddr, alist, proto, dir); 2218 #else 2219 bpf_error("'gateway' not supported in this configuration"); 2220 #endif /*INET6*/ 2221 2222 case Q_PROTO: 2223 real_proto = lookup_proto(name, proto); 2224 if (real_proto >= 0) 2225 return gen_proto(real_proto, proto, dir); 2226 else 2227 bpf_error("unknown protocol: %s", name); 2228 2229 case Q_PROTOCHAIN: 2230 real_proto = lookup_proto(name, proto); 2231 if (real_proto >= 0) 2232 return gen_protochain(real_proto, proto, dir); 2233 else 2234 bpf_error("unknown protocol: %s", name); 2235 2236 2237 case Q_UNDEF: 2238 syntax(); 2239 /* NOTREACHED */ 2240 } 2241 abort(); 2242 /* NOTREACHED */ 2243 } 2244 2245 struct block * 2246 gen_mcode(s1, s2, masklen, q) 2247 register const char *s1, *s2; 2248 register int masklen; 2249 struct qual q; 2250 { 2251 register int nlen, mlen; 2252 bpf_u_int32 n, m; 2253 2254 nlen = __pcap_atoin(s1, &n); 2255 /* Promote short ipaddr */ 2256 n <<= 32 - nlen; 2257 2258 if (s2 != NULL) { 2259 mlen = __pcap_atoin(s2, &m); 2260 /* Promote short ipaddr */ 2261 m <<= 32 - mlen; 2262 if ((n & ~m) != 0) 2263 bpf_error("non-network bits set in \"%s mask %s\"", 2264 s1, s2); 2265 } else { 2266 /* Convert mask len to mask */ 2267 if (masklen > 32) 2268 bpf_error("mask length must be <= 32"); 2269 m = 0xffffffff << (32 - masklen); 2270 if ((n & ~m) != 0) 2271 bpf_error("non-network bits set in \"%s/%d\"", 2272 s1, masklen); 2273 } 2274 2275 switch (q.addr) { 2276 2277 case Q_NET: 2278 return gen_host(n, m, q.proto, q.dir); 2279 2280 default: 2281 bpf_error("Mask syntax for networks only"); 2282 /* NOTREACHED */ 2283 } 2284 } 2285 2286 struct block * 2287 gen_ncode(s, v, q) 2288 register const char *s; 2289 bpf_u_int32 v; 2290 struct qual q; 2291 { 2292 bpf_u_int32 mask; 2293 int proto = q.proto; 2294 int dir = q.dir; 2295 register int vlen; 2296 2297 if (s == NULL) 2298 vlen = 32; 2299 else if (q.proto == Q_DECNET) 2300 vlen = __pcap_atodn(s, &v); 2301 else 2302 vlen = __pcap_atoin(s, &v); 2303 2304 switch (q.addr) { 2305 2306 case Q_DEFAULT: 2307 case Q_HOST: 2308 case Q_NET: 2309 if (proto == Q_DECNET) 2310 return gen_host(v, 0, proto, dir); 2311 else if (proto == Q_LINK) { 2312 bpf_error("illegal link layer address"); 2313 } else { 2314 mask = 0xffffffff; 2315 if (s == NULL && q.addr == Q_NET) { 2316 /* Promote short net number */ 2317 while (v && (v & 0xff000000) == 0) { 2318 v <<= 8; 2319 mask <<= 8; 2320 } 2321 } else { 2322 /* Promote short ipaddr */ 2323 v <<= 32 - vlen; 2324 mask <<= 32 - vlen; 2325 } 2326 return gen_host(v, mask, proto, dir); 2327 } 2328 2329 case Q_PORT: 2330 if (proto == Q_UDP) 2331 proto = IPPROTO_UDP; 2332 else if (proto == Q_TCP) 2333 proto = IPPROTO_TCP; 2334 else if (proto == Q_DEFAULT) 2335 proto = PROTO_UNDEF; 2336 else 2337 bpf_error("illegal qualifier of 'port'"); 2338 2339 #ifndef INET6 2340 return gen_port((int)v, proto, dir); 2341 #else 2342 { 2343 struct block *b; 2344 b = gen_port((int)v, proto, dir); 2345 gen_or(gen_port6((int)v, proto, dir), b); 2346 return b; 2347 } 2348 #endif /* INET6 */ 2349 2350 case Q_GATEWAY: 2351 bpf_error("'gateway' requires a name"); 2352 /* NOTREACHED */ 2353 2354 case Q_PROTO: 2355 return gen_proto((int)v, proto, dir); 2356 2357 case Q_PROTOCHAIN: 2358 return gen_protochain((int)v, proto, dir); 2359 2360 case Q_UNDEF: 2361 syntax(); 2362 /* NOTREACHED */ 2363 2364 default: 2365 abort(); 2366 /* NOTREACHED */ 2367 } 2368 /* NOTREACHED */ 2369 } 2370 2371 #ifdef INET6 2372 struct block * 2373 gen_mcode6(s1, s2, masklen, q) 2374 register const char *s1, *s2; 2375 register int masklen; 2376 struct qual q; 2377 { 2378 struct addrinfo *res; 2379 struct in6_addr *addr; 2380 struct in6_addr mask; 2381 struct block *b; 2382 u_int32_t *a, *m; 2383 2384 if (s2) 2385 bpf_error("no mask %s supported", s2); 2386 2387 res = pcap_nametoaddrinfo(s1); 2388 if (!res) 2389 bpf_error("invalid ip6 address %s", s1); 2390 if (res->ai_next) 2391 bpf_error("%s resolved to multiple address", s1); 2392 addr = &((struct sockaddr_in6 *)res->ai_addr)->sin6_addr; 2393 2394 if (sizeof(mask) * 8 < masklen) 2395 bpf_error("mask length must be <= %u", (unsigned int)(sizeof(mask) * 8)); 2396 memset(&mask, 0xff, masklen / 8); 2397 if (masklen % 8) { 2398 mask.s6_addr[masklen / 8] = 2399 (0xff << (8 - masklen % 8)) & 0xff; 2400 } 2401 2402 a = (u_int32_t *)addr; 2403 m = (u_int32_t *)&mask; 2404 if ((a[0] & ~m[0]) || (a[1] & ~m[1]) 2405 || (a[2] & ~m[2]) || (a[3] & ~m[3])) { 2406 bpf_error("non-network bits set in \"%s/%d\"", s1, masklen); 2407 } 2408 2409 switch (q.addr) { 2410 2411 case Q_DEFAULT: 2412 case Q_HOST: 2413 if (masklen != 128) 2414 bpf_error("Mask syntax for networks only"); 2415 /* FALLTHROUGH */ 2416 2417 case Q_NET: 2418 b = gen_host6(addr, &mask, q.proto, q.dir); 2419 freeaddrinfo(res); 2420 return b; 2421 2422 default: 2423 bpf_error("invalid qualifier against IPv6 address"); 2424 /* NOTREACHED */ 2425 } 2426 } 2427 #endif /*INET6*/ 2428 2429 struct block * 2430 gen_ecode(eaddr, q) 2431 register const u_char *eaddr; 2432 struct qual q; 2433 { 2434 if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) && q.proto == Q_LINK) { 2435 if (linktype == DLT_EN10MB) 2436 return gen_ehostop(eaddr, (int)q.dir); 2437 if (linktype == DLT_FDDI) 2438 return gen_fhostop(eaddr, (int)q.dir); 2439 } 2440 bpf_error("ethernet address used in non-ether expression"); 2441 /* NOTREACHED */ 2442 } 2443 2444 void 2445 sappend(s0, s1) 2446 struct slist *s0, *s1; 2447 { 2448 /* 2449 * This is definitely not the best way to do this, but the 2450 * lists will rarely get long. 2451 */ 2452 while (s0->next) 2453 s0 = s0->next; 2454 s0->next = s1; 2455 } 2456 2457 static struct slist * 2458 xfer_to_x(a) 2459 struct arth *a; 2460 { 2461 struct slist *s; 2462 2463 s = new_stmt(BPF_LDX|BPF_MEM); 2464 s->s.k = a->regno; 2465 return s; 2466 } 2467 2468 static struct slist * 2469 xfer_to_a(a) 2470 struct arth *a; 2471 { 2472 struct slist *s; 2473 2474 s = new_stmt(BPF_LD|BPF_MEM); 2475 s->s.k = a->regno; 2476 return s; 2477 } 2478 2479 struct arth * 2480 gen_load(proto, index, size) 2481 int proto; 2482 struct arth *index; 2483 int size; 2484 { 2485 struct slist *s, *tmp; 2486 struct block *b; 2487 int regno = alloc_reg(); 2488 2489 free_reg(index->regno); 2490 switch (size) { 2491 2492 default: 2493 bpf_error("data size must be 1, 2, or 4"); 2494 2495 case 1: 2496 size = BPF_B; 2497 break; 2498 2499 case 2: 2500 size = BPF_H; 2501 break; 2502 2503 case 4: 2504 size = BPF_W; 2505 break; 2506 } 2507 switch (proto) { 2508 default: 2509 bpf_error("unsupported index operation"); 2510 2511 case Q_LINK: 2512 s = xfer_to_x(index); 2513 tmp = new_stmt(BPF_LD|BPF_IND|size); 2514 sappend(s, tmp); 2515 sappend(index->s, s); 2516 break; 2517 2518 case Q_IP: 2519 case Q_ARP: 2520 case Q_RARP: 2521 case Q_ATALK: 2522 case Q_DECNET: 2523 case Q_SCA: 2524 case Q_LAT: 2525 case Q_MOPRC: 2526 case Q_MOPDL: 2527 #ifdef INET6 2528 case Q_IPV6: 2529 #endif 2530 /* XXX Note that we assume a fixed link header here. */ 2531 s = xfer_to_x(index); 2532 tmp = new_stmt(BPF_LD|BPF_IND|size); 2533 tmp->s.k = off_nl; 2534 sappend(s, tmp); 2535 sappend(index->s, s); 2536 2537 b = gen_proto_abbrev(proto); 2538 if (index->b) 2539 gen_and(index->b, b); 2540 index->b = b; 2541 break; 2542 2543 case Q_TCP: 2544 case Q_UDP: 2545 case Q_ICMP: 2546 case Q_IGMP: 2547 case Q_IGRP: 2548 case Q_PIM: 2549 s = new_stmt(BPF_LDX|BPF_MSH|BPF_B); 2550 s->s.k = off_nl; 2551 sappend(s, xfer_to_a(index)); 2552 sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X)); 2553 sappend(s, new_stmt(BPF_MISC|BPF_TAX)); 2554 sappend(s, tmp = new_stmt(BPF_LD|BPF_IND|size)); 2555 tmp->s.k = off_nl; 2556 sappend(index->s, s); 2557 2558 gen_and(gen_proto_abbrev(proto), b = gen_ipfrag()); 2559 if (index->b) 2560 gen_and(index->b, b); 2561 #ifdef INET6 2562 gen_and(gen_proto_abbrev(Q_IP), b); 2563 #endif 2564 index->b = b; 2565 break; 2566 #ifdef INET6 2567 case Q_ICMPV6: 2568 bpf_error("IPv6 upper-layer protocol is not supported by proto[x]"); 2569 /*NOTREACHED*/ 2570 #endif 2571 } 2572 index->regno = regno; 2573 s = new_stmt(BPF_ST); 2574 s->s.k = regno; 2575 sappend(index->s, s); 2576 2577 return index; 2578 } 2579 2580 struct block * 2581 gen_relation(code, a0, a1, reversed) 2582 int code; 2583 struct arth *a0, *a1; 2584 int reversed; 2585 { 2586 struct slist *s0, *s1, *s2; 2587 struct block *b, *tmp; 2588 2589 s0 = xfer_to_x(a1); 2590 s1 = xfer_to_a(a0); 2591 s2 = new_stmt(BPF_ALU|BPF_SUB|BPF_X); 2592 b = new_block(JMP(code)); 2593 if (code == BPF_JGT || code == BPF_JGE) { 2594 reversed = !reversed; 2595 b->s.k = 0x80000000; 2596 } 2597 if (reversed) 2598 gen_not(b); 2599 2600 sappend(s1, s2); 2601 sappend(s0, s1); 2602 sappend(a1->s, s0); 2603 sappend(a0->s, a1->s); 2604 2605 b->stmts = a0->s; 2606 2607 free_reg(a0->regno); 2608 free_reg(a1->regno); 2609 2610 /* 'and' together protocol checks */ 2611 if (a0->b) { 2612 if (a1->b) { 2613 gen_and(a0->b, tmp = a1->b); 2614 } 2615 else 2616 tmp = a0->b; 2617 } else 2618 tmp = a1->b; 2619 2620 if (tmp) 2621 gen_and(tmp, b); 2622 2623 return b; 2624 } 2625 2626 struct arth * 2627 gen_loadlen() 2628 { 2629 int regno = alloc_reg(); 2630 struct arth *a = (struct arth *)newchunk(sizeof(*a)); 2631 struct slist *s; 2632 2633 s = new_stmt(BPF_LD|BPF_LEN); 2634 s->next = new_stmt(BPF_ST); 2635 s->next->s.k = regno; 2636 a->s = s; 2637 a->regno = regno; 2638 2639 return a; 2640 } 2641 2642 struct arth * 2643 gen_loadi(val) 2644 int val; 2645 { 2646 struct arth *a; 2647 struct slist *s; 2648 int reg; 2649 2650 a = (struct arth *)newchunk(sizeof(*a)); 2651 2652 reg = alloc_reg(); 2653 2654 s = new_stmt(BPF_LD|BPF_IMM); 2655 s->s.k = val; 2656 s->next = new_stmt(BPF_ST); 2657 s->next->s.k = reg; 2658 a->s = s; 2659 a->regno = reg; 2660 2661 return a; 2662 } 2663 2664 struct arth * 2665 gen_neg(a) 2666 struct arth *a; 2667 { 2668 struct slist *s; 2669 2670 s = xfer_to_a(a); 2671 sappend(a->s, s); 2672 s = new_stmt(BPF_ALU|BPF_NEG); 2673 s->s.k = 0; 2674 sappend(a->s, s); 2675 s = new_stmt(BPF_ST); 2676 s->s.k = a->regno; 2677 sappend(a->s, s); 2678 2679 return a; 2680 } 2681 2682 struct arth * 2683 gen_arth(code, a0, a1) 2684 int code; 2685 struct arth *a0, *a1; 2686 { 2687 struct slist *s0, *s1, *s2; 2688 2689 s0 = xfer_to_x(a1); 2690 s1 = xfer_to_a(a0); 2691 s2 = new_stmt(BPF_ALU|BPF_X|code); 2692 2693 sappend(s1, s2); 2694 sappend(s0, s1); 2695 sappend(a1->s, s0); 2696 sappend(a0->s, a1->s); 2697 2698 free_reg(a1->regno); 2699 2700 s0 = new_stmt(BPF_ST); 2701 a0->regno = s0->s.k = alloc_reg(); 2702 sappend(a0->s, s0); 2703 2704 return a0; 2705 } 2706 2707 /* 2708 * Here we handle simple allocation of the scratch registers. 2709 * If too many registers are alloc'd, the allocator punts. 2710 */ 2711 static int regused[BPF_MEMWORDS]; 2712 static int curreg; 2713 2714 /* 2715 * Return the next free register. 2716 */ 2717 static int 2718 alloc_reg() 2719 { 2720 int n = BPF_MEMWORDS; 2721 2722 while (--n >= 0) { 2723 if (regused[curreg]) 2724 curreg = (curreg + 1) % BPF_MEMWORDS; 2725 else { 2726 regused[curreg] = 1; 2727 return curreg; 2728 } 2729 } 2730 bpf_error("too many registers needed to evaluate expression"); 2731 /* NOTREACHED */ 2732 } 2733 2734 /* 2735 * Return a register to the table so it can 2736 * be used later. 2737 */ 2738 static void 2739 free_reg(n) 2740 int n; 2741 { 2742 regused[n] = 0; 2743 } 2744 2745 static struct block * 2746 gen_len(jmp, n) 2747 int jmp, n; 2748 { 2749 struct slist *s; 2750 struct block *b; 2751 2752 s = new_stmt(BPF_LD|BPF_LEN); 2753 b = new_block(JMP(jmp)); 2754 b->stmts = s; 2755 b->s.k = n; 2756 2757 return b; 2758 } 2759 2760 struct block * 2761 gen_greater(n) 2762 int n; 2763 { 2764 return gen_len(BPF_JGE, n); 2765 } 2766 2767 struct block * 2768 gen_less(n) 2769 int n; 2770 { 2771 struct block *b; 2772 2773 b = gen_len(BPF_JGT, n); 2774 gen_not(b); 2775 2776 return b; 2777 } 2778 2779 struct block * 2780 gen_byteop(op, idx, val) 2781 int op, idx, val; 2782 { 2783 struct block *b; 2784 struct slist *s; 2785 2786 switch (op) { 2787 default: 2788 abort(); 2789 2790 case '=': 2791 return gen_cmp((u_int)idx, BPF_B, (bpf_int32)val); 2792 2793 case '<': 2794 b = gen_cmp((u_int)idx, BPF_B, (bpf_int32)val); 2795 b->s.code = JMP(BPF_JGE); 2796 gen_not(b); 2797 return b; 2798 2799 case '>': 2800 b = gen_cmp((u_int)idx, BPF_B, (bpf_int32)val); 2801 b->s.code = JMP(BPF_JGT); 2802 return b; 2803 2804 case '|': 2805 s = new_stmt(BPF_ALU|BPF_OR|BPF_K); 2806 break; 2807 2808 case '&': 2809 s = new_stmt(BPF_ALU|BPF_AND|BPF_K); 2810 break; 2811 } 2812 s->s.k = val; 2813 b = new_block(JMP(BPF_JEQ)); 2814 b->stmts = s; 2815 gen_not(b); 2816 2817 return b; 2818 } 2819 2820 static u_char abroadcast[] = { 0x0 }; 2821 2822 struct block * 2823 gen_broadcast(proto) 2824 int proto; 2825 { 2826 bpf_u_int32 hostmask; 2827 struct block *b0, *b1, *b2; 2828 static u_char ebroadcast[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; 2829 2830 switch (proto) { 2831 2832 case Q_DEFAULT: 2833 case Q_LINK: 2834 if (linktype == DLT_ARCNET) 2835 return gen_ahostop(abroadcast, Q_DST); 2836 if (linktype == DLT_EN10MB) 2837 return gen_ehostop(ebroadcast, Q_DST); 2838 if (linktype == DLT_FDDI) 2839 return gen_fhostop(ebroadcast, Q_DST); 2840 bpf_error("not a broadcast link"); 2841 break; 2842 2843 case Q_IP: 2844 b0 = gen_linktype(ETHERTYPE_IP); 2845 hostmask = ~netmask; 2846 b1 = gen_mcmp(off_nl + 16, BPF_W, (bpf_int32)0, hostmask); 2847 b2 = gen_mcmp(off_nl + 16, BPF_W, 2848 (bpf_int32)(~0 & hostmask), hostmask); 2849 gen_or(b1, b2); 2850 gen_and(b0, b2); 2851 return b2; 2852 } 2853 bpf_error("only ether/ip broadcast filters supported"); 2854 } 2855 2856 struct block * 2857 gen_multicast(proto) 2858 int proto; 2859 { 2860 register struct block *b0, *b1; 2861 register struct slist *s; 2862 2863 switch (proto) { 2864 2865 case Q_DEFAULT: 2866 case Q_LINK: 2867 if (linktype == DLT_ARCNET) 2868 /* all ARCnet multicasts use the same address */ 2869 return gen_ahostop(abroadcast, Q_DST); 2870 2871 if (linktype == DLT_EN10MB) { 2872 /* ether[0] & 1 != 0 */ 2873 s = new_stmt(BPF_LD|BPF_B|BPF_ABS); 2874 s->s.k = 0; 2875 b0 = new_block(JMP(BPF_JSET)); 2876 b0->s.k = 1; 2877 b0->stmts = s; 2878 return b0; 2879 } 2880 2881 if (linktype == DLT_FDDI) { 2882 /* XXX TEST THIS: MIGHT NOT PORT PROPERLY XXX */ 2883 /* fddi[1] & 1 != 0 */ 2884 s = new_stmt(BPF_LD|BPF_B|BPF_ABS); 2885 s->s.k = 1; 2886 b0 = new_block(JMP(BPF_JSET)); 2887 b0->s.k = 1; 2888 b0->stmts = s; 2889 return b0; 2890 } 2891 /* Link not known to support multicasts */ 2892 break; 2893 2894 case Q_IP: 2895 b0 = gen_linktype(ETHERTYPE_IP); 2896 b1 = gen_cmp(off_nl + 16, BPF_B, (bpf_int32)224); 2897 b1->s.code = JMP(BPF_JGE); 2898 gen_and(b0, b1); 2899 return b1; 2900 2901 #ifdef INET6 2902 case Q_IPV6: 2903 b0 = gen_linktype(ETHERTYPE_IPV6); 2904 b1 = gen_cmp(off_nl + 24, BPF_B, (bpf_int32)255); 2905 gen_and(b0, b1); 2906 return b1; 2907 #endif /* INET6 */ 2908 } 2909 bpf_error("only IP multicast filters supported on ethernet/FDDI"); 2910 } 2911 2912 /* 2913 * generate command for inbound/outbound. It's here so we can 2914 * make it link-type specific. 'dir' = 0 implies "inbound", 2915 * = 1 implies "outbound". 2916 */ 2917 struct block * 2918 gen_inbound(dir) 2919 int dir; 2920 { 2921 register struct block *b0; 2922 2923 /* 2924 * Only SLIP and old-style PPP data link types support 2925 * inbound/outbound qualifiers. 2926 */ 2927 switch (linktype) { 2928 case DLT_SLIP: 2929 case DLT_PPP: 2930 b0 = gen_relation(BPF_JEQ, 2931 gen_load(Q_LINK, gen_loadi(0), 1), 2932 gen_loadi(0), 2933 dir); 2934 break; 2935 2936 case DLT_PFLOG: 2937 b0 = gen_cmp(offsetof(struct pfloghdr, dir), BPF_B, 2938 (bpf_int32)((dir == 0) ? PF_IN : PF_OUT)); 2939 break; 2940 2941 case DLT_OLD_PFLOG: 2942 b0 = gen_cmp(offsetof(struct old_pfloghdr, dir), BPF_H, 2943 (bpf_int32)((dir == 0) ? PF_IN : PF_OUT)); 2944 break; 2945 2946 default: 2947 bpf_error("inbound/outbound not supported on linktype 0x%x\n", 2948 linktype); 2949 /* NOTREACHED */ 2950 } 2951 2952 return (b0); 2953 } 2954 2955 2956 /* PF firewall log matched interface */ 2957 struct block * 2958 gen_pf_ifname(char *ifname) 2959 { 2960 struct block *b0; 2961 u_int len, off; 2962 2963 if (linktype == DLT_PFLOG) { 2964 len = sizeof(((struct pfloghdr *)0)->ifname); 2965 off = offsetof(struct pfloghdr, ifname); 2966 } else if (linktype == DLT_OLD_PFLOG) { 2967 len = sizeof(((struct old_pfloghdr *)0)->ifname); 2968 off = offsetof(struct old_pfloghdr, ifname); 2969 } else { 2970 bpf_error("ifname not supported on linktype 0x%x\n", linktype); 2971 /* NOTREACHED */ 2972 } 2973 if (strlen(ifname) >= len) { 2974 bpf_error("ifname interface names can only be %d characters\n", 2975 len - 1); 2976 /* NOTREACHED */ 2977 } 2978 b0 = gen_bcmp(off, strlen(ifname), ifname); 2979 return (b0); 2980 } 2981 2982 2983 /* PF firewall log matched interface */ 2984 struct block * 2985 gen_pf_ruleset(char *ruleset) 2986 { 2987 struct block *b0; 2988 2989 if (linktype != DLT_PFLOG) { 2990 bpf_error("ruleset not supported on linktype 0x%x\n", linktype); 2991 /* NOTREACHED */ 2992 } 2993 if (strlen(ruleset) >= sizeof(((struct pfloghdr *)0)->ruleset)) { 2994 bpf_error("ruleset names can only be %d characters\n", 2995 sizeof(((struct pfloghdr *)0)->ruleset) - 1); 2996 /* NOTREACHED */ 2997 } 2998 b0 = gen_bcmp(offsetof(struct pfloghdr, ruleset), 2999 strlen(ruleset), ruleset); 3000 return (b0); 3001 } 3002 3003 3004 /* PF firewall log rule number */ 3005 struct block * 3006 gen_pf_rnr(int rnr) 3007 { 3008 struct block *b0; 3009 3010 if (linktype == DLT_PFLOG) { 3011 b0 = gen_cmp(offsetof(struct pfloghdr, rulenr), BPF_W, 3012 (bpf_int32)rnr); 3013 } else if (linktype == DLT_OLD_PFLOG) { 3014 b0 = gen_cmp(offsetof(struct old_pfloghdr, rnr), BPF_H, 3015 (bpf_int32)rnr); 3016 } else { 3017 bpf_error("rnr not supported on linktype 0x%x\n", linktype); 3018 /* NOTREACHED */ 3019 } 3020 3021 return (b0); 3022 } 3023 3024 3025 /* PF firewall log sub-rule number */ 3026 struct block * 3027 gen_pf_srnr(int srnr) 3028 { 3029 struct block *b0; 3030 3031 if (linktype != DLT_PFLOG) { 3032 bpf_error("srnr not supported on linktype 0x%x\n", linktype); 3033 /* NOTREACHED */ 3034 } 3035 3036 b0 = gen_cmp(offsetof(struct pfloghdr, subrulenr), BPF_W, 3037 (bpf_int32)srnr); 3038 return (b0); 3039 } 3040 3041 /* PF firewall log reason code */ 3042 struct block * 3043 gen_pf_reason(int reason) 3044 { 3045 struct block *b0; 3046 3047 if (linktype == DLT_PFLOG) { 3048 b0 = gen_cmp(offsetof(struct pfloghdr, reason), BPF_B, 3049 (bpf_int32)reason); 3050 } else if (linktype == DLT_OLD_PFLOG) { 3051 b0 = gen_cmp(offsetof(struct old_pfloghdr, reason), BPF_H, 3052 (bpf_int32)reason); 3053 } else { 3054 bpf_error("reason not supported on linktype 0x%x\n", linktype); 3055 /* NOTREACHED */ 3056 } 3057 3058 return (b0); 3059 } 3060 3061 /* PF firewall log action */ 3062 struct block * 3063 gen_pf_action(int action) 3064 { 3065 struct block *b0; 3066 3067 if (linktype == DLT_PFLOG) { 3068 b0 = gen_cmp(offsetof(struct pfloghdr, action), BPF_B, 3069 (bpf_int32)action); 3070 } else if (linktype == DLT_OLD_PFLOG) { 3071 b0 = gen_cmp(offsetof(struct old_pfloghdr, action), BPF_H, 3072 (bpf_int32)action); 3073 } else { 3074 bpf_error("action not supported on linktype 0x%x\n", linktype); 3075 /* NOTREACHED */ 3076 } 3077 3078 return (b0); 3079 } 3080 3081 struct block * 3082 gen_acode(eaddr, q) 3083 register const u_char *eaddr; 3084 struct qual q; 3085 { 3086 if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) && q.proto == Q_LINK) { 3087 if (linktype == DLT_ARCNET) 3088 return gen_ahostop(eaddr, (int)q.dir); 3089 } 3090 bpf_error("ARCnet address used in non-arc expression"); 3091 /* NOTREACHED */ 3092 } 3093 3094 static struct block * 3095 gen_ahostop(eaddr, dir) 3096 register const u_char *eaddr; 3097 register int dir; 3098 { 3099 register struct block *b0, *b1; 3100 3101 switch (dir) { 3102 /* src comes first, different from Ethernet */ 3103 case Q_SRC: 3104 return gen_bcmp(0, 1, eaddr); 3105 3106 case Q_DST: 3107 return gen_bcmp(1, 1, eaddr); 3108 3109 case Q_AND: 3110 b0 = gen_ahostop(eaddr, Q_SRC); 3111 b1 = gen_ahostop(eaddr, Q_DST); 3112 gen_and(b0, b1); 3113 return b1; 3114 3115 case Q_DEFAULT: 3116 case Q_OR: 3117 b0 = gen_ahostop(eaddr, Q_SRC); 3118 b1 = gen_ahostop(eaddr, Q_DST); 3119 gen_or(b0, b1); 3120 return b1; 3121 } 3122 abort(); 3123 /* NOTREACHED */ 3124 } 3125