1 /* $OpenBSD: gencode.c,v 1.17 2002/07/09 17:03:00 provos 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 #ifndef lint 24 static const char rcsid[] = 25 "@(#) $Header: /home/cvs/src/lib/libpcap/gencode.c,v 1.17 2002/07/09 17:03:00 provos Exp $ (LBL)"; 26 #endif 27 28 #include <sys/types.h> 29 #include <sys/socket.h> 30 #include <sys/time.h> 31 32 struct mbuf; 33 struct rtentry; 34 35 #include <net/if.h> 36 37 #include <netinet/in.h> 38 #include <netinet/if_ether.h> 39 #include <netinet/if_arc.h> 40 41 #include <net/if_pflog.h> 42 #include <net/pfvar.h> 43 44 #include <stdlib.h> 45 #include <stddef.h> 46 #include <memory.h> 47 #include <setjmp.h> 48 #include <stdarg.h> 49 50 #include "pcap-int.h" 51 52 #include "ethertype.h" 53 #include "gencode.h" 54 #include "ppp.h" 55 #include <pcap-namedb.h> 56 #ifdef INET6 57 #include <netdb.h> 58 #include <sys/socket.h> 59 #endif /*INET6*/ 60 61 #ifdef HAVE_OS_PROTO_H 62 #include "os-proto.h" 63 #endif 64 65 #define JMP(c) ((c)|BPF_JMP|BPF_K) 66 67 /* Locals */ 68 static jmp_buf top_ctx; 69 static pcap_t *bpf_pcap; 70 71 /* XXX */ 72 #ifdef PCAP_FDDIPAD 73 int pcap_fddipad = PCAP_FDDIPAD; 74 #else 75 int pcap_fddipad; 76 #endif 77 78 /* VARARGS */ 79 __dead void 80 bpf_error(const char *fmt, ...) 81 { 82 va_list ap; 83 84 va_start(ap, fmt); 85 if (bpf_pcap != NULL) 86 (void)vsnprintf(pcap_geterr(bpf_pcap), PCAP_ERRBUF_SIZE, 87 fmt, ap); 88 va_end(ap); 89 longjmp(top_ctx, 1); 90 /* NOTREACHED */ 91 } 92 93 static void init_linktype(int); 94 95 static int alloc_reg(void); 96 static void free_reg(int); 97 98 static struct block *root; 99 100 /* 101 * We divy out chunks of memory rather than call malloc each time so 102 * we don't have to worry about leaking memory. It's probably 103 * not a big deal if all this memory was wasted but it this ever 104 * goes into a library that would probably not be a good idea. 105 */ 106 #define NCHUNKS 16 107 #define CHUNK0SIZE 1024 108 struct chunk { 109 u_int n_left; 110 void *m; 111 }; 112 113 static struct chunk chunks[NCHUNKS]; 114 static int cur_chunk; 115 116 static void *newchunk(u_int); 117 static void freechunks(void); 118 static __inline struct block *new_block(int); 119 static __inline struct slist *new_stmt(int); 120 static struct block *gen_retblk(int); 121 static __inline void syntax(void); 122 123 static void backpatch(struct block *, struct block *); 124 static void merge(struct block *, struct block *); 125 static struct block *gen_cmp(u_int, u_int, bpf_int32); 126 static struct block *gen_mcmp(u_int, u_int, bpf_int32, bpf_u_int32); 127 static struct block *gen_bcmp(u_int, u_int, const u_char *); 128 static struct block *gen_uncond(int); 129 static __inline struct block *gen_true(void); 130 static __inline struct block *gen_false(void); 131 static struct block *gen_linktype(int); 132 static struct block *gen_hostop(bpf_u_int32, bpf_u_int32, int, int, u_int, u_int); 133 #ifdef INET6 134 static struct block *gen_hostop6(struct in6_addr *, struct in6_addr *, int, int, u_int, u_int); 135 #endif 136 static struct block *gen_ahostop(const u_char *, int); 137 static struct block *gen_ehostop(const u_char *, int); 138 static struct block *gen_fhostop(const u_char *, int); 139 static struct block *gen_dnhostop(bpf_u_int32, int, u_int); 140 static struct block *gen_host(bpf_u_int32, bpf_u_int32, int, int); 141 #ifdef INET6 142 static struct block *gen_host6(struct in6_addr *, struct in6_addr *, int, int); 143 #endif 144 #ifndef INET6 145 static struct block *gen_gateway(const u_char *, bpf_u_int32 **, int, int); 146 #endif 147 static struct block *gen_ipfrag(void); 148 static struct block *gen_portatom(int, bpf_int32); 149 #ifdef INET6 150 static struct block *gen_portatom6(int, bpf_int32); 151 #endif 152 struct block *gen_portop(int, int, int); 153 static struct block *gen_port(int, int, int); 154 #ifdef INET6 155 struct block *gen_portop6(int, int, int); 156 static struct block *gen_port6(int, int, int); 157 #endif 158 static int lookup_proto(const char *, int); 159 static struct block *gen_protochain(int, int, int); 160 static struct block *gen_proto(int, int, int); 161 static struct slist *xfer_to_x(struct arth *); 162 static struct slist *xfer_to_a(struct arth *); 163 static struct block *gen_len(int, int); 164 165 static void * 166 newchunk(n) 167 u_int n; 168 { 169 struct chunk *cp; 170 int k, size; 171 172 /* XXX Round to structure boundary. */ 173 n = ALIGN(n); 174 175 cp = &chunks[cur_chunk]; 176 if (n > cp->n_left) { 177 ++cp, k = ++cur_chunk; 178 if (k >= NCHUNKS) 179 bpf_error("out of memory"); 180 size = CHUNK0SIZE << k; 181 cp->m = (void *)malloc(size); 182 if (cp->m == NULL) 183 bpf_error("out of memory"); 184 185 memset((char *)cp->m, 0, size); 186 cp->n_left = size; 187 if (n > size) 188 bpf_error("out of memory"); 189 } 190 cp->n_left -= n; 191 return (void *)((char *)cp->m + cp->n_left); 192 } 193 194 static void 195 freechunks() 196 { 197 int i; 198 199 cur_chunk = 0; 200 for (i = 0; i < NCHUNKS; ++i) 201 if (chunks[i].m != NULL) { 202 free(chunks[i].m); 203 chunks[i].m = NULL; 204 } 205 } 206 207 /* 208 * A strdup whose allocations are freed after code generation is over. 209 */ 210 char * 211 sdup(s) 212 register const char *s; 213 { 214 int n = strlen(s) + 1; 215 char *cp = newchunk(n); 216 217 strlcpy(cp, s, n); 218 return (cp); 219 } 220 221 static __inline struct block * 222 new_block(code) 223 int code; 224 { 225 struct block *p; 226 227 p = (struct block *)newchunk(sizeof(*p)); 228 p->s.code = code; 229 p->head = p; 230 231 return p; 232 } 233 234 static __inline struct slist * 235 new_stmt(code) 236 int code; 237 { 238 struct slist *p; 239 240 p = (struct slist *)newchunk(sizeof(*p)); 241 p->s.code = code; 242 243 return p; 244 } 245 246 static struct block * 247 gen_retblk(v) 248 int v; 249 { 250 struct block *b = new_block(BPF_RET|BPF_K); 251 252 b->s.k = v; 253 return b; 254 } 255 256 static __inline void 257 syntax() 258 { 259 bpf_error("syntax error in filter expression"); 260 } 261 262 static bpf_u_int32 netmask; 263 static int snaplen; 264 int no_optimize; 265 266 int 267 pcap_compile(pcap_t *p, struct bpf_program *program, 268 char *buf, int optimize, bpf_u_int32 mask) 269 { 270 extern int n_errors; 271 int len; 272 273 no_optimize = 0; 274 n_errors = 0; 275 root = NULL; 276 bpf_pcap = p; 277 if (setjmp(top_ctx)) { 278 freechunks(); 279 return (-1); 280 } 281 282 netmask = mask; 283 snaplen = pcap_snapshot(p); 284 285 lex_init(buf ? buf : ""); 286 init_linktype(pcap_datalink(p)); 287 (void)pcap_parse(); 288 289 if (n_errors) 290 syntax(); 291 292 if (root == NULL) 293 root = gen_retblk(snaplen); 294 295 if (optimize && !no_optimize) { 296 bpf_optimize(&root); 297 if (root == NULL || 298 (root->s.code == (BPF_RET|BPF_K) && root->s.k == 0)) 299 bpf_error("expression rejects all packets"); 300 } 301 program->bf_insns = icode_to_fcode(root, &len); 302 program->bf_len = len; 303 304 freechunks(); 305 return (0); 306 } 307 308 /* 309 * entry point for using the compiler with no pcap open 310 * pass in all the stuff that is needed explicitly instead. 311 */ 312 int 313 pcap_compile_nopcap(int snaplen_arg, int linktype_arg, 314 struct bpf_program *program, 315 char *buf, int optimize, bpf_u_int32 mask) 316 { 317 extern int n_errors; 318 int len; 319 320 n_errors = 0; 321 root = NULL; 322 bpf_pcap = NULL; 323 if (setjmp(top_ctx)) { 324 freechunks(); 325 return (-1); 326 } 327 328 netmask = mask; 329 330 /* XXX needed? I don't grok the use of globals here. */ 331 snaplen = snaplen_arg; 332 333 lex_init(buf ? buf : ""); 334 init_linktype(linktype_arg); 335 (void)pcap_parse(); 336 337 if (n_errors) 338 syntax(); 339 340 if (root == NULL) 341 root = gen_retblk(snaplen_arg); 342 343 if (optimize) { 344 bpf_optimize(&root); 345 if (root == NULL || 346 (root->s.code == (BPF_RET|BPF_K) && root->s.k == 0)) 347 bpf_error("expression rejects all packets"); 348 } 349 program->bf_insns = icode_to_fcode(root, &len); 350 program->bf_len = len; 351 352 freechunks(); 353 return (0); 354 } 355 356 /* 357 * Clean up a "struct bpf_program" by freeing all the memory allocated 358 * in it. 359 */ 360 void 361 pcap_freecode(struct bpf_program *program) 362 { 363 program->bf_len = 0; 364 if (program->bf_insns != NULL) { 365 free((char *)program->bf_insns); 366 program->bf_insns = NULL; 367 } 368 } 369 370 /* 371 * Backpatch the blocks in 'list' to 'target'. The 'sense' field indicates 372 * which of the jt and jf fields has been resolved and which is a pointer 373 * back to another unresolved block (or nil). At least one of the fields 374 * in each block is already resolved. 375 */ 376 static void 377 backpatch(list, target) 378 struct block *list, *target; 379 { 380 struct block *next; 381 382 while (list) { 383 if (!list->sense) { 384 next = JT(list); 385 JT(list) = target; 386 } else { 387 next = JF(list); 388 JF(list) = target; 389 } 390 list = next; 391 } 392 } 393 394 /* 395 * Merge the lists in b0 and b1, using the 'sense' field to indicate 396 * which of jt and jf is the link. 397 */ 398 static void 399 merge(b0, b1) 400 struct block *b0, *b1; 401 { 402 register struct block **p = &b0; 403 404 /* Find end of list. */ 405 while (*p) 406 p = !((*p)->sense) ? &JT(*p) : &JF(*p); 407 408 /* Concatenate the lists. */ 409 *p = b1; 410 } 411 412 void 413 finish_parse(p) 414 struct block *p; 415 { 416 backpatch(p, gen_retblk(snaplen)); 417 p->sense = !p->sense; 418 backpatch(p, gen_retblk(0)); 419 root = p->head; 420 } 421 422 void 423 gen_and(b0, b1) 424 struct block *b0, *b1; 425 { 426 backpatch(b0, b1->head); 427 b0->sense = !b0->sense; 428 b1->sense = !b1->sense; 429 merge(b1, b0); 430 b1->sense = !b1->sense; 431 b1->head = b0->head; 432 } 433 434 void 435 gen_or(b0, b1) 436 struct block *b0, *b1; 437 { 438 b0->sense = !b0->sense; 439 backpatch(b0, b1->head); 440 b0->sense = !b0->sense; 441 merge(b1, b0); 442 b1->head = b0->head; 443 } 444 445 void 446 gen_not(b) 447 struct block *b; 448 { 449 b->sense = !b->sense; 450 } 451 452 static struct block * 453 gen_cmp(offset, size, v) 454 u_int offset, size; 455 bpf_int32 v; 456 { 457 struct slist *s; 458 struct block *b; 459 460 s = new_stmt(BPF_LD|BPF_ABS|size); 461 s->s.k = offset; 462 463 b = new_block(JMP(BPF_JEQ)); 464 b->stmts = s; 465 b->s.k = v; 466 467 return b; 468 } 469 470 static struct block * 471 gen_mcmp(offset, size, v, mask) 472 u_int offset, size; 473 bpf_int32 v; 474 bpf_u_int32 mask; 475 { 476 struct block *b = gen_cmp(offset, size, v); 477 struct slist *s; 478 479 if (mask != 0xffffffff) { 480 s = new_stmt(BPF_ALU|BPF_AND|BPF_K); 481 s->s.k = mask; 482 b->stmts->next = s; 483 } 484 return b; 485 } 486 487 static struct block * 488 gen_bcmp(offset, size, v) 489 register u_int offset, size; 490 register const u_char *v; 491 { 492 register struct block *b, *tmp; 493 494 b = NULL; 495 while (size >= 4) { 496 register const u_char *p = &v[size - 4]; 497 bpf_int32 w = ((bpf_int32)p[0] << 24) | 498 ((bpf_int32)p[1] << 16) | ((bpf_int32)p[2] << 8) | p[3]; 499 500 tmp = gen_cmp(offset + size - 4, BPF_W, w); 501 if (b != NULL) 502 gen_and(b, tmp); 503 b = tmp; 504 size -= 4; 505 } 506 while (size >= 2) { 507 register const u_char *p = &v[size - 2]; 508 bpf_int32 w = ((bpf_int32)p[0] << 8) | p[1]; 509 510 tmp = gen_cmp(offset + size - 2, BPF_H, w); 511 if (b != NULL) 512 gen_and(b, tmp); 513 b = tmp; 514 size -= 2; 515 } 516 if (size > 0) { 517 tmp = gen_cmp(offset, BPF_B, (bpf_int32)v[0]); 518 if (b != NULL) 519 gen_and(b, tmp); 520 b = tmp; 521 } 522 return b; 523 } 524 525 /* 526 * Various code constructs need to know the layout of the data link 527 * layer. These variables give the necessary offsets. off_linktype 528 * is set to -1 for no encapsulation, in which case, IP is assumed. 529 */ 530 static u_int off_linktype; 531 static u_int off_nl; 532 static int linktype; 533 534 static void 535 init_linktype(type) 536 int type; 537 { 538 linktype = type; 539 540 switch (type) { 541 542 case DLT_ARCNET: 543 off_linktype = 2; 544 off_nl = 6; /* XXX in reality, variable! */ 545 return; 546 547 case DLT_EN10MB: 548 off_linktype = 12; 549 off_nl = 14; 550 return; 551 552 case DLT_SLIP: 553 /* 554 * SLIP doesn't have a link level type. The 16 byte 555 * header is hacked into our SLIP driver. 556 */ 557 off_linktype = -1; 558 off_nl = 16; 559 return; 560 561 case DLT_SLIP_BSDOS: 562 /* XXX this may be the same as the DLT_PPP_BSDOS case */ 563 off_linktype = -1; 564 /* XXX end */ 565 off_nl = 24; 566 return; 567 568 case DLT_NULL: 569 off_linktype = 0; 570 off_nl = 4; 571 return; 572 573 case DLT_PPP: 574 off_linktype = 2; 575 off_nl = 4; 576 return; 577 578 case DLT_PPP_BSDOS: 579 off_linktype = 5; 580 off_nl = 24; 581 return; 582 583 case DLT_FDDI: 584 /* 585 * FDDI doesn't really have a link-level type field. 586 * We assume that SSAP = SNAP is being used and pick 587 * out the encapsulated Ethernet type. 588 */ 589 off_linktype = 19; 590 #ifdef PCAP_FDDIPAD 591 off_linktype += pcap_fddipad; 592 #endif 593 off_nl = 21; 594 #ifdef PCAP_FDDIPAD 595 off_nl += pcap_fddipad; 596 #endif 597 return; 598 599 case DLT_IEEE802: 600 off_linktype = 20; 601 off_nl = 22; 602 return; 603 604 case DLT_ATM_RFC1483: 605 /* 606 * assume routed, non-ISO PDUs 607 * (i.e., LLC = 0xAA-AA-03, OUT = 0x00-00-00) 608 */ 609 off_linktype = 6; 610 off_nl = 8; 611 return; 612 613 case DLT_LOOP: 614 off_linktype = -1; 615 off_nl = 4; 616 return; 617 618 case DLT_ENC: 619 off_linktype = -1; 620 off_nl = 12; 621 return; 622 623 case DLT_PFLOG: 624 off_linktype = 0; 625 off_nl = 28; 626 return; 627 628 case DLT_RAW: 629 off_linktype = -1; 630 off_nl = 0; 631 return; 632 } 633 bpf_error("unknown data link type 0x%x", linktype); 634 /* NOTREACHED */ 635 } 636 637 static struct block * 638 gen_uncond(rsense) 639 int rsense; 640 { 641 struct block *b; 642 struct slist *s; 643 644 s = new_stmt(BPF_LD|BPF_IMM); 645 s->s.k = !rsense; 646 b = new_block(JMP(BPF_JEQ)); 647 b->stmts = s; 648 649 return b; 650 } 651 652 static __inline struct block * 653 gen_true() 654 { 655 return gen_uncond(1); 656 } 657 658 static __inline struct block * 659 gen_false() 660 { 661 return gen_uncond(0); 662 } 663 664 static struct block * 665 gen_linktype(proto) 666 register int proto; 667 { 668 struct block *b0, *b1; 669 670 /* If we're not using encapsulation and checking for IP, we're done */ 671 if (off_linktype == -1 && proto == ETHERTYPE_IP) 672 return gen_true(); 673 #ifdef INET6 674 /* this isn't the right thing to do, but sometimes necessary */ 675 if (off_linktype == -1 && proto == ETHERTYPE_IPV6) 676 return gen_true(); 677 #endif 678 679 switch (linktype) { 680 681 case DLT_SLIP: 682 return gen_false(); 683 684 case DLT_PPP: 685 if (proto == ETHERTYPE_IP) 686 proto = PPP_IP; /* XXX was 0x21 */ 687 #ifdef INET6 688 else if (proto == ETHERTYPE_IPV6) 689 proto = PPP_IPV6; 690 #endif 691 break; 692 693 case DLT_PPP_BSDOS: 694 switch (proto) { 695 696 case ETHERTYPE_IP: 697 b0 = gen_cmp(off_linktype, BPF_H, PPP_IP); 698 b1 = gen_cmp(off_linktype, BPF_H, PPP_VJC); 699 gen_or(b0, b1); 700 b0 = gen_cmp(off_linktype, BPF_H, PPP_VJNC); 701 gen_or(b1, b0); 702 return b0; 703 704 #ifdef INET6 705 case ETHERTYPE_IPV6: 706 proto = PPP_IPV6; 707 /* more to go? */ 708 break; 709 #endif /* INET6 */ 710 711 case ETHERTYPE_DN: 712 proto = PPP_DECNET; 713 break; 714 715 case ETHERTYPE_ATALK: 716 proto = PPP_APPLE; 717 break; 718 719 case ETHERTYPE_NS: 720 proto = PPP_NS; 721 break; 722 } 723 break; 724 725 case DLT_LOOP: 726 case DLT_ENC: 727 case DLT_NULL: 728 /* XXX */ 729 if (proto == ETHERTYPE_IP) 730 return (gen_cmp(0, BPF_W, (bpf_int32)htonl(AF_INET))); 731 #ifdef INET6 732 else if (proto == ETHERTYPE_IPV6) 733 return (gen_cmp(0, BPF_W, (bpf_int32)htonl(AF_INET6))); 734 #endif /* INET6 */ 735 else 736 return gen_false(); 737 break; 738 case DLT_PFLOG: 739 if (proto == ETHERTYPE_IP) 740 return (gen_cmp(0, BPF_W, (bpf_int32)AF_INET)); 741 #ifdef INET6 742 else if (proto == ETHERTYPE_IPV6) 743 return (gen_cmp(0, BPF_W, (bpf_int32)AF_INET6)); 744 #endif /* INET6 */ 745 else 746 return gen_false(); 747 break; 748 case DLT_ARCNET: 749 /* 750 * XXX should we check for first fragment if the protocol 751 * uses PHDS? 752 */ 753 switch(proto) { 754 default: 755 return gen_false(); 756 #ifdef INET6 757 case ETHERTYPE_IPV6: 758 return(gen_cmp(2, BPF_B, 759 (bpf_int32)htonl(ARCTYPE_INET6))); 760 #endif /* INET6 */ 761 case ETHERTYPE_IP: 762 b0 = gen_cmp(2, BPF_B, (bpf_int32)htonl(ARCTYPE_IP)); 763 b1 = gen_cmp(2, BPF_B, 764 (bpf_int32)htonl(ARCTYPE_IP_OLD)); 765 gen_or(b0, b1); 766 return(b1); 767 case ETHERTYPE_ARP: 768 b0 = gen_cmp(2, BPF_B, (bpf_int32)htonl(ARCTYPE_ARP)); 769 b1 = gen_cmp(2, BPF_B, 770 (bpf_int32)htonl(ARCTYPE_ARP_OLD)); 771 gen_or(b0, b1); 772 return(b1); 773 case ETHERTYPE_REVARP: 774 return(gen_cmp(2, BPF_B, 775 (bpf_int32)htonl(ARCTYPE_REVARP))); 776 case ETHERTYPE_ATALK: 777 return(gen_cmp(2, BPF_B, 778 (bpf_int32)htonl(ARCTYPE_ATALK))); 779 } 780 } 781 return gen_cmp(off_linktype, BPF_H, (bpf_int32)proto); 782 } 783 784 static struct block * 785 gen_hostop(addr, mask, dir, proto, src_off, dst_off) 786 bpf_u_int32 addr; 787 bpf_u_int32 mask; 788 int dir, proto; 789 u_int src_off, dst_off; 790 { 791 struct block *b0, *b1; 792 u_int offset; 793 794 switch (dir) { 795 796 case Q_SRC: 797 offset = src_off; 798 break; 799 800 case Q_DST: 801 offset = dst_off; 802 break; 803 804 case Q_AND: 805 b0 = gen_hostop(addr, mask, Q_SRC, proto, src_off, dst_off); 806 b1 = gen_hostop(addr, mask, Q_DST, proto, src_off, dst_off); 807 gen_and(b0, b1); 808 return b1; 809 810 case Q_OR: 811 case Q_DEFAULT: 812 b0 = gen_hostop(addr, mask, Q_SRC, proto, src_off, dst_off); 813 b1 = gen_hostop(addr, mask, Q_DST, proto, src_off, dst_off); 814 gen_or(b0, b1); 815 return b1; 816 817 default: 818 abort(); 819 } 820 b0 = gen_linktype(proto); 821 b1 = gen_mcmp(offset, BPF_W, (bpf_int32)addr, mask); 822 gen_and(b0, b1); 823 return b1; 824 } 825 826 #ifdef INET6 827 static struct block * 828 gen_hostop6(addr, mask, dir, proto, src_off, dst_off) 829 struct in6_addr *addr; 830 struct in6_addr *mask; 831 int dir, proto; 832 u_int src_off, dst_off; 833 { 834 struct block *b0, *b1; 835 u_int offset; 836 u_int32_t *a, *m; 837 838 switch (dir) { 839 840 case Q_SRC: 841 offset = src_off; 842 break; 843 844 case Q_DST: 845 offset = dst_off; 846 break; 847 848 case Q_AND: 849 b0 = gen_hostop6(addr, mask, Q_SRC, proto, src_off, dst_off); 850 b1 = gen_hostop6(addr, mask, Q_DST, proto, src_off, dst_off); 851 gen_and(b0, b1); 852 return b1; 853 854 case Q_OR: 855 case Q_DEFAULT: 856 b0 = gen_hostop6(addr, mask, Q_SRC, proto, src_off, dst_off); 857 b1 = gen_hostop6(addr, mask, Q_DST, proto, src_off, dst_off); 858 gen_or(b0, b1); 859 return b1; 860 861 default: 862 abort(); 863 } 864 /* this order is important */ 865 a = (u_int32_t *)addr; 866 m = (u_int32_t *)mask; 867 b1 = gen_mcmp(offset + 12, BPF_W, ntohl(a[3]), ntohl(m[3])); 868 b0 = gen_mcmp(offset + 8, BPF_W, ntohl(a[2]), ntohl(m[2])); 869 gen_and(b0, b1); 870 b0 = gen_mcmp(offset + 4, BPF_W, ntohl(a[1]), ntohl(m[1])); 871 gen_and(b0, b1); 872 b0 = gen_mcmp(offset + 0, BPF_W, ntohl(a[0]), ntohl(m[0])); 873 gen_and(b0, b1); 874 b0 = gen_linktype(proto); 875 gen_and(b0, b1); 876 return b1; 877 } 878 #endif /*INET6*/ 879 880 static struct block * 881 gen_ehostop(eaddr, dir) 882 register const u_char *eaddr; 883 register int dir; 884 { 885 struct block *b0, *b1; 886 887 switch (dir) { 888 case Q_SRC: 889 return gen_bcmp(6, 6, eaddr); 890 891 case Q_DST: 892 return gen_bcmp(0, 6, eaddr); 893 894 case Q_AND: 895 b0 = gen_ehostop(eaddr, Q_SRC); 896 b1 = gen_ehostop(eaddr, Q_DST); 897 gen_and(b0, b1); 898 return b1; 899 900 case Q_DEFAULT: 901 case Q_OR: 902 b0 = gen_ehostop(eaddr, Q_SRC); 903 b1 = gen_ehostop(eaddr, Q_DST); 904 gen_or(b0, b1); 905 return b1; 906 } 907 abort(); 908 /* NOTREACHED */ 909 } 910 911 /* 912 * Like gen_ehostop, but for DLT_FDDI 913 */ 914 static struct block * 915 gen_fhostop(eaddr, dir) 916 register const u_char *eaddr; 917 register int dir; 918 { 919 struct block *b0, *b1; 920 921 switch (dir) { 922 case Q_SRC: 923 #ifdef PCAP_FDDIPAD 924 return gen_bcmp(6 + 1 + pcap_fddipad, 6, eaddr); 925 #else 926 return gen_bcmp(6 + 1, 6, eaddr); 927 #endif 928 929 case Q_DST: 930 #ifdef PCAP_FDDIPAD 931 return gen_bcmp(0 + 1 + pcap_fddipad, 6, eaddr); 932 #else 933 return gen_bcmp(0 + 1, 6, eaddr); 934 #endif 935 936 case Q_AND: 937 b0 = gen_fhostop(eaddr, Q_SRC); 938 b1 = gen_fhostop(eaddr, Q_DST); 939 gen_and(b0, b1); 940 return b1; 941 942 case Q_DEFAULT: 943 case Q_OR: 944 b0 = gen_fhostop(eaddr, Q_SRC); 945 b1 = gen_fhostop(eaddr, Q_DST); 946 gen_or(b0, b1); 947 return b1; 948 } 949 abort(); 950 /* NOTREACHED */ 951 } 952 953 /* 954 * This is quite tricky because there may be pad bytes in front of the 955 * DECNET header, and then there are two possible data packet formats that 956 * carry both src and dst addresses, plus 5 packet types in a format that 957 * carries only the src node, plus 2 types that use a different format and 958 * also carry just the src node. 959 * 960 * Yuck. 961 * 962 * Instead of doing those all right, we just look for data packets with 963 * 0 or 1 bytes of padding. If you want to look at other packets, that 964 * will require a lot more hacking. 965 * 966 * To add support for filtering on DECNET "areas" (network numbers) 967 * one would want to add a "mask" argument to this routine. That would 968 * make the filter even more inefficient, although one could be clever 969 * and not generate masking instructions if the mask is 0xFFFF. 970 */ 971 static struct block * 972 gen_dnhostop(addr, dir, base_off) 973 bpf_u_int32 addr; 974 int dir; 975 u_int base_off; 976 { 977 struct block *b0, *b1, *b2, *tmp; 978 u_int offset_lh; /* offset if long header is received */ 979 u_int offset_sh; /* offset if short header is received */ 980 981 switch (dir) { 982 983 case Q_DST: 984 offset_sh = 1; /* follows flags */ 985 offset_lh = 7; /* flgs,darea,dsubarea,HIORD */ 986 break; 987 988 case Q_SRC: 989 offset_sh = 3; /* follows flags, dstnode */ 990 offset_lh = 15; /* flgs,darea,dsubarea,did,sarea,ssub,HIORD */ 991 break; 992 993 case Q_AND: 994 /* Inefficient because we do our Calvinball dance twice */ 995 b0 = gen_dnhostop(addr, Q_SRC, base_off); 996 b1 = gen_dnhostop(addr, Q_DST, base_off); 997 gen_and(b0, b1); 998 return b1; 999 1000 case Q_OR: 1001 case Q_DEFAULT: 1002 /* Inefficient because we do our Calvinball dance twice */ 1003 b0 = gen_dnhostop(addr, Q_SRC, base_off); 1004 b1 = gen_dnhostop(addr, Q_DST, base_off); 1005 gen_or(b0, b1); 1006 return b1; 1007 1008 default: 1009 abort(); 1010 } 1011 b0 = gen_linktype(ETHERTYPE_DN); 1012 /* Check for pad = 1, long header case */ 1013 tmp = gen_mcmp(base_off + 2, BPF_H, 1014 (bpf_int32)ntohs(0x0681), (bpf_int32)ntohs(0x07FF)); 1015 b1 = gen_cmp(base_off + 2 + 1 + offset_lh, 1016 BPF_H, (bpf_int32)ntohs(addr)); 1017 gen_and(tmp, b1); 1018 /* Check for pad = 0, long header case */ 1019 tmp = gen_mcmp(base_off + 2, BPF_B, (bpf_int32)0x06, (bpf_int32)0x7); 1020 b2 = gen_cmp(base_off + 2 + offset_lh, BPF_H, (bpf_int32)ntohs(addr)); 1021 gen_and(tmp, b2); 1022 gen_or(b2, b1); 1023 /* Check for pad = 1, short header case */ 1024 tmp = gen_mcmp(base_off + 2, BPF_H, 1025 (bpf_int32)ntohs(0x0281), (bpf_int32)ntohs(0x07FF)); 1026 b2 = gen_cmp(base_off + 2 + 1 + offset_sh, 1027 BPF_H, (bpf_int32)ntohs(addr)); 1028 gen_and(tmp, b2); 1029 gen_or(b2, b1); 1030 /* Check for pad = 0, short header case */ 1031 tmp = gen_mcmp(base_off + 2, BPF_B, (bpf_int32)0x02, (bpf_int32)0x7); 1032 b2 = gen_cmp(base_off + 2 + offset_sh, BPF_H, (bpf_int32)ntohs(addr)); 1033 gen_and(tmp, b2); 1034 gen_or(b2, b1); 1035 1036 /* Combine with test for linktype */ 1037 gen_and(b0, b1); 1038 return b1; 1039 } 1040 1041 static struct block * 1042 gen_host(addr, mask, proto, dir) 1043 bpf_u_int32 addr; 1044 bpf_u_int32 mask; 1045 int proto; 1046 int dir; 1047 { 1048 struct block *b0, *b1; 1049 1050 switch (proto) { 1051 1052 case Q_DEFAULT: 1053 b0 = gen_host(addr, mask, Q_IP, dir); 1054 b1 = gen_host(addr, mask, Q_ARP, dir); 1055 gen_or(b0, b1); 1056 b0 = gen_host(addr, mask, Q_RARP, dir); 1057 gen_or(b1, b0); 1058 return b0; 1059 1060 case Q_IP: 1061 return gen_hostop(addr, mask, dir, ETHERTYPE_IP, 1062 off_nl + 12, off_nl + 16); 1063 1064 case Q_RARP: 1065 return gen_hostop(addr, mask, dir, ETHERTYPE_REVARP, 1066 off_nl + 14, off_nl + 24); 1067 1068 case Q_ARP: 1069 return gen_hostop(addr, mask, dir, ETHERTYPE_ARP, 1070 off_nl + 14, off_nl + 24); 1071 1072 case Q_TCP: 1073 bpf_error("'tcp' modifier applied to host"); 1074 1075 case Q_UDP: 1076 bpf_error("'udp' modifier applied to host"); 1077 1078 case Q_ICMP: 1079 bpf_error("'icmp' modifier applied to host"); 1080 1081 case Q_IGMP: 1082 bpf_error("'igmp' modifier applied to host"); 1083 1084 case Q_IGRP: 1085 bpf_error("'igrp' modifier applied to host"); 1086 1087 case Q_PIM: 1088 bpf_error("'pim' modifier applied to host"); 1089 1090 case Q_ATALK: 1091 bpf_error("ATALK host filtering not implemented"); 1092 1093 case Q_DECNET: 1094 return gen_dnhostop(addr, dir, off_nl); 1095 1096 case Q_SCA: 1097 bpf_error("SCA host filtering not implemented"); 1098 1099 case Q_LAT: 1100 bpf_error("LAT host filtering not implemented"); 1101 1102 case Q_MOPDL: 1103 bpf_error("MOPDL host filtering not implemented"); 1104 1105 case Q_MOPRC: 1106 bpf_error("MOPRC host filtering not implemented"); 1107 1108 #ifdef INET6 1109 case Q_IPV6: 1110 bpf_error("'ip6' modifier applied to ip host"); 1111 1112 case Q_ICMPV6: 1113 bpf_error("'icmp6' modifier applied to host"); 1114 #endif /* INET6 */ 1115 1116 case Q_AH: 1117 bpf_error("'ah' modifier applied to host"); 1118 1119 case Q_ESP: 1120 bpf_error("'esp' modifier applied to host"); 1121 1122 default: 1123 abort(); 1124 } 1125 /* NOTREACHED */ 1126 } 1127 1128 #ifdef INET6 1129 static struct block * 1130 gen_host6(addr, mask, proto, dir) 1131 struct in6_addr *addr; 1132 struct in6_addr *mask; 1133 int proto; 1134 int dir; 1135 { 1136 switch (proto) { 1137 1138 case Q_DEFAULT: 1139 return gen_host6(addr, mask, Q_IPV6, dir); 1140 1141 case Q_IP: 1142 bpf_error("'ip' modifier applied to ip6 host"); 1143 1144 case Q_RARP: 1145 bpf_error("'rarp' modifier applied to ip6 host"); 1146 1147 case Q_ARP: 1148 bpf_error("'arp' modifier applied to ip6 host"); 1149 1150 case Q_TCP: 1151 bpf_error("'tcp' modifier applied to host"); 1152 1153 case Q_UDP: 1154 bpf_error("'udp' modifier applied to host"); 1155 1156 case Q_ICMP: 1157 bpf_error("'icmp' modifier applied to host"); 1158 1159 case Q_IGMP: 1160 bpf_error("'igmp' modifier applied to host"); 1161 1162 case Q_IGRP: 1163 bpf_error("'igrp' modifier applied to host"); 1164 1165 case Q_PIM: 1166 bpf_error("'pim' modifier applied to host"); 1167 1168 case Q_ATALK: 1169 bpf_error("ATALK host filtering not implemented"); 1170 1171 case Q_DECNET: 1172 bpf_error("'decnet' modifier applied to ip6 host"); 1173 1174 case Q_SCA: 1175 bpf_error("SCA host filtering not implemented"); 1176 1177 case Q_LAT: 1178 bpf_error("LAT host filtering not implemented"); 1179 1180 case Q_MOPDL: 1181 bpf_error("MOPDL host filtering not implemented"); 1182 1183 case Q_MOPRC: 1184 bpf_error("MOPRC host filtering not implemented"); 1185 1186 case Q_IPV6: 1187 return gen_hostop6(addr, mask, dir, ETHERTYPE_IPV6, 1188 off_nl + 8, off_nl + 24); 1189 1190 case Q_ICMPV6: 1191 bpf_error("'icmp6' modifier applied to host"); 1192 1193 case Q_AH: 1194 bpf_error("'ah' modifier applied to host"); 1195 1196 case Q_ESP: 1197 bpf_error("'esp' modifier applied to host"); 1198 1199 default: 1200 abort(); 1201 } 1202 /* NOTREACHED */ 1203 } 1204 #endif /*INET6*/ 1205 1206 #ifndef INET6 1207 static struct block * 1208 gen_gateway(eaddr, alist, proto, dir) 1209 const u_char *eaddr; 1210 bpf_u_int32 **alist; 1211 int proto; 1212 int dir; 1213 { 1214 struct block *b0, *b1, *tmp; 1215 1216 if (dir != 0) 1217 bpf_error("direction applied to 'gateway'"); 1218 1219 switch (proto) { 1220 case Q_DEFAULT: 1221 case Q_IP: 1222 case Q_ARP: 1223 case Q_RARP: 1224 if (linktype == DLT_EN10MB) 1225 b0 = gen_ehostop(eaddr, Q_OR); 1226 else if (linktype == DLT_FDDI) 1227 b0 = gen_fhostop(eaddr, Q_OR); 1228 else 1229 bpf_error( 1230 "'gateway' supported only on ethernet or FDDI"); 1231 1232 b1 = gen_host(**alist++, 0xffffffff, proto, Q_OR); 1233 while (*alist) { 1234 tmp = gen_host(**alist++, 0xffffffff, proto, Q_OR); 1235 gen_or(b1, tmp); 1236 b1 = tmp; 1237 } 1238 gen_not(b1); 1239 gen_and(b0, b1); 1240 return b1; 1241 } 1242 bpf_error("illegal modifier of 'gateway'"); 1243 /* NOTREACHED */ 1244 } 1245 #endif /*INET6*/ 1246 1247 struct block * 1248 gen_proto_abbrev(proto) 1249 int proto; 1250 { 1251 struct block *b0 = NULL, *b1; 1252 1253 switch (proto) { 1254 1255 case Q_TCP: 1256 b1 = gen_proto(IPPROTO_TCP, Q_IP, Q_DEFAULT); 1257 #ifdef INET6 1258 b0 = gen_proto(IPPROTO_TCP, Q_IPV6, Q_DEFAULT); 1259 gen_or(b0, b1); 1260 #endif 1261 break; 1262 1263 case Q_UDP: 1264 b1 = gen_proto(IPPROTO_UDP, Q_IP, Q_DEFAULT); 1265 #ifdef INET6 1266 b0 = gen_proto(IPPROTO_UDP, Q_IPV6, Q_DEFAULT); 1267 gen_or(b0, b1); 1268 #endif 1269 break; 1270 1271 case Q_ICMP: 1272 b1 = gen_proto(IPPROTO_ICMP, Q_IP, Q_DEFAULT); 1273 break; 1274 1275 #ifndef IPPROTO_IGMP 1276 #define IPPROTO_IGMP 2 1277 #endif 1278 1279 case Q_IGMP: 1280 b1 = gen_proto(IPPROTO_IGMP, Q_IP, Q_DEFAULT); 1281 break; 1282 1283 #ifndef IPPROTO_IGRP 1284 #define IPPROTO_IGRP 9 1285 #endif 1286 case Q_IGRP: 1287 b1 = gen_proto(IPPROTO_IGRP, Q_IP, Q_DEFAULT); 1288 break; 1289 1290 #ifndef IPPROTO_PIM 1291 #define IPPROTO_PIM 103 1292 #endif 1293 1294 case Q_PIM: 1295 b1 = gen_proto(IPPROTO_PIM, Q_IP, Q_DEFAULT); 1296 #ifdef INET6 1297 b0 = gen_proto(IPPROTO_PIM, Q_IPV6, Q_DEFAULT); 1298 gen_or(b0, b1); 1299 #endif 1300 break; 1301 1302 case Q_IP: 1303 b1 = gen_linktype(ETHERTYPE_IP); 1304 break; 1305 1306 case Q_ARP: 1307 b1 = gen_linktype(ETHERTYPE_ARP); 1308 break; 1309 1310 case Q_RARP: 1311 b1 = gen_linktype(ETHERTYPE_REVARP); 1312 break; 1313 1314 case Q_LINK: 1315 bpf_error("link layer applied in wrong context"); 1316 1317 case Q_ATALK: 1318 b1 = gen_linktype(ETHERTYPE_ATALK); 1319 break; 1320 1321 case Q_DECNET: 1322 b1 = gen_linktype(ETHERTYPE_DN); 1323 break; 1324 1325 case Q_SCA: 1326 b1 = gen_linktype(ETHERTYPE_SCA); 1327 break; 1328 1329 case Q_LAT: 1330 b1 = gen_linktype(ETHERTYPE_LAT); 1331 break; 1332 1333 case Q_MOPDL: 1334 b1 = gen_linktype(ETHERTYPE_MOPDL); 1335 break; 1336 1337 case Q_MOPRC: 1338 b1 = gen_linktype(ETHERTYPE_MOPRC); 1339 break; 1340 1341 #ifdef INET6 1342 case Q_IPV6: 1343 b1 = gen_linktype(ETHERTYPE_IPV6); 1344 break; 1345 1346 #ifndef IPPROTO_ICMPV6 1347 #define IPPROTO_ICMPV6 58 1348 #endif 1349 case Q_ICMPV6: 1350 b1 = gen_proto(IPPROTO_ICMPV6, Q_IPV6, Q_DEFAULT); 1351 break; 1352 #endif /* INET6 */ 1353 1354 #ifndef IPPROTO_AH 1355 #define IPPROTO_AH 51 1356 #endif 1357 case Q_AH: 1358 b1 = gen_proto(IPPROTO_AH, Q_IP, Q_DEFAULT); 1359 #ifdef INET6 1360 b0 = gen_proto(IPPROTO_AH, Q_IPV6, Q_DEFAULT); 1361 gen_or(b0, b1); 1362 #endif 1363 break; 1364 1365 #ifndef IPPROTO_ESP 1366 #define IPPROTO_ESP 50 1367 #endif 1368 case Q_ESP: 1369 b1 = gen_proto(IPPROTO_ESP, Q_IP, Q_DEFAULT); 1370 #ifdef INET6 1371 b0 = gen_proto(IPPROTO_ESP, Q_IPV6, Q_DEFAULT); 1372 gen_or(b0, b1); 1373 #endif 1374 break; 1375 1376 default: 1377 abort(); 1378 } 1379 return b1; 1380 } 1381 1382 static struct block * 1383 gen_ipfrag() 1384 { 1385 struct slist *s; 1386 struct block *b; 1387 1388 /* not ip frag */ 1389 s = new_stmt(BPF_LD|BPF_H|BPF_ABS); 1390 s->s.k = off_nl + 6; 1391 b = new_block(JMP(BPF_JSET)); 1392 b->s.k = 0x1fff; 1393 b->stmts = s; 1394 gen_not(b); 1395 1396 return b; 1397 } 1398 1399 static struct block * 1400 gen_portatom(off, v) 1401 int off; 1402 bpf_int32 v; 1403 { 1404 struct slist *s; 1405 struct block *b; 1406 1407 s = new_stmt(BPF_LDX|BPF_MSH|BPF_B); 1408 s->s.k = off_nl; 1409 1410 s->next = new_stmt(BPF_LD|BPF_IND|BPF_H); 1411 s->next->s.k = off_nl + off; 1412 1413 b = new_block(JMP(BPF_JEQ)); 1414 b->stmts = s; 1415 b->s.k = v; 1416 1417 return b; 1418 } 1419 1420 #ifdef INET6 1421 static struct block * 1422 gen_portatom6(off, v) 1423 int off; 1424 bpf_int32 v; 1425 { 1426 return gen_cmp(off_nl + 40 + off, BPF_H, v); 1427 } 1428 #endif/*INET6*/ 1429 1430 struct block * 1431 gen_portop(port, proto, dir) 1432 int port, proto, dir; 1433 { 1434 struct block *b0, *b1, *tmp; 1435 1436 /* ip proto 'proto' */ 1437 tmp = gen_cmp(off_nl + 9, BPF_B, (bpf_int32)proto); 1438 b0 = gen_ipfrag(); 1439 gen_and(tmp, b0); 1440 1441 switch (dir) { 1442 case Q_SRC: 1443 b1 = gen_portatom(0, (bpf_int32)port); 1444 break; 1445 1446 case Q_DST: 1447 b1 = gen_portatom(2, (bpf_int32)port); 1448 break; 1449 1450 case Q_OR: 1451 case Q_DEFAULT: 1452 tmp = gen_portatom(0, (bpf_int32)port); 1453 b1 = gen_portatom(2, (bpf_int32)port); 1454 gen_or(tmp, b1); 1455 break; 1456 1457 case Q_AND: 1458 tmp = gen_portatom(0, (bpf_int32)port); 1459 b1 = gen_portatom(2, (bpf_int32)port); 1460 gen_and(tmp, b1); 1461 break; 1462 1463 default: 1464 abort(); 1465 } 1466 gen_and(b0, b1); 1467 1468 return b1; 1469 } 1470 1471 static struct block * 1472 gen_port(port, ip_proto, dir) 1473 int port; 1474 int ip_proto; 1475 int dir; 1476 { 1477 struct block *b0, *b1, *tmp; 1478 1479 /* ether proto ip */ 1480 b0 = gen_linktype(ETHERTYPE_IP); 1481 1482 switch (ip_proto) { 1483 case IPPROTO_UDP: 1484 case IPPROTO_TCP: 1485 b1 = gen_portop(port, ip_proto, dir); 1486 break; 1487 1488 case PROTO_UNDEF: 1489 tmp = gen_portop(port, IPPROTO_TCP, dir); 1490 b1 = gen_portop(port, IPPROTO_UDP, dir); 1491 gen_or(tmp, b1); 1492 break; 1493 1494 default: 1495 abort(); 1496 } 1497 gen_and(b0, b1); 1498 return b1; 1499 } 1500 1501 #ifdef INET6 1502 struct block * 1503 gen_portop6(port, proto, dir) 1504 int port, proto, dir; 1505 { 1506 struct block *b0, *b1, *tmp; 1507 1508 /* ip proto 'proto' */ 1509 b0 = gen_cmp(off_nl + 6, BPF_B, (bpf_int32)proto); 1510 1511 switch (dir) { 1512 case Q_SRC: 1513 b1 = gen_portatom6(0, (bpf_int32)port); 1514 break; 1515 1516 case Q_DST: 1517 b1 = gen_portatom6(2, (bpf_int32)port); 1518 break; 1519 1520 case Q_OR: 1521 case Q_DEFAULT: 1522 tmp = gen_portatom6(0, (bpf_int32)port); 1523 b1 = gen_portatom6(2, (bpf_int32)port); 1524 gen_or(tmp, b1); 1525 break; 1526 1527 case Q_AND: 1528 tmp = gen_portatom6(0, (bpf_int32)port); 1529 b1 = gen_portatom6(2, (bpf_int32)port); 1530 gen_and(tmp, b1); 1531 break; 1532 1533 default: 1534 abort(); 1535 } 1536 gen_and(b0, b1); 1537 1538 return b1; 1539 } 1540 1541 static struct block * 1542 gen_port6(port, ip_proto, dir) 1543 int port; 1544 int ip_proto; 1545 int dir; 1546 { 1547 struct block *b0, *b1, *tmp; 1548 1549 /* ether proto ip */ 1550 b0 = gen_linktype(ETHERTYPE_IPV6); 1551 1552 switch (ip_proto) { 1553 case IPPROTO_UDP: 1554 case IPPROTO_TCP: 1555 b1 = gen_portop6(port, ip_proto, dir); 1556 break; 1557 1558 case PROTO_UNDEF: 1559 tmp = gen_portop6(port, IPPROTO_TCP, dir); 1560 b1 = gen_portop6(port, IPPROTO_UDP, dir); 1561 gen_or(tmp, b1); 1562 break; 1563 1564 default: 1565 abort(); 1566 } 1567 gen_and(b0, b1); 1568 return b1; 1569 } 1570 #endif /* INET6 */ 1571 1572 static int 1573 lookup_proto(name, proto) 1574 register const char *name; 1575 register int proto; 1576 { 1577 register int v; 1578 1579 switch (proto) { 1580 1581 case Q_DEFAULT: 1582 case Q_IP: 1583 v = pcap_nametoproto(name); 1584 if (v == PROTO_UNDEF) 1585 bpf_error("unknown ip proto '%s'", name); 1586 break; 1587 1588 case Q_LINK: 1589 /* XXX should look up h/w protocol type based on linktype */ 1590 v = pcap_nametoeproto(name); 1591 if (v == PROTO_UNDEF) 1592 bpf_error("unknown ether proto '%s'", name); 1593 break; 1594 1595 default: 1596 v = PROTO_UNDEF; 1597 break; 1598 } 1599 return v; 1600 } 1601 1602 static struct block * 1603 gen_protochain(v, proto, dir) 1604 int v; 1605 int proto; 1606 int dir; 1607 { 1608 struct block *b0, *b; 1609 struct slist *s[100]; 1610 int fix2, fix3, fix4, fix5; 1611 int ahcheck, again, end; 1612 int i, max; 1613 int reg1 = alloc_reg(); 1614 int reg2 = alloc_reg(); 1615 1616 memset(s, 0, sizeof(s)); 1617 fix2 = fix3 = fix4 = fix5 = 0; 1618 1619 switch (proto) { 1620 case Q_IP: 1621 case Q_IPV6: 1622 break; 1623 case Q_DEFAULT: 1624 b0 = gen_protochain(v, Q_IP, dir); 1625 b = gen_protochain(v, Q_IPV6, dir); 1626 gen_or(b0, b); 1627 return b; 1628 default: 1629 bpf_error("bad protocol applied for 'protochain'"); 1630 /*NOTREACHED*/ 1631 } 1632 1633 no_optimize = 1; /*this code is not compatible with optimzer yet */ 1634 1635 /* 1636 * s[0] is a dummy entry to protect other BPF insn from damaged 1637 * by s[fix] = foo with uninitialized variable "fix". It is somewhat 1638 * hard to find interdependency made by jump table fixup. 1639 */ 1640 i = 0; 1641 s[i] = new_stmt(0); /*dummy*/ 1642 i++; 1643 1644 switch (proto) { 1645 case Q_IP: 1646 b0 = gen_linktype(ETHERTYPE_IP); 1647 1648 /* A = ip->ip_p */ 1649 s[i] = new_stmt(BPF_LD|BPF_ABS|BPF_B); 1650 s[i]->s.k = off_nl + 9; 1651 i++; 1652 /* X = ip->ip_hl << 2 */ 1653 s[i] = new_stmt(BPF_LDX|BPF_MSH|BPF_B); 1654 s[i]->s.k = off_nl; 1655 i++; 1656 break; 1657 case Q_IPV6: 1658 b0 = gen_linktype(ETHERTYPE_IPV6); 1659 1660 /* A = ip6->ip_nxt */ 1661 s[i] = new_stmt(BPF_LD|BPF_ABS|BPF_B); 1662 s[i]->s.k = off_nl + 6; 1663 i++; 1664 /* X = sizeof(struct ip6_hdr) */ 1665 s[i] = new_stmt(BPF_LDX|BPF_IMM); 1666 s[i]->s.k = 40; 1667 i++; 1668 break; 1669 default: 1670 bpf_error("unsupported proto to gen_protochain"); 1671 /*NOTREACHED*/ 1672 } 1673 1674 /* again: if (A == v) goto end; else fall through; */ 1675 again = i; 1676 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1677 s[i]->s.k = v; 1678 s[i]->s.jt = NULL; /*later*/ 1679 s[i]->s.jf = NULL; /*update in next stmt*/ 1680 fix5 = i; 1681 i++; 1682 1683 /* if (A == IPPROTO_NONE) goto end */ 1684 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1685 s[i]->s.jt = NULL; /*later*/ 1686 s[i]->s.jf = NULL; /*update in next stmt*/ 1687 s[i]->s.k = IPPROTO_NONE; 1688 s[fix5]->s.jf = s[i]; 1689 fix2 = i; 1690 i++; 1691 1692 if (proto == Q_IPV6) { 1693 int v6start, v6end, v6advance, j; 1694 1695 v6start = i; 1696 /* if (A == IPPROTO_HOPOPTS) goto v6advance */ 1697 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1698 s[i]->s.jt = NULL; /*later*/ 1699 s[i]->s.jf = NULL; /*update in next stmt*/ 1700 s[i]->s.k = IPPROTO_HOPOPTS; 1701 s[fix2]->s.jf = s[i]; 1702 i++; 1703 /* if (A == IPPROTO_DSTOPTS) goto v6advance */ 1704 s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1705 s[i]->s.jt = NULL; /*later*/ 1706 s[i]->s.jf = NULL; /*update in next stmt*/ 1707 s[i]->s.k = IPPROTO_DSTOPTS; 1708 i++; 1709 /* if (A == IPPROTO_ROUTING) goto v6advance */ 1710 s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1711 s[i]->s.jt = NULL; /*later*/ 1712 s[i]->s.jf = NULL; /*update in next stmt*/ 1713 s[i]->s.k = IPPROTO_ROUTING; 1714 i++; 1715 /* if (A == IPPROTO_FRAGMENT) goto v6advance; else goto ahcheck; */ 1716 s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1717 s[i]->s.jt = NULL; /*later*/ 1718 s[i]->s.jf = NULL; /*later*/ 1719 s[i]->s.k = IPPROTO_FRAGMENT; 1720 fix3 = i; 1721 v6end = i; 1722 i++; 1723 1724 /* v6advance: */ 1725 v6advance = i; 1726 1727 /* 1728 * in short, 1729 * A = P[X + 1]; 1730 * X = X + (P[X] + 1) * 8; 1731 */ 1732 /* A = X */ 1733 s[i] = new_stmt(BPF_MISC|BPF_TXA); 1734 i++; 1735 /* MEM[reg1] = A */ 1736 s[i] = new_stmt(BPF_ST); 1737 s[i]->s.k = reg1; 1738 i++; 1739 /* A += 1 */ 1740 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1741 s[i]->s.k = 1; 1742 i++; 1743 /* X = A */ 1744 s[i] = new_stmt(BPF_MISC|BPF_TAX); 1745 i++; 1746 /* A = P[X + packet head]; */ 1747 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B); 1748 s[i]->s.k = off_nl; 1749 i++; 1750 /* MEM[reg2] = A */ 1751 s[i] = new_stmt(BPF_ST); 1752 s[i]->s.k = reg2; 1753 i++; 1754 /* X = MEM[reg1] */ 1755 s[i] = new_stmt(BPF_LDX|BPF_MEM); 1756 s[i]->s.k = reg1; 1757 i++; 1758 /* A = P[X + packet head] */ 1759 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B); 1760 s[i]->s.k = off_nl; 1761 i++; 1762 /* A += 1 */ 1763 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1764 s[i]->s.k = 1; 1765 i++; 1766 /* A *= 8 */ 1767 s[i] = new_stmt(BPF_ALU|BPF_MUL|BPF_K); 1768 s[i]->s.k = 8; 1769 i++; 1770 /* X = A; */ 1771 s[i] = new_stmt(BPF_MISC|BPF_TAX); 1772 i++; 1773 /* A = MEM[reg2] */ 1774 s[i] = new_stmt(BPF_LD|BPF_MEM); 1775 s[i]->s.k = reg2; 1776 i++; 1777 1778 /* goto again; (must use BPF_JA for backward jump) */ 1779 s[i] = new_stmt(BPF_JMP|BPF_JA); 1780 s[i]->s.k = again - i - 1; 1781 s[i - 1]->s.jf = s[i]; 1782 i++; 1783 1784 /* fixup */ 1785 for (j = v6start; j <= v6end; j++) 1786 s[j]->s.jt = s[v6advance]; 1787 } else { 1788 /* nop */ 1789 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1790 s[i]->s.k = 0; 1791 s[fix2]->s.jf = s[i]; 1792 i++; 1793 } 1794 1795 /* ahcheck: */ 1796 ahcheck = i; 1797 /* if (A == IPPROTO_AH) then fall through; else goto end; */ 1798 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1799 s[i]->s.jt = NULL; /*later*/ 1800 s[i]->s.jf = NULL; /*later*/ 1801 s[i]->s.k = IPPROTO_AH; 1802 if (fix3) 1803 s[fix3]->s.jf = s[ahcheck]; 1804 fix4 = i; 1805 i++; 1806 1807 /* 1808 * in short, 1809 * A = P[X + 1]; 1810 * X = X + (P[X] + 2) * 4; 1811 */ 1812 /* A = X */ 1813 s[i - 1]->s.jt = s[i] = new_stmt(BPF_MISC|BPF_TXA); 1814 i++; 1815 /* MEM[reg1] = A */ 1816 s[i] = new_stmt(BPF_ST); 1817 s[i]->s.k = reg1; 1818 i++; 1819 /* A += 1 */ 1820 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1821 s[i]->s.k = 1; 1822 i++; 1823 /* X = A */ 1824 s[i] = new_stmt(BPF_MISC|BPF_TAX); 1825 i++; 1826 /* A = P[X + packet head]; */ 1827 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B); 1828 s[i]->s.k = off_nl; 1829 i++; 1830 /* MEM[reg2] = A */ 1831 s[i] = new_stmt(BPF_ST); 1832 s[i]->s.k = reg2; 1833 i++; 1834 /* X = MEM[reg1] */ 1835 s[i] = new_stmt(BPF_LDX|BPF_MEM); 1836 s[i]->s.k = reg1; 1837 i++; 1838 /* A = P[X + packet head] */ 1839 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B); 1840 s[i]->s.k = off_nl; 1841 i++; 1842 /* A += 2 */ 1843 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1844 s[i]->s.k = 2; 1845 i++; 1846 /* A *= 4 */ 1847 s[i] = new_stmt(BPF_ALU|BPF_MUL|BPF_K); 1848 s[i]->s.k = 4; 1849 i++; 1850 /* X = A; */ 1851 s[i] = new_stmt(BPF_MISC|BPF_TAX); 1852 i++; 1853 /* A = MEM[reg2] */ 1854 s[i] = new_stmt(BPF_LD|BPF_MEM); 1855 s[i]->s.k = reg2; 1856 i++; 1857 1858 /* goto again; (must use BPF_JA for backward jump) */ 1859 s[i] = new_stmt(BPF_JMP|BPF_JA); 1860 s[i]->s.k = again - i - 1; 1861 i++; 1862 1863 /* end: nop */ 1864 end = i; 1865 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1866 s[i]->s.k = 0; 1867 s[fix2]->s.jt = s[end]; 1868 s[fix4]->s.jf = s[end]; 1869 s[fix5]->s.jt = s[end]; 1870 i++; 1871 1872 /* 1873 * make slist chain 1874 */ 1875 max = i; 1876 for (i = 0; i < max - 1; i++) 1877 s[i]->next = s[i + 1]; 1878 s[max - 1]->next = NULL; 1879 1880 /* 1881 * emit final check 1882 */ 1883 b = new_block(JMP(BPF_JEQ)); 1884 b->stmts = s[1]; /*remember, s[0] is dummy*/ 1885 b->s.k = v; 1886 1887 free_reg(reg1); 1888 free_reg(reg2); 1889 1890 gen_and(b0, b); 1891 return b; 1892 } 1893 1894 static struct block * 1895 gen_proto(v, proto, dir) 1896 int v; 1897 int proto; 1898 int dir; 1899 { 1900 struct block *b0, *b1; 1901 1902 if (dir != Q_DEFAULT) 1903 bpf_error("direction applied to 'proto'"); 1904 1905 switch (proto) { 1906 case Q_DEFAULT: 1907 #ifdef INET6 1908 b0 = gen_proto(v, Q_IP, dir); 1909 b1 = gen_proto(v, Q_IPV6, dir); 1910 gen_or(b0, b1); 1911 return b1; 1912 #else 1913 /*FALLTHROUGH*/ 1914 #endif 1915 case Q_IP: 1916 b0 = gen_linktype(ETHERTYPE_IP); 1917 #ifndef CHASE_CHAIN 1918 b1 = gen_cmp(off_nl + 9, BPF_B, (bpf_int32)v); 1919 #else 1920 b1 = gen_protochain(v, Q_IP); 1921 #endif 1922 gen_and(b0, b1); 1923 return b1; 1924 1925 case Q_ARP: 1926 bpf_error("arp does not encapsulate another protocol"); 1927 /* NOTREACHED */ 1928 1929 case Q_RARP: 1930 bpf_error("rarp does not encapsulate another protocol"); 1931 /* NOTREACHED */ 1932 1933 case Q_ATALK: 1934 bpf_error("atalk encapsulation is not specifiable"); 1935 /* NOTREACHED */ 1936 1937 case Q_DECNET: 1938 bpf_error("decnet encapsulation is not specifiable"); 1939 /* NOTREACHED */ 1940 1941 case Q_SCA: 1942 bpf_error("sca does not encapsulate another protocol"); 1943 /* NOTREACHED */ 1944 1945 case Q_LAT: 1946 bpf_error("lat does not encapsulate another protocol"); 1947 /* NOTREACHED */ 1948 1949 case Q_MOPRC: 1950 bpf_error("moprc does not encapsulate another protocol"); 1951 /* NOTREACHED */ 1952 1953 case Q_MOPDL: 1954 bpf_error("mopdl does not encapsulate another protocol"); 1955 /* NOTREACHED */ 1956 1957 case Q_LINK: 1958 return gen_linktype(v); 1959 1960 case Q_UDP: 1961 bpf_error("'udp proto' is bogus"); 1962 /* NOTREACHED */ 1963 1964 case Q_TCP: 1965 bpf_error("'tcp proto' is bogus"); 1966 /* NOTREACHED */ 1967 1968 case Q_ICMP: 1969 bpf_error("'icmp proto' is bogus"); 1970 /* NOTREACHED */ 1971 1972 case Q_IGMP: 1973 bpf_error("'igmp proto' is bogus"); 1974 /* NOTREACHED */ 1975 1976 case Q_IGRP: 1977 bpf_error("'igrp proto' is bogus"); 1978 /* NOTREACHED */ 1979 1980 case Q_PIM: 1981 bpf_error("'pim proto' is bogus"); 1982 /* NOTREACHED */ 1983 1984 #ifdef INET6 1985 case Q_IPV6: 1986 b0 = gen_linktype(ETHERTYPE_IPV6); 1987 #ifndef CHASE_CHAIN 1988 b1 = gen_cmp(off_nl + 6, BPF_B, (bpf_int32)v); 1989 #else 1990 b1 = gen_protochain(v, Q_IPV6); 1991 #endif 1992 gen_and(b0, b1); 1993 return b1; 1994 1995 case Q_ICMPV6: 1996 bpf_error("'icmp6 proto' is bogus"); 1997 #endif /* INET6 */ 1998 1999 case Q_AH: 2000 bpf_error("'ah proto' is bogus"); 2001 2002 case Q_ESP: 2003 bpf_error("'ah proto' is bogus"); 2004 2005 default: 2006 abort(); 2007 /* NOTREACHED */ 2008 } 2009 /* NOTREACHED */ 2010 } 2011 2012 struct block * 2013 gen_scode(name, q) 2014 register const char *name; 2015 struct qual q; 2016 { 2017 int proto = q.proto; 2018 int dir = q.dir; 2019 int tproto; 2020 u_char *eaddr; 2021 bpf_u_int32 mask, addr; 2022 #ifndef INET6 2023 bpf_u_int32 **alist; 2024 #else 2025 int tproto6; 2026 struct sockaddr_in *sin; 2027 struct sockaddr_in6 *sin6; 2028 struct addrinfo *res, *res0; 2029 struct in6_addr mask128; 2030 #endif /*INET6*/ 2031 struct block *b, *tmp; 2032 int port, real_proto; 2033 2034 switch (q.addr) { 2035 2036 case Q_NET: 2037 addr = pcap_nametonetaddr(name); 2038 if (addr == 0) 2039 bpf_error("unknown network '%s'", name); 2040 /* Left justify network addr and calculate its network mask */ 2041 mask = 0xffffffff; 2042 while (addr && (addr & 0xff000000) == 0) { 2043 addr <<= 8; 2044 mask <<= 8; 2045 } 2046 return gen_host(addr, mask, proto, dir); 2047 2048 case Q_DEFAULT: 2049 case Q_HOST: 2050 if (proto == Q_LINK) { 2051 switch (linktype) { 2052 2053 case DLT_EN10MB: 2054 eaddr = pcap_ether_hostton(name); 2055 if (eaddr == NULL) 2056 bpf_error( 2057 "unknown ether host '%s'", name); 2058 return gen_ehostop(eaddr, dir); 2059 2060 case DLT_FDDI: 2061 eaddr = pcap_ether_hostton(name); 2062 if (eaddr == NULL) 2063 bpf_error( 2064 "unknown FDDI host '%s'", name); 2065 return gen_fhostop(eaddr, dir); 2066 2067 default: 2068 bpf_error( 2069 "only ethernet/FDDI supports link-level host name"); 2070 break; 2071 } 2072 } else if (proto == Q_DECNET) { 2073 unsigned short dn_addr = __pcap_nametodnaddr(name); 2074 /* 2075 * I don't think DECNET hosts can be multihomed, so 2076 * there is no need to build up a list of addresses 2077 */ 2078 return (gen_host(dn_addr, 0, proto, dir)); 2079 } else { 2080 #ifndef INET6 2081 alist = pcap_nametoaddr(name); 2082 if (alist == NULL || *alist == NULL) 2083 bpf_error("unknown host '%s'", name); 2084 tproto = proto; 2085 if (off_linktype == -1 && tproto == Q_DEFAULT) 2086 tproto = Q_IP; 2087 b = gen_host(**alist++, 0xffffffff, tproto, dir); 2088 while (*alist) { 2089 tmp = gen_host(**alist++, 0xffffffff, 2090 tproto, dir); 2091 gen_or(b, tmp); 2092 b = tmp; 2093 } 2094 return b; 2095 #else 2096 memset(&mask128, 0xff, sizeof(mask128)); 2097 res0 = res = pcap_nametoaddrinfo(name); 2098 if (res == NULL) 2099 bpf_error("unknown host '%s'", name); 2100 b = tmp = NULL; 2101 tproto = tproto6 = proto; 2102 if (off_linktype == -1 && tproto == Q_DEFAULT) { 2103 tproto = Q_IP; 2104 tproto6 = Q_IPV6; 2105 } 2106 for (res = res0; res; res = res->ai_next) { 2107 switch (res->ai_family) { 2108 case AF_INET: 2109 if (tproto == Q_IPV6) 2110 continue; 2111 2112 sin = (struct sockaddr_in *) 2113 res->ai_addr; 2114 tmp = gen_host(ntohl(sin->sin_addr.s_addr), 2115 0xffffffff, tproto, dir); 2116 break; 2117 case AF_INET6: 2118 if (tproto6 == Q_IP) 2119 continue; 2120 2121 sin6 = (struct sockaddr_in6 *) 2122 res->ai_addr; 2123 tmp = gen_host6(&sin6->sin6_addr, 2124 &mask128, tproto6, dir); 2125 break; 2126 } 2127 if (b) 2128 gen_or(b, tmp); 2129 b = tmp; 2130 } 2131 freeaddrinfo(res0); 2132 if (b == NULL) { 2133 bpf_error("unknown host '%s'%s", name, 2134 (proto == Q_DEFAULT) 2135 ? "" 2136 : " for specified address family"); 2137 } 2138 return b; 2139 #endif /*INET6*/ 2140 } 2141 2142 case Q_PORT: 2143 if (proto != Q_DEFAULT && proto != Q_UDP && proto != Q_TCP) 2144 bpf_error("illegal qualifier of 'port'"); 2145 if (pcap_nametoport(name, &port, &real_proto) == 0) 2146 bpf_error("unknown port '%s'", name); 2147 if (proto == Q_UDP) { 2148 if (real_proto == IPPROTO_TCP) 2149 bpf_error("port '%s' is tcp", name); 2150 else 2151 /* override PROTO_UNDEF */ 2152 real_proto = IPPROTO_UDP; 2153 } 2154 if (proto == Q_TCP) { 2155 if (real_proto == IPPROTO_UDP) 2156 bpf_error("port '%s' is udp", name); 2157 else 2158 /* override PROTO_UNDEF */ 2159 real_proto = IPPROTO_TCP; 2160 } 2161 #ifndef INET6 2162 return gen_port(port, real_proto, dir); 2163 #else 2164 { 2165 struct block *b; 2166 b = gen_port(port, real_proto, dir); 2167 gen_or(gen_port6(port, real_proto, dir), b); 2168 return b; 2169 } 2170 #endif /* INET6 */ 2171 2172 case Q_GATEWAY: 2173 #ifndef INET6 2174 eaddr = pcap_ether_hostton(name); 2175 if (eaddr == NULL) 2176 bpf_error("unknown ether host: %s", name); 2177 2178 alist = pcap_nametoaddr(name); 2179 if (alist == NULL || *alist == NULL) 2180 bpf_error("unknown host '%s'", name); 2181 return gen_gateway(eaddr, alist, proto, dir); 2182 #else 2183 bpf_error("'gateway' not supported in this configuration"); 2184 #endif /*INET6*/ 2185 2186 case Q_PROTO: 2187 real_proto = lookup_proto(name, proto); 2188 if (real_proto >= 0) 2189 return gen_proto(real_proto, proto, dir); 2190 else 2191 bpf_error("unknown protocol: %s", name); 2192 2193 case Q_PROTOCHAIN: 2194 real_proto = lookup_proto(name, proto); 2195 if (real_proto >= 0) 2196 return gen_protochain(real_proto, proto, dir); 2197 else 2198 bpf_error("unknown protocol: %s", name); 2199 2200 2201 case Q_UNDEF: 2202 syntax(); 2203 /* NOTREACHED */ 2204 } 2205 abort(); 2206 /* NOTREACHED */ 2207 } 2208 2209 struct block * 2210 gen_mcode(s1, s2, masklen, q) 2211 register const char *s1, *s2; 2212 register int masklen; 2213 struct qual q; 2214 { 2215 register int nlen, mlen; 2216 bpf_u_int32 n, m; 2217 2218 nlen = __pcap_atoin(s1, &n); 2219 /* Promote short ipaddr */ 2220 n <<= 32 - nlen; 2221 2222 if (s2 != NULL) { 2223 mlen = __pcap_atoin(s2, &m); 2224 /* Promote short ipaddr */ 2225 m <<= 32 - mlen; 2226 if ((n & ~m) != 0) 2227 bpf_error("non-network bits set in \"%s mask %s\"", 2228 s1, s2); 2229 } else { 2230 /* Convert mask len to mask */ 2231 if (masklen > 32) 2232 bpf_error("mask length must be <= 32"); 2233 m = 0xffffffff << (32 - masklen); 2234 if ((n & ~m) != 0) 2235 bpf_error("non-network bits set in \"%s/%d\"", 2236 s1, masklen); 2237 } 2238 2239 switch (q.addr) { 2240 2241 case Q_NET: 2242 return gen_host(n, m, q.proto, q.dir); 2243 2244 default: 2245 bpf_error("Mask syntax for networks only"); 2246 /* NOTREACHED */ 2247 } 2248 } 2249 2250 struct block * 2251 gen_ncode(s, v, q) 2252 register const char *s; 2253 bpf_u_int32 v; 2254 struct qual q; 2255 { 2256 bpf_u_int32 mask; 2257 int proto = q.proto; 2258 int dir = q.dir; 2259 register int vlen; 2260 2261 if (s == NULL) 2262 vlen = 32; 2263 else if (q.proto == Q_DECNET) 2264 vlen = __pcap_atodn(s, &v); 2265 else 2266 vlen = __pcap_atoin(s, &v); 2267 2268 switch (q.addr) { 2269 2270 case Q_DEFAULT: 2271 case Q_HOST: 2272 case Q_NET: 2273 if (proto == Q_DECNET) 2274 return gen_host(v, 0, proto, dir); 2275 else if (proto == Q_LINK) { 2276 bpf_error("illegal link layer address"); 2277 } else { 2278 mask = 0xffffffff; 2279 if (s == NULL && q.addr == Q_NET) { 2280 /* Promote short net number */ 2281 while (v && (v & 0xff000000) == 0) { 2282 v <<= 8; 2283 mask <<= 8; 2284 } 2285 } else { 2286 /* Promote short ipaddr */ 2287 v <<= 32 - vlen; 2288 mask <<= 32 - vlen; 2289 } 2290 return gen_host(v, mask, proto, dir); 2291 } 2292 2293 case Q_PORT: 2294 if (proto == Q_UDP) 2295 proto = IPPROTO_UDP; 2296 else if (proto == Q_TCP) 2297 proto = IPPROTO_TCP; 2298 else if (proto == Q_DEFAULT) 2299 proto = PROTO_UNDEF; 2300 else 2301 bpf_error("illegal qualifier of 'port'"); 2302 2303 #ifndef INET6 2304 return gen_port((int)v, proto, dir); 2305 #else 2306 { 2307 struct block *b; 2308 b = gen_port((int)v, proto, dir); 2309 gen_or(gen_port6((int)v, proto, dir), b); 2310 return b; 2311 } 2312 #endif /* INET6 */ 2313 2314 case Q_GATEWAY: 2315 bpf_error("'gateway' requires a name"); 2316 /* NOTREACHED */ 2317 2318 case Q_PROTO: 2319 return gen_proto((int)v, proto, dir); 2320 2321 case Q_PROTOCHAIN: 2322 return gen_protochain((int)v, proto, dir); 2323 2324 case Q_UNDEF: 2325 syntax(); 2326 /* NOTREACHED */ 2327 2328 default: 2329 abort(); 2330 /* NOTREACHED */ 2331 } 2332 /* NOTREACHED */ 2333 } 2334 2335 #ifdef INET6 2336 struct block * 2337 gen_mcode6(s1, s2, masklen, q) 2338 register const char *s1, *s2; 2339 register int masklen; 2340 struct qual q; 2341 { 2342 struct addrinfo *res; 2343 struct in6_addr *addr; 2344 struct in6_addr mask; 2345 struct block *b; 2346 u_int32_t *a, *m; 2347 2348 if (s2) 2349 bpf_error("no mask %s supported", s2); 2350 2351 res = pcap_nametoaddrinfo(s1); 2352 if (!res) 2353 bpf_error("invalid ip6 address %s", s1); 2354 if (res->ai_next) 2355 bpf_error("%s resolved to multiple address", s1); 2356 addr = &((struct sockaddr_in6 *)res->ai_addr)->sin6_addr; 2357 2358 if (sizeof(mask) * 8 < masklen) 2359 bpf_error("mask length must be <= %u", (unsigned int)(sizeof(mask) * 8)); 2360 memset(&mask, 0xff, masklen / 8); 2361 if (masklen % 8) { 2362 mask.s6_addr[masklen / 8] = 2363 (0xff << (8 - masklen % 8)) & 0xff; 2364 } 2365 2366 a = (u_int32_t *)addr; 2367 m = (u_int32_t *)&mask; 2368 if ((a[0] & ~m[0]) || (a[1] & ~m[1]) 2369 || (a[2] & ~m[2]) || (a[3] & ~m[3])) { 2370 bpf_error("non-network bits set in \"%s/%d\"", s1, masklen); 2371 } 2372 2373 switch (q.addr) { 2374 2375 case Q_DEFAULT: 2376 case Q_HOST: 2377 if (masklen != 128) 2378 bpf_error("Mask syntax for networks only"); 2379 /* FALLTHROUGH */ 2380 2381 case Q_NET: 2382 b = gen_host6(addr, &mask, q.proto, q.dir); 2383 freeaddrinfo(res); 2384 return b; 2385 2386 default: 2387 bpf_error("invalid qualifier against IPv6 address"); 2388 /* NOTREACHED */ 2389 } 2390 } 2391 #endif /*INET6*/ 2392 2393 struct block * 2394 gen_ecode(eaddr, q) 2395 register const u_char *eaddr; 2396 struct qual q; 2397 { 2398 if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) && q.proto == Q_LINK) { 2399 if (linktype == DLT_EN10MB) 2400 return gen_ehostop(eaddr, (int)q.dir); 2401 if (linktype == DLT_FDDI) 2402 return gen_fhostop(eaddr, (int)q.dir); 2403 } 2404 bpf_error("ethernet address used in non-ether expression"); 2405 /* NOTREACHED */ 2406 } 2407 2408 void 2409 sappend(s0, s1) 2410 struct slist *s0, *s1; 2411 { 2412 /* 2413 * This is definitely not the best way to do this, but the 2414 * lists will rarely get long. 2415 */ 2416 while (s0->next) 2417 s0 = s0->next; 2418 s0->next = s1; 2419 } 2420 2421 static struct slist * 2422 xfer_to_x(a) 2423 struct arth *a; 2424 { 2425 struct slist *s; 2426 2427 s = new_stmt(BPF_LDX|BPF_MEM); 2428 s->s.k = a->regno; 2429 return s; 2430 } 2431 2432 static struct slist * 2433 xfer_to_a(a) 2434 struct arth *a; 2435 { 2436 struct slist *s; 2437 2438 s = new_stmt(BPF_LD|BPF_MEM); 2439 s->s.k = a->regno; 2440 return s; 2441 } 2442 2443 struct arth * 2444 gen_load(proto, index, size) 2445 int proto; 2446 struct arth *index; 2447 int size; 2448 { 2449 struct slist *s, *tmp; 2450 struct block *b; 2451 int regno = alloc_reg(); 2452 2453 free_reg(index->regno); 2454 switch (size) { 2455 2456 default: 2457 bpf_error("data size must be 1, 2, or 4"); 2458 2459 case 1: 2460 size = BPF_B; 2461 break; 2462 2463 case 2: 2464 size = BPF_H; 2465 break; 2466 2467 case 4: 2468 size = BPF_W; 2469 break; 2470 } 2471 switch (proto) { 2472 default: 2473 bpf_error("unsupported index operation"); 2474 2475 case Q_LINK: 2476 s = xfer_to_x(index); 2477 tmp = new_stmt(BPF_LD|BPF_IND|size); 2478 sappend(s, tmp); 2479 sappend(index->s, s); 2480 break; 2481 2482 case Q_IP: 2483 case Q_ARP: 2484 case Q_RARP: 2485 case Q_ATALK: 2486 case Q_DECNET: 2487 case Q_SCA: 2488 case Q_LAT: 2489 case Q_MOPRC: 2490 case Q_MOPDL: 2491 #ifdef INET6 2492 case Q_IPV6: 2493 #endif 2494 /* XXX Note that we assume a fixed link header here. */ 2495 s = xfer_to_x(index); 2496 tmp = new_stmt(BPF_LD|BPF_IND|size); 2497 tmp->s.k = off_nl; 2498 sappend(s, tmp); 2499 sappend(index->s, s); 2500 2501 b = gen_proto_abbrev(proto); 2502 if (index->b) 2503 gen_and(index->b, b); 2504 index->b = b; 2505 break; 2506 2507 case Q_TCP: 2508 case Q_UDP: 2509 case Q_ICMP: 2510 case Q_IGMP: 2511 case Q_IGRP: 2512 case Q_PIM: 2513 s = new_stmt(BPF_LDX|BPF_MSH|BPF_B); 2514 s->s.k = off_nl; 2515 sappend(s, xfer_to_a(index)); 2516 sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X)); 2517 sappend(s, new_stmt(BPF_MISC|BPF_TAX)); 2518 sappend(s, tmp = new_stmt(BPF_LD|BPF_IND|size)); 2519 tmp->s.k = off_nl; 2520 sappend(index->s, s); 2521 2522 gen_and(gen_proto_abbrev(proto), b = gen_ipfrag()); 2523 if (index->b) 2524 gen_and(index->b, b); 2525 #ifdef INET6 2526 gen_and(gen_proto_abbrev(Q_IP), b); 2527 #endif 2528 index->b = b; 2529 break; 2530 #ifdef INET6 2531 case Q_ICMPV6: 2532 bpf_error("IPv6 upper-layer protocol is not supported by proto[x]"); 2533 /*NOTREACHED*/ 2534 #endif 2535 } 2536 index->regno = regno; 2537 s = new_stmt(BPF_ST); 2538 s->s.k = regno; 2539 sappend(index->s, s); 2540 2541 return index; 2542 } 2543 2544 struct block * 2545 gen_relation(code, a0, a1, reversed) 2546 int code; 2547 struct arth *a0, *a1; 2548 int reversed; 2549 { 2550 struct slist *s0, *s1, *s2; 2551 struct block *b, *tmp; 2552 2553 s0 = xfer_to_x(a1); 2554 s1 = xfer_to_a(a0); 2555 s2 = new_stmt(BPF_ALU|BPF_SUB|BPF_X); 2556 b = new_block(JMP(code)); 2557 if (code == BPF_JGT || code == BPF_JGE) { 2558 reversed = !reversed; 2559 b->s.k = 0x80000000; 2560 } 2561 if (reversed) 2562 gen_not(b); 2563 2564 sappend(s1, s2); 2565 sappend(s0, s1); 2566 sappend(a1->s, s0); 2567 sappend(a0->s, a1->s); 2568 2569 b->stmts = a0->s; 2570 2571 free_reg(a0->regno); 2572 free_reg(a1->regno); 2573 2574 /* 'and' together protocol checks */ 2575 if (a0->b) { 2576 if (a1->b) { 2577 gen_and(a0->b, tmp = a1->b); 2578 } 2579 else 2580 tmp = a0->b; 2581 } else 2582 tmp = a1->b; 2583 2584 if (tmp) 2585 gen_and(tmp, b); 2586 2587 return b; 2588 } 2589 2590 struct arth * 2591 gen_loadlen() 2592 { 2593 int regno = alloc_reg(); 2594 struct arth *a = (struct arth *)newchunk(sizeof(*a)); 2595 struct slist *s; 2596 2597 s = new_stmt(BPF_LD|BPF_LEN); 2598 s->next = new_stmt(BPF_ST); 2599 s->next->s.k = regno; 2600 a->s = s; 2601 a->regno = regno; 2602 2603 return a; 2604 } 2605 2606 struct arth * 2607 gen_loadi(val) 2608 int val; 2609 { 2610 struct arth *a; 2611 struct slist *s; 2612 int reg; 2613 2614 a = (struct arth *)newchunk(sizeof(*a)); 2615 2616 reg = alloc_reg(); 2617 2618 s = new_stmt(BPF_LD|BPF_IMM); 2619 s->s.k = val; 2620 s->next = new_stmt(BPF_ST); 2621 s->next->s.k = reg; 2622 a->s = s; 2623 a->regno = reg; 2624 2625 return a; 2626 } 2627 2628 struct arth * 2629 gen_neg(a) 2630 struct arth *a; 2631 { 2632 struct slist *s; 2633 2634 s = xfer_to_a(a); 2635 sappend(a->s, s); 2636 s = new_stmt(BPF_ALU|BPF_NEG); 2637 s->s.k = 0; 2638 sappend(a->s, s); 2639 s = new_stmt(BPF_ST); 2640 s->s.k = a->regno; 2641 sappend(a->s, s); 2642 2643 return a; 2644 } 2645 2646 struct arth * 2647 gen_arth(code, a0, a1) 2648 int code; 2649 struct arth *a0, *a1; 2650 { 2651 struct slist *s0, *s1, *s2; 2652 2653 s0 = xfer_to_x(a1); 2654 s1 = xfer_to_a(a0); 2655 s2 = new_stmt(BPF_ALU|BPF_X|code); 2656 2657 sappend(s1, s2); 2658 sappend(s0, s1); 2659 sappend(a1->s, s0); 2660 sappend(a0->s, a1->s); 2661 2662 free_reg(a1->regno); 2663 2664 s0 = new_stmt(BPF_ST); 2665 a0->regno = s0->s.k = alloc_reg(); 2666 sappend(a0->s, s0); 2667 2668 return a0; 2669 } 2670 2671 /* 2672 * Here we handle simple allocation of the scratch registers. 2673 * If too many registers are alloc'd, the allocator punts. 2674 */ 2675 static int regused[BPF_MEMWORDS]; 2676 static int curreg; 2677 2678 /* 2679 * Return the next free register. 2680 */ 2681 static int 2682 alloc_reg() 2683 { 2684 int n = BPF_MEMWORDS; 2685 2686 while (--n >= 0) { 2687 if (regused[curreg]) 2688 curreg = (curreg + 1) % BPF_MEMWORDS; 2689 else { 2690 regused[curreg] = 1; 2691 return curreg; 2692 } 2693 } 2694 bpf_error("too many registers needed to evaluate expression"); 2695 /* NOTREACHED */ 2696 } 2697 2698 /* 2699 * Return a register to the table so it can 2700 * be used later. 2701 */ 2702 static void 2703 free_reg(n) 2704 int n; 2705 { 2706 regused[n] = 0; 2707 } 2708 2709 static struct block * 2710 gen_len(jmp, n) 2711 int jmp, n; 2712 { 2713 struct slist *s; 2714 struct block *b; 2715 2716 s = new_stmt(BPF_LD|BPF_LEN); 2717 b = new_block(JMP(jmp)); 2718 b->stmts = s; 2719 b->s.k = n; 2720 2721 return b; 2722 } 2723 2724 struct block * 2725 gen_greater(n) 2726 int n; 2727 { 2728 return gen_len(BPF_JGE, n); 2729 } 2730 2731 struct block * 2732 gen_less(n) 2733 int n; 2734 { 2735 struct block *b; 2736 2737 b = gen_len(BPF_JGT, n); 2738 gen_not(b); 2739 2740 return b; 2741 } 2742 2743 struct block * 2744 gen_byteop(op, idx, val) 2745 int op, idx, val; 2746 { 2747 struct block *b; 2748 struct slist *s; 2749 2750 switch (op) { 2751 default: 2752 abort(); 2753 2754 case '=': 2755 return gen_cmp((u_int)idx, BPF_B, (bpf_int32)val); 2756 2757 case '<': 2758 b = gen_cmp((u_int)idx, BPF_B, (bpf_int32)val); 2759 b->s.code = JMP(BPF_JGE); 2760 gen_not(b); 2761 return b; 2762 2763 case '>': 2764 b = gen_cmp((u_int)idx, BPF_B, (bpf_int32)val); 2765 b->s.code = JMP(BPF_JGT); 2766 return b; 2767 2768 case '|': 2769 s = new_stmt(BPF_ALU|BPF_OR|BPF_K); 2770 break; 2771 2772 case '&': 2773 s = new_stmt(BPF_ALU|BPF_AND|BPF_K); 2774 break; 2775 } 2776 s->s.k = val; 2777 b = new_block(JMP(BPF_JEQ)); 2778 b->stmts = s; 2779 gen_not(b); 2780 2781 return b; 2782 } 2783 2784 static u_char abroadcast[] = { 0x0 }; 2785 2786 struct block * 2787 gen_broadcast(proto) 2788 int proto; 2789 { 2790 bpf_u_int32 hostmask; 2791 struct block *b0, *b1, *b2; 2792 static u_char ebroadcast[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; 2793 2794 switch (proto) { 2795 2796 case Q_DEFAULT: 2797 case Q_LINK: 2798 if (linktype == DLT_ARCNET) 2799 return gen_ahostop(abroadcast, Q_DST); 2800 if (linktype == DLT_EN10MB) 2801 return gen_ehostop(ebroadcast, Q_DST); 2802 if (linktype == DLT_FDDI) 2803 return gen_fhostop(ebroadcast, Q_DST); 2804 bpf_error("not a broadcast link"); 2805 break; 2806 2807 case Q_IP: 2808 b0 = gen_linktype(ETHERTYPE_IP); 2809 hostmask = ~netmask; 2810 b1 = gen_mcmp(off_nl + 16, BPF_W, (bpf_int32)0, hostmask); 2811 b2 = gen_mcmp(off_nl + 16, BPF_W, 2812 (bpf_int32)(~0 & hostmask), hostmask); 2813 gen_or(b1, b2); 2814 gen_and(b0, b2); 2815 return b2; 2816 } 2817 bpf_error("only ether/ip broadcast filters supported"); 2818 } 2819 2820 struct block * 2821 gen_multicast(proto) 2822 int proto; 2823 { 2824 register struct block *b0, *b1; 2825 register struct slist *s; 2826 2827 switch (proto) { 2828 2829 case Q_DEFAULT: 2830 case Q_LINK: 2831 if (linktype == DLT_ARCNET) 2832 /* all ARCnet multicasts use the same address */ 2833 return gen_ahostop(abroadcast, Q_DST); 2834 2835 if (linktype == DLT_EN10MB) { 2836 /* ether[0] & 1 != 0 */ 2837 s = new_stmt(BPF_LD|BPF_B|BPF_ABS); 2838 s->s.k = 0; 2839 b0 = new_block(JMP(BPF_JSET)); 2840 b0->s.k = 1; 2841 b0->stmts = s; 2842 return b0; 2843 } 2844 2845 if (linktype == DLT_FDDI) { 2846 /* XXX TEST THIS: MIGHT NOT PORT PROPERLY XXX */ 2847 /* fddi[1] & 1 != 0 */ 2848 s = new_stmt(BPF_LD|BPF_B|BPF_ABS); 2849 s->s.k = 1; 2850 b0 = new_block(JMP(BPF_JSET)); 2851 b0->s.k = 1; 2852 b0->stmts = s; 2853 return b0; 2854 } 2855 /* Link not known to support multicasts */ 2856 break; 2857 2858 case Q_IP: 2859 b0 = gen_linktype(ETHERTYPE_IP); 2860 b1 = gen_cmp(off_nl + 16, BPF_B, (bpf_int32)224); 2861 b1->s.code = JMP(BPF_JGE); 2862 gen_and(b0, b1); 2863 return b1; 2864 2865 #ifdef INET6 2866 case Q_IPV6: 2867 b0 = gen_linktype(ETHERTYPE_IPV6); 2868 b1 = gen_cmp(off_nl + 24, BPF_B, (bpf_int32)255); 2869 gen_and(b0, b1); 2870 return b1; 2871 #endif /* INET6 */ 2872 } 2873 bpf_error("only IP multicast filters supported on ethernet/FDDI"); 2874 } 2875 2876 /* 2877 * generate command for inbound/outbound. It's here so we can 2878 * make it link-type specific. 'dir' = 0 implies "inbound", 2879 * = 1 implies "outbound". 2880 */ 2881 struct block * 2882 gen_inbound(dir) 2883 int dir; 2884 { 2885 register struct block *b0; 2886 2887 /* 2888 * Only SLIP and old-style PPP data link types support 2889 * inbound/outbound qualifiers. 2890 */ 2891 switch (linktype) { 2892 case DLT_SLIP: 2893 case DLT_PPP: 2894 b0 = gen_relation(BPF_JEQ, 2895 gen_load(Q_LINK, gen_loadi(0), 1), 2896 gen_loadi(0), 2897 dir); 2898 break; 2899 2900 case DLT_PFLOG: 2901 b0 = gen_cmp(offsetof(struct pfloghdr, dir), BPF_H, 2902 (bpf_int32)((dir == 0) ? PF_IN : PF_OUT)); 2903 break; 2904 2905 default: 2906 bpf_error("inbound/outbound not supported on linktype 0x%x\n", 2907 linktype); 2908 /* NOTREACHED */ 2909 } 2910 2911 return (b0); 2912 } 2913 2914 2915 /* PF firewall log matched interface */ 2916 struct block * 2917 gen_pf_ifname(char *ifname) 2918 { 2919 struct block *b0; 2920 2921 if (linktype != DLT_PFLOG) { 2922 bpf_error("ifname not supported on linktype 0x%x\n", linktype); 2923 /* NOTREACHED */ 2924 } 2925 if (strlen(ifname) >= sizeof(((struct pfloghdr *)0)->ifname)) { 2926 bpf_error("ifname interface names can only be %d characters\n", 2927 sizeof(((struct pfloghdr *)0)->ifname) - 1); 2928 2929 /* NOTREACHED */ 2930 } 2931 b0 = gen_bcmp(offsetof(struct pfloghdr, ifname), strlen(ifname), 2932 ifname); 2933 return (b0); 2934 } 2935 2936 2937 /* PF firewall log rule number */ 2938 struct block * 2939 gen_pf_rnr(int rnr) 2940 { 2941 struct block *b0; 2942 2943 if (linktype != DLT_PFLOG) { 2944 bpf_error("rnr not supported on linktype 0x%x\n", linktype); 2945 /* NOTREACHED */ 2946 } 2947 2948 b0 = gen_cmp(offsetof(struct pfloghdr, rnr), BPF_H, (bpf_int32)rnr); 2949 return (b0); 2950 } 2951 2952 /* PF firewall log reason code */ 2953 struct block * 2954 gen_pf_reason(int reason) 2955 { 2956 struct block *b0; 2957 2958 if (linktype != DLT_PFLOG) { 2959 bpf_error("reason not supported on linktype 0x%x\n", linktype); 2960 /* NOTREACHED */ 2961 } 2962 2963 b0 = gen_cmp(offsetof(struct pfloghdr, reason), BPF_H, 2964 (bpf_int32)reason); 2965 return (b0); 2966 } 2967 2968 /* PF firewall log action */ 2969 struct block * 2970 gen_pf_action(int action) 2971 { 2972 struct block *b0; 2973 2974 if (linktype != DLT_PFLOG) { 2975 bpf_error("action not supported on linktype 0x%x\n", linktype); 2976 /* NOTREACHED */ 2977 } 2978 2979 b0 = gen_cmp(offsetof(struct pfloghdr, action), BPF_H, 2980 (bpf_int32)action); 2981 return (b0); 2982 } 2983 2984 struct block * 2985 gen_acode(eaddr, q) 2986 register const u_char *eaddr; 2987 struct qual q; 2988 { 2989 if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) && q.proto == Q_LINK) { 2990 if (linktype == DLT_ARCNET) 2991 return gen_ahostop(eaddr, (int)q.dir); 2992 } 2993 bpf_error("ARCnet address used in non-arc expression"); 2994 /* NOTREACHED */ 2995 } 2996 2997 static struct block * 2998 gen_ahostop(eaddr, dir) 2999 register const u_char *eaddr; 3000 register int dir; 3001 { 3002 register struct block *b0, *b1; 3003 3004 switch (dir) { 3005 /* src comes first, different from Ethernet */ 3006 case Q_SRC: 3007 return gen_bcmp(0, 1, eaddr); 3008 3009 case Q_DST: 3010 return gen_bcmp(1, 1, eaddr); 3011 3012 case Q_AND: 3013 b0 = gen_ahostop(eaddr, Q_SRC); 3014 b1 = gen_ahostop(eaddr, Q_DST); 3015 gen_and(b0, b1); 3016 return b1; 3017 3018 case Q_DEFAULT: 3019 case Q_OR: 3020 b0 = gen_ahostop(eaddr, Q_SRC); 3021 b1 = gen_ahostop(eaddr, Q_DST); 3022 gen_or(b0, b1); 3023 return b1; 3024 } 3025 abort(); 3026 /* NOTREACHED */ 3027 } 3028