1 /* $OpenBSD: gencode.c,v 1.16 2002/03/23 01:33:16 frantzen 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 1.16 2002/03/23 01:33:16 frantzen 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 memset((char *)cp->m, 0, size); 183 cp->n_left = size; 184 if (n > size) 185 bpf_error("out of memory"); 186 } 187 cp->n_left -= n; 188 return (void *)((char *)cp->m + cp->n_left); 189 } 190 191 static void 192 freechunks() 193 { 194 int i; 195 196 cur_chunk = 0; 197 for (i = 0; i < NCHUNKS; ++i) 198 if (chunks[i].m != NULL) { 199 free(chunks[i].m); 200 chunks[i].m = NULL; 201 } 202 } 203 204 /* 205 * A strdup whose allocations are freed after code generation is over. 206 */ 207 char * 208 sdup(s) 209 register const char *s; 210 { 211 int n = strlen(s) + 1; 212 char *cp = newchunk(n); 213 214 strlcpy(cp, s, n); 215 return (cp); 216 } 217 218 static __inline struct block * 219 new_block(code) 220 int code; 221 { 222 struct block *p; 223 224 p = (struct block *)newchunk(sizeof(*p)); 225 p->s.code = code; 226 p->head = p; 227 228 return p; 229 } 230 231 static __inline struct slist * 232 new_stmt(code) 233 int code; 234 { 235 struct slist *p; 236 237 p = (struct slist *)newchunk(sizeof(*p)); 238 p->s.code = code; 239 240 return p; 241 } 242 243 static struct block * 244 gen_retblk(v) 245 int v; 246 { 247 struct block *b = new_block(BPF_RET|BPF_K); 248 249 b->s.k = v; 250 return b; 251 } 252 253 static __inline void 254 syntax() 255 { 256 bpf_error("syntax error in filter expression"); 257 } 258 259 static bpf_u_int32 netmask; 260 static int snaplen; 261 int no_optimize; 262 263 int 264 pcap_compile(pcap_t *p, struct bpf_program *program, 265 char *buf, int optimize, bpf_u_int32 mask) 266 { 267 extern int n_errors; 268 int len; 269 270 no_optimize = 0; 271 n_errors = 0; 272 root = NULL; 273 bpf_pcap = p; 274 if (setjmp(top_ctx)) { 275 freechunks(); 276 return (-1); 277 } 278 279 netmask = mask; 280 snaplen = pcap_snapshot(p); 281 282 lex_init(buf ? buf : ""); 283 init_linktype(pcap_datalink(p)); 284 (void)pcap_parse(); 285 286 if (n_errors) 287 syntax(); 288 289 if (root == NULL) 290 root = gen_retblk(snaplen); 291 292 if (optimize && !no_optimize) { 293 bpf_optimize(&root); 294 if (root == NULL || 295 (root->s.code == (BPF_RET|BPF_K) && root->s.k == 0)) 296 bpf_error("expression rejects all packets"); 297 } 298 program->bf_insns = icode_to_fcode(root, &len); 299 program->bf_len = len; 300 301 freechunks(); 302 return (0); 303 } 304 305 /* 306 * entry point for using the compiler with no pcap open 307 * pass in all the stuff that is needed explicitly instead. 308 */ 309 int 310 pcap_compile_nopcap(int snaplen_arg, int linktype_arg, 311 struct bpf_program *program, 312 char *buf, int optimize, bpf_u_int32 mask) 313 { 314 extern int n_errors; 315 int len; 316 317 n_errors = 0; 318 root = NULL; 319 bpf_pcap = NULL; 320 if (setjmp(top_ctx)) { 321 freechunks(); 322 return (-1); 323 } 324 325 netmask = mask; 326 327 /* XXX needed? I don't grok the use of globals here. */ 328 snaplen = snaplen_arg; 329 330 lex_init(buf ? buf : ""); 331 init_linktype(linktype_arg); 332 (void)pcap_parse(); 333 334 if (n_errors) 335 syntax(); 336 337 if (root == NULL) 338 root = gen_retblk(snaplen_arg); 339 340 if (optimize) { 341 bpf_optimize(&root); 342 if (root == NULL || 343 (root->s.code == (BPF_RET|BPF_K) && root->s.k == 0)) 344 bpf_error("expression rejects all packets"); 345 } 346 program->bf_insns = icode_to_fcode(root, &len); 347 program->bf_len = len; 348 349 freechunks(); 350 return (0); 351 } 352 353 /* 354 * Clean up a "struct bpf_program" by freeing all the memory allocated 355 * in it. 356 */ 357 void 358 pcap_freecode(struct bpf_program *program) 359 { 360 program->bf_len = 0; 361 if (program->bf_insns != NULL) { 362 free((char *)program->bf_insns); 363 program->bf_insns = NULL; 364 } 365 } 366 367 /* 368 * Backpatch the blocks in 'list' to 'target'. The 'sense' field indicates 369 * which of the jt and jf fields has been resolved and which is a pointer 370 * back to another unresolved block (or nil). At least one of the fields 371 * in each block is already resolved. 372 */ 373 static void 374 backpatch(list, target) 375 struct block *list, *target; 376 { 377 struct block *next; 378 379 while (list) { 380 if (!list->sense) { 381 next = JT(list); 382 JT(list) = target; 383 } else { 384 next = JF(list); 385 JF(list) = target; 386 } 387 list = next; 388 } 389 } 390 391 /* 392 * Merge the lists in b0 and b1, using the 'sense' field to indicate 393 * which of jt and jf is the link. 394 */ 395 static void 396 merge(b0, b1) 397 struct block *b0, *b1; 398 { 399 register struct block **p = &b0; 400 401 /* Find end of list. */ 402 while (*p) 403 p = !((*p)->sense) ? &JT(*p) : &JF(*p); 404 405 /* Concatenate the lists. */ 406 *p = b1; 407 } 408 409 void 410 finish_parse(p) 411 struct block *p; 412 { 413 backpatch(p, gen_retblk(snaplen)); 414 p->sense = !p->sense; 415 backpatch(p, gen_retblk(0)); 416 root = p->head; 417 } 418 419 void 420 gen_and(b0, b1) 421 struct block *b0, *b1; 422 { 423 backpatch(b0, b1->head); 424 b0->sense = !b0->sense; 425 b1->sense = !b1->sense; 426 merge(b1, b0); 427 b1->sense = !b1->sense; 428 b1->head = b0->head; 429 } 430 431 void 432 gen_or(b0, b1) 433 struct block *b0, *b1; 434 { 435 b0->sense = !b0->sense; 436 backpatch(b0, b1->head); 437 b0->sense = !b0->sense; 438 merge(b1, b0); 439 b1->head = b0->head; 440 } 441 442 void 443 gen_not(b) 444 struct block *b; 445 { 446 b->sense = !b->sense; 447 } 448 449 static struct block * 450 gen_cmp(offset, size, v) 451 u_int offset, size; 452 bpf_int32 v; 453 { 454 struct slist *s; 455 struct block *b; 456 457 s = new_stmt(BPF_LD|BPF_ABS|size); 458 s->s.k = offset; 459 460 b = new_block(JMP(BPF_JEQ)); 461 b->stmts = s; 462 b->s.k = v; 463 464 return b; 465 } 466 467 static struct block * 468 gen_mcmp(offset, size, v, mask) 469 u_int offset, size; 470 bpf_int32 v; 471 bpf_u_int32 mask; 472 { 473 struct block *b = gen_cmp(offset, size, v); 474 struct slist *s; 475 476 if (mask != 0xffffffff) { 477 s = new_stmt(BPF_ALU|BPF_AND|BPF_K); 478 s->s.k = mask; 479 b->stmts->next = s; 480 } 481 return b; 482 } 483 484 static struct block * 485 gen_bcmp(offset, size, v) 486 register u_int offset, size; 487 register const u_char *v; 488 { 489 register struct block *b, *tmp; 490 491 b = NULL; 492 while (size >= 4) { 493 register const u_char *p = &v[size - 4]; 494 bpf_int32 w = ((bpf_int32)p[0] << 24) | 495 ((bpf_int32)p[1] << 16) | ((bpf_int32)p[2] << 8) | p[3]; 496 497 tmp = gen_cmp(offset + size - 4, BPF_W, w); 498 if (b != NULL) 499 gen_and(b, tmp); 500 b = tmp; 501 size -= 4; 502 } 503 while (size >= 2) { 504 register const u_char *p = &v[size - 2]; 505 bpf_int32 w = ((bpf_int32)p[0] << 8) | p[1]; 506 507 tmp = gen_cmp(offset + size - 2, BPF_H, w); 508 if (b != NULL) 509 gen_and(b, tmp); 510 b = tmp; 511 size -= 2; 512 } 513 if (size > 0) { 514 tmp = gen_cmp(offset, BPF_B, (bpf_int32)v[0]); 515 if (b != NULL) 516 gen_and(b, tmp); 517 b = tmp; 518 } 519 return b; 520 } 521 522 /* 523 * Various code constructs need to know the layout of the data link 524 * layer. These variables give the necessary offsets. off_linktype 525 * is set to -1 for no encapsulation, in which case, IP is assumed. 526 */ 527 static u_int off_linktype; 528 static u_int off_nl; 529 static int linktype; 530 531 static void 532 init_linktype(type) 533 int type; 534 { 535 linktype = type; 536 537 switch (type) { 538 539 case DLT_ARCNET: 540 off_linktype = 2; 541 off_nl = 6; /* XXX in reality, variable! */ 542 return; 543 544 case DLT_EN10MB: 545 off_linktype = 12; 546 off_nl = 14; 547 return; 548 549 case DLT_SLIP: 550 /* 551 * SLIP doesn't have a link level type. The 16 byte 552 * header is hacked into our SLIP driver. 553 */ 554 off_linktype = -1; 555 off_nl = 16; 556 return; 557 558 case DLT_SLIP_BSDOS: 559 /* XXX this may be the same as the DLT_PPP_BSDOS case */ 560 off_linktype = -1; 561 /* XXX end */ 562 off_nl = 24; 563 return; 564 565 case DLT_NULL: 566 off_linktype = 0; 567 off_nl = 4; 568 return; 569 570 case DLT_PPP: 571 off_linktype = 2; 572 off_nl = 4; 573 return; 574 575 case DLT_PPP_BSDOS: 576 off_linktype = 5; 577 off_nl = 24; 578 return; 579 580 case DLT_FDDI: 581 /* 582 * FDDI doesn't really have a link-level type field. 583 * We assume that SSAP = SNAP is being used and pick 584 * out the encapsulated Ethernet type. 585 */ 586 off_linktype = 19; 587 #ifdef PCAP_FDDIPAD 588 off_linktype += pcap_fddipad; 589 #endif 590 off_nl = 21; 591 #ifdef PCAP_FDDIPAD 592 off_nl += pcap_fddipad; 593 #endif 594 return; 595 596 case DLT_IEEE802: 597 off_linktype = 20; 598 off_nl = 22; 599 return; 600 601 case DLT_ATM_RFC1483: 602 /* 603 * assume routed, non-ISO PDUs 604 * (i.e., LLC = 0xAA-AA-03, OUT = 0x00-00-00) 605 */ 606 off_linktype = 6; 607 off_nl = 8; 608 return; 609 610 case DLT_LOOP: 611 off_linktype = -1; 612 off_nl = 4; 613 return; 614 615 case DLT_ENC: 616 off_linktype = -1; 617 off_nl = 12; 618 return; 619 620 case DLT_PFLOG: 621 off_linktype = 0; 622 off_nl = 28; 623 return; 624 625 case DLT_RAW: 626 off_linktype = -1; 627 off_nl = 0; 628 return; 629 } 630 bpf_error("unknown data link type 0x%x", linktype); 631 /* NOTREACHED */ 632 } 633 634 static struct block * 635 gen_uncond(rsense) 636 int rsense; 637 { 638 struct block *b; 639 struct slist *s; 640 641 s = new_stmt(BPF_LD|BPF_IMM); 642 s->s.k = !rsense; 643 b = new_block(JMP(BPF_JEQ)); 644 b->stmts = s; 645 646 return b; 647 } 648 649 static __inline struct block * 650 gen_true() 651 { 652 return gen_uncond(1); 653 } 654 655 static __inline struct block * 656 gen_false() 657 { 658 return gen_uncond(0); 659 } 660 661 static struct block * 662 gen_linktype(proto) 663 register int proto; 664 { 665 struct block *b0, *b1; 666 667 /* If we're not using encapsulation and checking for IP, we're done */ 668 if (off_linktype == -1 && proto == ETHERTYPE_IP) 669 return gen_true(); 670 #ifdef INET6 671 /* this isn't the right thing to do, but sometimes necessary */ 672 if (off_linktype == -1 && proto == ETHERTYPE_IPV6) 673 return gen_true(); 674 #endif 675 676 switch (linktype) { 677 678 case DLT_SLIP: 679 return gen_false(); 680 681 case DLT_PPP: 682 if (proto == ETHERTYPE_IP) 683 proto = PPP_IP; /* XXX was 0x21 */ 684 #ifdef INET6 685 else if (proto == ETHERTYPE_IPV6) 686 proto = PPP_IPV6; 687 #endif 688 break; 689 690 case DLT_PPP_BSDOS: 691 switch (proto) { 692 693 case ETHERTYPE_IP: 694 b0 = gen_cmp(off_linktype, BPF_H, PPP_IP); 695 b1 = gen_cmp(off_linktype, BPF_H, PPP_VJC); 696 gen_or(b0, b1); 697 b0 = gen_cmp(off_linktype, BPF_H, PPP_VJNC); 698 gen_or(b1, b0); 699 return b0; 700 701 #ifdef INET6 702 case ETHERTYPE_IPV6: 703 proto = PPP_IPV6; 704 /* more to go? */ 705 break; 706 #endif /* INET6 */ 707 708 case ETHERTYPE_DN: 709 proto = PPP_DECNET; 710 break; 711 712 case ETHERTYPE_ATALK: 713 proto = PPP_APPLE; 714 break; 715 716 case ETHERTYPE_NS: 717 proto = PPP_NS; 718 break; 719 } 720 break; 721 722 case DLT_LOOP: 723 case DLT_ENC: 724 case DLT_NULL: 725 /* XXX */ 726 if (proto == ETHERTYPE_IP) 727 return (gen_cmp(0, BPF_W, (bpf_int32)htonl(AF_INET))); 728 #ifdef INET6 729 else if (proto == ETHERTYPE_IPV6) 730 return (gen_cmp(0, BPF_W, (bpf_int32)htonl(AF_INET6))); 731 #endif /* INET6 */ 732 else 733 return gen_false(); 734 break; 735 case DLT_PFLOG: 736 if (proto == ETHERTYPE_IP) 737 return (gen_cmp(0, BPF_W, (bpf_int32)AF_INET)); 738 #ifdef INET6 739 else if (proto == ETHERTYPE_IPV6) 740 return (gen_cmp(0, BPF_W, (bpf_int32)AF_INET6)); 741 #endif /* INET6 */ 742 else 743 return gen_false(); 744 break; 745 case DLT_ARCNET: 746 /* 747 * XXX should we check for first fragment if the protocol 748 * uses PHDS? 749 */ 750 switch(proto) { 751 default: 752 return gen_false(); 753 #ifdef INET6 754 case ETHERTYPE_IPV6: 755 return(gen_cmp(2, BPF_B, 756 (bpf_int32)htonl(ARCTYPE_INET6))); 757 #endif /* INET6 */ 758 case ETHERTYPE_IP: 759 b0 = gen_cmp(2, BPF_B, (bpf_int32)htonl(ARCTYPE_IP)); 760 b1 = gen_cmp(2, BPF_B, 761 (bpf_int32)htonl(ARCTYPE_IP_OLD)); 762 gen_or(b0, b1); 763 return(b1); 764 case ETHERTYPE_ARP: 765 b0 = gen_cmp(2, BPF_B, (bpf_int32)htonl(ARCTYPE_ARP)); 766 b1 = gen_cmp(2, BPF_B, 767 (bpf_int32)htonl(ARCTYPE_ARP_OLD)); 768 gen_or(b0, b1); 769 return(b1); 770 case ETHERTYPE_REVARP: 771 return(gen_cmp(2, BPF_B, 772 (bpf_int32)htonl(ARCTYPE_REVARP))); 773 case ETHERTYPE_ATALK: 774 return(gen_cmp(2, BPF_B, 775 (bpf_int32)htonl(ARCTYPE_ATALK))); 776 } 777 } 778 return gen_cmp(off_linktype, BPF_H, (bpf_int32)proto); 779 } 780 781 static struct block * 782 gen_hostop(addr, mask, dir, proto, src_off, dst_off) 783 bpf_u_int32 addr; 784 bpf_u_int32 mask; 785 int dir, proto; 786 u_int src_off, dst_off; 787 { 788 struct block *b0, *b1; 789 u_int offset; 790 791 switch (dir) { 792 793 case Q_SRC: 794 offset = src_off; 795 break; 796 797 case Q_DST: 798 offset = dst_off; 799 break; 800 801 case Q_AND: 802 b0 = gen_hostop(addr, mask, Q_SRC, proto, src_off, dst_off); 803 b1 = gen_hostop(addr, mask, Q_DST, proto, src_off, dst_off); 804 gen_and(b0, b1); 805 return b1; 806 807 case Q_OR: 808 case Q_DEFAULT: 809 b0 = gen_hostop(addr, mask, Q_SRC, proto, src_off, dst_off); 810 b1 = gen_hostop(addr, mask, Q_DST, proto, src_off, dst_off); 811 gen_or(b0, b1); 812 return b1; 813 814 default: 815 abort(); 816 } 817 b0 = gen_linktype(proto); 818 b1 = gen_mcmp(offset, BPF_W, (bpf_int32)addr, mask); 819 gen_and(b0, b1); 820 return b1; 821 } 822 823 #ifdef INET6 824 static struct block * 825 gen_hostop6(addr, mask, dir, proto, src_off, dst_off) 826 struct in6_addr *addr; 827 struct in6_addr *mask; 828 int dir, proto; 829 u_int src_off, dst_off; 830 { 831 struct block *b0, *b1; 832 u_int offset; 833 u_int32_t *a, *m; 834 835 switch (dir) { 836 837 case Q_SRC: 838 offset = src_off; 839 break; 840 841 case Q_DST: 842 offset = dst_off; 843 break; 844 845 case Q_AND: 846 b0 = gen_hostop6(addr, mask, Q_SRC, proto, src_off, dst_off); 847 b1 = gen_hostop6(addr, mask, Q_DST, proto, src_off, dst_off); 848 gen_and(b0, b1); 849 return b1; 850 851 case Q_OR: 852 case Q_DEFAULT: 853 b0 = gen_hostop6(addr, mask, Q_SRC, proto, src_off, dst_off); 854 b1 = gen_hostop6(addr, mask, Q_DST, proto, src_off, dst_off); 855 gen_or(b0, b1); 856 return b1; 857 858 default: 859 abort(); 860 } 861 /* this order is important */ 862 a = (u_int32_t *)addr; 863 m = (u_int32_t *)mask; 864 b1 = gen_mcmp(offset + 12, BPF_W, ntohl(a[3]), ntohl(m[3])); 865 b0 = gen_mcmp(offset + 8, BPF_W, ntohl(a[2]), ntohl(m[2])); 866 gen_and(b0, b1); 867 b0 = gen_mcmp(offset + 4, BPF_W, ntohl(a[1]), ntohl(m[1])); 868 gen_and(b0, b1); 869 b0 = gen_mcmp(offset + 0, BPF_W, ntohl(a[0]), ntohl(m[0])); 870 gen_and(b0, b1); 871 b0 = gen_linktype(proto); 872 gen_and(b0, b1); 873 return b1; 874 } 875 #endif /*INET6*/ 876 877 static struct block * 878 gen_ehostop(eaddr, dir) 879 register const u_char *eaddr; 880 register int dir; 881 { 882 struct block *b0, *b1; 883 884 switch (dir) { 885 case Q_SRC: 886 return gen_bcmp(6, 6, eaddr); 887 888 case Q_DST: 889 return gen_bcmp(0, 6, eaddr); 890 891 case Q_AND: 892 b0 = gen_ehostop(eaddr, Q_SRC); 893 b1 = gen_ehostop(eaddr, Q_DST); 894 gen_and(b0, b1); 895 return b1; 896 897 case Q_DEFAULT: 898 case Q_OR: 899 b0 = gen_ehostop(eaddr, Q_SRC); 900 b1 = gen_ehostop(eaddr, Q_DST); 901 gen_or(b0, b1); 902 return b1; 903 } 904 abort(); 905 /* NOTREACHED */ 906 } 907 908 /* 909 * Like gen_ehostop, but for DLT_FDDI 910 */ 911 static struct block * 912 gen_fhostop(eaddr, dir) 913 register const u_char *eaddr; 914 register int dir; 915 { 916 struct block *b0, *b1; 917 918 switch (dir) { 919 case Q_SRC: 920 #ifdef PCAP_FDDIPAD 921 return gen_bcmp(6 + 1 + pcap_fddipad, 6, eaddr); 922 #else 923 return gen_bcmp(6 + 1, 6, eaddr); 924 #endif 925 926 case Q_DST: 927 #ifdef PCAP_FDDIPAD 928 return gen_bcmp(0 + 1 + pcap_fddipad, 6, eaddr); 929 #else 930 return gen_bcmp(0 + 1, 6, eaddr); 931 #endif 932 933 case Q_AND: 934 b0 = gen_fhostop(eaddr, Q_SRC); 935 b1 = gen_fhostop(eaddr, Q_DST); 936 gen_and(b0, b1); 937 return b1; 938 939 case Q_DEFAULT: 940 case Q_OR: 941 b0 = gen_fhostop(eaddr, Q_SRC); 942 b1 = gen_fhostop(eaddr, Q_DST); 943 gen_or(b0, b1); 944 return b1; 945 } 946 abort(); 947 /* NOTREACHED */ 948 } 949 950 /* 951 * This is quite tricky because there may be pad bytes in front of the 952 * DECNET header, and then there are two possible data packet formats that 953 * carry both src and dst addresses, plus 5 packet types in a format that 954 * carries only the src node, plus 2 types that use a different format and 955 * also carry just the src node. 956 * 957 * Yuck. 958 * 959 * Instead of doing those all right, we just look for data packets with 960 * 0 or 1 bytes of padding. If you want to look at other packets, that 961 * will require a lot more hacking. 962 * 963 * To add support for filtering on DECNET "areas" (network numbers) 964 * one would want to add a "mask" argument to this routine. That would 965 * make the filter even more inefficient, although one could be clever 966 * and not generate masking instructions if the mask is 0xFFFF. 967 */ 968 static struct block * 969 gen_dnhostop(addr, dir, base_off) 970 bpf_u_int32 addr; 971 int dir; 972 u_int base_off; 973 { 974 struct block *b0, *b1, *b2, *tmp; 975 u_int offset_lh; /* offset if long header is received */ 976 u_int offset_sh; /* offset if short header is received */ 977 978 switch (dir) { 979 980 case Q_DST: 981 offset_sh = 1; /* follows flags */ 982 offset_lh = 7; /* flgs,darea,dsubarea,HIORD */ 983 break; 984 985 case Q_SRC: 986 offset_sh = 3; /* follows flags, dstnode */ 987 offset_lh = 15; /* flgs,darea,dsubarea,did,sarea,ssub,HIORD */ 988 break; 989 990 case Q_AND: 991 /* Inefficient because we do our Calvinball dance twice */ 992 b0 = gen_dnhostop(addr, Q_SRC, base_off); 993 b1 = gen_dnhostop(addr, Q_DST, base_off); 994 gen_and(b0, b1); 995 return b1; 996 997 case Q_OR: 998 case Q_DEFAULT: 999 /* Inefficient because we do our Calvinball dance twice */ 1000 b0 = gen_dnhostop(addr, Q_SRC, base_off); 1001 b1 = gen_dnhostop(addr, Q_DST, base_off); 1002 gen_or(b0, b1); 1003 return b1; 1004 1005 default: 1006 abort(); 1007 } 1008 b0 = gen_linktype(ETHERTYPE_DN); 1009 /* Check for pad = 1, long header case */ 1010 tmp = gen_mcmp(base_off + 2, BPF_H, 1011 (bpf_int32)ntohs(0x0681), (bpf_int32)ntohs(0x07FF)); 1012 b1 = gen_cmp(base_off + 2 + 1 + offset_lh, 1013 BPF_H, (bpf_int32)ntohs(addr)); 1014 gen_and(tmp, b1); 1015 /* Check for pad = 0, long header case */ 1016 tmp = gen_mcmp(base_off + 2, BPF_B, (bpf_int32)0x06, (bpf_int32)0x7); 1017 b2 = gen_cmp(base_off + 2 + offset_lh, BPF_H, (bpf_int32)ntohs(addr)); 1018 gen_and(tmp, b2); 1019 gen_or(b2, b1); 1020 /* Check for pad = 1, short header case */ 1021 tmp = gen_mcmp(base_off + 2, BPF_H, 1022 (bpf_int32)ntohs(0x0281), (bpf_int32)ntohs(0x07FF)); 1023 b2 = gen_cmp(base_off + 2 + 1 + offset_sh, 1024 BPF_H, (bpf_int32)ntohs(addr)); 1025 gen_and(tmp, b2); 1026 gen_or(b2, b1); 1027 /* Check for pad = 0, short header case */ 1028 tmp = gen_mcmp(base_off + 2, BPF_B, (bpf_int32)0x02, (bpf_int32)0x7); 1029 b2 = gen_cmp(base_off + 2 + offset_sh, BPF_H, (bpf_int32)ntohs(addr)); 1030 gen_and(tmp, b2); 1031 gen_or(b2, b1); 1032 1033 /* Combine with test for linktype */ 1034 gen_and(b0, b1); 1035 return b1; 1036 } 1037 1038 static struct block * 1039 gen_host(addr, mask, proto, dir) 1040 bpf_u_int32 addr; 1041 bpf_u_int32 mask; 1042 int proto; 1043 int dir; 1044 { 1045 struct block *b0, *b1; 1046 1047 switch (proto) { 1048 1049 case Q_DEFAULT: 1050 b0 = gen_host(addr, mask, Q_IP, dir); 1051 b1 = gen_host(addr, mask, Q_ARP, dir); 1052 gen_or(b0, b1); 1053 b0 = gen_host(addr, mask, Q_RARP, dir); 1054 gen_or(b1, b0); 1055 return b0; 1056 1057 case Q_IP: 1058 return gen_hostop(addr, mask, dir, ETHERTYPE_IP, 1059 off_nl + 12, off_nl + 16); 1060 1061 case Q_RARP: 1062 return gen_hostop(addr, mask, dir, ETHERTYPE_REVARP, 1063 off_nl + 14, off_nl + 24); 1064 1065 case Q_ARP: 1066 return gen_hostop(addr, mask, dir, ETHERTYPE_ARP, 1067 off_nl + 14, off_nl + 24); 1068 1069 case Q_TCP: 1070 bpf_error("'tcp' modifier applied to host"); 1071 1072 case Q_UDP: 1073 bpf_error("'udp' modifier applied to host"); 1074 1075 case Q_ICMP: 1076 bpf_error("'icmp' modifier applied to host"); 1077 1078 case Q_IGMP: 1079 bpf_error("'igmp' modifier applied to host"); 1080 1081 case Q_IGRP: 1082 bpf_error("'igrp' modifier applied to host"); 1083 1084 case Q_PIM: 1085 bpf_error("'pim' modifier applied to host"); 1086 1087 case Q_ATALK: 1088 bpf_error("ATALK host filtering not implemented"); 1089 1090 case Q_DECNET: 1091 return gen_dnhostop(addr, dir, off_nl); 1092 1093 case Q_SCA: 1094 bpf_error("SCA host filtering not implemented"); 1095 1096 case Q_LAT: 1097 bpf_error("LAT host filtering not implemented"); 1098 1099 case Q_MOPDL: 1100 bpf_error("MOPDL host filtering not implemented"); 1101 1102 case Q_MOPRC: 1103 bpf_error("MOPRC host filtering not implemented"); 1104 1105 #ifdef INET6 1106 case Q_IPV6: 1107 bpf_error("'ip6' modifier applied to ip host"); 1108 1109 case Q_ICMPV6: 1110 bpf_error("'icmp6' modifier applied to host"); 1111 #endif /* INET6 */ 1112 1113 case Q_AH: 1114 bpf_error("'ah' modifier applied to host"); 1115 1116 case Q_ESP: 1117 bpf_error("'esp' modifier applied to host"); 1118 1119 default: 1120 abort(); 1121 } 1122 /* NOTREACHED */ 1123 } 1124 1125 #ifdef INET6 1126 static struct block * 1127 gen_host6(addr, mask, proto, dir) 1128 struct in6_addr *addr; 1129 struct in6_addr *mask; 1130 int proto; 1131 int dir; 1132 { 1133 switch (proto) { 1134 1135 case Q_DEFAULT: 1136 return gen_host6(addr, mask, Q_IPV6, dir); 1137 1138 case Q_IP: 1139 bpf_error("'ip' modifier applied to ip6 host"); 1140 1141 case Q_RARP: 1142 bpf_error("'rarp' modifier applied to ip6 host"); 1143 1144 case Q_ARP: 1145 bpf_error("'arp' modifier applied to ip6 host"); 1146 1147 case Q_TCP: 1148 bpf_error("'tcp' modifier applied to host"); 1149 1150 case Q_UDP: 1151 bpf_error("'udp' modifier applied to host"); 1152 1153 case Q_ICMP: 1154 bpf_error("'icmp' modifier applied to host"); 1155 1156 case Q_IGMP: 1157 bpf_error("'igmp' modifier applied to host"); 1158 1159 case Q_IGRP: 1160 bpf_error("'igrp' modifier applied to host"); 1161 1162 case Q_PIM: 1163 bpf_error("'pim' modifier applied to host"); 1164 1165 case Q_ATALK: 1166 bpf_error("ATALK host filtering not implemented"); 1167 1168 case Q_DECNET: 1169 bpf_error("'decnet' modifier applied to ip6 host"); 1170 1171 case Q_SCA: 1172 bpf_error("SCA host filtering not implemented"); 1173 1174 case Q_LAT: 1175 bpf_error("LAT host filtering not implemented"); 1176 1177 case Q_MOPDL: 1178 bpf_error("MOPDL host filtering not implemented"); 1179 1180 case Q_MOPRC: 1181 bpf_error("MOPRC host filtering not implemented"); 1182 1183 case Q_IPV6: 1184 return gen_hostop6(addr, mask, dir, ETHERTYPE_IPV6, 1185 off_nl + 8, off_nl + 24); 1186 1187 case Q_ICMPV6: 1188 bpf_error("'icmp6' modifier applied to host"); 1189 1190 case Q_AH: 1191 bpf_error("'ah' modifier applied to host"); 1192 1193 case Q_ESP: 1194 bpf_error("'esp' modifier applied to host"); 1195 1196 default: 1197 abort(); 1198 } 1199 /* NOTREACHED */ 1200 } 1201 #endif /*INET6*/ 1202 1203 #ifndef INET6 1204 static struct block * 1205 gen_gateway(eaddr, alist, proto, dir) 1206 const u_char *eaddr; 1207 bpf_u_int32 **alist; 1208 int proto; 1209 int dir; 1210 { 1211 struct block *b0, *b1, *tmp; 1212 1213 if (dir != 0) 1214 bpf_error("direction applied to 'gateway'"); 1215 1216 switch (proto) { 1217 case Q_DEFAULT: 1218 case Q_IP: 1219 case Q_ARP: 1220 case Q_RARP: 1221 if (linktype == DLT_EN10MB) 1222 b0 = gen_ehostop(eaddr, Q_OR); 1223 else if (linktype == DLT_FDDI) 1224 b0 = gen_fhostop(eaddr, Q_OR); 1225 else 1226 bpf_error( 1227 "'gateway' supported only on ethernet or FDDI"); 1228 1229 b1 = gen_host(**alist++, 0xffffffff, proto, Q_OR); 1230 while (*alist) { 1231 tmp = gen_host(**alist++, 0xffffffff, proto, Q_OR); 1232 gen_or(b1, tmp); 1233 b1 = tmp; 1234 } 1235 gen_not(b1); 1236 gen_and(b0, b1); 1237 return b1; 1238 } 1239 bpf_error("illegal modifier of 'gateway'"); 1240 /* NOTREACHED */ 1241 } 1242 #endif /*INET6*/ 1243 1244 struct block * 1245 gen_proto_abbrev(proto) 1246 int proto; 1247 { 1248 struct block *b0 = NULL, *b1; 1249 1250 switch (proto) { 1251 1252 case Q_TCP: 1253 b1 = gen_proto(IPPROTO_TCP, Q_IP, Q_DEFAULT); 1254 #ifdef INET6 1255 b0 = gen_proto(IPPROTO_TCP, Q_IPV6, Q_DEFAULT); 1256 gen_or(b0, b1); 1257 #endif 1258 break; 1259 1260 case Q_UDP: 1261 b1 = gen_proto(IPPROTO_UDP, Q_IP, Q_DEFAULT); 1262 #ifdef INET6 1263 b0 = gen_proto(IPPROTO_UDP, Q_IPV6, Q_DEFAULT); 1264 gen_or(b0, b1); 1265 #endif 1266 break; 1267 1268 case Q_ICMP: 1269 b1 = gen_proto(IPPROTO_ICMP, Q_IP, Q_DEFAULT); 1270 break; 1271 1272 #ifndef IPPROTO_IGMP 1273 #define IPPROTO_IGMP 2 1274 #endif 1275 1276 case Q_IGMP: 1277 b1 = gen_proto(IPPROTO_IGMP, Q_IP, Q_DEFAULT); 1278 break; 1279 1280 #ifndef IPPROTO_IGRP 1281 #define IPPROTO_IGRP 9 1282 #endif 1283 case Q_IGRP: 1284 b1 = gen_proto(IPPROTO_IGRP, Q_IP, Q_DEFAULT); 1285 break; 1286 1287 #ifndef IPPROTO_PIM 1288 #define IPPROTO_PIM 103 1289 #endif 1290 1291 case Q_PIM: 1292 b1 = gen_proto(IPPROTO_PIM, Q_IP, Q_DEFAULT); 1293 #ifdef INET6 1294 b0 = gen_proto(IPPROTO_PIM, Q_IPV6, Q_DEFAULT); 1295 gen_or(b0, b1); 1296 #endif 1297 break; 1298 1299 case Q_IP: 1300 b1 = gen_linktype(ETHERTYPE_IP); 1301 break; 1302 1303 case Q_ARP: 1304 b1 = gen_linktype(ETHERTYPE_ARP); 1305 break; 1306 1307 case Q_RARP: 1308 b1 = gen_linktype(ETHERTYPE_REVARP); 1309 break; 1310 1311 case Q_LINK: 1312 bpf_error("link layer applied in wrong context"); 1313 1314 case Q_ATALK: 1315 b1 = gen_linktype(ETHERTYPE_ATALK); 1316 break; 1317 1318 case Q_DECNET: 1319 b1 = gen_linktype(ETHERTYPE_DN); 1320 break; 1321 1322 case Q_SCA: 1323 b1 = gen_linktype(ETHERTYPE_SCA); 1324 break; 1325 1326 case Q_LAT: 1327 b1 = gen_linktype(ETHERTYPE_LAT); 1328 break; 1329 1330 case Q_MOPDL: 1331 b1 = gen_linktype(ETHERTYPE_MOPDL); 1332 break; 1333 1334 case Q_MOPRC: 1335 b1 = gen_linktype(ETHERTYPE_MOPRC); 1336 break; 1337 1338 #ifdef INET6 1339 case Q_IPV6: 1340 b1 = gen_linktype(ETHERTYPE_IPV6); 1341 break; 1342 1343 #ifndef IPPROTO_ICMPV6 1344 #define IPPROTO_ICMPV6 58 1345 #endif 1346 case Q_ICMPV6: 1347 b1 = gen_proto(IPPROTO_ICMPV6, Q_IPV6, Q_DEFAULT); 1348 break; 1349 #endif /* INET6 */ 1350 1351 #ifndef IPPROTO_AH 1352 #define IPPROTO_AH 51 1353 #endif 1354 case Q_AH: 1355 b1 = gen_proto(IPPROTO_AH, Q_IP, Q_DEFAULT); 1356 #ifdef INET6 1357 b0 = gen_proto(IPPROTO_AH, Q_IPV6, Q_DEFAULT); 1358 gen_or(b0, b1); 1359 #endif 1360 break; 1361 1362 #ifndef IPPROTO_ESP 1363 #define IPPROTO_ESP 50 1364 #endif 1365 case Q_ESP: 1366 b1 = gen_proto(IPPROTO_ESP, Q_IP, Q_DEFAULT); 1367 #ifdef INET6 1368 b0 = gen_proto(IPPROTO_ESP, Q_IPV6, Q_DEFAULT); 1369 gen_or(b0, b1); 1370 #endif 1371 break; 1372 1373 default: 1374 abort(); 1375 } 1376 return b1; 1377 } 1378 1379 static struct block * 1380 gen_ipfrag() 1381 { 1382 struct slist *s; 1383 struct block *b; 1384 1385 /* not ip frag */ 1386 s = new_stmt(BPF_LD|BPF_H|BPF_ABS); 1387 s->s.k = off_nl + 6; 1388 b = new_block(JMP(BPF_JSET)); 1389 b->s.k = 0x1fff; 1390 b->stmts = s; 1391 gen_not(b); 1392 1393 return b; 1394 } 1395 1396 static struct block * 1397 gen_portatom(off, v) 1398 int off; 1399 bpf_int32 v; 1400 { 1401 struct slist *s; 1402 struct block *b; 1403 1404 s = new_stmt(BPF_LDX|BPF_MSH|BPF_B); 1405 s->s.k = off_nl; 1406 1407 s->next = new_stmt(BPF_LD|BPF_IND|BPF_H); 1408 s->next->s.k = off_nl + off; 1409 1410 b = new_block(JMP(BPF_JEQ)); 1411 b->stmts = s; 1412 b->s.k = v; 1413 1414 return b; 1415 } 1416 1417 #ifdef INET6 1418 static struct block * 1419 gen_portatom6(off, v) 1420 int off; 1421 bpf_int32 v; 1422 { 1423 return gen_cmp(off_nl + 40 + off, BPF_H, v); 1424 } 1425 #endif/*INET6*/ 1426 1427 struct block * 1428 gen_portop(port, proto, dir) 1429 int port, proto, dir; 1430 { 1431 struct block *b0, *b1, *tmp; 1432 1433 /* ip proto 'proto' */ 1434 tmp = gen_cmp(off_nl + 9, BPF_B, (bpf_int32)proto); 1435 b0 = gen_ipfrag(); 1436 gen_and(tmp, b0); 1437 1438 switch (dir) { 1439 case Q_SRC: 1440 b1 = gen_portatom(0, (bpf_int32)port); 1441 break; 1442 1443 case Q_DST: 1444 b1 = gen_portatom(2, (bpf_int32)port); 1445 break; 1446 1447 case Q_OR: 1448 case Q_DEFAULT: 1449 tmp = gen_portatom(0, (bpf_int32)port); 1450 b1 = gen_portatom(2, (bpf_int32)port); 1451 gen_or(tmp, b1); 1452 break; 1453 1454 case Q_AND: 1455 tmp = gen_portatom(0, (bpf_int32)port); 1456 b1 = gen_portatom(2, (bpf_int32)port); 1457 gen_and(tmp, b1); 1458 break; 1459 1460 default: 1461 abort(); 1462 } 1463 gen_and(b0, b1); 1464 1465 return b1; 1466 } 1467 1468 static struct block * 1469 gen_port(port, ip_proto, dir) 1470 int port; 1471 int ip_proto; 1472 int dir; 1473 { 1474 struct block *b0, *b1, *tmp; 1475 1476 /* ether proto ip */ 1477 b0 = gen_linktype(ETHERTYPE_IP); 1478 1479 switch (ip_proto) { 1480 case IPPROTO_UDP: 1481 case IPPROTO_TCP: 1482 b1 = gen_portop(port, ip_proto, dir); 1483 break; 1484 1485 case PROTO_UNDEF: 1486 tmp = gen_portop(port, IPPROTO_TCP, dir); 1487 b1 = gen_portop(port, IPPROTO_UDP, dir); 1488 gen_or(tmp, b1); 1489 break; 1490 1491 default: 1492 abort(); 1493 } 1494 gen_and(b0, b1); 1495 return b1; 1496 } 1497 1498 #ifdef INET6 1499 struct block * 1500 gen_portop6(port, proto, dir) 1501 int port, proto, dir; 1502 { 1503 struct block *b0, *b1, *tmp; 1504 1505 /* ip proto 'proto' */ 1506 b0 = gen_cmp(off_nl + 6, BPF_B, (bpf_int32)proto); 1507 1508 switch (dir) { 1509 case Q_SRC: 1510 b1 = gen_portatom6(0, (bpf_int32)port); 1511 break; 1512 1513 case Q_DST: 1514 b1 = gen_portatom6(2, (bpf_int32)port); 1515 break; 1516 1517 case Q_OR: 1518 case Q_DEFAULT: 1519 tmp = gen_portatom6(0, (bpf_int32)port); 1520 b1 = gen_portatom6(2, (bpf_int32)port); 1521 gen_or(tmp, b1); 1522 break; 1523 1524 case Q_AND: 1525 tmp = gen_portatom6(0, (bpf_int32)port); 1526 b1 = gen_portatom6(2, (bpf_int32)port); 1527 gen_and(tmp, b1); 1528 break; 1529 1530 default: 1531 abort(); 1532 } 1533 gen_and(b0, b1); 1534 1535 return b1; 1536 } 1537 1538 static struct block * 1539 gen_port6(port, ip_proto, dir) 1540 int port; 1541 int ip_proto; 1542 int dir; 1543 { 1544 struct block *b0, *b1, *tmp; 1545 1546 /* ether proto ip */ 1547 b0 = gen_linktype(ETHERTYPE_IPV6); 1548 1549 switch (ip_proto) { 1550 case IPPROTO_UDP: 1551 case IPPROTO_TCP: 1552 b1 = gen_portop6(port, ip_proto, dir); 1553 break; 1554 1555 case PROTO_UNDEF: 1556 tmp = gen_portop6(port, IPPROTO_TCP, dir); 1557 b1 = gen_portop6(port, IPPROTO_UDP, dir); 1558 gen_or(tmp, b1); 1559 break; 1560 1561 default: 1562 abort(); 1563 } 1564 gen_and(b0, b1); 1565 return b1; 1566 } 1567 #endif /* INET6 */ 1568 1569 static int 1570 lookup_proto(name, proto) 1571 register const char *name; 1572 register int proto; 1573 { 1574 register int v; 1575 1576 switch (proto) { 1577 1578 case Q_DEFAULT: 1579 case Q_IP: 1580 v = pcap_nametoproto(name); 1581 if (v == PROTO_UNDEF) 1582 bpf_error("unknown ip proto '%s'", name); 1583 break; 1584 1585 case Q_LINK: 1586 /* XXX should look up h/w protocol type based on linktype */ 1587 v = pcap_nametoeproto(name); 1588 if (v == PROTO_UNDEF) 1589 bpf_error("unknown ether proto '%s'", name); 1590 break; 1591 1592 default: 1593 v = PROTO_UNDEF; 1594 break; 1595 } 1596 return v; 1597 } 1598 1599 static struct block * 1600 gen_protochain(v, proto, dir) 1601 int v; 1602 int proto; 1603 int dir; 1604 { 1605 struct block *b0, *b; 1606 struct slist *s[100]; 1607 int fix2, fix3, fix4, fix5; 1608 int ahcheck, again, end; 1609 int i, max; 1610 int reg1 = alloc_reg(); 1611 int reg2 = alloc_reg(); 1612 1613 memset(s, 0, sizeof(s)); 1614 fix2 = fix3 = fix4 = fix5 = 0; 1615 1616 switch (proto) { 1617 case Q_IP: 1618 case Q_IPV6: 1619 break; 1620 case Q_DEFAULT: 1621 b0 = gen_protochain(v, Q_IP, dir); 1622 b = gen_protochain(v, Q_IPV6, dir); 1623 gen_or(b0, b); 1624 return b; 1625 default: 1626 bpf_error("bad protocol applied for 'protochain'"); 1627 /*NOTREACHED*/ 1628 } 1629 1630 no_optimize = 1; /*this code is not compatible with optimzer yet */ 1631 1632 /* 1633 * s[0] is a dummy entry to protect other BPF insn from damaged 1634 * by s[fix] = foo with uninitialized variable "fix". It is somewhat 1635 * hard to find interdependency made by jump table fixup. 1636 */ 1637 i = 0; 1638 s[i] = new_stmt(0); /*dummy*/ 1639 i++; 1640 1641 switch (proto) { 1642 case Q_IP: 1643 b0 = gen_linktype(ETHERTYPE_IP); 1644 1645 /* A = ip->ip_p */ 1646 s[i] = new_stmt(BPF_LD|BPF_ABS|BPF_B); 1647 s[i]->s.k = off_nl + 9; 1648 i++; 1649 /* X = ip->ip_hl << 2 */ 1650 s[i] = new_stmt(BPF_LDX|BPF_MSH|BPF_B); 1651 s[i]->s.k = off_nl; 1652 i++; 1653 break; 1654 case Q_IPV6: 1655 b0 = gen_linktype(ETHERTYPE_IPV6); 1656 1657 /* A = ip6->ip_nxt */ 1658 s[i] = new_stmt(BPF_LD|BPF_ABS|BPF_B); 1659 s[i]->s.k = off_nl + 6; 1660 i++; 1661 /* X = sizeof(struct ip6_hdr) */ 1662 s[i] = new_stmt(BPF_LDX|BPF_IMM); 1663 s[i]->s.k = 40; 1664 i++; 1665 break; 1666 default: 1667 bpf_error("unsupported proto to gen_protochain"); 1668 /*NOTREACHED*/ 1669 } 1670 1671 /* again: if (A == v) goto end; else fall through; */ 1672 again = i; 1673 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1674 s[i]->s.k = v; 1675 s[i]->s.jt = NULL; /*later*/ 1676 s[i]->s.jf = NULL; /*update in next stmt*/ 1677 fix5 = i; 1678 i++; 1679 1680 /* if (A == IPPROTO_NONE) goto end */ 1681 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1682 s[i]->s.jt = NULL; /*later*/ 1683 s[i]->s.jf = NULL; /*update in next stmt*/ 1684 s[i]->s.k = IPPROTO_NONE; 1685 s[fix5]->s.jf = s[i]; 1686 fix2 = i; 1687 i++; 1688 1689 if (proto == Q_IPV6) { 1690 int v6start, v6end, v6advance, j; 1691 1692 v6start = i; 1693 /* if (A == IPPROTO_HOPOPTS) goto v6advance */ 1694 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1695 s[i]->s.jt = NULL; /*later*/ 1696 s[i]->s.jf = NULL; /*update in next stmt*/ 1697 s[i]->s.k = IPPROTO_HOPOPTS; 1698 s[fix2]->s.jf = s[i]; 1699 i++; 1700 /* if (A == IPPROTO_DSTOPTS) goto v6advance */ 1701 s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1702 s[i]->s.jt = NULL; /*later*/ 1703 s[i]->s.jf = NULL; /*update in next stmt*/ 1704 s[i]->s.k = IPPROTO_DSTOPTS; 1705 i++; 1706 /* if (A == IPPROTO_ROUTING) goto v6advance */ 1707 s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1708 s[i]->s.jt = NULL; /*later*/ 1709 s[i]->s.jf = NULL; /*update in next stmt*/ 1710 s[i]->s.k = IPPROTO_ROUTING; 1711 i++; 1712 /* if (A == IPPROTO_FRAGMENT) goto v6advance; else goto ahcheck; */ 1713 s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1714 s[i]->s.jt = NULL; /*later*/ 1715 s[i]->s.jf = NULL; /*later*/ 1716 s[i]->s.k = IPPROTO_FRAGMENT; 1717 fix3 = i; 1718 v6end = i; 1719 i++; 1720 1721 /* v6advance: */ 1722 v6advance = i; 1723 1724 /* 1725 * in short, 1726 * A = P[X + 1]; 1727 * X = X + (P[X] + 1) * 8; 1728 */ 1729 /* A = X */ 1730 s[i] = new_stmt(BPF_MISC|BPF_TXA); 1731 i++; 1732 /* MEM[reg1] = A */ 1733 s[i] = new_stmt(BPF_ST); 1734 s[i]->s.k = reg1; 1735 i++; 1736 /* A += 1 */ 1737 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1738 s[i]->s.k = 1; 1739 i++; 1740 /* X = A */ 1741 s[i] = new_stmt(BPF_MISC|BPF_TAX); 1742 i++; 1743 /* A = P[X + packet head]; */ 1744 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B); 1745 s[i]->s.k = off_nl; 1746 i++; 1747 /* MEM[reg2] = A */ 1748 s[i] = new_stmt(BPF_ST); 1749 s[i]->s.k = reg2; 1750 i++; 1751 /* X = MEM[reg1] */ 1752 s[i] = new_stmt(BPF_LDX|BPF_MEM); 1753 s[i]->s.k = reg1; 1754 i++; 1755 /* A = P[X + packet head] */ 1756 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B); 1757 s[i]->s.k = off_nl; 1758 i++; 1759 /* A += 1 */ 1760 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1761 s[i]->s.k = 1; 1762 i++; 1763 /* A *= 8 */ 1764 s[i] = new_stmt(BPF_ALU|BPF_MUL|BPF_K); 1765 s[i]->s.k = 8; 1766 i++; 1767 /* X = A; */ 1768 s[i] = new_stmt(BPF_MISC|BPF_TAX); 1769 i++; 1770 /* A = MEM[reg2] */ 1771 s[i] = new_stmt(BPF_LD|BPF_MEM); 1772 s[i]->s.k = reg2; 1773 i++; 1774 1775 /* goto again; (must use BPF_JA for backward jump) */ 1776 s[i] = new_stmt(BPF_JMP|BPF_JA); 1777 s[i]->s.k = again - i - 1; 1778 s[i - 1]->s.jf = s[i]; 1779 i++; 1780 1781 /* fixup */ 1782 for (j = v6start; j <= v6end; j++) 1783 s[j]->s.jt = s[v6advance]; 1784 } else { 1785 /* nop */ 1786 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1787 s[i]->s.k = 0; 1788 s[fix2]->s.jf = s[i]; 1789 i++; 1790 } 1791 1792 /* ahcheck: */ 1793 ahcheck = i; 1794 /* if (A == IPPROTO_AH) then fall through; else goto end; */ 1795 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K); 1796 s[i]->s.jt = NULL; /*later*/ 1797 s[i]->s.jf = NULL; /*later*/ 1798 s[i]->s.k = IPPROTO_AH; 1799 if (fix3) 1800 s[fix3]->s.jf = s[ahcheck]; 1801 fix4 = i; 1802 i++; 1803 1804 /* 1805 * in short, 1806 * A = P[X + 1]; 1807 * X = X + (P[X] + 2) * 4; 1808 */ 1809 /* A = X */ 1810 s[i - 1]->s.jt = s[i] = new_stmt(BPF_MISC|BPF_TXA); 1811 i++; 1812 /* MEM[reg1] = A */ 1813 s[i] = new_stmt(BPF_ST); 1814 s[i]->s.k = reg1; 1815 i++; 1816 /* A += 1 */ 1817 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1818 s[i]->s.k = 1; 1819 i++; 1820 /* X = A */ 1821 s[i] = new_stmt(BPF_MISC|BPF_TAX); 1822 i++; 1823 /* A = P[X + packet head]; */ 1824 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B); 1825 s[i]->s.k = off_nl; 1826 i++; 1827 /* MEM[reg2] = A */ 1828 s[i] = new_stmt(BPF_ST); 1829 s[i]->s.k = reg2; 1830 i++; 1831 /* X = MEM[reg1] */ 1832 s[i] = new_stmt(BPF_LDX|BPF_MEM); 1833 s[i]->s.k = reg1; 1834 i++; 1835 /* A = P[X + packet head] */ 1836 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B); 1837 s[i]->s.k = off_nl; 1838 i++; 1839 /* A += 2 */ 1840 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1841 s[i]->s.k = 2; 1842 i++; 1843 /* A *= 4 */ 1844 s[i] = new_stmt(BPF_ALU|BPF_MUL|BPF_K); 1845 s[i]->s.k = 4; 1846 i++; 1847 /* X = A; */ 1848 s[i] = new_stmt(BPF_MISC|BPF_TAX); 1849 i++; 1850 /* A = MEM[reg2] */ 1851 s[i] = new_stmt(BPF_LD|BPF_MEM); 1852 s[i]->s.k = reg2; 1853 i++; 1854 1855 /* goto again; (must use BPF_JA for backward jump) */ 1856 s[i] = new_stmt(BPF_JMP|BPF_JA); 1857 s[i]->s.k = again - i - 1; 1858 i++; 1859 1860 /* end: nop */ 1861 end = i; 1862 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K); 1863 s[i]->s.k = 0; 1864 s[fix2]->s.jt = s[end]; 1865 s[fix4]->s.jf = s[end]; 1866 s[fix5]->s.jt = s[end]; 1867 i++; 1868 1869 /* 1870 * make slist chain 1871 */ 1872 max = i; 1873 for (i = 0; i < max - 1; i++) 1874 s[i]->next = s[i + 1]; 1875 s[max - 1]->next = NULL; 1876 1877 /* 1878 * emit final check 1879 */ 1880 b = new_block(JMP(BPF_JEQ)); 1881 b->stmts = s[1]; /*remember, s[0] is dummy*/ 1882 b->s.k = v; 1883 1884 free_reg(reg1); 1885 free_reg(reg2); 1886 1887 gen_and(b0, b); 1888 return b; 1889 } 1890 1891 static struct block * 1892 gen_proto(v, proto, dir) 1893 int v; 1894 int proto; 1895 int dir; 1896 { 1897 struct block *b0, *b1; 1898 1899 if (dir != Q_DEFAULT) 1900 bpf_error("direction applied to 'proto'"); 1901 1902 switch (proto) { 1903 case Q_DEFAULT: 1904 #ifdef INET6 1905 b0 = gen_proto(v, Q_IP, dir); 1906 b1 = gen_proto(v, Q_IPV6, dir); 1907 gen_or(b0, b1); 1908 return b1; 1909 #else 1910 /*FALLTHROUGH*/ 1911 #endif 1912 case Q_IP: 1913 b0 = gen_linktype(ETHERTYPE_IP); 1914 #ifndef CHASE_CHAIN 1915 b1 = gen_cmp(off_nl + 9, BPF_B, (bpf_int32)v); 1916 #else 1917 b1 = gen_protochain(v, Q_IP); 1918 #endif 1919 gen_and(b0, b1); 1920 return b1; 1921 1922 case Q_ARP: 1923 bpf_error("arp does not encapsulate another protocol"); 1924 /* NOTREACHED */ 1925 1926 case Q_RARP: 1927 bpf_error("rarp does not encapsulate another protocol"); 1928 /* NOTREACHED */ 1929 1930 case Q_ATALK: 1931 bpf_error("atalk encapsulation is not specifiable"); 1932 /* NOTREACHED */ 1933 1934 case Q_DECNET: 1935 bpf_error("decnet encapsulation is not specifiable"); 1936 /* NOTREACHED */ 1937 1938 case Q_SCA: 1939 bpf_error("sca does not encapsulate another protocol"); 1940 /* NOTREACHED */ 1941 1942 case Q_LAT: 1943 bpf_error("lat does not encapsulate another protocol"); 1944 /* NOTREACHED */ 1945 1946 case Q_MOPRC: 1947 bpf_error("moprc does not encapsulate another protocol"); 1948 /* NOTREACHED */ 1949 1950 case Q_MOPDL: 1951 bpf_error("mopdl does not encapsulate another protocol"); 1952 /* NOTREACHED */ 1953 1954 case Q_LINK: 1955 return gen_linktype(v); 1956 1957 case Q_UDP: 1958 bpf_error("'udp proto' is bogus"); 1959 /* NOTREACHED */ 1960 1961 case Q_TCP: 1962 bpf_error("'tcp proto' is bogus"); 1963 /* NOTREACHED */ 1964 1965 case Q_ICMP: 1966 bpf_error("'icmp proto' is bogus"); 1967 /* NOTREACHED */ 1968 1969 case Q_IGMP: 1970 bpf_error("'igmp proto' is bogus"); 1971 /* NOTREACHED */ 1972 1973 case Q_IGRP: 1974 bpf_error("'igrp proto' is bogus"); 1975 /* NOTREACHED */ 1976 1977 case Q_PIM: 1978 bpf_error("'pim proto' is bogus"); 1979 /* NOTREACHED */ 1980 1981 #ifdef INET6 1982 case Q_IPV6: 1983 b0 = gen_linktype(ETHERTYPE_IPV6); 1984 #ifndef CHASE_CHAIN 1985 b1 = gen_cmp(off_nl + 6, BPF_B, (bpf_int32)v); 1986 #else 1987 b1 = gen_protochain(v, Q_IPV6); 1988 #endif 1989 gen_and(b0, b1); 1990 return b1; 1991 1992 case Q_ICMPV6: 1993 bpf_error("'icmp6 proto' is bogus"); 1994 #endif /* INET6 */ 1995 1996 case Q_AH: 1997 bpf_error("'ah proto' is bogus"); 1998 1999 case Q_ESP: 2000 bpf_error("'ah proto' is bogus"); 2001 2002 default: 2003 abort(); 2004 /* NOTREACHED */ 2005 } 2006 /* NOTREACHED */ 2007 } 2008 2009 struct block * 2010 gen_scode(name, q) 2011 register const char *name; 2012 struct qual q; 2013 { 2014 int proto = q.proto; 2015 int dir = q.dir; 2016 int tproto; 2017 u_char *eaddr; 2018 bpf_u_int32 mask, addr; 2019 #ifndef INET6 2020 bpf_u_int32 **alist; 2021 #else 2022 int tproto6; 2023 struct sockaddr_in *sin; 2024 struct sockaddr_in6 *sin6; 2025 struct addrinfo *res, *res0; 2026 struct in6_addr mask128; 2027 #endif /*INET6*/ 2028 struct block *b, *tmp; 2029 int port, real_proto; 2030 2031 switch (q.addr) { 2032 2033 case Q_NET: 2034 addr = pcap_nametonetaddr(name); 2035 if (addr == 0) 2036 bpf_error("unknown network '%s'", name); 2037 /* Left justify network addr and calculate its network mask */ 2038 mask = 0xffffffff; 2039 while (addr && (addr & 0xff000000) == 0) { 2040 addr <<= 8; 2041 mask <<= 8; 2042 } 2043 return gen_host(addr, mask, proto, dir); 2044 2045 case Q_DEFAULT: 2046 case Q_HOST: 2047 if (proto == Q_LINK) { 2048 switch (linktype) { 2049 2050 case DLT_EN10MB: 2051 eaddr = pcap_ether_hostton(name); 2052 if (eaddr == NULL) 2053 bpf_error( 2054 "unknown ether host '%s'", name); 2055 return gen_ehostop(eaddr, dir); 2056 2057 case DLT_FDDI: 2058 eaddr = pcap_ether_hostton(name); 2059 if (eaddr == NULL) 2060 bpf_error( 2061 "unknown FDDI host '%s'", name); 2062 return gen_fhostop(eaddr, dir); 2063 2064 default: 2065 bpf_error( 2066 "only ethernet/FDDI supports link-level host name"); 2067 break; 2068 } 2069 } else if (proto == Q_DECNET) { 2070 unsigned short dn_addr = __pcap_nametodnaddr(name); 2071 /* 2072 * I don't think DECNET hosts can be multihomed, so 2073 * there is no need to build up a list of addresses 2074 */ 2075 return (gen_host(dn_addr, 0, proto, dir)); 2076 } else { 2077 #ifndef INET6 2078 alist = pcap_nametoaddr(name); 2079 if (alist == NULL || *alist == NULL) 2080 bpf_error("unknown host '%s'", name); 2081 tproto = proto; 2082 if (off_linktype == -1 && tproto == Q_DEFAULT) 2083 tproto = Q_IP; 2084 b = gen_host(**alist++, 0xffffffff, tproto, dir); 2085 while (*alist) { 2086 tmp = gen_host(**alist++, 0xffffffff, 2087 tproto, dir); 2088 gen_or(b, tmp); 2089 b = tmp; 2090 } 2091 return b; 2092 #else 2093 memset(&mask128, 0xff, sizeof(mask128)); 2094 res0 = res = pcap_nametoaddrinfo(name); 2095 if (res == NULL) 2096 bpf_error("unknown host '%s'", name); 2097 b = tmp = NULL; 2098 tproto = tproto6 = proto; 2099 if (off_linktype == -1 && tproto == Q_DEFAULT) { 2100 tproto = Q_IP; 2101 tproto6 = Q_IPV6; 2102 } 2103 for (res = res0; res; res = res->ai_next) { 2104 switch (res->ai_family) { 2105 case AF_INET: 2106 if (tproto == Q_IPV6) 2107 continue; 2108 2109 sin = (struct sockaddr_in *) 2110 res->ai_addr; 2111 tmp = gen_host(ntohl(sin->sin_addr.s_addr), 2112 0xffffffff, tproto, dir); 2113 break; 2114 case AF_INET6: 2115 if (tproto6 == Q_IP) 2116 continue; 2117 2118 sin6 = (struct sockaddr_in6 *) 2119 res->ai_addr; 2120 tmp = gen_host6(&sin6->sin6_addr, 2121 &mask128, tproto6, dir); 2122 break; 2123 } 2124 if (b) 2125 gen_or(b, tmp); 2126 b = tmp; 2127 } 2128 freeaddrinfo(res0); 2129 if (b == NULL) { 2130 bpf_error("unknown host '%s'%s", name, 2131 (proto == Q_DEFAULT) 2132 ? "" 2133 : " for specified address family"); 2134 } 2135 return b; 2136 #endif /*INET6*/ 2137 } 2138 2139 case Q_PORT: 2140 if (proto != Q_DEFAULT && proto != Q_UDP && proto != Q_TCP) 2141 bpf_error("illegal qualifier of 'port'"); 2142 if (pcap_nametoport(name, &port, &real_proto) == 0) 2143 bpf_error("unknown port '%s'", name); 2144 if (proto == Q_UDP) { 2145 if (real_proto == IPPROTO_TCP) 2146 bpf_error("port '%s' is tcp", name); 2147 else 2148 /* override PROTO_UNDEF */ 2149 real_proto = IPPROTO_UDP; 2150 } 2151 if (proto == Q_TCP) { 2152 if (real_proto == IPPROTO_UDP) 2153 bpf_error("port '%s' is udp", name); 2154 else 2155 /* override PROTO_UNDEF */ 2156 real_proto = IPPROTO_TCP; 2157 } 2158 #ifndef INET6 2159 return gen_port(port, real_proto, dir); 2160 #else 2161 { 2162 struct block *b; 2163 b = gen_port(port, real_proto, dir); 2164 gen_or(gen_port6(port, real_proto, dir), b); 2165 return b; 2166 } 2167 #endif /* INET6 */ 2168 2169 case Q_GATEWAY: 2170 #ifndef INET6 2171 eaddr = pcap_ether_hostton(name); 2172 if (eaddr == NULL) 2173 bpf_error("unknown ether host: %s", name); 2174 2175 alist = pcap_nametoaddr(name); 2176 if (alist == NULL || *alist == NULL) 2177 bpf_error("unknown host '%s'", name); 2178 return gen_gateway(eaddr, alist, proto, dir); 2179 #else 2180 bpf_error("'gateway' not supported in this configuration"); 2181 #endif /*INET6*/ 2182 2183 case Q_PROTO: 2184 real_proto = lookup_proto(name, proto); 2185 if (real_proto >= 0) 2186 return gen_proto(real_proto, proto, dir); 2187 else 2188 bpf_error("unknown protocol: %s", name); 2189 2190 case Q_PROTOCHAIN: 2191 real_proto = lookup_proto(name, proto); 2192 if (real_proto >= 0) 2193 return gen_protochain(real_proto, proto, dir); 2194 else 2195 bpf_error("unknown protocol: %s", name); 2196 2197 2198 case Q_UNDEF: 2199 syntax(); 2200 /* NOTREACHED */ 2201 } 2202 abort(); 2203 /* NOTREACHED */ 2204 } 2205 2206 struct block * 2207 gen_mcode(s1, s2, masklen, q) 2208 register const char *s1, *s2; 2209 register int masklen; 2210 struct qual q; 2211 { 2212 register int nlen, mlen; 2213 bpf_u_int32 n, m; 2214 2215 nlen = __pcap_atoin(s1, &n); 2216 /* Promote short ipaddr */ 2217 n <<= 32 - nlen; 2218 2219 if (s2 != NULL) { 2220 mlen = __pcap_atoin(s2, &m); 2221 /* Promote short ipaddr */ 2222 m <<= 32 - mlen; 2223 if ((n & ~m) != 0) 2224 bpf_error("non-network bits set in \"%s mask %s\"", 2225 s1, s2); 2226 } else { 2227 /* Convert mask len to mask */ 2228 if (masklen > 32) 2229 bpf_error("mask length must be <= 32"); 2230 m = 0xffffffff << (32 - masklen); 2231 if ((n & ~m) != 0) 2232 bpf_error("non-network bits set in \"%s/%d\"", 2233 s1, masklen); 2234 } 2235 2236 switch (q.addr) { 2237 2238 case Q_NET: 2239 return gen_host(n, m, q.proto, q.dir); 2240 2241 default: 2242 bpf_error("Mask syntax for networks only"); 2243 /* NOTREACHED */ 2244 } 2245 } 2246 2247 struct block * 2248 gen_ncode(s, v, q) 2249 register const char *s; 2250 bpf_u_int32 v; 2251 struct qual q; 2252 { 2253 bpf_u_int32 mask; 2254 int proto = q.proto; 2255 int dir = q.dir; 2256 register int vlen; 2257 2258 if (s == NULL) 2259 vlen = 32; 2260 else if (q.proto == Q_DECNET) 2261 vlen = __pcap_atodn(s, &v); 2262 else 2263 vlen = __pcap_atoin(s, &v); 2264 2265 switch (q.addr) { 2266 2267 case Q_DEFAULT: 2268 case Q_HOST: 2269 case Q_NET: 2270 if (proto == Q_DECNET) 2271 return gen_host(v, 0, proto, dir); 2272 else if (proto == Q_LINK) { 2273 bpf_error("illegal link layer address"); 2274 } else { 2275 mask = 0xffffffff; 2276 if (s == NULL && q.addr == Q_NET) { 2277 /* Promote short net number */ 2278 while (v && (v & 0xff000000) == 0) { 2279 v <<= 8; 2280 mask <<= 8; 2281 } 2282 } else { 2283 /* Promote short ipaddr */ 2284 v <<= 32 - vlen; 2285 mask <<= 32 - vlen; 2286 } 2287 return gen_host(v, mask, proto, dir); 2288 } 2289 2290 case Q_PORT: 2291 if (proto == Q_UDP) 2292 proto = IPPROTO_UDP; 2293 else if (proto == Q_TCP) 2294 proto = IPPROTO_TCP; 2295 else if (proto == Q_DEFAULT) 2296 proto = PROTO_UNDEF; 2297 else 2298 bpf_error("illegal qualifier of 'port'"); 2299 2300 #ifndef INET6 2301 return gen_port((int)v, proto, dir); 2302 #else 2303 { 2304 struct block *b; 2305 b = gen_port((int)v, proto, dir); 2306 gen_or(gen_port6((int)v, proto, dir), b); 2307 return b; 2308 } 2309 #endif /* INET6 */ 2310 2311 case Q_GATEWAY: 2312 bpf_error("'gateway' requires a name"); 2313 /* NOTREACHED */ 2314 2315 case Q_PROTO: 2316 return gen_proto((int)v, proto, dir); 2317 2318 case Q_PROTOCHAIN: 2319 return gen_protochain((int)v, proto, dir); 2320 2321 case Q_UNDEF: 2322 syntax(); 2323 /* NOTREACHED */ 2324 2325 default: 2326 abort(); 2327 /* NOTREACHED */ 2328 } 2329 /* NOTREACHED */ 2330 } 2331 2332 #ifdef INET6 2333 struct block * 2334 gen_mcode6(s1, s2, masklen, q) 2335 register const char *s1, *s2; 2336 register int masklen; 2337 struct qual q; 2338 { 2339 struct addrinfo *res; 2340 struct in6_addr *addr; 2341 struct in6_addr mask; 2342 struct block *b; 2343 u_int32_t *a, *m; 2344 2345 if (s2) 2346 bpf_error("no mask %s supported", s2); 2347 2348 res = pcap_nametoaddrinfo(s1); 2349 if (!res) 2350 bpf_error("invalid ip6 address %s", s1); 2351 if (res->ai_next) 2352 bpf_error("%s resolved to multiple address", s1); 2353 addr = &((struct sockaddr_in6 *)res->ai_addr)->sin6_addr; 2354 2355 if (sizeof(mask) * 8 < masklen) 2356 bpf_error("mask length must be <= %u", (unsigned int)(sizeof(mask) * 8)); 2357 memset(&mask, 0xff, masklen / 8); 2358 if (masklen % 8) { 2359 mask.s6_addr[masklen / 8] = 2360 (0xff << (8 - masklen % 8)) & 0xff; 2361 } 2362 2363 a = (u_int32_t *)addr; 2364 m = (u_int32_t *)&mask; 2365 if ((a[0] & ~m[0]) || (a[1] & ~m[1]) 2366 || (a[2] & ~m[2]) || (a[3] & ~m[3])) { 2367 bpf_error("non-network bits set in \"%s/%d\"", s1, masklen); 2368 } 2369 2370 switch (q.addr) { 2371 2372 case Q_DEFAULT: 2373 case Q_HOST: 2374 if (masklen != 128) 2375 bpf_error("Mask syntax for networks only"); 2376 /* FALLTHROUGH */ 2377 2378 case Q_NET: 2379 b = gen_host6(addr, &mask, q.proto, q.dir); 2380 freeaddrinfo(res); 2381 return b; 2382 2383 default: 2384 bpf_error("invalid qualifier against IPv6 address"); 2385 /* NOTREACHED */ 2386 } 2387 } 2388 #endif /*INET6*/ 2389 2390 struct block * 2391 gen_ecode(eaddr, q) 2392 register const u_char *eaddr; 2393 struct qual q; 2394 { 2395 if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) && q.proto == Q_LINK) { 2396 if (linktype == DLT_EN10MB) 2397 return gen_ehostop(eaddr, (int)q.dir); 2398 if (linktype == DLT_FDDI) 2399 return gen_fhostop(eaddr, (int)q.dir); 2400 } 2401 bpf_error("ethernet address used in non-ether expression"); 2402 /* NOTREACHED */ 2403 } 2404 2405 void 2406 sappend(s0, s1) 2407 struct slist *s0, *s1; 2408 { 2409 /* 2410 * This is definitely not the best way to do this, but the 2411 * lists will rarely get long. 2412 */ 2413 while (s0->next) 2414 s0 = s0->next; 2415 s0->next = s1; 2416 } 2417 2418 static struct slist * 2419 xfer_to_x(a) 2420 struct arth *a; 2421 { 2422 struct slist *s; 2423 2424 s = new_stmt(BPF_LDX|BPF_MEM); 2425 s->s.k = a->regno; 2426 return s; 2427 } 2428 2429 static struct slist * 2430 xfer_to_a(a) 2431 struct arth *a; 2432 { 2433 struct slist *s; 2434 2435 s = new_stmt(BPF_LD|BPF_MEM); 2436 s->s.k = a->regno; 2437 return s; 2438 } 2439 2440 struct arth * 2441 gen_load(proto, index, size) 2442 int proto; 2443 struct arth *index; 2444 int size; 2445 { 2446 struct slist *s, *tmp; 2447 struct block *b; 2448 int regno = alloc_reg(); 2449 2450 free_reg(index->regno); 2451 switch (size) { 2452 2453 default: 2454 bpf_error("data size must be 1, 2, or 4"); 2455 2456 case 1: 2457 size = BPF_B; 2458 break; 2459 2460 case 2: 2461 size = BPF_H; 2462 break; 2463 2464 case 4: 2465 size = BPF_W; 2466 break; 2467 } 2468 switch (proto) { 2469 default: 2470 bpf_error("unsupported index operation"); 2471 2472 case Q_LINK: 2473 s = xfer_to_x(index); 2474 tmp = new_stmt(BPF_LD|BPF_IND|size); 2475 sappend(s, tmp); 2476 sappend(index->s, s); 2477 break; 2478 2479 case Q_IP: 2480 case Q_ARP: 2481 case Q_RARP: 2482 case Q_ATALK: 2483 case Q_DECNET: 2484 case Q_SCA: 2485 case Q_LAT: 2486 case Q_MOPRC: 2487 case Q_MOPDL: 2488 #ifdef INET6 2489 case Q_IPV6: 2490 #endif 2491 /* XXX Note that we assume a fixed link header here. */ 2492 s = xfer_to_x(index); 2493 tmp = new_stmt(BPF_LD|BPF_IND|size); 2494 tmp->s.k = off_nl; 2495 sappend(s, tmp); 2496 sappend(index->s, s); 2497 2498 b = gen_proto_abbrev(proto); 2499 if (index->b) 2500 gen_and(index->b, b); 2501 index->b = b; 2502 break; 2503 2504 case Q_TCP: 2505 case Q_UDP: 2506 case Q_ICMP: 2507 case Q_IGMP: 2508 case Q_IGRP: 2509 case Q_PIM: 2510 s = new_stmt(BPF_LDX|BPF_MSH|BPF_B); 2511 s->s.k = off_nl; 2512 sappend(s, xfer_to_a(index)); 2513 sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X)); 2514 sappend(s, new_stmt(BPF_MISC|BPF_TAX)); 2515 sappend(s, tmp = new_stmt(BPF_LD|BPF_IND|size)); 2516 tmp->s.k = off_nl; 2517 sappend(index->s, s); 2518 2519 gen_and(gen_proto_abbrev(proto), b = gen_ipfrag()); 2520 if (index->b) 2521 gen_and(index->b, b); 2522 #ifdef INET6 2523 gen_and(gen_proto_abbrev(Q_IP), b); 2524 #endif 2525 index->b = b; 2526 break; 2527 #ifdef INET6 2528 case Q_ICMPV6: 2529 bpf_error("IPv6 upper-layer protocol is not supported by proto[x]"); 2530 /*NOTREACHED*/ 2531 #endif 2532 } 2533 index->regno = regno; 2534 s = new_stmt(BPF_ST); 2535 s->s.k = regno; 2536 sappend(index->s, s); 2537 2538 return index; 2539 } 2540 2541 struct block * 2542 gen_relation(code, a0, a1, reversed) 2543 int code; 2544 struct arth *a0, *a1; 2545 int reversed; 2546 { 2547 struct slist *s0, *s1, *s2; 2548 struct block *b, *tmp; 2549 2550 s0 = xfer_to_x(a1); 2551 s1 = xfer_to_a(a0); 2552 s2 = new_stmt(BPF_ALU|BPF_SUB|BPF_X); 2553 b = new_block(JMP(code)); 2554 if (code == BPF_JGT || code == BPF_JGE) { 2555 reversed = !reversed; 2556 b->s.k = 0x80000000; 2557 } 2558 if (reversed) 2559 gen_not(b); 2560 2561 sappend(s1, s2); 2562 sappend(s0, s1); 2563 sappend(a1->s, s0); 2564 sappend(a0->s, a1->s); 2565 2566 b->stmts = a0->s; 2567 2568 free_reg(a0->regno); 2569 free_reg(a1->regno); 2570 2571 /* 'and' together protocol checks */ 2572 if (a0->b) { 2573 if (a1->b) { 2574 gen_and(a0->b, tmp = a1->b); 2575 } 2576 else 2577 tmp = a0->b; 2578 } else 2579 tmp = a1->b; 2580 2581 if (tmp) 2582 gen_and(tmp, b); 2583 2584 return b; 2585 } 2586 2587 struct arth * 2588 gen_loadlen() 2589 { 2590 int regno = alloc_reg(); 2591 struct arth *a = (struct arth *)newchunk(sizeof(*a)); 2592 struct slist *s; 2593 2594 s = new_stmt(BPF_LD|BPF_LEN); 2595 s->next = new_stmt(BPF_ST); 2596 s->next->s.k = regno; 2597 a->s = s; 2598 a->regno = regno; 2599 2600 return a; 2601 } 2602 2603 struct arth * 2604 gen_loadi(val) 2605 int val; 2606 { 2607 struct arth *a; 2608 struct slist *s; 2609 int reg; 2610 2611 a = (struct arth *)newchunk(sizeof(*a)); 2612 2613 reg = alloc_reg(); 2614 2615 s = new_stmt(BPF_LD|BPF_IMM); 2616 s->s.k = val; 2617 s->next = new_stmt(BPF_ST); 2618 s->next->s.k = reg; 2619 a->s = s; 2620 a->regno = reg; 2621 2622 return a; 2623 } 2624 2625 struct arth * 2626 gen_neg(a) 2627 struct arth *a; 2628 { 2629 struct slist *s; 2630 2631 s = xfer_to_a(a); 2632 sappend(a->s, s); 2633 s = new_stmt(BPF_ALU|BPF_NEG); 2634 s->s.k = 0; 2635 sappend(a->s, s); 2636 s = new_stmt(BPF_ST); 2637 s->s.k = a->regno; 2638 sappend(a->s, s); 2639 2640 return a; 2641 } 2642 2643 struct arth * 2644 gen_arth(code, a0, a1) 2645 int code; 2646 struct arth *a0, *a1; 2647 { 2648 struct slist *s0, *s1, *s2; 2649 2650 s0 = xfer_to_x(a1); 2651 s1 = xfer_to_a(a0); 2652 s2 = new_stmt(BPF_ALU|BPF_X|code); 2653 2654 sappend(s1, s2); 2655 sappend(s0, s1); 2656 sappend(a1->s, s0); 2657 sappend(a0->s, a1->s); 2658 2659 free_reg(a1->regno); 2660 2661 s0 = new_stmt(BPF_ST); 2662 a0->regno = s0->s.k = alloc_reg(); 2663 sappend(a0->s, s0); 2664 2665 return a0; 2666 } 2667 2668 /* 2669 * Here we handle simple allocation of the scratch registers. 2670 * If too many registers are alloc'd, the allocator punts. 2671 */ 2672 static int regused[BPF_MEMWORDS]; 2673 static int curreg; 2674 2675 /* 2676 * Return the next free register. 2677 */ 2678 static int 2679 alloc_reg() 2680 { 2681 int n = BPF_MEMWORDS; 2682 2683 while (--n >= 0) { 2684 if (regused[curreg]) 2685 curreg = (curreg + 1) % BPF_MEMWORDS; 2686 else { 2687 regused[curreg] = 1; 2688 return curreg; 2689 } 2690 } 2691 bpf_error("too many registers needed to evaluate expression"); 2692 /* NOTREACHED */ 2693 } 2694 2695 /* 2696 * Return a register to the table so it can 2697 * be used later. 2698 */ 2699 static void 2700 free_reg(n) 2701 int n; 2702 { 2703 regused[n] = 0; 2704 } 2705 2706 static struct block * 2707 gen_len(jmp, n) 2708 int jmp, n; 2709 { 2710 struct slist *s; 2711 struct block *b; 2712 2713 s = new_stmt(BPF_LD|BPF_LEN); 2714 b = new_block(JMP(jmp)); 2715 b->stmts = s; 2716 b->s.k = n; 2717 2718 return b; 2719 } 2720 2721 struct block * 2722 gen_greater(n) 2723 int n; 2724 { 2725 return gen_len(BPF_JGE, n); 2726 } 2727 2728 struct block * 2729 gen_less(n) 2730 int n; 2731 { 2732 struct block *b; 2733 2734 b = gen_len(BPF_JGT, n); 2735 gen_not(b); 2736 2737 return b; 2738 } 2739 2740 struct block * 2741 gen_byteop(op, idx, val) 2742 int op, idx, val; 2743 { 2744 struct block *b; 2745 struct slist *s; 2746 2747 switch (op) { 2748 default: 2749 abort(); 2750 2751 case '=': 2752 return gen_cmp((u_int)idx, BPF_B, (bpf_int32)val); 2753 2754 case '<': 2755 b = gen_cmp((u_int)idx, BPF_B, (bpf_int32)val); 2756 b->s.code = JMP(BPF_JGE); 2757 gen_not(b); 2758 return b; 2759 2760 case '>': 2761 b = gen_cmp((u_int)idx, BPF_B, (bpf_int32)val); 2762 b->s.code = JMP(BPF_JGT); 2763 return b; 2764 2765 case '|': 2766 s = new_stmt(BPF_ALU|BPF_OR|BPF_K); 2767 break; 2768 2769 case '&': 2770 s = new_stmt(BPF_ALU|BPF_AND|BPF_K); 2771 break; 2772 } 2773 s->s.k = val; 2774 b = new_block(JMP(BPF_JEQ)); 2775 b->stmts = s; 2776 gen_not(b); 2777 2778 return b; 2779 } 2780 2781 static u_char abroadcast[] = { 0x0 }; 2782 2783 struct block * 2784 gen_broadcast(proto) 2785 int proto; 2786 { 2787 bpf_u_int32 hostmask; 2788 struct block *b0, *b1, *b2; 2789 static u_char ebroadcast[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; 2790 2791 switch (proto) { 2792 2793 case Q_DEFAULT: 2794 case Q_LINK: 2795 if (linktype == DLT_ARCNET) 2796 return gen_ahostop(abroadcast, Q_DST); 2797 if (linktype == DLT_EN10MB) 2798 return gen_ehostop(ebroadcast, Q_DST); 2799 if (linktype == DLT_FDDI) 2800 return gen_fhostop(ebroadcast, Q_DST); 2801 bpf_error("not a broadcast link"); 2802 break; 2803 2804 case Q_IP: 2805 b0 = gen_linktype(ETHERTYPE_IP); 2806 hostmask = ~netmask; 2807 b1 = gen_mcmp(off_nl + 16, BPF_W, (bpf_int32)0, hostmask); 2808 b2 = gen_mcmp(off_nl + 16, BPF_W, 2809 (bpf_int32)(~0 & hostmask), hostmask); 2810 gen_or(b1, b2); 2811 gen_and(b0, b2); 2812 return b2; 2813 } 2814 bpf_error("only ether/ip broadcast filters supported"); 2815 } 2816 2817 struct block * 2818 gen_multicast(proto) 2819 int proto; 2820 { 2821 register struct block *b0, *b1; 2822 register struct slist *s; 2823 2824 switch (proto) { 2825 2826 case Q_DEFAULT: 2827 case Q_LINK: 2828 if (linktype == DLT_ARCNET) 2829 /* all ARCnet multicasts use the same address */ 2830 return gen_ahostop(abroadcast, Q_DST); 2831 2832 if (linktype == DLT_EN10MB) { 2833 /* ether[0] & 1 != 0 */ 2834 s = new_stmt(BPF_LD|BPF_B|BPF_ABS); 2835 s->s.k = 0; 2836 b0 = new_block(JMP(BPF_JSET)); 2837 b0->s.k = 1; 2838 b0->stmts = s; 2839 return b0; 2840 } 2841 2842 if (linktype == DLT_FDDI) { 2843 /* XXX TEST THIS: MIGHT NOT PORT PROPERLY XXX */ 2844 /* fddi[1] & 1 != 0 */ 2845 s = new_stmt(BPF_LD|BPF_B|BPF_ABS); 2846 s->s.k = 1; 2847 b0 = new_block(JMP(BPF_JSET)); 2848 b0->s.k = 1; 2849 b0->stmts = s; 2850 return b0; 2851 } 2852 /* Link not known to support multicasts */ 2853 break; 2854 2855 case Q_IP: 2856 b0 = gen_linktype(ETHERTYPE_IP); 2857 b1 = gen_cmp(off_nl + 16, BPF_B, (bpf_int32)224); 2858 b1->s.code = JMP(BPF_JGE); 2859 gen_and(b0, b1); 2860 return b1; 2861 2862 #ifdef INET6 2863 case Q_IPV6: 2864 b0 = gen_linktype(ETHERTYPE_IPV6); 2865 b1 = gen_cmp(off_nl + 24, BPF_B, (bpf_int32)255); 2866 gen_and(b0, b1); 2867 return b1; 2868 #endif /* INET6 */ 2869 } 2870 bpf_error("only IP multicast filters supported on ethernet/FDDI"); 2871 } 2872 2873 /* 2874 * generate command for inbound/outbound. It's here so we can 2875 * make it link-type specific. 'dir' = 0 implies "inbound", 2876 * = 1 implies "outbound". 2877 */ 2878 struct block * 2879 gen_inbound(dir) 2880 int dir; 2881 { 2882 register struct block *b0; 2883 2884 /* 2885 * Only SLIP and old-style PPP data link types support 2886 * inbound/outbound qualifiers. 2887 */ 2888 switch (linktype) { 2889 case DLT_SLIP: 2890 case DLT_PPP: 2891 b0 = gen_relation(BPF_JEQ, 2892 gen_load(Q_LINK, gen_loadi(0), 1), 2893 gen_loadi(0), 2894 dir); 2895 break; 2896 2897 case DLT_PFLOG: 2898 b0 = gen_cmp(offsetof(struct pfloghdr, dir), BPF_H, 2899 (bpf_int32)((dir == 0) ? PF_IN : PF_OUT)); 2900 break; 2901 2902 default: 2903 bpf_error("inbound/outbound not supported on linktype 0x%x\n", 2904 linktype); 2905 /* NOTREACHED */ 2906 } 2907 2908 return (b0); 2909 } 2910 2911 2912 /* PF firewall log matched interface */ 2913 struct block * 2914 gen_pf_ifname(char *ifname) 2915 { 2916 struct block *b0; 2917 2918 if (linktype != DLT_PFLOG) { 2919 bpf_error("ifname not supported on linktype 0x%x\n", linktype); 2920 /* NOTREACHED */ 2921 } 2922 if (strlen(ifname) >= sizeof(((struct pfloghdr *)0)->ifname)) { 2923 bpf_error("ifname interface names can only be %d characters\n", 2924 sizeof(((struct pfloghdr *)0)->ifname) - 1); 2925 2926 /* NOTREACHED */ 2927 } 2928 b0 = gen_bcmp(offsetof(struct pfloghdr, ifname), strlen(ifname), 2929 ifname); 2930 return (b0); 2931 } 2932 2933 2934 /* PF firewall log rule number */ 2935 struct block * 2936 gen_pf_rnr(int rnr) 2937 { 2938 struct block *b0; 2939 2940 if (linktype != DLT_PFLOG) { 2941 bpf_error("rnr not supported on linktype 0x%x\n", linktype); 2942 /* NOTREACHED */ 2943 } 2944 2945 b0 = gen_cmp(offsetof(struct pfloghdr, rnr), BPF_H, (bpf_int32)rnr); 2946 return (b0); 2947 } 2948 2949 /* PF firewall log reason code */ 2950 struct block * 2951 gen_pf_reason(int reason) 2952 { 2953 struct block *b0; 2954 2955 if (linktype != DLT_PFLOG) { 2956 bpf_error("reason not supported on linktype 0x%x\n", linktype); 2957 /* NOTREACHED */ 2958 } 2959 2960 b0 = gen_cmp(offsetof(struct pfloghdr, reason), BPF_H, 2961 (bpf_int32)reason); 2962 return (b0); 2963 } 2964 2965 /* PF firewall log action */ 2966 struct block * 2967 gen_pf_action(int action) 2968 { 2969 struct block *b0; 2970 2971 if (linktype != DLT_PFLOG) { 2972 bpf_error("action not supported on linktype 0x%x\n", linktype); 2973 /* NOTREACHED */ 2974 } 2975 2976 b0 = gen_cmp(offsetof(struct pfloghdr, action), BPF_H, 2977 (bpf_int32)action); 2978 return (b0); 2979 } 2980 2981 struct block * 2982 gen_acode(eaddr, q) 2983 register const u_char *eaddr; 2984 struct qual q; 2985 { 2986 if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) && q.proto == Q_LINK) { 2987 if (linktype == DLT_ARCNET) 2988 return gen_ahostop(eaddr, (int)q.dir); 2989 } 2990 bpf_error("ARCnet address used in non-arc expression"); 2991 /* NOTREACHED */ 2992 } 2993 2994 static struct block * 2995 gen_ahostop(eaddr, dir) 2996 register const u_char *eaddr; 2997 register int dir; 2998 { 2999 register struct block *b0, *b1; 3000 3001 switch (dir) { 3002 /* src comes first, different from Ethernet */ 3003 case Q_SRC: 3004 return gen_bcmp(0, 1, eaddr); 3005 3006 case Q_DST: 3007 return gen_bcmp(1, 1, eaddr); 3008 3009 case Q_AND: 3010 b0 = gen_ahostop(eaddr, Q_SRC); 3011 b1 = gen_ahostop(eaddr, Q_DST); 3012 gen_and(b0, b1); 3013 return b1; 3014 3015 case Q_DEFAULT: 3016 case Q_OR: 3017 b0 = gen_ahostop(eaddr, Q_SRC); 3018 b1 = gen_ahostop(eaddr, Q_DST); 3019 gen_or(b0, b1); 3020 return b1; 3021 } 3022 abort(); 3023 /* NOTREACHED */ 3024 } 3025