1 /* $OpenBSD: gencode.c,v 1.26 2006/07/18 11:52:12 dlg 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 <stdlib.h> 40 #include <stddef.h> 41 #include <memory.h> 42 #include <setjmp.h> 43 #include <stdarg.h> 44 45 #include "pcap-int.h" 46 47 #include "ethertype.h" 48 #include "llc.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_cmp_gt(u_int, u_int, bpf_int32); 123 static struct block *gen_mcmp(u_int, u_int, bpf_int32, bpf_u_int32); 124 static struct block *gen_bcmp(u_int, u_int, const u_char *); 125 static struct block *gen_uncond(int); 126 static __inline struct block *gen_true(void); 127 static __inline struct block *gen_false(void); 128 static struct block *gen_linktype(int); 129 static struct block *gen_hostop(bpf_u_int32, bpf_u_int32, int, int, u_int, u_int); 130 #ifdef INET6 131 static struct block *gen_hostop6(struct in6_addr *, struct in6_addr *, int, int, u_int, u_int); 132 #endif 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_cmp_gt(offset, size, v) 468 u_int offset, size; 469 bpf_int32 v; 470 { 471 struct slist *s; 472 struct block *b; 473 474 s = new_stmt(BPF_LD|BPF_ABS|size); 475 s->s.k = offset; 476 477 b = new_block(JMP(BPF_JGT)); 478 b->stmts = s; 479 b->s.k = v; 480 481 return b; 482 } 483 484 static struct block * 485 gen_mcmp(offset, size, v, mask) 486 u_int offset, size; 487 bpf_int32 v; 488 bpf_u_int32 mask; 489 { 490 struct block *b = gen_cmp(offset, size, v); 491 struct slist *s; 492 493 if (mask != 0xffffffff) { 494 s = new_stmt(BPF_ALU|BPF_AND|BPF_K); 495 s->s.k = mask; 496 b->stmts->next = s; 497 } 498 return b; 499 } 500 501 static struct block * 502 gen_bcmp(offset, size, v) 503 register u_int offset, size; 504 register const u_char *v; 505 { 506 register struct block *b, *tmp; 507 508 b = NULL; 509 while (size >= 4) { 510 register const u_char *p = &v[size - 4]; 511 bpf_int32 w = ((bpf_int32)p[0] << 24) | 512 ((bpf_int32)p[1] << 16) | ((bpf_int32)p[2] << 8) | p[3]; 513 514 tmp = gen_cmp(offset + size - 4, BPF_W, w); 515 if (b != NULL) 516 gen_and(b, tmp); 517 b = tmp; 518 size -= 4; 519 } 520 while (size >= 2) { 521 register const u_char *p = &v[size - 2]; 522 bpf_int32 w = ((bpf_int32)p[0] << 8) | p[1]; 523 524 tmp = gen_cmp(offset + size - 2, BPF_H, w); 525 if (b != NULL) 526 gen_and(b, tmp); 527 b = tmp; 528 size -= 2; 529 } 530 if (size > 0) { 531 tmp = gen_cmp(offset, BPF_B, (bpf_int32)v[0]); 532 if (b != NULL) 533 gen_and(b, tmp); 534 b = tmp; 535 } 536 return b; 537 } 538 539 /* 540 * Various code constructs need to know the layout of the data link 541 * layer. These variables give the necessary offsets. off_linktype 542 * is set to -1 for no encapsulation, in which case, IP is assumed. 543 */ 544 static u_int off_linktype; 545 static u_int off_nl; 546 static int linktype; 547 548 static void 549 init_linktype(type) 550 int type; 551 { 552 linktype = type; 553 554 switch (type) { 555 556 case DLT_EN10MB: 557 off_linktype = 12; 558 off_nl = 14; 559 return; 560 561 case DLT_SLIP: 562 /* 563 * SLIP doesn't have a link level type. The 16 byte 564 * header is hacked into our SLIP driver. 565 */ 566 off_linktype = -1; 567 off_nl = 16; 568 return; 569 570 case DLT_SLIP_BSDOS: 571 /* XXX this may be the same as the DLT_PPP_BSDOS case */ 572 off_linktype = -1; 573 /* XXX end */ 574 off_nl = 24; 575 return; 576 577 case DLT_NULL: 578 off_linktype = 0; 579 off_nl = 4; 580 return; 581 582 case DLT_PPP: 583 off_linktype = 2; 584 off_nl = 4; 585 return; 586 587 case DLT_PPP_ETHER: 588 /* 589 * This does not include the Ethernet header, and 590 * only covers session state. 591 */ 592 off_linktype = 6; 593 off_nl = 8; 594 return; 595 596 case DLT_PPP_BSDOS: 597 off_linktype = 5; 598 off_nl = 24; 599 return; 600 601 case DLT_FDDI: 602 /* 603 * FDDI doesn't really have a link-level type field. 604 * We assume that SSAP = SNAP is being used and pick 605 * out the encapsulated Ethernet type. 606 */ 607 off_linktype = 19; 608 #ifdef PCAP_FDDIPAD 609 off_linktype += pcap_fddipad; 610 #endif 611 off_nl = 21; 612 #ifdef PCAP_FDDIPAD 613 off_nl += pcap_fddipad; 614 #endif 615 return; 616 617 case DLT_IEEE802: 618 off_linktype = 20; 619 off_nl = 22; 620 return; 621 622 case DLT_IEEE802_11: 623 off_linktype = 30; /* XXX variable */ 624 off_nl = 32; 625 return; 626 627 case DLT_IEEE802_11_RADIO: 628 off_linktype = 30 + 64; /* XXX variable */ 629 off_nl = 32 + 64; 630 return; 631 632 case DLT_ATM_RFC1483: 633 /* 634 * assume routed, non-ISO PDUs 635 * (i.e., LLC = 0xAA-AA-03, OUT = 0x00-00-00) 636 */ 637 off_linktype = 6; 638 off_nl = 8; 639 return; 640 641 case DLT_LOOP: 642 off_linktype = -1; 643 off_nl = 4; 644 return; 645 646 case DLT_ENC: 647 off_linktype = -1; 648 off_nl = 12; 649 return; 650 651 case DLT_OLD_PFLOG: 652 off_linktype = 0; 653 off_nl = 28; 654 return; 655 656 case DLT_PFLOG: 657 off_linktype = 0; 658 /* XXX read from header? */ 659 off_nl = PFLOG_HDRLEN; 660 return; 661 662 case DLT_PFSYNC: 663 off_linktype = -1; 664 off_nl = 4; 665 return; 666 667 case DLT_RAW: 668 off_linktype = -1; 669 off_nl = 0; 670 return; 671 } 672 bpf_error("unknown data link type 0x%x", linktype); 673 /* NOTREACHED */ 674 } 675 676 static struct block * 677 gen_uncond(rsense) 678 int rsense; 679 { 680 struct block *b; 681 struct slist *s; 682 683 s = new_stmt(BPF_LD|BPF_IMM); 684 s->s.k = !rsense; 685 b = new_block(JMP(BPF_JEQ)); 686 b->stmts = s; 687 688 return b; 689 } 690 691 static __inline struct block * 692 gen_true() 693 { 694 return gen_uncond(1); 695 } 696 697 static __inline struct block * 698 gen_false() 699 { 700 return gen_uncond(0); 701 } 702 703 static struct block * 704 gen_linktype(proto) 705 register int proto; 706 { 707 struct block *b0, *b1; 708 709 /* If we're not using encapsulation and checking for IP, we're done */ 710 if (off_linktype == -1 && proto == ETHERTYPE_IP) 711 return gen_true(); 712 #ifdef INET6 713 /* this isn't the right thing to do, but sometimes necessary */ 714 if (off_linktype == -1 && proto == ETHERTYPE_IPV6) 715 return gen_true(); 716 #endif 717 718 switch (linktype) { 719 720 case DLT_EN10MB: 721 if (proto <= ETHERMTU) { 722 /* This is an LLC SAP value */ 723 b0 = gen_cmp_gt(off_linktype, BPF_H, ETHERMTU); 724 gen_not(b0); 725 b1 = gen_cmp(off_linktype + 2, BPF_B, (bpf_int32)proto); 726 gen_and(b0, b1); 727 return b1; 728 } else { 729 /* This is an Ethernet type */ 730 return gen_cmp(off_linktype, BPF_H, (bpf_int32)proto); 731 } 732 break; 733 734 case DLT_SLIP: 735 return gen_false(); 736 737 case DLT_PPP: 738 case DLT_PPP_ETHER: 739 if (proto == ETHERTYPE_IP) 740 proto = PPP_IP; /* XXX was 0x21 */ 741 #ifdef INET6 742 else if (proto == ETHERTYPE_IPV6) 743 proto = PPP_IPV6; 744 #endif 745 break; 746 747 case DLT_PPP_BSDOS: 748 switch (proto) { 749 750 case ETHERTYPE_IP: 751 b0 = gen_cmp(off_linktype, BPF_H, PPP_IP); 752 b1 = gen_cmp(off_linktype, BPF_H, PPP_VJC); 753 gen_or(b0, b1); 754 b0 = gen_cmp(off_linktype, BPF_H, PPP_VJNC); 755 gen_or(b1, b0); 756 return b0; 757 758 #ifdef INET6 759 case ETHERTYPE_IPV6: 760 proto = PPP_IPV6; 761 /* more to go? */ 762 break; 763 #endif /* INET6 */ 764 765 case ETHERTYPE_DN: 766 proto = PPP_DECNET; 767 break; 768 769 case ETHERTYPE_ATALK: 770 proto = PPP_APPLE; 771 break; 772 773 case ETHERTYPE_NS: 774 proto = PPP_NS; 775 break; 776 } 777 break; 778 779 case DLT_LOOP: 780 case DLT_ENC: 781 case DLT_NULL: 782 /* XXX */ 783 if (proto == ETHERTYPE_IP) 784 return (gen_cmp(0, BPF_W, (bpf_int32)htonl(AF_INET))); 785 #ifdef INET6 786 else if (proto == ETHERTYPE_IPV6) 787 return (gen_cmp(0, BPF_W, (bpf_int32)htonl(AF_INET6))); 788 #endif /* INET6 */ 789 else 790 return gen_false(); 791 break; 792 case DLT_OLD_PFLOG: 793 if (proto == ETHERTYPE_IP) 794 return (gen_cmp(0, BPF_W, (bpf_int32)AF_INET)); 795 #ifdef INET6 796 else if (proto == ETHERTYPE_IPV6) 797 return (gen_cmp(0, BPF_W, (bpf_int32)AF_INET6)); 798 #endif /* INET6 */ 799 else 800 return gen_false(); 801 break; 802 803 case DLT_PFLOG: 804 if (proto == ETHERTYPE_IP) 805 return (gen_cmp(offsetof(struct pfloghdr, af), BPF_B, 806 (bpf_int32)AF_INET)); 807 #ifdef INET6 808 else if (proto == ETHERTYPE_IPV6) 809 return (gen_cmp(offsetof(struct pfloghdr, af), BPF_B, 810 (bpf_int32)AF_INET6)); 811 #endif /* INET6 */ 812 else 813 return gen_false(); 814 break; 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_STP: 1127 bpf_error("'stp' modifier applied to host"); 1128 1129 case Q_ATALK: 1130 bpf_error("ATALK host filtering not implemented"); 1131 1132 case Q_DECNET: 1133 return gen_dnhostop(addr, dir, off_nl); 1134 1135 case Q_SCA: 1136 bpf_error("SCA host filtering not implemented"); 1137 1138 case Q_LAT: 1139 bpf_error("LAT host filtering not implemented"); 1140 1141 case Q_MOPDL: 1142 bpf_error("MOPDL host filtering not implemented"); 1143 1144 case Q_MOPRC: 1145 bpf_error("MOPRC host filtering not implemented"); 1146 1147 #ifdef INET6 1148 case Q_IPV6: 1149 bpf_error("'ip6' modifier applied to ip host"); 1150 1151 case Q_ICMPV6: 1152 bpf_error("'icmp6' modifier applied to host"); 1153 #endif /* INET6 */ 1154 1155 case Q_AH: 1156 bpf_error("'ah' modifier applied to host"); 1157 1158 case Q_ESP: 1159 bpf_error("'esp' modifier applied to host"); 1160 1161 default: 1162 abort(); 1163 } 1164 /* NOTREACHED */ 1165 } 1166 1167 #ifdef INET6 1168 static struct block * 1169 gen_host6(addr, mask, proto, dir) 1170 struct in6_addr *addr; 1171 struct in6_addr *mask; 1172 int proto; 1173 int dir; 1174 { 1175 switch (proto) { 1176 1177 case Q_DEFAULT: 1178 return gen_host6(addr, mask, Q_IPV6, dir); 1179 1180 case Q_IP: 1181 bpf_error("'ip' modifier applied to ip6 host"); 1182 1183 case Q_RARP: 1184 bpf_error("'rarp' modifier applied to ip6 host"); 1185 1186 case Q_ARP: 1187 bpf_error("'arp' modifier applied to ip6 host"); 1188 1189 case Q_TCP: 1190 bpf_error("'tcp' modifier applied to host"); 1191 1192 case Q_UDP: 1193 bpf_error("'udp' modifier applied to host"); 1194 1195 case Q_ICMP: 1196 bpf_error("'icmp' modifier applied to host"); 1197 1198 case Q_IGMP: 1199 bpf_error("'igmp' modifier applied to host"); 1200 1201 case Q_IGRP: 1202 bpf_error("'igrp' modifier applied to host"); 1203 1204 case Q_PIM: 1205 bpf_error("'pim' modifier applied to host"); 1206 1207 case Q_STP: 1208 bpf_error("'stp' modifier applied to host"); 1209 1210 case Q_ATALK: 1211 bpf_error("ATALK host filtering not implemented"); 1212 1213 case Q_DECNET: 1214 bpf_error("'decnet' modifier applied to ip6 host"); 1215 1216 case Q_SCA: 1217 bpf_error("SCA host filtering not implemented"); 1218 1219 case Q_LAT: 1220 bpf_error("LAT host filtering not implemented"); 1221 1222 case Q_MOPDL: 1223 bpf_error("MOPDL host filtering not implemented"); 1224 1225 case Q_MOPRC: 1226 bpf_error("MOPRC host filtering not implemented"); 1227 1228 case Q_IPV6: 1229 return gen_hostop6(addr, mask, dir, ETHERTYPE_IPV6, 1230 off_nl + 8, off_nl + 24); 1231 1232 case Q_ICMPV6: 1233 bpf_error("'icmp6' modifier applied to host"); 1234 1235 case Q_AH: 1236 bpf_error("'ah' modifier applied to host"); 1237 1238 case Q_ESP: 1239 bpf_error("'esp' modifier applied to host"); 1240 1241 default: 1242 abort(); 1243 } 1244 /* NOTREACHED */ 1245 } 1246 #endif /*INET6*/ 1247 1248 #ifndef INET6 1249 static struct block * 1250 gen_gateway(eaddr, alist, proto, dir) 1251 const u_char *eaddr; 1252 bpf_u_int32 **alist; 1253 int proto; 1254 int dir; 1255 { 1256 struct block *b0, *b1, *tmp; 1257 1258 if (dir != 0) 1259 bpf_error("direction applied to 'gateway'"); 1260 1261 switch (proto) { 1262 case Q_DEFAULT: 1263 case Q_IP: 1264 case Q_ARP: 1265 case Q_RARP: 1266 if (linktype == DLT_EN10MB) 1267 b0 = gen_ehostop(eaddr, Q_OR); 1268 else if (linktype == DLT_FDDI) 1269 b0 = gen_fhostop(eaddr, Q_OR); 1270 else 1271 bpf_error( 1272 "'gateway' supported only on ethernet or FDDI"); 1273 1274 b1 = gen_host(**alist++, 0xffffffff, proto, Q_OR); 1275 while (*alist) { 1276 tmp = gen_host(**alist++, 0xffffffff, proto, Q_OR); 1277 gen_or(b1, tmp); 1278 b1 = tmp; 1279 } 1280 gen_not(b1); 1281 gen_and(b0, b1); 1282 return b1; 1283 } 1284 bpf_error("illegal modifier of 'gateway'"); 1285 /* NOTREACHED */ 1286 } 1287 #endif /*INET6*/ 1288 1289 struct block * 1290 gen_proto_abbrev(proto) 1291 int proto; 1292 { 1293 struct block *b0 = NULL, *b1; 1294 1295 switch (proto) { 1296 1297 case Q_TCP: 1298 b1 = gen_proto(IPPROTO_TCP, Q_IP, Q_DEFAULT); 1299 #ifdef INET6 1300 b0 = gen_proto(IPPROTO_TCP, Q_IPV6, Q_DEFAULT); 1301 gen_or(b0, b1); 1302 #endif 1303 break; 1304 1305 case Q_UDP: 1306 b1 = gen_proto(IPPROTO_UDP, Q_IP, Q_DEFAULT); 1307 #ifdef INET6 1308 b0 = gen_proto(IPPROTO_UDP, Q_IPV6, Q_DEFAULT); 1309 gen_or(b0, b1); 1310 #endif 1311 break; 1312 1313 case Q_ICMP: 1314 b1 = gen_proto(IPPROTO_ICMP, Q_IP, Q_DEFAULT); 1315 break; 1316 1317 #ifndef IPPROTO_IGMP 1318 #define IPPROTO_IGMP 2 1319 #endif 1320 1321 case Q_IGMP: 1322 b1 = gen_proto(IPPROTO_IGMP, Q_IP, Q_DEFAULT); 1323 break; 1324 1325 #ifndef IPPROTO_IGRP 1326 #define IPPROTO_IGRP 9 1327 #endif 1328 case Q_IGRP: 1329 b1 = gen_proto(IPPROTO_IGRP, Q_IP, Q_DEFAULT); 1330 break; 1331 1332 #ifndef IPPROTO_PIM 1333 #define IPPROTO_PIM 103 1334 #endif 1335 1336 case Q_PIM: 1337 b1 = gen_proto(IPPROTO_PIM, Q_IP, Q_DEFAULT); 1338 #ifdef INET6 1339 b0 = gen_proto(IPPROTO_PIM, Q_IPV6, Q_DEFAULT); 1340 gen_or(b0, b1); 1341 #endif 1342 break; 1343 1344 case Q_IP: 1345 b1 = gen_linktype(ETHERTYPE_IP); 1346 break; 1347 1348 case Q_ARP: 1349 b1 = gen_linktype(ETHERTYPE_ARP); 1350 break; 1351 1352 case Q_RARP: 1353 b1 = gen_linktype(ETHERTYPE_REVARP); 1354 break; 1355 1356 case Q_LINK: 1357 bpf_error("link layer applied in wrong context"); 1358 1359 case Q_ATALK: 1360 b1 = gen_linktype(ETHERTYPE_ATALK); 1361 break; 1362 1363 case Q_DECNET: 1364 b1 = gen_linktype(ETHERTYPE_DN); 1365 break; 1366 1367 case Q_SCA: 1368 b1 = gen_linktype(ETHERTYPE_SCA); 1369 break; 1370 1371 case Q_LAT: 1372 b1 = gen_linktype(ETHERTYPE_LAT); 1373 break; 1374 1375 case Q_MOPDL: 1376 b1 = gen_linktype(ETHERTYPE_MOPDL); 1377 break; 1378 1379 case Q_MOPRC: 1380 b1 = gen_linktype(ETHERTYPE_MOPRC); 1381 break; 1382 1383 case Q_STP: 1384 b1 = gen_linktype(LLCSAP_8021D); 1385 break; 1386 1387 #ifdef INET6 1388 case Q_IPV6: 1389 b1 = gen_linktype(ETHERTYPE_IPV6); 1390 break; 1391 1392 #ifndef IPPROTO_ICMPV6 1393 #define IPPROTO_ICMPV6 58 1394 #endif 1395 case Q_ICMPV6: 1396 b1 = gen_proto(IPPROTO_ICMPV6, Q_IPV6, Q_DEFAULT); 1397 break; 1398 #endif /* INET6 */ 1399 1400 #ifndef IPPROTO_AH 1401 #define IPPROTO_AH 51 1402 #endif 1403 case Q_AH: 1404 b1 = gen_proto(IPPROTO_AH, Q_IP, Q_DEFAULT); 1405 #ifdef INET6 1406 b0 = gen_proto(IPPROTO_AH, Q_IPV6, Q_DEFAULT); 1407 gen_or(b0, b1); 1408 #endif 1409 break; 1410 1411 #ifndef IPPROTO_ESP 1412 #define IPPROTO_ESP 50 1413 #endif 1414 case Q_ESP: 1415 b1 = gen_proto(IPPROTO_ESP, Q_IP, Q_DEFAULT); 1416 #ifdef INET6 1417 b0 = gen_proto(IPPROTO_ESP, Q_IPV6, Q_DEFAULT); 1418 gen_or(b0, b1); 1419 #endif 1420 break; 1421 1422 default: 1423 abort(); 1424 } 1425 return b1; 1426 } 1427 1428 static struct block * 1429 gen_ipfrag() 1430 { 1431 struct slist *s; 1432 struct block *b; 1433 1434 /* not ip frag */ 1435 s = new_stmt(BPF_LD|BPF_H|BPF_ABS); 1436 s->s.k = off_nl + 6; 1437 b = new_block(JMP(BPF_JSET)); 1438 b->s.k = 0x1fff; 1439 b->stmts = s; 1440 gen_not(b); 1441 1442 return b; 1443 } 1444 1445 static struct block * 1446 gen_portatom(off, v) 1447 int off; 1448 bpf_int32 v; 1449 { 1450 struct slist *s; 1451 struct block *b; 1452 1453 s = new_stmt(BPF_LDX|BPF_MSH|BPF_B); 1454 s->s.k = off_nl; 1455 1456 s->next = new_stmt(BPF_LD|BPF_IND|BPF_H); 1457 s->next->s.k = off_nl + off; 1458 1459 b = new_block(JMP(BPF_JEQ)); 1460 b->stmts = s; 1461 b->s.k = v; 1462 1463 return b; 1464 } 1465 1466 #ifdef INET6 1467 static struct block * 1468 gen_portatom6(off, v) 1469 int off; 1470 bpf_int32 v; 1471 { 1472 return gen_cmp(off_nl + 40 + off, BPF_H, v); 1473 } 1474 #endif/*INET6*/ 1475 1476 struct block * 1477 gen_portop(port, proto, dir) 1478 int port, proto, dir; 1479 { 1480 struct block *b0, *b1, *tmp; 1481 1482 /* ip proto 'proto' */ 1483 tmp = gen_cmp(off_nl + 9, BPF_B, (bpf_int32)proto); 1484 b0 = gen_ipfrag(); 1485 gen_and(tmp, b0); 1486 1487 switch (dir) { 1488 case Q_SRC: 1489 b1 = gen_portatom(0, (bpf_int32)port); 1490 break; 1491 1492 case Q_DST: 1493 b1 = gen_portatom(2, (bpf_int32)port); 1494 break; 1495 1496 case Q_OR: 1497 case Q_DEFAULT: 1498 tmp = gen_portatom(0, (bpf_int32)port); 1499 b1 = gen_portatom(2, (bpf_int32)port); 1500 gen_or(tmp, b1); 1501 break; 1502 1503 case Q_AND: 1504 tmp = gen_portatom(0, (bpf_int32)port); 1505 b1 = gen_portatom(2, (bpf_int32)port); 1506 gen_and(tmp, b1); 1507 break; 1508 1509 default: 1510 abort(); 1511 } 1512 gen_and(b0, b1); 1513 1514 return b1; 1515 } 1516 1517 static struct block * 1518 gen_port(port, ip_proto, dir) 1519 int port; 1520 int ip_proto; 1521 int dir; 1522 { 1523 struct block *b0, *b1, *tmp; 1524 1525 /* ether proto ip */ 1526 b0 = gen_linktype(ETHERTYPE_IP); 1527 1528 switch (ip_proto) { 1529 case IPPROTO_UDP: 1530 case IPPROTO_TCP: 1531 b1 = gen_portop(port, ip_proto, dir); 1532 break; 1533 1534 case PROTO_UNDEF: 1535 tmp = gen_portop(port, IPPROTO_TCP, dir); 1536 b1 = gen_portop(port, IPPROTO_UDP, dir); 1537 gen_or(tmp, b1); 1538 break; 1539 1540 default: 1541 abort(); 1542 } 1543 gen_and(b0, b1); 1544 return b1; 1545 } 1546 1547 #ifdef INET6 1548 struct block * 1549 gen_portop6(port, proto, dir) 1550 int port, proto, dir; 1551 { 1552 struct block *b0, *b1, *tmp; 1553 1554 /* ip proto 'proto' */ 1555 b0 = gen_cmp(off_nl + 6, BPF_B, (bpf_int32)proto); 1556 1557 switch (dir) { 1558 case Q_SRC: 1559 b1 = gen_portatom6(0, (bpf_int32)port); 1560 break; 1561 1562 case Q_DST: 1563 b1 = gen_portatom6(2, (bpf_int32)port); 1564 break; 1565 1566 case Q_OR: 1567 case Q_DEFAULT: 1568 tmp = gen_portatom6(0, (bpf_int32)port); 1569 b1 = gen_portatom6(2, (bpf_int32)port); 1570 gen_or(tmp, b1); 1571 break; 1572 1573 case Q_AND: 1574 tmp = gen_portatom6(0, (bpf_int32)port); 1575 b1 = gen_portatom6(2, (bpf_int32)port); 1576 gen_and(tmp, b1); 1577 break; 1578 1579 default: 1580 abort(); 1581 } 1582 gen_and(b0, b1); 1583 1584 return b1; 1585 } 1586 1587 static struct block * 1588 gen_port6(port, ip_proto, dir) 1589 int port; 1590 int ip_proto; 1591 int dir; 1592 { 1593 struct block *b0, *b1, *tmp; 1594 1595 /* ether proto ip */ 1596 b0 = gen_linktype(ETHERTYPE_IPV6); 1597 1598 switch (ip_proto) { 1599 case IPPROTO_UDP: 1600 case IPPROTO_TCP: 1601 b1 = gen_portop6(port, ip_proto, dir); 1602 break; 1603 1604 case PROTO_UNDEF: 1605 tmp = gen_portop6(port, IPPROTO_TCP, dir); 1606 b1 = gen_portop6(port, IPPROTO_UDP, dir); 1607 gen_or(tmp, b1); 1608 break; 1609 1610 default: 1611 abort(); 1612 } 1613 gen_and(b0, b1); 1614 return b1; 1615 } 1616 #endif /* INET6 */ 1617 1618 static int 1619 lookup_proto(name, proto) 1620 register const char *name; 1621 register int proto; 1622 { 1623 register int v; 1624 1625 switch (proto) { 1626 1627 case Q_DEFAULT: 1628 case Q_IP: 1629 v = pcap_nametoproto(name); 1630 if (v == PROTO_UNDEF) 1631 bpf_error("unknown ip proto '%s'", name); 1632 break; 1633 1634 case Q_LINK: 1635 /* XXX should look up h/w protocol type based on linktype */ 1636 v = pcap_nametoeproto(name); 1637 if (v == PROTO_UNDEF) { 1638 v = pcap_nametollc(name); 1639 if (v == PROTO_UNDEF) 1640 bpf_error("unknown ether proto '%s'", name); 1641 } 1642 break; 1643 1644 default: 1645 v = PROTO_UNDEF; 1646 break; 1647 } 1648 return v; 1649 } 1650 1651 static struct block * 1652 gen_protochain(v, proto, dir) 1653 int v; 1654 int proto; 1655 int dir; 1656 { 1657 struct block *b0, *b; 1658 struct slist *s[100]; 1659 int fix2, fix3, fix4, fix5; 1660 int ahcheck, again, end; 1661 int i, max; 1662 int reg1 = alloc_reg(); 1663 int reg2 = alloc_reg(); 1664 1665 memset(s, 0, sizeof(s)); 1666 fix2 = fix3 = fix4 = fix5 = 0; 1667 1668 switch (proto) { 1669 case Q_IP: 1670 case Q_IPV6: 1671 break; 1672 case Q_DEFAULT: 1673 b0 = gen_protochain(v, Q_IP, dir); 1674 b = gen_protochain(v, Q_IPV6, dir); 1675 gen_or(b0, b); 1676 return b; 1677 default: 1678 bpf_error("bad protocol applied for 'protochain'"); 1679 /*NOTREACHED*/ 1680 } 1681 1682 no_optimize = 1; /*this code is not compatible with optimzer yet */ 1683 1684 /* 1685 * s[0] is a dummy entry to protect other BPF insn from damaged 1686 * by s[fix] = foo with uninitialized variable "fix". It is somewhat 1687 * hard to find interdependency made by jump table fixup. 1688 */ 1689 i = 0; 1690 s[i] = new_stmt(0); /*dummy*/ 1691 i++; 1692 1693 switch (proto) { 1694 case Q_IP: 1695 b0 = gen_linktype(ETHERTYPE_IP); 1696 1697 /* A = ip->ip_p */ 1698 s[i] = new_stmt(BPF_LD|BPF_ABS|BPF_B); 1699 s[i]->s.k = off_nl + 9; 1700 i++; 1701 /* X = ip->ip_hl << 2 */ 1702 s[i] = new_stmt(BPF_LDX|BPF_MSH|BPF_B); 1703 s[i]->s.k = off_nl; 1704 i++; 1705 break; 1706 case Q_IPV6: 1707 b0 = gen_linktype(ETHERTYPE_IPV6); 1708 1709 /* A = ip6->ip_nxt */ 1710 s[i] = new_stmt(BPF_LD|BPF_ABS|BPF_B); 1711 s[i]->s.k = off_nl + 6; 1712 i++; 1713 /* X = sizeof(struct ip6_hdr) */ 1714 s[i] = new_stmt(BPF_LDX|BPF_IMM); 1715 s[i]->s.k = 40; 1716 i++; 1717 break; 1718 default: 1719 bpf_error("unsupported proto to gen_protochain"); 1720 /*NOTREACHED*/ 1721 } 1722 1723 /* again: if (A == v) goto end; else fall through; */ 1724 again = i; 1725 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1726 s[i]->s.k = v; 1727 s[i]->s.jt = NULL; /*later*/ 1728 s[i]->s.jf = NULL; /*update in next stmt*/ 1729 fix5 = i; 1730 i++; 1731 1732 /* if (A == IPPROTO_NONE) goto end */ 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_NONE; 1737 s[fix5]->s.jf = s[i]; 1738 fix2 = i; 1739 i++; 1740 1741 if (proto == Q_IPV6) { 1742 int v6start, v6end, v6advance, j; 1743 1744 v6start = i; 1745 /* if (A == IPPROTO_HOPOPTS) goto v6advance */ 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_HOPOPTS; 1750 s[fix2]->s.jf = s[i]; 1751 i++; 1752 /* if (A == IPPROTO_DSTOPTS) goto v6advance */ 1753 s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1754 s[i]->s.jt = NULL; /*later*/ 1755 s[i]->s.jf = NULL; /*update in next stmt*/ 1756 s[i]->s.k = IPPROTO_DSTOPTS; 1757 i++; 1758 /* if (A == IPPROTO_ROUTING) goto v6advance */ 1759 s[i - 1]->s.jf = 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_ROUTING; 1763 i++; 1764 /* if (A == IPPROTO_FRAGMENT) goto v6advance; else goto ahcheck; */ 1765 s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1766 s[i]->s.jt = NULL; /*later*/ 1767 s[i]->s.jf = NULL; /*later*/ 1768 s[i]->s.k = IPPROTO_FRAGMENT; 1769 fix3 = i; 1770 v6end = i; 1771 i++; 1772 1773 /* v6advance: */ 1774 v6advance = i; 1775 1776 /* 1777 * in short, 1778 * A = P[X + 1]; 1779 * X = X + (P[X] + 1) * 8; 1780 */ 1781 /* A = X */ 1782 s[i] = new_stmt(BPF_MISC|BPF_TXA); 1783 i++; 1784 /* MEM[reg1] = A */ 1785 s[i] = new_stmt(BPF_ST); 1786 s[i]->s.k = reg1; 1787 i++; 1788 /* A += 1 */ 1789 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1790 s[i]->s.k = 1; 1791 i++; 1792 /* X = A */ 1793 s[i] = new_stmt(BPF_MISC|BPF_TAX); 1794 i++; 1795 /* A = P[X + packet head]; */ 1796 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B); 1797 s[i]->s.k = off_nl; 1798 i++; 1799 /* MEM[reg2] = A */ 1800 s[i] = new_stmt(BPF_ST); 1801 s[i]->s.k = reg2; 1802 i++; 1803 /* X = MEM[reg1] */ 1804 s[i] = new_stmt(BPF_LDX|BPF_MEM); 1805 s[i]->s.k = reg1; 1806 i++; 1807 /* A = P[X + packet head] */ 1808 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B); 1809 s[i]->s.k = off_nl; 1810 i++; 1811 /* A += 1 */ 1812 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1813 s[i]->s.k = 1; 1814 i++; 1815 /* A *= 8 */ 1816 s[i] = new_stmt(BPF_ALU|BPF_MUL|BPF_K); 1817 s[i]->s.k = 8; 1818 i++; 1819 /* X = A; */ 1820 s[i] = new_stmt(BPF_MISC|BPF_TAX); 1821 i++; 1822 /* A = MEM[reg2] */ 1823 s[i] = new_stmt(BPF_LD|BPF_MEM); 1824 s[i]->s.k = reg2; 1825 i++; 1826 1827 /* goto again; (must use BPF_JA for backward jump) */ 1828 s[i] = new_stmt(BPF_JMP|BPF_JA); 1829 s[i]->s.k = again - i - 1; 1830 s[i - 1]->s.jf = s[i]; 1831 i++; 1832 1833 /* fixup */ 1834 for (j = v6start; j <= v6end; j++) 1835 s[j]->s.jt = s[v6advance]; 1836 } else { 1837 /* nop */ 1838 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1839 s[i]->s.k = 0; 1840 s[fix2]->s.jf = s[i]; 1841 i++; 1842 } 1843 1844 /* ahcheck: */ 1845 ahcheck = i; 1846 /* if (A == IPPROTO_AH) then fall through; else goto end; */ 1847 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1848 s[i]->s.jt = NULL; /*later*/ 1849 s[i]->s.jf = NULL; /*later*/ 1850 s[i]->s.k = IPPROTO_AH; 1851 if (fix3) 1852 s[fix3]->s.jf = s[ahcheck]; 1853 fix4 = i; 1854 i++; 1855 1856 /* 1857 * in short, 1858 * A = P[X + 1]; 1859 * X = X + (P[X] + 2) * 4; 1860 */ 1861 /* A = X */ 1862 s[i - 1]->s.jt = s[i] = new_stmt(BPF_MISC|BPF_TXA); 1863 i++; 1864 /* MEM[reg1] = A */ 1865 s[i] = new_stmt(BPF_ST); 1866 s[i]->s.k = reg1; 1867 i++; 1868 /* A += 1 */ 1869 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1870 s[i]->s.k = 1; 1871 i++; 1872 /* X = A */ 1873 s[i] = new_stmt(BPF_MISC|BPF_TAX); 1874 i++; 1875 /* A = P[X + packet head]; */ 1876 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B); 1877 s[i]->s.k = off_nl; 1878 i++; 1879 /* MEM[reg2] = A */ 1880 s[i] = new_stmt(BPF_ST); 1881 s[i]->s.k = reg2; 1882 i++; 1883 /* X = MEM[reg1] */ 1884 s[i] = new_stmt(BPF_LDX|BPF_MEM); 1885 s[i]->s.k = reg1; 1886 i++; 1887 /* A = P[X + packet head] */ 1888 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B); 1889 s[i]->s.k = off_nl; 1890 i++; 1891 /* A += 2 */ 1892 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1893 s[i]->s.k = 2; 1894 i++; 1895 /* A *= 4 */ 1896 s[i] = new_stmt(BPF_ALU|BPF_MUL|BPF_K); 1897 s[i]->s.k = 4; 1898 i++; 1899 /* X = A; */ 1900 s[i] = new_stmt(BPF_MISC|BPF_TAX); 1901 i++; 1902 /* A = MEM[reg2] */ 1903 s[i] = new_stmt(BPF_LD|BPF_MEM); 1904 s[i]->s.k = reg2; 1905 i++; 1906 1907 /* goto again; (must use BPF_JA for backward jump) */ 1908 s[i] = new_stmt(BPF_JMP|BPF_JA); 1909 s[i]->s.k = again - i - 1; 1910 i++; 1911 1912 /* end: nop */ 1913 end = i; 1914 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1915 s[i]->s.k = 0; 1916 s[fix2]->s.jt = s[end]; 1917 s[fix4]->s.jf = s[end]; 1918 s[fix5]->s.jt = s[end]; 1919 i++; 1920 1921 /* 1922 * make slist chain 1923 */ 1924 max = i; 1925 for (i = 0; i < max - 1; i++) 1926 s[i]->next = s[i + 1]; 1927 s[max - 1]->next = NULL; 1928 1929 /* 1930 * emit final check 1931 */ 1932 b = new_block(JMP(BPF_JEQ)); 1933 b->stmts = s[1]; /*remember, s[0] is dummy*/ 1934 b->s.k = v; 1935 1936 free_reg(reg1); 1937 free_reg(reg2); 1938 1939 gen_and(b0, b); 1940 return b; 1941 } 1942 1943 static struct block * 1944 gen_proto(v, proto, dir) 1945 int v; 1946 int proto; 1947 int dir; 1948 { 1949 struct block *b0, *b1; 1950 1951 if (dir != Q_DEFAULT) 1952 bpf_error("direction applied to 'proto'"); 1953 1954 switch (proto) { 1955 case Q_DEFAULT: 1956 #ifdef INET6 1957 b0 = gen_proto(v, Q_IP, dir); 1958 b1 = gen_proto(v, Q_IPV6, dir); 1959 gen_or(b0, b1); 1960 return b1; 1961 #else 1962 /*FALLTHROUGH*/ 1963 #endif 1964 case Q_IP: 1965 b0 = gen_linktype(ETHERTYPE_IP); 1966 #ifndef CHASE_CHAIN 1967 b1 = gen_cmp(off_nl + 9, BPF_B, (bpf_int32)v); 1968 #else 1969 b1 = gen_protochain(v, Q_IP); 1970 #endif 1971 gen_and(b0, b1); 1972 return b1; 1973 1974 case Q_ARP: 1975 bpf_error("arp does not encapsulate another protocol"); 1976 /* NOTREACHED */ 1977 1978 case Q_RARP: 1979 bpf_error("rarp does not encapsulate another protocol"); 1980 /* NOTREACHED */ 1981 1982 case Q_ATALK: 1983 bpf_error("atalk encapsulation is not specifiable"); 1984 /* NOTREACHED */ 1985 1986 case Q_DECNET: 1987 bpf_error("decnet encapsulation is not specifiable"); 1988 /* NOTREACHED */ 1989 1990 case Q_SCA: 1991 bpf_error("sca does not encapsulate another protocol"); 1992 /* NOTREACHED */ 1993 1994 case Q_LAT: 1995 bpf_error("lat does not encapsulate another protocol"); 1996 /* NOTREACHED */ 1997 1998 case Q_MOPRC: 1999 bpf_error("moprc does not encapsulate another protocol"); 2000 /* NOTREACHED */ 2001 2002 case Q_MOPDL: 2003 bpf_error("mopdl does not encapsulate another protocol"); 2004 /* NOTREACHED */ 2005 2006 case Q_LINK: 2007 return gen_linktype(v); 2008 2009 case Q_UDP: 2010 bpf_error("'udp proto' is bogus"); 2011 /* NOTREACHED */ 2012 2013 case Q_TCP: 2014 bpf_error("'tcp proto' is bogus"); 2015 /* NOTREACHED */ 2016 2017 case Q_ICMP: 2018 bpf_error("'icmp proto' is bogus"); 2019 /* NOTREACHED */ 2020 2021 case Q_IGMP: 2022 bpf_error("'igmp proto' is bogus"); 2023 /* NOTREACHED */ 2024 2025 case Q_IGRP: 2026 bpf_error("'igrp proto' is bogus"); 2027 /* NOTREACHED */ 2028 2029 case Q_PIM: 2030 bpf_error("'pim proto' is bogus"); 2031 /* NOTREACHED */ 2032 2033 case Q_STP: 2034 bpf_error("'stp proto' is bogus"); 2035 /* NOTREACHED */ 2036 2037 #ifdef INET6 2038 case Q_IPV6: 2039 b0 = gen_linktype(ETHERTYPE_IPV6); 2040 #ifndef CHASE_CHAIN 2041 b1 = gen_cmp(off_nl + 6, BPF_B, (bpf_int32)v); 2042 #else 2043 b1 = gen_protochain(v, Q_IPV6); 2044 #endif 2045 gen_and(b0, b1); 2046 return b1; 2047 2048 case Q_ICMPV6: 2049 bpf_error("'icmp6 proto' is bogus"); 2050 #endif /* INET6 */ 2051 2052 case Q_AH: 2053 bpf_error("'ah proto' is bogus"); 2054 2055 case Q_ESP: 2056 bpf_error("'ah proto' is bogus"); 2057 2058 default: 2059 abort(); 2060 /* NOTREACHED */ 2061 } 2062 /* NOTREACHED */ 2063 } 2064 2065 struct block * 2066 gen_scode(name, q) 2067 register const char *name; 2068 struct qual q; 2069 { 2070 int proto = q.proto; 2071 int dir = q.dir; 2072 int tproto; 2073 u_char *eaddr; 2074 bpf_u_int32 mask, addr; 2075 #ifndef INET6 2076 bpf_u_int32 **alist; 2077 #else 2078 int tproto6; 2079 struct sockaddr_in *sin; 2080 struct sockaddr_in6 *sin6; 2081 struct addrinfo *res, *res0; 2082 struct in6_addr mask128; 2083 #endif /*INET6*/ 2084 struct block *b, *tmp; 2085 int port, real_proto; 2086 2087 switch (q.addr) { 2088 2089 case Q_NET: 2090 addr = pcap_nametonetaddr(name); 2091 if (addr == 0) 2092 bpf_error("unknown network '%s'", name); 2093 /* Left justify network addr and calculate its network mask */ 2094 mask = 0xffffffff; 2095 while (addr && (addr & 0xff000000) == 0) { 2096 addr <<= 8; 2097 mask <<= 8; 2098 } 2099 return gen_host(addr, mask, proto, dir); 2100 2101 case Q_DEFAULT: 2102 case Q_HOST: 2103 if (proto == Q_LINK) { 2104 switch (linktype) { 2105 2106 case DLT_EN10MB: 2107 eaddr = pcap_ether_hostton(name); 2108 if (eaddr == NULL) 2109 bpf_error( 2110 "unknown ether host '%s'", name); 2111 return gen_ehostop(eaddr, dir); 2112 2113 case DLT_FDDI: 2114 eaddr = pcap_ether_hostton(name); 2115 if (eaddr == NULL) 2116 bpf_error( 2117 "unknown FDDI host '%s'", name); 2118 return gen_fhostop(eaddr, dir); 2119 2120 default: 2121 bpf_error( 2122 "only ethernet/FDDI supports link-level host name"); 2123 break; 2124 } 2125 } else if (proto == Q_DECNET) { 2126 unsigned short dn_addr = __pcap_nametodnaddr(name); 2127 /* 2128 * I don't think DECNET hosts can be multihomed, so 2129 * there is no need to build up a list of addresses 2130 */ 2131 return (gen_host(dn_addr, 0, proto, dir)); 2132 } else { 2133 #ifndef INET6 2134 alist = pcap_nametoaddr(name); 2135 if (alist == NULL || *alist == NULL) 2136 bpf_error("unknown host '%s'", name); 2137 tproto = proto; 2138 if (off_linktype == -1 && tproto == Q_DEFAULT) 2139 tproto = Q_IP; 2140 b = gen_host(**alist++, 0xffffffff, tproto, dir); 2141 while (*alist) { 2142 tmp = gen_host(**alist++, 0xffffffff, 2143 tproto, dir); 2144 gen_or(b, tmp); 2145 b = tmp; 2146 } 2147 return b; 2148 #else 2149 memset(&mask128, 0xff, sizeof(mask128)); 2150 res0 = res = pcap_nametoaddrinfo(name); 2151 if (res == NULL) 2152 bpf_error("unknown host '%s'", name); 2153 b = tmp = NULL; 2154 tproto = tproto6 = proto; 2155 if (off_linktype == -1 && tproto == Q_DEFAULT) { 2156 tproto = Q_IP; 2157 tproto6 = Q_IPV6; 2158 } 2159 for (res = res0; res; res = res->ai_next) { 2160 switch (res->ai_family) { 2161 case AF_INET: 2162 if (tproto == Q_IPV6) 2163 continue; 2164 2165 sin = (struct sockaddr_in *) 2166 res->ai_addr; 2167 tmp = gen_host(ntohl(sin->sin_addr.s_addr), 2168 0xffffffff, tproto, dir); 2169 break; 2170 case AF_INET6: 2171 if (tproto6 == Q_IP) 2172 continue; 2173 2174 sin6 = (struct sockaddr_in6 *) 2175 res->ai_addr; 2176 tmp = gen_host6(&sin6->sin6_addr, 2177 &mask128, tproto6, dir); 2178 break; 2179 } 2180 if (b) 2181 gen_or(b, tmp); 2182 b = tmp; 2183 } 2184 freeaddrinfo(res0); 2185 if (b == NULL) { 2186 bpf_error("unknown host '%s'%s", name, 2187 (proto == Q_DEFAULT) 2188 ? "" 2189 : " for specified address family"); 2190 } 2191 return b; 2192 #endif /*INET6*/ 2193 } 2194 2195 case Q_PORT: 2196 if (proto != Q_DEFAULT && proto != Q_UDP && proto != Q_TCP) 2197 bpf_error("illegal qualifier of 'port'"); 2198 if (pcap_nametoport(name, &port, &real_proto) == 0) 2199 bpf_error("unknown port '%s'", name); 2200 if (proto == Q_UDP) { 2201 if (real_proto == IPPROTO_TCP) 2202 bpf_error("port '%s' is tcp", name); 2203 else 2204 /* override PROTO_UNDEF */ 2205 real_proto = IPPROTO_UDP; 2206 } 2207 if (proto == Q_TCP) { 2208 if (real_proto == IPPROTO_UDP) 2209 bpf_error("port '%s' is udp", name); 2210 else 2211 /* override PROTO_UNDEF */ 2212 real_proto = IPPROTO_TCP; 2213 } 2214 #ifndef INET6 2215 return gen_port(port, real_proto, dir); 2216 #else 2217 { 2218 struct block *b; 2219 b = gen_port(port, real_proto, dir); 2220 gen_or(gen_port6(port, real_proto, dir), b); 2221 return b; 2222 } 2223 #endif /* INET6 */ 2224 2225 case Q_GATEWAY: 2226 #ifndef INET6 2227 eaddr = pcap_ether_hostton(name); 2228 if (eaddr == NULL) 2229 bpf_error("unknown ether host: %s", name); 2230 2231 alist = pcap_nametoaddr(name); 2232 if (alist == NULL || *alist == NULL) 2233 bpf_error("unknown host '%s'", name); 2234 return gen_gateway(eaddr, alist, proto, dir); 2235 #else 2236 bpf_error("'gateway' not supported in this configuration"); 2237 #endif /*INET6*/ 2238 2239 case Q_PROTO: 2240 real_proto = lookup_proto(name, proto); 2241 if (real_proto >= 0) 2242 return gen_proto(real_proto, proto, dir); 2243 else 2244 bpf_error("unknown protocol: %s", name); 2245 2246 case Q_PROTOCHAIN: 2247 real_proto = lookup_proto(name, proto); 2248 if (real_proto >= 0) 2249 return gen_protochain(real_proto, proto, dir); 2250 else 2251 bpf_error("unknown protocol: %s", name); 2252 2253 2254 case Q_UNDEF: 2255 syntax(); 2256 /* NOTREACHED */ 2257 } 2258 abort(); 2259 /* NOTREACHED */ 2260 } 2261 2262 struct block * 2263 gen_mcode(s1, s2, masklen, q) 2264 register const char *s1, *s2; 2265 register int masklen; 2266 struct qual q; 2267 { 2268 register int nlen, mlen; 2269 bpf_u_int32 n, m; 2270 2271 nlen = __pcap_atoin(s1, &n); 2272 /* Promote short ipaddr */ 2273 n <<= 32 - nlen; 2274 2275 if (s2 != NULL) { 2276 mlen = __pcap_atoin(s2, &m); 2277 /* Promote short ipaddr */ 2278 m <<= 32 - mlen; 2279 if ((n & ~m) != 0) 2280 bpf_error("non-network bits set in \"%s mask %s\"", 2281 s1, s2); 2282 } else { 2283 /* Convert mask len to mask */ 2284 if (masklen > 32) 2285 bpf_error("mask length must be <= 32"); 2286 m = 0xffffffff << (32 - masklen); 2287 if ((n & ~m) != 0) 2288 bpf_error("non-network bits set in \"%s/%d\"", 2289 s1, masklen); 2290 } 2291 2292 switch (q.addr) { 2293 2294 case Q_NET: 2295 return gen_host(n, m, q.proto, q.dir); 2296 2297 default: 2298 bpf_error("Mask syntax for networks only"); 2299 /* NOTREACHED */ 2300 } 2301 } 2302 2303 struct block * 2304 gen_ncode(s, v, q) 2305 register const char *s; 2306 bpf_u_int32 v; 2307 struct qual q; 2308 { 2309 bpf_u_int32 mask; 2310 int proto = q.proto; 2311 int dir = q.dir; 2312 register int vlen; 2313 2314 if (s == NULL) 2315 vlen = 32; 2316 else if (q.proto == Q_DECNET) 2317 vlen = __pcap_atodn(s, &v); 2318 else 2319 vlen = __pcap_atoin(s, &v); 2320 2321 switch (q.addr) { 2322 2323 case Q_DEFAULT: 2324 case Q_HOST: 2325 case Q_NET: 2326 if (proto == Q_DECNET) 2327 return gen_host(v, 0, proto, dir); 2328 else if (proto == Q_LINK) { 2329 bpf_error("illegal link layer address"); 2330 } else { 2331 mask = 0xffffffff; 2332 if (s == NULL && q.addr == Q_NET) { 2333 /* Promote short net number */ 2334 while (v && (v & 0xff000000) == 0) { 2335 v <<= 8; 2336 mask <<= 8; 2337 } 2338 } else { 2339 /* Promote short ipaddr */ 2340 v <<= 32 - vlen; 2341 mask <<= 32 - vlen; 2342 } 2343 return gen_host(v, mask, proto, dir); 2344 } 2345 2346 case Q_PORT: 2347 if (proto == Q_UDP) 2348 proto = IPPROTO_UDP; 2349 else if (proto == Q_TCP) 2350 proto = IPPROTO_TCP; 2351 else if (proto == Q_DEFAULT) 2352 proto = PROTO_UNDEF; 2353 else 2354 bpf_error("illegal qualifier of 'port'"); 2355 2356 #ifndef INET6 2357 return gen_port((int)v, proto, dir); 2358 #else 2359 { 2360 struct block *b; 2361 b = gen_port((int)v, proto, dir); 2362 gen_or(gen_port6((int)v, proto, dir), b); 2363 return b; 2364 } 2365 #endif /* INET6 */ 2366 2367 case Q_GATEWAY: 2368 bpf_error("'gateway' requires a name"); 2369 /* NOTREACHED */ 2370 2371 case Q_PROTO: 2372 return gen_proto((int)v, proto, dir); 2373 2374 case Q_PROTOCHAIN: 2375 return gen_protochain((int)v, proto, dir); 2376 2377 case Q_UNDEF: 2378 syntax(); 2379 /* NOTREACHED */ 2380 2381 default: 2382 abort(); 2383 /* NOTREACHED */ 2384 } 2385 /* NOTREACHED */ 2386 } 2387 2388 #ifdef INET6 2389 struct block * 2390 gen_mcode6(s1, s2, masklen, q) 2391 register const char *s1, *s2; 2392 register int masklen; 2393 struct qual q; 2394 { 2395 struct addrinfo *res; 2396 struct in6_addr *addr; 2397 struct in6_addr mask; 2398 struct block *b; 2399 u_int32_t *a, *m; 2400 2401 if (s2) 2402 bpf_error("no mask %s supported", s2); 2403 2404 res = pcap_nametoaddrinfo(s1); 2405 if (!res) 2406 bpf_error("invalid ip6 address %s", s1); 2407 if (res->ai_next) 2408 bpf_error("%s resolved to multiple address", s1); 2409 addr = &((struct sockaddr_in6 *)res->ai_addr)->sin6_addr; 2410 2411 if (sizeof(mask) * 8 < masklen) 2412 bpf_error("mask length must be <= %u", (unsigned int)(sizeof(mask) * 8)); 2413 memset(&mask, 0xff, masklen / 8); 2414 if (masklen % 8) { 2415 mask.s6_addr[masklen / 8] = 2416 (0xff << (8 - masklen % 8)) & 0xff; 2417 } 2418 2419 a = (u_int32_t *)addr; 2420 m = (u_int32_t *)&mask; 2421 if ((a[0] & ~m[0]) || (a[1] & ~m[1]) 2422 || (a[2] & ~m[2]) || (a[3] & ~m[3])) { 2423 bpf_error("non-network bits set in \"%s/%d\"", s1, masklen); 2424 } 2425 2426 switch (q.addr) { 2427 2428 case Q_DEFAULT: 2429 case Q_HOST: 2430 if (masklen != 128) 2431 bpf_error("Mask syntax for networks only"); 2432 /* FALLTHROUGH */ 2433 2434 case Q_NET: 2435 b = gen_host6(addr, &mask, q.proto, q.dir); 2436 freeaddrinfo(res); 2437 return b; 2438 2439 default: 2440 bpf_error("invalid qualifier against IPv6 address"); 2441 /* NOTREACHED */ 2442 } 2443 } 2444 #endif /*INET6*/ 2445 2446 struct block * 2447 gen_ecode(eaddr, q) 2448 register const u_char *eaddr; 2449 struct qual q; 2450 { 2451 if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) && q.proto == Q_LINK) { 2452 if (linktype == DLT_EN10MB) 2453 return gen_ehostop(eaddr, (int)q.dir); 2454 if (linktype == DLT_FDDI) 2455 return gen_fhostop(eaddr, (int)q.dir); 2456 } 2457 bpf_error("ethernet address used in non-ether expression"); 2458 /* NOTREACHED */ 2459 } 2460 2461 void 2462 sappend(s0, s1) 2463 struct slist *s0, *s1; 2464 { 2465 /* 2466 * This is definitely not the best way to do this, but the 2467 * lists will rarely get long. 2468 */ 2469 while (s0->next) 2470 s0 = s0->next; 2471 s0->next = s1; 2472 } 2473 2474 static struct slist * 2475 xfer_to_x(a) 2476 struct arth *a; 2477 { 2478 struct slist *s; 2479 2480 s = new_stmt(BPF_LDX|BPF_MEM); 2481 s->s.k = a->regno; 2482 return s; 2483 } 2484 2485 static struct slist * 2486 xfer_to_a(a) 2487 struct arth *a; 2488 { 2489 struct slist *s; 2490 2491 s = new_stmt(BPF_LD|BPF_MEM); 2492 s->s.k = a->regno; 2493 return s; 2494 } 2495 2496 struct arth * 2497 gen_load(proto, index, size) 2498 int proto; 2499 struct arth *index; 2500 int size; 2501 { 2502 struct slist *s, *tmp; 2503 struct block *b; 2504 int regno = alloc_reg(); 2505 2506 free_reg(index->regno); 2507 switch (size) { 2508 2509 default: 2510 bpf_error("data size must be 1, 2, or 4"); 2511 2512 case 1: 2513 size = BPF_B; 2514 break; 2515 2516 case 2: 2517 size = BPF_H; 2518 break; 2519 2520 case 4: 2521 size = BPF_W; 2522 break; 2523 } 2524 switch (proto) { 2525 default: 2526 bpf_error("unsupported index operation"); 2527 2528 case Q_LINK: 2529 s = xfer_to_x(index); 2530 tmp = new_stmt(BPF_LD|BPF_IND|size); 2531 sappend(s, tmp); 2532 sappend(index->s, s); 2533 break; 2534 2535 case Q_IP: 2536 case Q_ARP: 2537 case Q_RARP: 2538 case Q_ATALK: 2539 case Q_DECNET: 2540 case Q_SCA: 2541 case Q_LAT: 2542 case Q_MOPRC: 2543 case Q_MOPDL: 2544 #ifdef INET6 2545 case Q_IPV6: 2546 #endif 2547 /* XXX Note that we assume a fixed link header here. */ 2548 s = xfer_to_x(index); 2549 tmp = new_stmt(BPF_LD|BPF_IND|size); 2550 tmp->s.k = off_nl; 2551 sappend(s, tmp); 2552 sappend(index->s, s); 2553 2554 b = gen_proto_abbrev(proto); 2555 if (index->b) 2556 gen_and(index->b, b); 2557 index->b = b; 2558 break; 2559 2560 case Q_TCP: 2561 case Q_UDP: 2562 case Q_ICMP: 2563 case Q_IGMP: 2564 case Q_IGRP: 2565 case Q_PIM: 2566 s = new_stmt(BPF_LDX|BPF_MSH|BPF_B); 2567 s->s.k = off_nl; 2568 sappend(s, xfer_to_a(index)); 2569 sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X)); 2570 sappend(s, new_stmt(BPF_MISC|BPF_TAX)); 2571 sappend(s, tmp = new_stmt(BPF_LD|BPF_IND|size)); 2572 tmp->s.k = off_nl; 2573 sappend(index->s, s); 2574 2575 gen_and(gen_proto_abbrev(proto), b = gen_ipfrag()); 2576 if (index->b) 2577 gen_and(index->b, b); 2578 #ifdef INET6 2579 gen_and(gen_proto_abbrev(Q_IP), b); 2580 #endif 2581 index->b = b; 2582 break; 2583 #ifdef INET6 2584 case Q_ICMPV6: 2585 bpf_error("IPv6 upper-layer protocol is not supported by proto[x]"); 2586 /*NOTREACHED*/ 2587 #endif 2588 } 2589 index->regno = regno; 2590 s = new_stmt(BPF_ST); 2591 s->s.k = regno; 2592 sappend(index->s, s); 2593 2594 return index; 2595 } 2596 2597 struct block * 2598 gen_relation(code, a0, a1, reversed) 2599 int code; 2600 struct arth *a0, *a1; 2601 int reversed; 2602 { 2603 struct slist *s0, *s1, *s2; 2604 struct block *b, *tmp; 2605 2606 s0 = xfer_to_x(a1); 2607 s1 = xfer_to_a(a0); 2608 s2 = new_stmt(BPF_ALU|BPF_SUB|BPF_X); 2609 b = new_block(JMP(code)); 2610 if (code == BPF_JGT || code == BPF_JGE) { 2611 reversed = !reversed; 2612 b->s.k = 0x80000000; 2613 } 2614 if (reversed) 2615 gen_not(b); 2616 2617 sappend(s1, s2); 2618 sappend(s0, s1); 2619 sappend(a1->s, s0); 2620 sappend(a0->s, a1->s); 2621 2622 b->stmts = a0->s; 2623 2624 free_reg(a0->regno); 2625 free_reg(a1->regno); 2626 2627 /* 'and' together protocol checks */ 2628 if (a0->b) { 2629 if (a1->b) { 2630 gen_and(a0->b, tmp = a1->b); 2631 } 2632 else 2633 tmp = a0->b; 2634 } else 2635 tmp = a1->b; 2636 2637 if (tmp) 2638 gen_and(tmp, b); 2639 2640 return b; 2641 } 2642 2643 struct arth * 2644 gen_loadlen() 2645 { 2646 int regno = alloc_reg(); 2647 struct arth *a = (struct arth *)newchunk(sizeof(*a)); 2648 struct slist *s; 2649 2650 s = new_stmt(BPF_LD|BPF_LEN); 2651 s->next = new_stmt(BPF_ST); 2652 s->next->s.k = regno; 2653 a->s = s; 2654 a->regno = regno; 2655 2656 return a; 2657 } 2658 2659 struct arth * 2660 gen_loadi(val) 2661 int val; 2662 { 2663 struct arth *a; 2664 struct slist *s; 2665 int reg; 2666 2667 a = (struct arth *)newchunk(sizeof(*a)); 2668 2669 reg = alloc_reg(); 2670 2671 s = new_stmt(BPF_LD|BPF_IMM); 2672 s->s.k = val; 2673 s->next = new_stmt(BPF_ST); 2674 s->next->s.k = reg; 2675 a->s = s; 2676 a->regno = reg; 2677 2678 return a; 2679 } 2680 2681 struct arth * 2682 gen_neg(a) 2683 struct arth *a; 2684 { 2685 struct slist *s; 2686 2687 s = xfer_to_a(a); 2688 sappend(a->s, s); 2689 s = new_stmt(BPF_ALU|BPF_NEG); 2690 s->s.k = 0; 2691 sappend(a->s, s); 2692 s = new_stmt(BPF_ST); 2693 s->s.k = a->regno; 2694 sappend(a->s, s); 2695 2696 return a; 2697 } 2698 2699 struct arth * 2700 gen_arth(code, a0, a1) 2701 int code; 2702 struct arth *a0, *a1; 2703 { 2704 struct slist *s0, *s1, *s2; 2705 2706 s0 = xfer_to_x(a1); 2707 s1 = xfer_to_a(a0); 2708 s2 = new_stmt(BPF_ALU|BPF_X|code); 2709 2710 sappend(s1, s2); 2711 sappend(s0, s1); 2712 sappend(a1->s, s0); 2713 sappend(a0->s, a1->s); 2714 2715 free_reg(a1->regno); 2716 2717 s0 = new_stmt(BPF_ST); 2718 a0->regno = s0->s.k = alloc_reg(); 2719 sappend(a0->s, s0); 2720 2721 return a0; 2722 } 2723 2724 /* 2725 * Here we handle simple allocation of the scratch registers. 2726 * If too many registers are alloc'd, the allocator punts. 2727 */ 2728 static int regused[BPF_MEMWORDS]; 2729 static int curreg; 2730 2731 /* 2732 * Return the next free register. 2733 */ 2734 static int 2735 alloc_reg() 2736 { 2737 int n = BPF_MEMWORDS; 2738 2739 while (--n >= 0) { 2740 if (regused[curreg]) 2741 curreg = (curreg + 1) % BPF_MEMWORDS; 2742 else { 2743 regused[curreg] = 1; 2744 return curreg; 2745 } 2746 } 2747 bpf_error("too many registers needed to evaluate expression"); 2748 /* NOTREACHED */ 2749 } 2750 2751 /* 2752 * Return a register to the table so it can 2753 * be used later. 2754 */ 2755 static void 2756 free_reg(n) 2757 int n; 2758 { 2759 regused[n] = 0; 2760 } 2761 2762 static struct block * 2763 gen_len(jmp, n) 2764 int jmp, n; 2765 { 2766 struct slist *s; 2767 struct block *b; 2768 2769 s = new_stmt(BPF_LD|BPF_LEN); 2770 b = new_block(JMP(jmp)); 2771 b->stmts = s; 2772 b->s.k = n; 2773 2774 return b; 2775 } 2776 2777 struct block * 2778 gen_greater(n) 2779 int n; 2780 { 2781 return gen_len(BPF_JGE, n); 2782 } 2783 2784 struct block * 2785 gen_less(n) 2786 int n; 2787 { 2788 struct block *b; 2789 2790 b = gen_len(BPF_JGT, n); 2791 gen_not(b); 2792 2793 return b; 2794 } 2795 2796 struct block * 2797 gen_byteop(op, idx, val) 2798 int op, idx, val; 2799 { 2800 struct block *b; 2801 struct slist *s; 2802 2803 switch (op) { 2804 default: 2805 abort(); 2806 2807 case '=': 2808 return gen_cmp((u_int)idx, BPF_B, (bpf_int32)val); 2809 2810 case '<': 2811 b = gen_cmp((u_int)idx, BPF_B, (bpf_int32)val); 2812 b->s.code = JMP(BPF_JGE); 2813 gen_not(b); 2814 return b; 2815 2816 case '>': 2817 b = gen_cmp((u_int)idx, BPF_B, (bpf_int32)val); 2818 b->s.code = JMP(BPF_JGT); 2819 return b; 2820 2821 case '|': 2822 s = new_stmt(BPF_ALU|BPF_OR|BPF_K); 2823 break; 2824 2825 case '&': 2826 s = new_stmt(BPF_ALU|BPF_AND|BPF_K); 2827 break; 2828 } 2829 s->s.k = val; 2830 b = new_block(JMP(BPF_JEQ)); 2831 b->stmts = s; 2832 gen_not(b); 2833 2834 return b; 2835 } 2836 2837 struct block * 2838 gen_broadcast(proto) 2839 int proto; 2840 { 2841 bpf_u_int32 hostmask; 2842 struct block *b0, *b1, *b2; 2843 static u_char ebroadcast[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; 2844 2845 switch (proto) { 2846 2847 case Q_DEFAULT: 2848 case Q_LINK: 2849 if (linktype == DLT_EN10MB) 2850 return gen_ehostop(ebroadcast, Q_DST); 2851 if (linktype == DLT_FDDI) 2852 return gen_fhostop(ebroadcast, Q_DST); 2853 bpf_error("not a broadcast link"); 2854 break; 2855 2856 case Q_IP: 2857 b0 = gen_linktype(ETHERTYPE_IP); 2858 hostmask = ~netmask; 2859 b1 = gen_mcmp(off_nl + 16, BPF_W, (bpf_int32)0, hostmask); 2860 b2 = gen_mcmp(off_nl + 16, BPF_W, 2861 (bpf_int32)(~0 & hostmask), hostmask); 2862 gen_or(b1, b2); 2863 gen_and(b0, b2); 2864 return b2; 2865 } 2866 bpf_error("only ether/ip broadcast filters supported"); 2867 } 2868 2869 struct block * 2870 gen_multicast(proto) 2871 int proto; 2872 { 2873 register struct block *b0, *b1; 2874 register struct slist *s; 2875 2876 switch (proto) { 2877 2878 case Q_DEFAULT: 2879 case Q_LINK: 2880 if (linktype == DLT_EN10MB) { 2881 /* ether[0] & 1 != 0 */ 2882 s = new_stmt(BPF_LD|BPF_B|BPF_ABS); 2883 s->s.k = 0; 2884 b0 = new_block(JMP(BPF_JSET)); 2885 b0->s.k = 1; 2886 b0->stmts = s; 2887 return b0; 2888 } 2889 2890 if (linktype == DLT_FDDI) { 2891 /* XXX TEST THIS: MIGHT NOT PORT PROPERLY XXX */ 2892 /* fddi[1] & 1 != 0 */ 2893 s = new_stmt(BPF_LD|BPF_B|BPF_ABS); 2894 s->s.k = 1; 2895 b0 = new_block(JMP(BPF_JSET)); 2896 b0->s.k = 1; 2897 b0->stmts = s; 2898 return b0; 2899 } 2900 /* Link not known to support multicasts */ 2901 break; 2902 2903 case Q_IP: 2904 b0 = gen_linktype(ETHERTYPE_IP); 2905 b1 = gen_cmp(off_nl + 16, BPF_B, (bpf_int32)224); 2906 b1->s.code = JMP(BPF_JGE); 2907 gen_and(b0, b1); 2908 return b1; 2909 2910 #ifdef INET6 2911 case Q_IPV6: 2912 b0 = gen_linktype(ETHERTYPE_IPV6); 2913 b1 = gen_cmp(off_nl + 24, BPF_B, (bpf_int32)255); 2914 gen_and(b0, b1); 2915 return b1; 2916 #endif /* INET6 */ 2917 } 2918 bpf_error("only IP multicast filters supported on ethernet/FDDI"); 2919 } 2920 2921 /* 2922 * generate command for inbound/outbound. It's here so we can 2923 * make it link-type specific. 'dir' = 0 implies "inbound", 2924 * = 1 implies "outbound". 2925 */ 2926 struct block * 2927 gen_inbound(dir) 2928 int dir; 2929 { 2930 register struct block *b0; 2931 2932 /* 2933 * Only SLIP and old-style PPP data link types support 2934 * inbound/outbound qualifiers. 2935 */ 2936 switch (linktype) { 2937 case DLT_SLIP: 2938 case DLT_PPP: 2939 b0 = gen_relation(BPF_JEQ, 2940 gen_load(Q_LINK, gen_loadi(0), 1), 2941 gen_loadi(0), 2942 dir); 2943 break; 2944 2945 case DLT_PFLOG: 2946 b0 = gen_cmp(offsetof(struct pfloghdr, dir), BPF_B, 2947 (bpf_int32)((dir == 0) ? PF_IN : PF_OUT)); 2948 break; 2949 2950 case DLT_OLD_PFLOG: 2951 b0 = gen_cmp(offsetof(struct old_pfloghdr, dir), BPF_H, 2952 (bpf_int32)((dir == 0) ? PF_IN : PF_OUT)); 2953 break; 2954 2955 default: 2956 bpf_error("inbound/outbound not supported on linktype 0x%x\n", 2957 linktype); 2958 /* NOTREACHED */ 2959 } 2960 2961 return (b0); 2962 } 2963 2964 2965 /* PF firewall log matched interface */ 2966 struct block * 2967 gen_pf_ifname(char *ifname) 2968 { 2969 struct block *b0; 2970 u_int len, off; 2971 2972 if (linktype == DLT_PFLOG) { 2973 len = sizeof(((struct pfloghdr *)0)->ifname); 2974 off = offsetof(struct pfloghdr, ifname); 2975 } else if (linktype == DLT_OLD_PFLOG) { 2976 len = sizeof(((struct old_pfloghdr *)0)->ifname); 2977 off = offsetof(struct old_pfloghdr, ifname); 2978 } else { 2979 bpf_error("ifname not supported on linktype 0x%x\n", linktype); 2980 /* NOTREACHED */ 2981 } 2982 if (strlen(ifname) >= len) { 2983 bpf_error("ifname interface names can only be %d characters\n", 2984 len - 1); 2985 /* NOTREACHED */ 2986 } 2987 b0 = gen_bcmp(off, strlen(ifname), ifname); 2988 return (b0); 2989 } 2990 2991 2992 /* PF firewall log ruleset name */ 2993 struct block * 2994 gen_pf_ruleset(char *ruleset) 2995 { 2996 struct block *b0; 2997 2998 if (linktype != DLT_PFLOG) { 2999 bpf_error("ruleset not supported on linktype 0x%x\n", linktype); 3000 /* NOTREACHED */ 3001 } 3002 if (strlen(ruleset) >= sizeof(((struct pfloghdr *)0)->ruleset)) { 3003 bpf_error("ruleset names can only be %d characters\n", 3004 sizeof(((struct pfloghdr *)0)->ruleset) - 1); 3005 /* NOTREACHED */ 3006 } 3007 b0 = gen_bcmp(offsetof(struct pfloghdr, ruleset), 3008 strlen(ruleset), ruleset); 3009 return (b0); 3010 } 3011 3012 3013 /* PF firewall log rule number */ 3014 struct block * 3015 gen_pf_rnr(int rnr) 3016 { 3017 struct block *b0; 3018 3019 if (linktype == DLT_PFLOG) { 3020 b0 = gen_cmp(offsetof(struct pfloghdr, rulenr), BPF_W, 3021 (bpf_int32)rnr); 3022 } else if (linktype == DLT_OLD_PFLOG) { 3023 b0 = gen_cmp(offsetof(struct old_pfloghdr, rnr), BPF_H, 3024 (bpf_int32)rnr); 3025 } else { 3026 bpf_error("rnr not supported on linktype 0x%x\n", linktype); 3027 /* NOTREACHED */ 3028 } 3029 3030 return (b0); 3031 } 3032 3033 3034 /* PF firewall log sub-rule number */ 3035 struct block * 3036 gen_pf_srnr(int srnr) 3037 { 3038 struct block *b0; 3039 3040 if (linktype != DLT_PFLOG) { 3041 bpf_error("srnr not supported on linktype 0x%x\n", linktype); 3042 /* NOTREACHED */ 3043 } 3044 3045 b0 = gen_cmp(offsetof(struct pfloghdr, subrulenr), BPF_W, 3046 (bpf_int32)srnr); 3047 return (b0); 3048 } 3049 3050 /* PF firewall log reason code */ 3051 struct block * 3052 gen_pf_reason(int reason) 3053 { 3054 struct block *b0; 3055 3056 if (linktype == DLT_PFLOG) { 3057 b0 = gen_cmp(offsetof(struct pfloghdr, reason), BPF_B, 3058 (bpf_int32)reason); 3059 } else if (linktype == DLT_OLD_PFLOG) { 3060 b0 = gen_cmp(offsetof(struct old_pfloghdr, reason), BPF_H, 3061 (bpf_int32)reason); 3062 } else { 3063 bpf_error("reason not supported on linktype 0x%x\n", linktype); 3064 /* NOTREACHED */ 3065 } 3066 3067 return (b0); 3068 } 3069 3070 /* PF firewall log action */ 3071 struct block * 3072 gen_pf_action(int action) 3073 { 3074 struct block *b0; 3075 3076 if (linktype == DLT_PFLOG) { 3077 b0 = gen_cmp(offsetof(struct pfloghdr, action), BPF_B, 3078 (bpf_int32)action); 3079 } else if (linktype == DLT_OLD_PFLOG) { 3080 b0 = gen_cmp(offsetof(struct old_pfloghdr, action), BPF_H, 3081 (bpf_int32)action); 3082 } else { 3083 bpf_error("action not supported on linktype 0x%x\n", linktype); 3084 /* NOTREACHED */ 3085 } 3086 3087 return (b0); 3088 } 3089