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turns printfs back on
[freebsd-src/fkvm-freebsd.git] / contrib / libpcap / gencode.c
blobb2d822221c3ef5762f3d38bc668938dc800225cf
1 /*#define CHASE_CHAIN*/
2 /*
3 * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998
4 * The Regents of the University of California. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that: (1) source code distributions
8 * retain the above copyright notice and this paragraph in its entirety, (2)
9 * distributions including binary code include the above copyright notice and
10 * this paragraph in its entirety in the documentation or other materials
11 * provided with the distribution, and (3) all advertising materials mentioning
12 * features or use of this software display the following acknowledgement:
13 * ``This product includes software developed by the University of California,
14 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
15 * the University nor the names of its contributors may be used to endorse
16 * or promote products derived from this software without specific prior
17 * written permission.
18 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
19 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
20 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
21 *
22 * $FreeBSD$
23 */
24 #ifndef lint
25 static const char rcsid[] _U_ =
26 "@(#) $Header: /tcpdump/master/libpcap/gencode.c,v 1.221.2.53 2007/09/12 19:17:24 guy Exp $ (LBL)";
27 #endif
28
29 #ifdef HAVE_CONFIG_H
30 #include "config.h"
31 #endif
32
33 #ifdef WIN32
34 #include <pcap-stdinc.h>
35 #else /* WIN32 */
36 #include <sys/types.h>
37 #include <sys/socket.h>
38 #endif /* WIN32 */
39
40 /*
41 * XXX - why was this included even on UNIX?
42 */
43 #ifdef __MINGW32__
44 #include "IP6_misc.h"
45 #endif
46
47 #ifndef WIN32
48
49 #ifdef __NetBSD__
50 #include <sys/param.h>
51 #endif
52
53 #include <netinet/in.h>
54
55 #endif /* WIN32 */
56
57 #include <stdlib.h>
58 #include <string.h>
59 #include <memory.h>
60 #include <setjmp.h>
61 #include <stdarg.h>
62
63 #ifdef MSDOS
64 #include "pcap-dos.h"
65 #endif
66
67 #include "pcap-int.h"
68
69 #include "ethertype.h"
70 #include "nlpid.h"
71 #include "llc.h"
72 #include "gencode.h"
73 #include "atmuni31.h"
74 #include "sunatmpos.h"
75 #include "ppp.h"
76 #include "sll.h"
77 #include "arcnet.h"
78 #ifdef HAVE_NET_PFVAR_H
79 #include <sys/socket.h>
80 #include <net/if.h>
81 #include <net/pfvar.h>
82 #include <net/if_pflog.h>
83 #endif
84 #ifndef offsetof
85 #define offsetof(s, e) ((size_t)&((s *)0)->e)
86 #endif
87 #ifdef INET6
88 #ifndef WIN32
89 #include <netdb.h> /* for "struct addrinfo" */
90 #endif /* WIN32 */
91 #endif /*INET6*/
92 #include <pcap-namedb.h>
93
94 #define ETHERMTU 1500
95
96 #ifndef IPPROTO_SCTP
97 #define IPPROTO_SCTP 132
98 #endif
99
100 #ifdef HAVE_OS_PROTO_H
101 #include "os-proto.h"
102 #endif
103
104 #define JMP(c) ((c)|BPF_JMP|BPF_K)
105
106 /* Locals */
107 static jmp_buf top_ctx;
108 static pcap_t *bpf_pcap;
109
110 #ifdef WIN32
111 /* Hack for updating VLAN, MPLS, and PPPoE offsets. */
112 static u_int orig_linktype = (u_int)-1, orig_nl = (u_int)-1, label_stack_depth = (u_int)-1;
113 #else
114 static u_int orig_linktype = -1U, orig_nl = -1U, label_stack_depth = -1U;
115 #endif
116
117 /* XXX */
118 #ifdef PCAP_FDDIPAD
119 static int pcap_fddipad;
120 #endif
121
122 /* VARARGS */
123 void
124 bpf_error(const char *fmt, ...)
125 {
126 va_list ap;
127
128 va_start(ap, fmt);
129 if (bpf_pcap != NULL)
130 (void)vsnprintf(pcap_geterr(bpf_pcap), PCAP_ERRBUF_SIZE,
131 fmt, ap);
132 va_end(ap);
133 longjmp(top_ctx, 1);
134 /* NOTREACHED */
135 }
136
137 static void init_linktype(pcap_t *);
138
139 static int alloc_reg(void);
140 static void free_reg(int);
141
142 static struct block *root;
143
144 /*
145 * Value passed to gen_load_a() to indicate what the offset argument
146 * is relative to.
147 */
148 enum e_offrel {
149 OR_PACKET, /* relative to the beginning of the packet */
150 OR_LINK, /* relative to the link-layer header */
151 OR_NET, /* relative to the network-layer header */
152 OR_NET_NOSNAP, /* relative to the network-layer header, with no SNAP header at the link layer */
153 OR_TRAN_IPV4, /* relative to the transport-layer header, with IPv4 network layer */
154 OR_TRAN_IPV6 /* relative to the transport-layer header, with IPv6 network layer */
155 };
156
157 /*
158 * We divy out chunks of memory rather than call malloc each time so
159 * we don't have to worry about leaking memory. It's probably
160 * not a big deal if all this memory was wasted but if this ever
161 * goes into a library that would probably not be a good idea.
162 *
163 * XXX - this *is* in a library....
164 */
165 #define NCHUNKS 16
166 #define CHUNK0SIZE 1024
167 struct chunk {
168 u_int n_left;
169 void *m;
170 };
171
172 static struct chunk chunks[NCHUNKS];
173 static int cur_chunk;
174
175 static void *newchunk(u_int);
176 static void freechunks(void);
177 static inline struct block *new_block(int);
178 static inline struct slist *new_stmt(int);
179 static struct block *gen_retblk(int);
180 static inline void syntax(void);
181
182 static void backpatch(struct block *, struct block *);
183 static void merge(struct block *, struct block *);
184 static struct block *gen_cmp(enum e_offrel, u_int, u_int, bpf_int32);
185 static struct block *gen_cmp_gt(enum e_offrel, u_int, u_int, bpf_int32);
186 static struct block *gen_cmp_ge(enum e_offrel, u_int, u_int, bpf_int32);
187 static struct block *gen_cmp_lt(enum e_offrel, u_int, u_int, bpf_int32);
188 static struct block *gen_cmp_le(enum e_offrel, u_int, u_int, bpf_int32);
189 static struct block *gen_mcmp(enum e_offrel, u_int, u_int, bpf_int32,
190 bpf_u_int32);
191 static struct block *gen_bcmp(enum e_offrel, u_int, u_int, const u_char *);
192 static struct block *gen_ncmp(enum e_offrel, bpf_u_int32, bpf_u_int32,
193 bpf_u_int32, bpf_u_int32, int, bpf_int32);
194 static struct slist *gen_load_llrel(u_int, u_int);
195 static struct slist *gen_load_a(enum e_offrel, u_int, u_int);
196 static struct slist *gen_loadx_iphdrlen(void);
197 static struct block *gen_uncond(int);
198 static inline struct block *gen_true(void);
199 static inline struct block *gen_false(void);
200 static struct block *gen_ether_linktype(int);
201 static struct block *gen_linux_sll_linktype(int);
202 static void insert_radiotap_load_llprefixlen(struct block *);
203 static void insert_ppi_load_llprefixlen(struct block *);
204 static void insert_load_llprefixlen(struct block *);
205 static struct slist *gen_llprefixlen(void);
206 static struct block *gen_linktype(int);
207 static struct block *gen_snap(bpf_u_int32, bpf_u_int32, u_int);
208 static struct block *gen_llc_linktype(int);
209 static struct block *gen_hostop(bpf_u_int32, bpf_u_int32, int, int, u_int, u_int);
210 #ifdef INET6
211 static struct block *gen_hostop6(struct in6_addr *, struct in6_addr *, int, int, u_int, u_int);
212 #endif
213 static struct block *gen_ahostop(const u_char *, int);
214 static struct block *gen_ehostop(const u_char *, int);
215 static struct block *gen_fhostop(const u_char *, int);
216 static struct block *gen_thostop(const u_char *, int);
217 static struct block *gen_wlanhostop(const u_char *, int);
218 static struct block *gen_ipfchostop(const u_char *, int);
219 static struct block *gen_dnhostop(bpf_u_int32, int);
220 static struct block *gen_mpls_linktype(int);
221 static struct block *gen_host(bpf_u_int32, bpf_u_int32, int, int, int);
222 #ifdef INET6
223 static struct block *gen_host6(struct in6_addr *, struct in6_addr *, int, int, int);
224 #endif
225 #ifndef INET6
226 static struct block *gen_gateway(const u_char *, bpf_u_int32 **, int, int);
227 #endif
228 static struct block *gen_ipfrag(void);
229 static struct block *gen_portatom(int, bpf_int32);
230 static struct block *gen_portrangeatom(int, bpf_int32, bpf_int32);
231 #ifdef INET6
232 static struct block *gen_portatom6(int, bpf_int32);
233 static struct block *gen_portrangeatom6(int, bpf_int32, bpf_int32);
234 #endif
235 struct block *gen_portop(int, int, int);
236 static struct block *gen_port(int, int, int);
237 struct block *gen_portrangeop(int, int, int, int);
238 static struct block *gen_portrange(int, int, int, int);
239 #ifdef INET6
240 struct block *gen_portop6(int, int, int);
241 static struct block *gen_port6(int, int, int);
242 struct block *gen_portrangeop6(int, int, int, int);
243 static struct block *gen_portrange6(int, int, int, int);
244 #endif
245 static int lookup_proto(const char *, int);
246 static struct block *gen_protochain(int, int, int);
247 static struct block *gen_proto(int, int, int);
248 static struct slist *xfer_to_x(struct arth *);
249 static struct slist *xfer_to_a(struct arth *);
250 static struct block *gen_mac_multicast(int);
251 static struct block *gen_len(int, int);
252
253 static struct block *gen_ppi_dlt_check(void);
254 static struct block *gen_msg_abbrev(int type);
255
256 static void *
257 newchunk(n)
258 u_int n;
259 {
260 struct chunk *cp;
261 int k;
262 size_t size;
263
264 #ifndef __NetBSD__
265 /* XXX Round up to nearest long. */
266 n = (n + sizeof(long) - 1) & ~(sizeof(long) - 1);
267 #else
268 /* XXX Round up to structure boundary. */
269 n = ALIGN(n);
270 #endif
271
272 cp = &chunks[cur_chunk];
273 if (n > cp->n_left) {
274 ++cp, k = ++cur_chunk;
275 if (k >= NCHUNKS)
276 bpf_error("out of memory");
277 size = CHUNK0SIZE << k;
278 cp->m = (void *)malloc(size);
279 if (cp->m == NULL)
280 bpf_error("out of memory");
281 memset((char *)cp->m, 0, size);
282 cp->n_left = size;
283 if (n > size)
284 bpf_error("out of memory");
285 }
286 cp->n_left -= n;
287 return (void *)((char *)cp->m + cp->n_left);
288 }
289
290 static void
291 freechunks()
292 {
293 int i;
294
295 cur_chunk = 0;
296 for (i = 0; i < NCHUNKS; ++i)
297 if (chunks[i].m != NULL) {
298 free(chunks[i].m);
299 chunks[i].m = NULL;
300 }
301 }
302
303 /*
304 * A strdup whose allocations are freed after code generation is over.
305 */
306 char *
307 sdup(s)
308 register const char *s;
309 {
310 int n = strlen(s) + 1;
311 char *cp = newchunk(n);
312
313 strlcpy(cp, s, n);
314 return (cp);
315 }
316
317 static inline struct block *
318 new_block(code)
319 int code;
320 {
321 struct block *p;
322
323 p = (struct block *)newchunk(sizeof(*p));
324 p->s.code = code;
325 p->head = p;
326
327 return p;
328 }
329
330 static inline struct slist *
331 new_stmt(code)
332 int code;
333 {
334 struct slist *p;
335
336 p = (struct slist *)newchunk(sizeof(*p));
337 p->s.code = code;
338
339 return p;
340 }
341
342 static struct block *
343 gen_retblk(v)
344 int v;
345 {
346 struct block *b = new_block(BPF_RET|BPF_K);
347
348 b->s.k = v;
349 return b;
350 }
351
352 static inline void
353 syntax()
354 {
355 bpf_error("syntax error in filter expression");
356 }
357
358 static bpf_u_int32 netmask;
359 static int snaplen;
360 int no_optimize;
361
362 int
363 pcap_compile(pcap_t *p, struct bpf_program *program,
364 const char *buf, int optimize, bpf_u_int32 mask)
365 {
366 extern int n_errors;
367 const char * volatile xbuf = buf;
368 int len;
369
370 no_optimize = 0;
371 n_errors = 0;
372 root = NULL;
373 bpf_pcap = p;
374 if (setjmp(top_ctx)) {
375 lex_cleanup();
376 freechunks();
377 return (-1);
378 }
379
380 netmask = mask;
381
382 snaplen = pcap_snapshot(p);
383 if (snaplen == 0) {
384 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
385 "snaplen of 0 rejects all packets");
386 return -1;
387 }
388
389 lex_init(xbuf ? xbuf : "");
390 init_linktype(p);
391 (void)pcap_parse();
392
393 if (n_errors)
394 syntax();
395
396 if (root == NULL)
397 root = gen_retblk(snaplen);
398
399 if (optimize && !no_optimize) {
400 bpf_optimize(&root);
401 if (root == NULL ||
402 (root->s.code == (BPF_RET|BPF_K) && root->s.k == 0))
403 bpf_error("expression rejects all packets");
404 }
405 program->bf_insns = icode_to_fcode(root, &len);
406 program->bf_len = len;
407
408 lex_cleanup();
409 freechunks();
410 return (0);
411 }
412
413 /*
414 * entry point for using the compiler with no pcap open
415 * pass in all the stuff that is needed explicitly instead.
416 */
417 int
418 pcap_compile_nopcap(int snaplen_arg, int linktype_arg,
419 struct bpf_program *program,
420 const char *buf, int optimize, bpf_u_int32 mask)
421 {
422 pcap_t *p;
423 int ret;
424
425 p = pcap_open_dead(linktype_arg, snaplen_arg);
426 if (p == NULL)
427 return (-1);
428 ret = pcap_compile(p, program, buf, optimize, mask);
429 pcap_close(p);
430 return (ret);
431 }
432
433 /*
434 * Clean up a "struct bpf_program" by freeing all the memory allocated
435 * in it.
436 */
437 void
438 pcap_freecode(struct bpf_program *program)
439 {
440 program->bf_len = 0;
441 if (program->bf_insns != NULL) {
442 free((char *)program->bf_insns);
443 program->bf_insns = NULL;
444 }
445 }
446
447 /*
448 * Backpatch the blocks in 'list' to 'target'. The 'sense' field indicates
449 * which of the jt and jf fields has been resolved and which is a pointer
450 * back to another unresolved block (or nil). At least one of the fields
451 * in each block is already resolved.
452 */
453 static void
454 backpatch(list, target)
455 struct block *list, *target;
456 {
457 struct block *next;
458
459 while (list) {
460 if (!list->sense) {
461 next = JT(list);
462 JT(list) = target;
463 } else {
464 next = JF(list);
465 JF(list) = target;
466 }
467 list = next;
468 }
469 }
470
471 /*
472 * Merge the lists in b0 and b1, using the 'sense' field to indicate
473 * which of jt and jf is the link.
474 */
475 static void
476 merge(b0, b1)
477 struct block *b0, *b1;
478 {
479 register struct block **p = &b0;
480
481 /* Find end of list. */
482 while (*p)
483 p = !((*p)->sense) ? &JT(*p) : &JF(*p);
484
485 /* Concatenate the lists. */
486 *p = b1;
487 }
488
489
490 void
491 finish_parse(p)
492 struct block *p;
493 {
494 struct block *ppi_dlt_check;
495
496 ppi_dlt_check = gen_ppi_dlt_check();
497
498 if (ppi_dlt_check != NULL)
499 {
500 gen_and(ppi_dlt_check, p);
501 }
502
503 backpatch(p, gen_retblk(snaplen));
504 p->sense = !p->sense;
505 backpatch(p, gen_retblk(0));
506 root = p->head;
507
508 /*
509 * Insert before the statements of the first (root) block any
510 * statements needed to load the lengths of any variable-length
511 * headers into registers.
512 *
513 * XXX - a fancier strategy would be to insert those before the
514 * statements of all blocks that use those lengths and that
515 * have no predecessors that use them, so that we only compute
516 * the lengths if we need them. There might be even better
517 * approaches than that. However, as we're currently only
518 * handling variable-length radiotap headers, and as all
519 * filtering expressions other than raw link[M:N] tests
520 * require the length of that header, doing more for that
521 * header length isn't really worth the effort.
522 */
523
524 insert_load_llprefixlen(root);
525 }
526
527 void
528 gen_and(b0, b1)
529 struct block *b0, *b1;
530 {
531 backpatch(b0, b1->head);
532 b0->sense = !b0->sense;
533 b1->sense = !b1->sense;
534 merge(b1, b0);
535 b1->sense = !b1->sense;
536 b1->head = b0->head;
537 }
538
539 void
540 gen_or(b0, b1)
541 struct block *b0, *b1;
542 {
543 b0->sense = !b0->sense;
544 backpatch(b0, b1->head);
545 b0->sense = !b0->sense;
546 merge(b1, b0);
547 b1->head = b0->head;
548 }
549
550 void
551 gen_not(b)
552 struct block *b;
553 {
554 b->sense = !b->sense;
555 }
556
557 static struct block *
558 gen_cmp(offrel, offset, size, v)
559 enum e_offrel offrel;
560 u_int offset, size;
561 bpf_int32 v;
562 {
563 return gen_ncmp(offrel, offset, size, 0xffffffff, BPF_JEQ, 0, v);
564 }
565
566 static struct block *
567 gen_cmp_gt(offrel, offset, size, v)
568 enum e_offrel offrel;
569 u_int offset, size;
570 bpf_int32 v;
571 {
572 return gen_ncmp(offrel, offset, size, 0xffffffff, BPF_JGT, 0, v);
573 }
574
575 static struct block *
576 gen_cmp_ge(offrel, offset, size, v)
577 enum e_offrel offrel;
578 u_int offset, size;
579 bpf_int32 v;
580 {
581 return gen_ncmp(offrel, offset, size, 0xffffffff, BPF_JGE, 0, v);
582 }
583
584 static struct block *
585 gen_cmp_lt(offrel, offset, size, v)
586 enum e_offrel offrel;
587 u_int offset, size;
588 bpf_int32 v;
589 {
590 return gen_ncmp(offrel, offset, size, 0xffffffff, BPF_JGE, 1, v);
591 }
592
593 static struct block *
594 gen_cmp_le(offrel, offset, size, v)
595 enum e_offrel offrel;
596 u_int offset, size;
597 bpf_int32 v;
598 {
599 return gen_ncmp(offrel, offset, size, 0xffffffff, BPF_JGT, 1, v);
600 }
601
602 static struct block *
603 gen_mcmp(offrel, offset, size, v, mask)
604 enum e_offrel offrel;
605 u_int offset, size;
606 bpf_int32 v;
607 bpf_u_int32 mask;
608 {
609 return gen_ncmp(offrel, offset, size, mask, BPF_JEQ, 0, v);
610 }
611
612 static struct block *
613 gen_bcmp(offrel, offset, size, v)
614 enum e_offrel offrel;
615 register u_int offset, size;
616 register const u_char *v;
617 {
618 register struct block *b, *tmp;
619
620 b = NULL;
621 while (size >= 4) {
622 register const u_char *p = &v[size - 4];
623 bpf_int32 w = ((bpf_int32)p[0] << 24) |
624 ((bpf_int32)p[1] << 16) | ((bpf_int32)p[2] << 8) | p[3];
625
626 tmp = gen_cmp(offrel, offset + size - 4, BPF_W, w);
627 if (b != NULL)
628 gen_and(b, tmp);
629 b = tmp;
630 size -= 4;
631 }
632 while (size >= 2) {
633 register const u_char *p = &v[size - 2];
634 bpf_int32 w = ((bpf_int32)p[0] << 8) | p[1];
635
636 tmp = gen_cmp(offrel, offset + size - 2, BPF_H, w);
637 if (b != NULL)
638 gen_and(b, tmp);
639 b = tmp;
640 size -= 2;
641 }
642 if (size > 0) {
643 tmp = gen_cmp(offrel, offset, BPF_B, (bpf_int32)v[0]);
644 if (b != NULL)
645 gen_and(b, tmp);
646 b = tmp;
647 }
648 return b;
649 }
650
651 /*
652 * AND the field of size "size" at offset "offset" relative to the header
653 * specified by "offrel" with "mask", and compare it with the value "v"
654 * with the test specified by "jtype"; if "reverse" is true, the test
655 * should test the opposite of "jtype".
656 */
657 static struct block *
658 gen_ncmp(offrel, offset, size, mask, jtype, reverse, v)
659 enum e_offrel offrel;
660 bpf_int32 v;
661 bpf_u_int32 offset, size, mask, jtype;
662 int reverse;
663 {
664 struct slist *s, *s2;
665 struct block *b;
666
667 s = gen_load_a(offrel, offset, size);
668
669 if (mask != 0xffffffff) {
670 s2 = new_stmt(BPF_ALU|BPF_AND|BPF_K);
671 s2->s.k = mask;
672 sappend(s, s2);
673 }
674
675 b = new_block(JMP(jtype));
676 b->stmts = s;
677 b->s.k = v;
678 if (reverse && (jtype == BPF_JGT || jtype == BPF_JGE))
679 gen_not(b);
680 return b;
681 }
682
683 /*
684 * Various code constructs need to know the layout of the data link
685 * layer. These variables give the necessary offsets from the beginning
686 * of the packet data.
687 *
688 * If the link layer has variable_length headers, the offsets are offsets
689 * from the end of the link-link-layer header, and "reg_ll_size" is
690 * the register number for a register containing the length of the
691 * link-layer header. Otherwise, "reg_ll_size" is -1.
692 */
693 static int reg_ll_size;
694
695 /*
696 * This is the offset of the beginning of the link-layer header from
697 * the beginning of the raw packet data.
698 *
699 * It's usually 0, except for 802.11 with a fixed-length radio header.
700 * (For 802.11 with a variable-length radio header, we have to generate
701 * code to compute that offset; off_ll is 0 in that case.)
702 */
703 static u_int off_ll;
704
705 /*
706 * This is the offset of the beginning of the MAC-layer header.
707 * It's usually 0, except for ATM LANE, where it's the offset, relative
708 * to the beginning of the raw packet data, of the Ethernet header.
709 */
710 static u_int off_mac;
711
712 /*
713 * "off_linktype" is the offset to information in the link-layer header
714 * giving the packet type. This offset is relative to the beginning
715 * of the link-layer header (i.e., it doesn't include off_ll).
716 *
717 * For Ethernet, it's the offset of the Ethernet type field.
718 *
719 * For link-layer types that always use 802.2 headers, it's the
720 * offset of the LLC header.
721 *
722 * For PPP, it's the offset of the PPP type field.
723 *
724 * For Cisco HDLC, it's the offset of the CHDLC type field.
725 *
726 * For BSD loopback, it's the offset of the AF_ value.
727 *
728 * For Linux cooked sockets, it's the offset of the type field.
729 *
730 * It's set to -1 for no encapsulation, in which case, IP is assumed.
731 */
732 static u_int off_linktype;
733
734 /*
735 * TRUE if the link layer includes an ATM pseudo-header.
736 */
737 static int is_atm = 0;
738
739 /*
740 * TRUE if "lane" appeared in the filter; it causes us to generate
741 * code that assumes LANE rather than LLC-encapsulated traffic in SunATM.
742 */
743 static int is_lane = 0;
744
745 /*
746 * These are offsets for the ATM pseudo-header.
747 */
748 static u_int off_vpi;
749 static u_int off_vci;
750 static u_int off_proto;
751
752 /*
753 * These are offsets for the MTP2 fields.
754 */
755 static u_int off_li;
756
757 /*
758 * These are offsets for the MTP3 fields.
759 */
760 static u_int off_sio;
761 static u_int off_opc;
762 static u_int off_dpc;
763 static u_int off_sls;
764
765 /*
766 * This is the offset of the first byte after the ATM pseudo_header,
767 * or -1 if there is no ATM pseudo-header.
768 */
769 static u_int off_payload;
770
771 /*
772 * These are offsets to the beginning of the network-layer header.
773 * They are relative to the beginning of the link-layer header (i.e.,
774 * they don't include off_ll).
775 *
776 * If the link layer never uses 802.2 LLC:
777 *
778 * "off_nl" and "off_nl_nosnap" are the same.
779 *
780 * If the link layer always uses 802.2 LLC:
781 *
782 * "off_nl" is the offset if there's a SNAP header following
783 * the 802.2 header;
784 *
785 * "off_nl_nosnap" is the offset if there's no SNAP header.
786 *
787 * If the link layer is Ethernet:
788 *
789 * "off_nl" is the offset if the packet is an Ethernet II packet
790 * (we assume no 802.3+802.2+SNAP);
791 *
792 * "off_nl_nosnap" is the offset if the packet is an 802.3 packet
793 * with an 802.2 header following it.
794 */
795 static u_int off_nl;
796 static u_int off_nl_nosnap;
797
798 static int linktype;
799
800 static void
801 init_linktype(p)
802 pcap_t *p;
803 {
804 linktype = pcap_datalink(p);
805 #ifdef PCAP_FDDIPAD
806 pcap_fddipad = p->fddipad;
807 #endif
808
809 /*
810 * Assume it's not raw ATM with a pseudo-header, for now.
811 */
812 off_mac = 0;
813 is_atm = 0;
814 is_lane = 0;
815 off_vpi = -1;
816 off_vci = -1;
817 off_proto = -1;
818 off_payload = -1;
819
820 /*
821 * And assume we're not doing SS7.
822 */
823 off_li = -1;
824 off_sio = -1;
825 off_opc = -1;
826 off_dpc = -1;
827 off_sls = -1;
828
829 /*
830 * Also assume it's not 802.11 with a fixed-length radio header.
831 */
832 off_ll = 0;
833
834 orig_linktype = -1;
835 orig_nl = -1;
836 label_stack_depth = 0;
837
838 reg_ll_size = -1;
839
840 switch (linktype) {
841
842 case DLT_ARCNET:
843 off_linktype = 2;
844 off_nl = 6; /* XXX in reality, variable! */
845 off_nl_nosnap = 6; /* no 802.2 LLC */
846 return;
847
848 case DLT_ARCNET_LINUX:
849 off_linktype = 4;
850 off_nl = 8; /* XXX in reality, variable! */
851 off_nl_nosnap = 8; /* no 802.2 LLC */
852 return;
853
854 case DLT_EN10MB:
855 off_linktype = 12;
856 off_nl = 14; /* Ethernet II */
857 off_nl_nosnap = 17; /* 802.3+802.2 */
858 return;
859
860 case DLT_SLIP:
861 /*
862 * SLIP doesn't have a link level type. The 16 byte
863 * header is hacked into our SLIP driver.
864 */
865 off_linktype = -1;
866 off_nl = 16;
867 off_nl_nosnap = 16; /* no 802.2 LLC */
868 return;
869
870 case DLT_SLIP_BSDOS:
871 /* XXX this may be the same as the DLT_PPP_BSDOS case */
872 off_linktype = -1;
873 /* XXX end */
874 off_nl = 24;
875 off_nl_nosnap = 24; /* no 802.2 LLC */
876 return;
877
878 case DLT_NULL:
879 case DLT_LOOP:
880 off_linktype = 0;
881 off_nl = 4;
882 off_nl_nosnap = 4; /* no 802.2 LLC */
883 return;
884
885 case DLT_ENC:
886 off_linktype = 0;
887 off_nl = 12;
888 off_nl_nosnap = 12; /* no 802.2 LLC */
889 return;
890
891 case DLT_PPP:
892 case DLT_PPP_PPPD:
893 case DLT_C_HDLC: /* BSD/OS Cisco HDLC */
894 case DLT_PPP_SERIAL: /* NetBSD sync/async serial PPP */
895 off_linktype = 2;
896 off_nl = 4;
897 off_nl_nosnap = 4; /* no 802.2 LLC */
898 return;
899
900 case DLT_PPP_ETHER:
901 /*
902 * This does no include the Ethernet header, and
903 * only covers session state.
904 */
905 off_linktype = 6;
906 off_nl = 8;
907 off_nl_nosnap = 8; /* no 802.2 LLC */
908 return;
909
910 case DLT_PPP_BSDOS:
911 off_linktype = 5;
912 off_nl = 24;
913 off_nl_nosnap = 24; /* no 802.2 LLC */
914 return;
915
916 case DLT_FDDI:
917 /*
918 * FDDI doesn't really have a link-level type field.
919 * We set "off_linktype" to the offset of the LLC header.
920 *
921 * To check for Ethernet types, we assume that SSAP = SNAP
922 * is being used and pick out the encapsulated Ethernet type.
923 * XXX - should we generate code to check for SNAP?
924 */
925 off_linktype = 13;
926 #ifdef PCAP_FDDIPAD
927 off_linktype += pcap_fddipad;
928 #endif
929 off_nl = 21; /* FDDI+802.2+SNAP */
930 off_nl_nosnap = 16; /* FDDI+802.2 */
931 #ifdef PCAP_FDDIPAD
932 off_nl += pcap_fddipad;
933 off_nl_nosnap += pcap_fddipad;
934 #endif
935 return;
936
937 case DLT_IEEE802:
938 /*
939 * Token Ring doesn't really have a link-level type field.
940 * We set "off_linktype" to the offset of the LLC header.
941 *
942 * To check for Ethernet types, we assume that SSAP = SNAP
943 * is being used and pick out the encapsulated Ethernet type.
944 * XXX - should we generate code to check for SNAP?
945 *
946 * XXX - the header is actually variable-length.
947 * Some various Linux patched versions gave 38
948 * as "off_linktype" and 40 as "off_nl"; however,
949 * if a token ring packet has *no* routing
950 * information, i.e. is not source-routed, the correct
951 * values are 20 and 22, as they are in the vanilla code.
952 *
953 * A packet is source-routed iff the uppermost bit
954 * of the first byte of the source address, at an
955 * offset of 8, has the uppermost bit set. If the
956 * packet is source-routed, the total number of bytes
957 * of routing information is 2 plus bits 0x1F00 of
958 * the 16-bit value at an offset of 14 (shifted right
959 * 8 - figure out which byte that is).
960 */
961 off_linktype = 14;
962 off_nl = 22; /* Token Ring+802.2+SNAP */
963 off_nl_nosnap = 17; /* Token Ring+802.2 */
964 return;
965
966 case DLT_IEEE802_11:
967 /*
968 * 802.11 doesn't really have a link-level type field.
969 * We set "off_linktype" to the offset of the LLC header.
970 *
971 * To check for Ethernet types, we assume that SSAP = SNAP
972 * is being used and pick out the encapsulated Ethernet type.
973 * XXX - should we generate code to check for SNAP?
974 *
975 * XXX - the header is actually variable-length. We
976 * assume a 24-byte link-layer header, as appears in
977 * data frames in networks with no bridges. If the
978 * fromds and tods 802.11 header bits are both set,
979 * it's actually supposed to be 30 bytes.
980 */
981 off_linktype = 24;
982 off_nl = 32; /* 802.11+802.2+SNAP */
983 off_nl_nosnap = 27; /* 802.11+802.2 */
984 return;
985
986 case DLT_PRISM_HEADER:
987 /*
988 * Same as 802.11, but with an additional header before
989 * the 802.11 header, containing a bunch of additional
990 * information including radio-level information.
991 *
992 * The header is 144 bytes long.
993 *
994 * XXX - same variable-length header problem; at least
995 * the Prism header is fixed-length.
996 */
997 off_ll = 144;
998 off_linktype = 24;
999 off_nl = 32; /* Prism+802.11+802.2+SNAP */
1000 off_nl_nosnap = 27; /* Prism+802.11+802.2 */
1001 return;
1002
1003 case DLT_IEEE802_11_RADIO_AVS:
1004 /*
1005 * Same as 802.11, but with an additional header before
1006 * the 802.11 header, containing a bunch of additional
1007 * information including radio-level information.
1008 *
1009 * The header is 64 bytes long, at least in its
1010 * current incarnation.
1011 *
1012 * XXX - same variable-length header problem, only
1013 * more so; this header is also variable-length,
1014 * with the length being the 32-bit big-endian
1015 * number at an offset of 4 from the beginning
1016 * of the radio header. We should handle that the
1017 * same way we handle the length at the beginning
1018 * of the radiotap header.
1019 *
1020 * XXX - in Linux, do any drivers that supply an AVS
1021 * header supply a link-layer type other than
1022 * ARPHRD_IEEE80211_PRISM? If so, we should map that
1023 * to DLT_IEEE802_11_RADIO_AVS; if not, or if there are
1024 * any drivers that supply an AVS header but supply
1025 * an ARPHRD value of ARPHRD_IEEE80211_PRISM, we'll
1026 * have to check the header in the generated code to
1027 * determine whether it's Prism or AVS.
1028 */
1029 off_ll = 64;
1030 off_linktype = 24;
1031 off_nl = 32; /* Radio+802.11+802.2+SNAP */
1032 off_nl_nosnap = 27; /* Radio+802.11+802.2 */
1033 return;
1034
1035
1036 /*
1037 * At the moment we treat PPI as normal Radiotap encoded
1038 * packets. The difference is in the function that generates
1039 * the code at the beginning to compute the header length.
1040 * Since this code generator of PPI supports bare 802.11
1041 * encapsulation only (i.e. the encapsulated DLT should be
1042 * DLT_IEEE802_11) we generate code to check for this too.
1043 */
1044 case DLT_PPI:
1045 case DLT_IEEE802_11_RADIO:
1046 /*
1047 * Same as 802.11, but with an additional header before
1048 * the 802.11 header, containing a bunch of additional
1049 * information including radio-level information.
1050 *
1051 * The radiotap header is variable length, and we
1052 * generate code to compute its length and store it
1053 * in a register. These offsets are relative to the
1054 * beginning of the 802.11 header.
1055 */
1056 off_linktype = 24;
1057 off_nl = 32; /* 802.11+802.2+SNAP */
1058 off_nl_nosnap = 27; /* 802.11+802.2 */
1059 return;
1060
1061 case DLT_ATM_RFC1483:
1062 case DLT_ATM_CLIP: /* Linux ATM defines this */
1063 /*
1064 * assume routed, non-ISO PDUs
1065 * (i.e., LLC = 0xAA-AA-03, OUT = 0x00-00-00)
1066 *
1067 * XXX - what about ISO PDUs, e.g. CLNP, ISIS, ESIS,
1068 * or PPP with the PPP NLPID (e.g., PPPoA)? The
1069 * latter would presumably be treated the way PPPoE
1070 * should be, so you can do "pppoe and udp port 2049"
1071 * or "pppoa and tcp port 80" and have it check for
1072 * PPPo{A,E} and a PPP protocol of IP and....
1073 */
1074 off_linktype = 0;
1075 off_nl = 8; /* 802.2+SNAP */
1076 off_nl_nosnap = 3; /* 802.2 */
1077 return;
1078
1079 case DLT_SUNATM:
1080 /*
1081 * Full Frontal ATM; you get AALn PDUs with an ATM
1082 * pseudo-header.
1083 */
1084 is_atm = 1;
1085 off_vpi = SUNATM_VPI_POS;
1086 off_vci = SUNATM_VCI_POS;
1087 off_proto = PROTO_POS;
1088 off_mac = -1; /* LLC-encapsulated, so no MAC-layer header */
1089 off_payload = SUNATM_PKT_BEGIN_POS;
1090 off_linktype = off_payload;
1091 off_nl = off_payload+8; /* 802.2+SNAP */
1092 off_nl_nosnap = off_payload+3; /* 802.2 */
1093 return;
1094
1095 case DLT_RAW:
1096 off_linktype = -1;
1097 off_nl = 0;
1098 off_nl_nosnap = 0; /* no 802.2 LLC */
1099 return;
1100
1101 case DLT_LINUX_SLL: /* fake header for Linux cooked socket */
1102 off_linktype = 14;
1103 off_nl = 16;
1104 off_nl_nosnap = 16; /* no 802.2 LLC */
1105 return;
1106
1107 case DLT_LTALK:
1108 /*
1109 * LocalTalk does have a 1-byte type field in the LLAP header,
1110 * but really it just indicates whether there is a "short" or
1111 * "long" DDP packet following.
1112 */
1113 off_linktype = -1;
1114 off_nl = 0;
1115 off_nl_nosnap = 0; /* no 802.2 LLC */
1116 return;
1117
1118 case DLT_IP_OVER_FC:
1119 /*
1120 * RFC 2625 IP-over-Fibre-Channel doesn't really have a
1121 * link-level type field. We set "off_linktype" to the
1122 * offset of the LLC header.
1123 *
1124 * To check for Ethernet types, we assume that SSAP = SNAP
1125 * is being used and pick out the encapsulated Ethernet type.
1126 * XXX - should we generate code to check for SNAP? RFC
1127 * 2625 says SNAP should be used.
1128 */
1129 off_linktype = 16;
1130 off_nl = 24; /* IPFC+802.2+SNAP */
1131 off_nl_nosnap = 19; /* IPFC+802.2 */
1132 return;
1133
1134 case DLT_FRELAY:
1135 /*
1136 * XXX - we should set this to handle SNAP-encapsulated
1137 * frames (NLPID of 0x80).
1138 */
1139 off_linktype = -1;
1140 off_nl = 0;
1141 off_nl_nosnap = 0; /* no 802.2 LLC */
1142 return;
1143
1144 /*
1145 * the only BPF-interesting FRF.16 frames are non-control frames;
1146 * Frame Relay has a variable length link-layer
1147 * so lets start with offset 4 for now and increments later on (FIXME);
1148 */
1149 case DLT_MFR:
1150 off_linktype = -1;
1151 off_nl = 4;
1152 off_nl_nosnap = 0; /* XXX - for now -> no 802.2 LLC */
1153 return;
1154
1155 case DLT_APPLE_IP_OVER_IEEE1394:
1156 off_linktype = 16;
1157 off_nl = 18;
1158 off_nl_nosnap = 18; /* no 802.2 LLC */
1159 return;
1160
1161 case DLT_LINUX_IRDA:
1162 /*
1163 * Currently, only raw "link[N:M]" filtering is supported.
1164 */
1165 off_linktype = -1;
1166 off_nl = -1;
1167 off_nl_nosnap = -1;
1168 return;
1169
1170 case DLT_DOCSIS:
1171 /*
1172 * Currently, only raw "link[N:M]" filtering is supported.
1173 */
1174 off_linktype = -1;
1175 off_nl = -1;
1176 off_nl_nosnap = -1;
1177 return;
1178
1179 case DLT_SYMANTEC_FIREWALL:
1180 off_linktype = 6;
1181 off_nl = 44; /* Ethernet II */
1182 off_nl_nosnap = 44; /* XXX - what does it do with 802.3 packets? */
1183 return;
1184
1185 #ifdef HAVE_NET_PFVAR_H
1186 case DLT_PFLOG:
1187 off_linktype = 0;
1188 off_nl = PFLOG_HDRLEN;
1189 off_nl_nosnap = PFLOG_HDRLEN; /* no 802.2 LLC */
1190 return;
1191 #endif
1192
1193 case DLT_JUNIPER_MFR:
1194 case DLT_JUNIPER_MLFR:
1195 case DLT_JUNIPER_MLPPP:
1196 case DLT_JUNIPER_PPP:
1197 case DLT_JUNIPER_CHDLC:
1198 case DLT_JUNIPER_FRELAY:
1199 off_linktype = 4;
1200 off_nl = 4;
1201 off_nl_nosnap = -1; /* no 802.2 LLC */
1202 return;
1203
1204 case DLT_JUNIPER_ATM1:
1205 off_linktype = 4; /* in reality variable between 4-8 */
1206 off_nl = 4;
1207 off_nl_nosnap = 14;
1208 return;
1209
1210 case DLT_JUNIPER_ATM2:
1211 off_linktype = 8; /* in reality variable between 8-12 */
1212 off_nl = 8;
1213 off_nl_nosnap = 18;
1214 return;
1215
1216 /* frames captured on a Juniper PPPoE service PIC
1217 * contain raw ethernet frames */
1218 case DLT_JUNIPER_PPPOE:
1219 case DLT_JUNIPER_ETHER:
1220 off_linktype = 16;
1221 off_nl = 18; /* Ethernet II */
1222 off_nl_nosnap = 21; /* 802.3+802.2 */
1223 return;
1224
1225 case DLT_JUNIPER_PPPOE_ATM:
1226 off_linktype = 4;
1227 off_nl = 6;
1228 off_nl_nosnap = -1; /* no 802.2 LLC */
1229 return;
1230
1231 case DLT_JUNIPER_GGSN:
1232 off_linktype = 6;
1233 off_nl = 12;
1234 off_nl_nosnap = -1; /* no 802.2 LLC */
1235 return;
1236
1237 case DLT_JUNIPER_ES:
1238 off_linktype = 6;
1239 off_nl = -1; /* not really a network layer but raw IP adresses */
1240 off_nl_nosnap = -1; /* no 802.2 LLC */
1241 return;
1242
1243 case DLT_JUNIPER_MONITOR:
1244 off_linktype = 12;
1245 off_nl = 12; /* raw IP/IP6 header */
1246 off_nl_nosnap = -1; /* no 802.2 LLC */
1247 return;
1248
1249 case DLT_JUNIPER_SERVICES:
1250 off_linktype = 12;
1251 off_nl = -1; /* L3 proto location dep. on cookie type */
1252 off_nl_nosnap = -1; /* no 802.2 LLC */
1253 return;
1254
1255 case DLT_JUNIPER_VP:
1256 off_linktype = 18;
1257 off_nl = -1;
1258 off_nl_nosnap = -1;
1259 return;
1260
1261 case DLT_MTP2:
1262 off_li = 2;
1263 off_sio = 3;
1264 off_opc = 4;
1265 off_dpc = 4;
1266 off_sls = 7;
1267 off_linktype = -1;
1268 off_nl = -1;
1269 off_nl_nosnap = -1;
1270 return;
1271
1272 case DLT_MTP2_WITH_PHDR:
1273 off_li = 6;
1274 off_sio = 7;
1275 off_opc = 8;
1276 off_dpc = 8;
1277 off_sls = 11;
1278 off_linktype = -1;
1279 off_nl = -1;
1280 off_nl_nosnap = -1;
1281 return;
1282
1283 #ifdef DLT_PFSYNC
1284 case DLT_PFSYNC:
1285 off_linktype = -1;
1286 off_nl = 4;
1287 off_nl_nosnap = 4;
1288 return;
1289 #endif
1290
1291 case DLT_LINUX_LAPD:
1292 /*
1293 * Currently, only raw "link[N:M]" filtering is supported.
1294 */
1295 off_linktype = -1;
1296 off_nl = -1;
1297 off_nl_nosnap = -1;
1298 return;
1299
1300 case DLT_USB:
1301 /*
1302 * Currently, only raw "link[N:M]" filtering is supported.
1303 */
1304 off_linktype = -1;
1305 off_nl = -1;
1306 off_nl_nosnap = -1;
1307 return;
1308
1309 case DLT_BLUETOOTH_HCI_H4:
1310 /*
1311 * Currently, only raw "link[N:M]" filtering is supported.
1312 */
1313 off_linktype = -1;
1314 off_nl = -1;
1315 off_nl_nosnap = -1;
1316 return;
1317 }
1318 bpf_error("unknown data link type %d", linktype);
1319 /* NOTREACHED */
1320 }
1321
1322 /*
1323 * Load a value relative to the beginning of the link-layer header.
1324 * The link-layer header doesn't necessarily begin at the beginning
1325 * of the packet data; there might be a variable-length prefix containing
1326 * radio information.
1327 */
1328 static struct slist *
1329 gen_load_llrel(offset, size)
1330 u_int offset, size;
1331 {
1332 struct slist *s, *s2;
1333
1334 s = gen_llprefixlen();
1335
1336 /*
1337 * If "s" is non-null, it has code to arrange that the X register
1338 * contains the length of the prefix preceding the link-layer
1339 * header.
1340 *
1341 * Otherwise, the length of the prefix preceding the link-layer
1342 * header is "off_ll".
1343 */
1344 if (s != NULL) {
1345 /*
1346 * There's a variable-length prefix preceding the
1347 * link-layer header. "s" points to a list of statements
1348 * that put the length of that prefix into the X register.
1349 * do an indirect load, to use the X register as an offset.
1350 */
1351 s2 = new_stmt(BPF_LD|BPF_IND|size);
1352 s2->s.k = offset;
1353 sappend(s, s2);
1354 } else {
1355 /*
1356 * There is no variable-length header preceding the
1357 * link-layer header; add in off_ll, which, if there's
1358 * a fixed-length header preceding the link-layer header,
1359 * is the length of that header.
1360 */
1361 s = new_stmt(BPF_LD|BPF_ABS|size);
1362 s->s.k = offset + off_ll;
1363 }
1364 return s;
1365 }
1366
1367
1368 /*
1369 * Load a value relative to the beginning of the specified header.
1370 */
1371 static struct slist *
1372 gen_load_a(offrel, offset, size)
1373 enum e_offrel offrel;
1374 u_int offset, size;
1375 {
1376 struct slist *s, *s2;
1377
1378 switch (offrel) {
1379
1380 case OR_PACKET:
1381 s = new_stmt(BPF_LD|BPF_ABS|size);
1382 s->s.k = offset;
1383 break;
1384
1385 case OR_LINK:
1386 s = gen_load_llrel(offset, size);
1387 break;
1388
1389 case OR_NET:
1390 s = gen_load_llrel(off_nl + offset, size);
1391 break;
1392
1393 case OR_NET_NOSNAP:
1394 s = gen_load_llrel(off_nl_nosnap + offset, size);
1395 break;
1396
1397 case OR_TRAN_IPV4:
1398 /*
1399 * Load the X register with the length of the IPv4 header
1400 * (plus the offset of the link-layer header, if it's
1401 * preceded by a variable-length header such as a radio
1402 * header), in bytes.
1403 */
1404 s = gen_loadx_iphdrlen();
1405
1406 /*
1407 * Load the item at {offset of the link-layer header} +
1408 * {offset, relative to the start of the link-layer
1409 * header, of the IPv4 header} + {length of the IPv4 header} +
1410 * {specified offset}.
1411 *
1412 * (If the link-layer is variable-length, it's included
1413 * in the value in the X register, and off_ll is 0.)
1414 */
1415 s2 = new_stmt(BPF_LD|BPF_IND|size);
1416 s2->s.k = off_ll + off_nl + offset;
1417 sappend(s, s2);
1418 break;
1419
1420 case OR_TRAN_IPV6:
1421 s = gen_load_llrel(off_nl + 40 + offset, size);
1422 break;
1423
1424 default:
1425 abort();
1426 return NULL;
1427 }
1428 return s;
1429 }
1430
1431 /*
1432 * Generate code to load into the X register the sum of the length of
1433 * the IPv4 header and any variable-length header preceding the link-layer
1434 * header.
1435 */
1436 static struct slist *
1437 gen_loadx_iphdrlen()
1438 {
1439 struct slist *s, *s2;
1440
1441 s = gen_llprefixlen();
1442 if (s != NULL) {
1443 /*
1444 * There's a variable-length prefix preceding the
1445 * link-layer header. "s" points to a list of statements
1446 * that put the length of that prefix into the X register.
1447 * The 4*([k]&0xf) addressing mode can't be used, as we
1448 * don't have a constant offset, so we have to load the
1449 * value in question into the A register and add to it
1450 * the value from the X register.
1451 */
1452 s2 = new_stmt(BPF_LD|BPF_IND|BPF_B);
1453 s2->s.k = off_nl;
1454 sappend(s, s2);
1455 s2 = new_stmt(BPF_ALU|BPF_AND|BPF_K);
1456 s2->s.k = 0xf;
1457 sappend(s, s2);
1458 s2 = new_stmt(BPF_ALU|BPF_LSH|BPF_K);
1459 s2->s.k = 2;
1460 sappend(s, s2);
1461
1462 /*
1463 * The A register now contains the length of the
1464 * IP header. We need to add to it the length
1465 * of the prefix preceding the link-layer
1466 * header, which is still in the X register, and
1467 * move the result into the X register.
1468 */
1469 sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X));
1470 sappend(s, new_stmt(BPF_MISC|BPF_TAX));
1471 } else {
1472 /*
1473 * There is no variable-length header preceding the
1474 * link-layer header; add in off_ll, which, if there's
1475 * a fixed-length header preceding the link-layer header,
1476 * is the length of that header.
1477 */
1478 s = new_stmt(BPF_LDX|BPF_MSH|BPF_B);
1479 s->s.k = off_ll + off_nl;
1480 }
1481 return s;
1482 }
1483
1484 static struct block *
1485 gen_uncond(rsense)
1486 int rsense;
1487 {
1488 struct block *b;
1489 struct slist *s;
1490
1491 s = new_stmt(BPF_LD|BPF_IMM);
1492 s->s.k = !rsense;
1493 b = new_block(JMP(BPF_JEQ));
1494 b->stmts = s;
1495
1496 return b;
1497 }
1498
1499 static inline struct block *
1500 gen_true()
1501 {
1502 return gen_uncond(1);
1503 }
1504
1505 static inline struct block *
1506 gen_false()
1507 {
1508 return gen_uncond(0);
1509 }
1510
1511 /*
1512 * Byte-swap a 32-bit number.
1513 * ("htonl()" or "ntohl()" won't work - we want to byte-swap even on
1514 * big-endian platforms.)
1515 */
1516 #define SWAPLONG(y) \
1517 ((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff))
1518
1519 /*
1520 * Generate code to match a particular packet type.
1521 *
1522 * "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP
1523 * value, if <= ETHERMTU. We use that to determine whether to
1524 * match the type/length field or to check the type/length field for
1525 * a value <= ETHERMTU to see whether it's a type field and then do
1526 * the appropriate test.
1527 */
1528 static struct block *
1529 gen_ether_linktype(proto)
1530 register int proto;
1531 {
1532 struct block *b0, *b1;
1533
1534 switch (proto) {
1535
1536 case LLCSAP_ISONS:
1537 case LLCSAP_IP:
1538 case LLCSAP_NETBEUI:
1539 /*
1540 * OSI protocols and NetBEUI always use 802.2 encapsulation,
1541 * so we check the DSAP and SSAP.
1542 *
1543 * LLCSAP_IP checks for IP-over-802.2, rather
1544 * than IP-over-Ethernet or IP-over-SNAP.
1545 *
1546 * XXX - should we check both the DSAP and the
1547 * SSAP, like this, or should we check just the
1548 * DSAP, as we do for other types <= ETHERMTU
1549 * (i.e., other SAP values)?
1550 */
1551 b0 = gen_cmp_gt(OR_LINK, off_linktype, BPF_H, ETHERMTU);
1552 gen_not(b0);
1553 b1 = gen_cmp(OR_LINK, off_linktype + 2, BPF_H, (bpf_int32)
1554 ((proto << 8) | proto));
1555 gen_and(b0, b1);
1556 return b1;
1557
1558 case LLCSAP_IPX:
1559 /*
1560 * Check for;
1561 *
1562 * Ethernet_II frames, which are Ethernet
1563 * frames with a frame type of ETHERTYPE_IPX;
1564 *
1565 * Ethernet_802.3 frames, which are 802.3
1566 * frames (i.e., the type/length field is
1567 * a length field, <= ETHERMTU, rather than
1568 * a type field) with the first two bytes
1569 * after the Ethernet/802.3 header being
1570 * 0xFFFF;
1571 *
1572 * Ethernet_802.2 frames, which are 802.3
1573 * frames with an 802.2 LLC header and
1574 * with the IPX LSAP as the DSAP in the LLC
1575 * header;
1576 *
1577 * Ethernet_SNAP frames, which are 802.3
1578 * frames with an LLC header and a SNAP
1579 * header and with an OUI of 0x000000
1580 * (encapsulated Ethernet) and a protocol
1581 * ID of ETHERTYPE_IPX in the SNAP header.
1582 *
1583 * XXX - should we generate the same code both
1584 * for tests for LLCSAP_IPX and for ETHERTYPE_IPX?
1585 */
1586
1587 /*
1588 * This generates code to check both for the
1589 * IPX LSAP (Ethernet_802.2) and for Ethernet_802.3.
1590 */
1591 b0 = gen_cmp(OR_LINK, off_linktype + 2, BPF_B,
1592 (bpf_int32)LLCSAP_IPX);
1593 b1 = gen_cmp(OR_LINK, off_linktype + 2, BPF_H,
1594 (bpf_int32)0xFFFF);
1595 gen_or(b0, b1);
1596
1597 /*
1598 * Now we add code to check for SNAP frames with
1599 * ETHERTYPE_IPX, i.e. Ethernet_SNAP.
1600 */
1601 b0 = gen_snap(0x000000, ETHERTYPE_IPX, 14);
1602 gen_or(b0, b1);
1603
1604 /*
1605 * Now we generate code to check for 802.3
1606 * frames in general.
1607 */
1608 b0 = gen_cmp_gt(OR_LINK, off_linktype, BPF_H, ETHERMTU);
1609 gen_not(b0);
1610
1611 /*
1612 * Now add the check for 802.3 frames before the
1613 * check for Ethernet_802.2 and Ethernet_802.3,
1614 * as those checks should only be done on 802.3
1615 * frames, not on Ethernet frames.
1616 */
1617 gen_and(b0, b1);
1618
1619 /*
1620 * Now add the check for Ethernet_II frames, and
1621 * do that before checking for the other frame
1622 * types.
1623 */
1624 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H,
1625 (bpf_int32)ETHERTYPE_IPX);
1626 gen_or(b0, b1);
1627 return b1;
1628
1629 case ETHERTYPE_ATALK:
1630 case ETHERTYPE_AARP:
1631 /*
1632 * EtherTalk (AppleTalk protocols on Ethernet link
1633 * layer) may use 802.2 encapsulation.
1634 */
1635
1636 /*
1637 * Check for 802.2 encapsulation (EtherTalk phase 2?);
1638 * we check for an Ethernet type field less than
1639 * 1500, which means it's an 802.3 length field.
1640 */
1641 b0 = gen_cmp_gt(OR_LINK, off_linktype, BPF_H, ETHERMTU);
1642 gen_not(b0);
1643
1644 /*
1645 * 802.2-encapsulated ETHERTYPE_ATALK packets are
1646 * SNAP packets with an organization code of
1647 * 0x080007 (Apple, for Appletalk) and a protocol
1648 * type of ETHERTYPE_ATALK (Appletalk).
1649 *
1650 * 802.2-encapsulated ETHERTYPE_AARP packets are
1651 * SNAP packets with an organization code of
1652 * 0x000000 (encapsulated Ethernet) and a protocol
1653 * type of ETHERTYPE_AARP (Appletalk ARP).
1654 */
1655 if (proto == ETHERTYPE_ATALK)
1656 b1 = gen_snap(0x080007, ETHERTYPE_ATALK, 14);
1657 else /* proto == ETHERTYPE_AARP */
1658 b1 = gen_snap(0x000000, ETHERTYPE_AARP, 14);
1659 gen_and(b0, b1);
1660
1661 /*
1662 * Check for Ethernet encapsulation (Ethertalk
1663 * phase 1?); we just check for the Ethernet
1664 * protocol type.
1665 */
1666 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, (bpf_int32)proto);
1667
1668 gen_or(b0, b1);
1669 return b1;
1670
1671 default:
1672 if (proto <= ETHERMTU) {
1673 /*
1674 * This is an LLC SAP value, so the frames
1675 * that match would be 802.2 frames.
1676 * Check that the frame is an 802.2 frame
1677 * (i.e., that the length/type field is
1678 * a length field, <= ETHERMTU) and
1679 * then check the DSAP.
1680 */
1681 b0 = gen_cmp_gt(OR_LINK, off_linktype, BPF_H, ETHERMTU);
1682 gen_not(b0);
1683 b1 = gen_cmp(OR_LINK, off_linktype + 2, BPF_B,
1684 (bpf_int32)proto);
1685 gen_and(b0, b1);
1686 return b1;
1687 } else {
1688 /*
1689 * This is an Ethernet type, so compare
1690 * the length/type field with it (if
1691 * the frame is an 802.2 frame, the length
1692 * field will be <= ETHERMTU, and, as
1693 * "proto" is > ETHERMTU, this test
1694 * will fail and the frame won't match,
1695 * which is what we want).
1696 */
1697 return gen_cmp(OR_LINK, off_linktype, BPF_H,
1698 (bpf_int32)proto);
1699 }
1700 }
1701 }
1702
1703 /*
1704 * Generate code to match a particular packet type.
1705 *
1706 * "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP
1707 * value, if <= ETHERMTU. We use that to determine whether to
1708 * match the type field or to check the type field for the special
1709 * LINUX_SLL_P_802_2 value and then do the appropriate test.
1710 */
1711 static struct block *
1712 gen_linux_sll_linktype(proto)
1713 register int proto;
1714 {
1715 struct block *b0, *b1;
1716
1717 switch (proto) {
1718
1719 case LLCSAP_ISONS:
1720 case LLCSAP_IP:
1721 case LLCSAP_NETBEUI:
1722 /*
1723 * OSI protocols and NetBEUI always use 802.2 encapsulation,
1724 * so we check the DSAP and SSAP.
1725 *
1726 * LLCSAP_IP checks for IP-over-802.2, rather
1727 * than IP-over-Ethernet or IP-over-SNAP.
1728 *
1729 * XXX - should we check both the DSAP and the
1730 * SSAP, like this, or should we check just the
1731 * DSAP, as we do for other types <= ETHERMTU
1732 * (i.e., other SAP values)?
1733 */
1734 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, LINUX_SLL_P_802_2);
1735 b1 = gen_cmp(OR_LINK, off_linktype + 2, BPF_H, (bpf_int32)
1736 ((proto << 8) | proto));
1737 gen_and(b0, b1);
1738 return b1;
1739
1740 case LLCSAP_IPX:
1741 /*
1742 * Ethernet_II frames, which are Ethernet
1743 * frames with a frame type of ETHERTYPE_IPX;
1744 *
1745 * Ethernet_802.3 frames, which have a frame
1746 * type of LINUX_SLL_P_802_3;
1747 *
1748 * Ethernet_802.2 frames, which are 802.3
1749 * frames with an 802.2 LLC header (i.e, have
1750 * a frame type of LINUX_SLL_P_802_2) and
1751 * with the IPX LSAP as the DSAP in the LLC
1752 * header;
1753 *
1754 * Ethernet_SNAP frames, which are 802.3
1755 * frames with an LLC header and a SNAP
1756 * header and with an OUI of 0x000000
1757 * (encapsulated Ethernet) and a protocol
1758 * ID of ETHERTYPE_IPX in the SNAP header.
1759 *
1760 * First, do the checks on LINUX_SLL_P_802_2
1761 * frames; generate the check for either
1762 * Ethernet_802.2 or Ethernet_SNAP frames, and
1763 * then put a check for LINUX_SLL_P_802_2 frames
1764 * before it.
1765 */
1766 b0 = gen_cmp(OR_LINK, off_linktype + 2, BPF_B,
1767 (bpf_int32)LLCSAP_IPX);
1768 b1 = gen_snap(0x000000, ETHERTYPE_IPX,
1769 off_linktype + 2);
1770 gen_or(b0, b1);
1771 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, LINUX_SLL_P_802_2);
1772 gen_and(b0, b1);
1773
1774 /*
1775 * Now check for 802.3 frames and OR that with
1776 * the previous test.
1777 */
1778 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, LINUX_SLL_P_802_3);
1779 gen_or(b0, b1);
1780
1781 /*
1782 * Now add the check for Ethernet_II frames, and
1783 * do that before checking for the other frame
1784 * types.
1785 */
1786 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H,
1787 (bpf_int32)ETHERTYPE_IPX);
1788 gen_or(b0, b1);
1789 return b1;
1790
1791 case ETHERTYPE_ATALK:
1792 case ETHERTYPE_AARP:
1793 /*
1794 * EtherTalk (AppleTalk protocols on Ethernet link
1795 * layer) may use 802.2 encapsulation.
1796 */
1797
1798 /*
1799 * Check for 802.2 encapsulation (EtherTalk phase 2?);
1800 * we check for the 802.2 protocol type in the
1801 * "Ethernet type" field.
1802 */
1803 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, LINUX_SLL_P_802_2);
1804
1805 /*
1806 * 802.2-encapsulated ETHERTYPE_ATALK packets are
1807 * SNAP packets with an organization code of
1808 * 0x080007 (Apple, for Appletalk) and a protocol
1809 * type of ETHERTYPE_ATALK (Appletalk).
1810 *
1811 * 802.2-encapsulated ETHERTYPE_AARP packets are
1812 * SNAP packets with an organization code of
1813 * 0x000000 (encapsulated Ethernet) and a protocol
1814 * type of ETHERTYPE_AARP (Appletalk ARP).
1815 */
1816 if (proto == ETHERTYPE_ATALK)
1817 b1 = gen_snap(0x080007, ETHERTYPE_ATALK,
1818 off_linktype + 2);
1819 else /* proto == ETHERTYPE_AARP */
1820 b1 = gen_snap(0x000000, ETHERTYPE_AARP,
1821 off_linktype + 2);
1822 gen_and(b0, b1);
1823
1824 /*
1825 * Check for Ethernet encapsulation (Ethertalk
1826 * phase 1?); we just check for the Ethernet
1827 * protocol type.
1828 */
1829 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, (bpf_int32)proto);
1830
1831 gen_or(b0, b1);
1832 return b1;
1833
1834 default:
1835 if (proto <= ETHERMTU) {
1836 /*
1837 * This is an LLC SAP value, so the frames
1838 * that match would be 802.2 frames.
1839 * Check for the 802.2 protocol type
1840 * in the "Ethernet type" field, and
1841 * then check the DSAP.
1842 */
1843 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H,
1844 LINUX_SLL_P_802_2);
1845 b1 = gen_cmp(OR_LINK, off_linktype + 2, BPF_B,
1846 (bpf_int32)proto);
1847 gen_and(b0, b1);
1848 return b1;
1849 } else {
1850 /*
1851 * This is an Ethernet type, so compare
1852 * the length/type field with it (if
1853 * the frame is an 802.2 frame, the length
1854 * field will be <= ETHERMTU, and, as
1855 * "proto" is > ETHERMTU, this test
1856 * will fail and the frame won't match,
1857 * which is what we want).
1858 */
1859 return gen_cmp(OR_LINK, off_linktype, BPF_H,
1860 (bpf_int32)proto);
1861 }
1862 }
1863 }
1864
1865 static void
1866 insert_radiotap_load_llprefixlen(b)
1867 struct block *b;
1868 {
1869 struct slist *s1, *s2;
1870
1871 /*
1872 * Prepend to the statements in this block code to load the
1873 * length of the radiotap header into the register assigned
1874 * to hold that length, if one has been assigned.
1875 */
1876 if (reg_ll_size != -1) {
1877 /*
1878 * The 2 bytes at offsets of 2 and 3 from the beginning
1879 * of the radiotap header are the length of the radiotap
1880 * header; unfortunately, it's little-endian, so we have
1881 * to load it a byte at a time and construct the value.
1882 */
1883
1884 /*
1885 * Load the high-order byte, at an offset of 3, shift it
1886 * left a byte, and put the result in the X register.
1887 */
1888 s1 = new_stmt(BPF_LD|BPF_B|BPF_ABS);
1889 s1->s.k = 3;
1890 s2 = new_stmt(BPF_ALU|BPF_LSH|BPF_K);
1891 sappend(s1, s2);
1892 s2->s.k = 8;
1893 s2 = new_stmt(BPF_MISC|BPF_TAX);
1894 sappend(s1, s2);
1895
1896 /*
1897 * Load the next byte, at an offset of 2, and OR the
1898 * value from the X register into it.
1899 */
1900 s2 = new_stmt(BPF_LD|BPF_B|BPF_ABS);
1901 sappend(s1, s2);
1902 s2->s.k = 2;
1903 s2 = new_stmt(BPF_ALU|BPF_OR|BPF_X);
1904 sappend(s1, s2);
1905
1906 /*
1907 * Now allocate a register to hold that value and store
1908 * it.
1909 */
1910 s2 = new_stmt(BPF_ST);
1911 s2->s.k = reg_ll_size;
1912 sappend(s1, s2);
1913
1914 /*
1915 * Now move it into the X register.
1916 */
1917 s2 = new_stmt(BPF_MISC|BPF_TAX);
1918 sappend(s1, s2);
1919
1920 /*
1921 * Now append all the existing statements in this
1922 * block to these statements.
1923 */
1924 sappend(s1, b->stmts);
1925 b->stmts = s1;
1926 }
1927 }
1928
1929 /*
1930 * At the moment we treat PPI as normal Radiotap encoded
1931 * packets. The difference is in the function that generates
1932 * the code at the beginning to compute the header length.
1933 * Since this code generator of PPI supports bare 802.11
1934 * encapsulation only (i.e. the encapsulated DLT should be
1935 * DLT_IEEE802_11) we generate code to check for this too.
1936 */
1937 static void
1938 insert_ppi_load_llprefixlen(b)
1939 struct block *b;
1940 {
1941 struct slist *s1, *s2;
1942
1943 /*
1944 * Prepend to the statements in this block code to load the
1945 * length of the radiotap header into the register assigned
1946 * to hold that length, if one has been assigned.
1947 */
1948 if (reg_ll_size != -1) {
1949 /*
1950 * The 2 bytes at offsets of 2 and 3 from the beginning
1951 * of the radiotap header are the length of the radiotap
1952 * header; unfortunately, it's little-endian, so we have
1953 * to load it a byte at a time and construct the value.
1954 */
1955
1956 /*
1957 * Load the high-order byte, at an offset of 3, shift it
1958 * left a byte, and put the result in the X register.
1959 */
1960 s1 = new_stmt(BPF_LD|BPF_B|BPF_ABS);
1961 s1->s.k = 3;
1962 s2 = new_stmt(BPF_ALU|BPF_LSH|BPF_K);
1963 sappend(s1, s2);
1964 s2->s.k = 8;
1965 s2 = new_stmt(BPF_MISC|BPF_TAX);
1966 sappend(s1, s2);
1967
1968 /*
1969 * Load the next byte, at an offset of 2, and OR the
1970 * value from the X register into it.
1971 */
1972 s2 = new_stmt(BPF_LD|BPF_B|BPF_ABS);
1973 sappend(s1, s2);
1974 s2->s.k = 2;
1975 s2 = new_stmt(BPF_ALU|BPF_OR|BPF_X);
1976 sappend(s1, s2);
1977
1978 /*
1979 * Now allocate a register to hold that value and store
1980 * it.
1981 */
1982 s2 = new_stmt(BPF_ST);
1983 s2->s.k = reg_ll_size;
1984 sappend(s1, s2);
1985
1986 /*
1987 * Now move it into the X register.
1988 */
1989 s2 = new_stmt(BPF_MISC|BPF_TAX);
1990 sappend(s1, s2);
1991
1992 /*
1993 * Now append all the existing statements in this
1994 * block to these statements.
1995 */
1996 sappend(s1, b->stmts);
1997 b->stmts = s1;
1998
1999 }
2000 }
2001
2002 static struct block *
2003 gen_ppi_dlt_check(void)
2004 {
2005 struct slist *s_load_dlt;
2006 struct block *b;
2007
2008 if (linktype == DLT_PPI)
2009 {
2010 /* Create the statements that check for the DLT
2011 */
2012 s_load_dlt = new_stmt(BPF_LD|BPF_W|BPF_ABS);
2013 s_load_dlt->s.k = 4;
2014
2015 b = new_block(JMP(BPF_JEQ));
2016
2017 b->stmts = s_load_dlt;
2018 b->s.k = SWAPLONG(DLT_IEEE802_11);
2019 }
2020 else
2021 {
2022 b = NULL;
2023 }
2024
2025 return b;
2026 }
2027
2028 static void
2029 insert_load_llprefixlen(b)
2030 struct block *b;
2031 {
2032 switch (linktype) {
2033
2034 /*
2035 * At the moment we treat PPI as normal Radiotap encoded
2036 * packets. The difference is in the function that generates
2037 * the code at the beginning to compute the header length.
2038 * Since this code generator of PPI supports bare 802.11
2039 * encapsulation only (i.e. the encapsulated DLT should be
2040 * DLT_IEEE802_11) we generate code to check for this too.
2041 */
2042 case DLT_PPI:
2043 insert_ppi_load_llprefixlen(b);
2044 break;
2045
2046 case DLT_IEEE802_11_RADIO:
2047 insert_radiotap_load_llprefixlen(b);
2048 break;
2049 }
2050 }
2051
2052
2053 static struct slist *
2054 gen_radiotap_llprefixlen(void)
2055 {
2056 struct slist *s;
2057
2058 if (reg_ll_size == -1) {
2059 /*
2060 * We haven't yet assigned a register for the length
2061 * of the radiotap header; allocate one.
2062 */
2063 reg_ll_size = alloc_reg();
2064 }
2065
2066 /*
2067 * Load the register containing the radiotap length
2068 * into the X register.
2069 */
2070 s = new_stmt(BPF_LDX|BPF_MEM);
2071 s->s.k = reg_ll_size;
2072 return s;
2073 }
2074
2075 /*
2076 * At the moment we treat PPI as normal Radiotap encoded
2077 * packets. The difference is in the function that generates
2078 * the code at the beginning to compute the header length.
2079 * Since this code generator of PPI supports bare 802.11
2080 * encapsulation only (i.e. the encapsulated DLT should be
2081 * DLT_IEEE802_11) we generate code to check for this too.
2082 */
2083 static struct slist *
2084 gen_ppi_llprefixlen(void)
2085 {
2086 struct slist *s;
2087
2088 if (reg_ll_size == -1) {
2089 /*
2090 * We haven't yet assigned a register for the length
2091 * of the radiotap header; allocate one.
2092 */
2093 reg_ll_size = alloc_reg();
2094 }
2095
2096 /*
2097 * Load the register containing the radiotap length
2098 * into the X register.
2099 */
2100 s = new_stmt(BPF_LDX|BPF_MEM);
2101 s->s.k = reg_ll_size;
2102 return s;
2103 }
2104
2105
2106
2107 /*
2108 * Generate code to compute the link-layer header length, if necessary,
2109 * putting it into the X register, and to return either a pointer to a
2110 * "struct slist" for the list of statements in that code, or NULL if
2111 * no code is necessary.
2112 */
2113 static struct slist *
2114 gen_llprefixlen(void)
2115 {
2116 switch (linktype) {
2117
2118 case DLT_PPI:
2119 return gen_ppi_llprefixlen();
2120
2121
2122 case DLT_IEEE802_11_RADIO:
2123 return gen_radiotap_llprefixlen();
2124
2125 default:
2126 return NULL;
2127 }
2128 }
2129
2130 /*
2131 * Generate code to match a particular packet type by matching the
2132 * link-layer type field or fields in the 802.2 LLC header.
2133 *
2134 * "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP
2135 * value, if <= ETHERMTU.
2136 */
2137 static struct block *
2138 gen_linktype(proto)
2139 register int proto;
2140 {
2141 struct block *b0, *b1, *b2;
2142
2143 /* are we checking MPLS-encapsulated packets? */
2144 if (label_stack_depth > 0) {
2145 switch (proto) {
2146 case ETHERTYPE_IP:
2147 case PPP_IP:
2148 /* FIXME add other L3 proto IDs */
2149 return gen_mpls_linktype(Q_IP);
2150
2151 case ETHERTYPE_IPV6:
2152 case PPP_IPV6:
2153 /* FIXME add other L3 proto IDs */
2154 return gen_mpls_linktype(Q_IPV6);
2155
2156 default:
2157 bpf_error("unsupported protocol over mpls");
2158 /* NOTREACHED */
2159 }
2160 }
2161
2162 switch (linktype) {
2163
2164 case DLT_EN10MB:
2165 return gen_ether_linktype(proto);
2166 /*NOTREACHED*/
2167 break;
2168
2169 case DLT_C_HDLC:
2170 switch (proto) {
2171
2172 case LLCSAP_ISONS:
2173 proto = (proto << 8 | LLCSAP_ISONS);
2174 /* fall through */
2175
2176 default:
2177 return gen_cmp(OR_LINK, off_linktype, BPF_H,
2178 (bpf_int32)proto);
2179 /*NOTREACHED*/
2180 break;
2181 }
2182 break;
2183
2184 case DLT_PPI:
2185 case DLT_FDDI:
2186 case DLT_IEEE802:
2187 case DLT_IEEE802_11:
2188 case DLT_IEEE802_11_RADIO_AVS:
2189 case DLT_IEEE802_11_RADIO:
2190 case DLT_PRISM_HEADER:
2191 case DLT_ATM_RFC1483:
2192 case DLT_ATM_CLIP:
2193 case DLT_IP_OVER_FC:
2194 return gen_llc_linktype(proto);
2195 /*NOTREACHED*/
2196 break;
2197
2198 case DLT_SUNATM:
2199 /*
2200 * If "is_lane" is set, check for a LANE-encapsulated
2201 * version of this protocol, otherwise check for an
2202 * LLC-encapsulated version of this protocol.
2203 *
2204 * We assume LANE means Ethernet, not Token Ring.
2205 */
2206 if (is_lane) {
2207 /*
2208 * Check that the packet doesn't begin with an
2209 * LE Control marker. (We've already generated
2210 * a test for LANE.)
2211 */
2212 b0 = gen_cmp(OR_LINK, SUNATM_PKT_BEGIN_POS, BPF_H,
2213 0xFF00);
2214 gen_not(b0);
2215
2216 /*
2217 * Now generate an Ethernet test.
2218 */
2219 b1 = gen_ether_linktype(proto);
2220 gen_and(b0, b1);
2221 return b1;
2222 } else {
2223 /*
2224 * Check for LLC encapsulation and then check the
2225 * protocol.
2226 */
2227 b0 = gen_atmfield_code(A_PROTOTYPE, PT_LLC, BPF_JEQ, 0);
2228 b1 = gen_llc_linktype(proto);
2229 gen_and(b0, b1);
2230 return b1;
2231 }
2232 /*NOTREACHED*/
2233 break;
2234
2235 case DLT_LINUX_SLL:
2236 return gen_linux_sll_linktype(proto);
2237 /*NOTREACHED*/
2238 break;
2239
2240 case DLT_SLIP:
2241 case DLT_SLIP_BSDOS:
2242 case DLT_RAW:
2243 /*
2244 * These types don't provide any type field; packets
2245 * are always IPv4 or IPv6.
2246 *
2247 * XXX - for IPv4, check for a version number of 4, and,
2248 * for IPv6, check for a version number of 6?
2249 */
2250 switch (proto) {
2251
2252 case ETHERTYPE_IP:
2253 /* Check for a version number of 4. */
2254 return gen_mcmp(OR_LINK, 0, BPF_B, 0x40, 0xF0);
2255 #ifdef INET6
2256 case ETHERTYPE_IPV6:
2257 /* Check for a version number of 6. */
2258 return gen_mcmp(OR_LINK, 0, BPF_B, 0x60, 0xF0);
2259 #endif
2260
2261 default:
2262 return gen_false(); /* always false */
2263 }
2264 /*NOTREACHED*/
2265 break;
2266
2267 case DLT_PPP:
2268 case DLT_PPP_PPPD:
2269 case DLT_PPP_SERIAL:
2270 case DLT_PPP_ETHER:
2271 /*
2272 * We use Ethernet protocol types inside libpcap;
2273 * map them to the corresponding PPP protocol types.
2274 */
2275 switch (proto) {
2276
2277 case ETHERTYPE_IP:
2278 proto = PPP_IP;
2279 break;
2280
2281 #ifdef INET6
2282 case ETHERTYPE_IPV6:
2283 proto = PPP_IPV6;
2284 break;
2285 #endif
2286
2287 case ETHERTYPE_DN:
2288 proto = PPP_DECNET;
2289 break;
2290
2291 case ETHERTYPE_ATALK:
2292 proto = PPP_APPLE;
2293 break;
2294
2295 case ETHERTYPE_NS:
2296 proto = PPP_NS;
2297 break;
2298
2299 case LLCSAP_ISONS:
2300 proto = PPP_OSI;
2301 break;
2302
2303 case LLCSAP_8021D:
2304 /*
2305 * I'm assuming the "Bridging PDU"s that go
2306 * over PPP are Spanning Tree Protocol
2307 * Bridging PDUs.
2308 */
2309 proto = PPP_BRPDU;
2310 break;
2311
2312 case LLCSAP_IPX:
2313 proto = PPP_IPX;
2314 break;
2315 }
2316 break;
2317
2318 case DLT_PPP_BSDOS:
2319 /*
2320 * We use Ethernet protocol types inside libpcap;
2321 * map them to the corresponding PPP protocol types.
2322 */
2323 switch (proto) {
2324
2325 case ETHERTYPE_IP:
2326 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, PPP_IP);
2327 b1 = gen_cmp(OR_LINK, off_linktype, BPF_H, PPP_VJC);
2328 gen_or(b0, b1);
2329 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, PPP_VJNC);
2330 gen_or(b1, b0);
2331 return b0;
2332
2333 #ifdef INET6
2334 case ETHERTYPE_IPV6:
2335 proto = PPP_IPV6;
2336 /* more to go? */
2337 break;
2338 #endif
2339
2340 case ETHERTYPE_DN:
2341 proto = PPP_DECNET;
2342 break;
2343
2344 case ETHERTYPE_ATALK:
2345 proto = PPP_APPLE;
2346 break;
2347
2348 case ETHERTYPE_NS:
2349 proto = PPP_NS;
2350 break;
2351
2352 case LLCSAP_ISONS:
2353 proto = PPP_OSI;
2354 break;
2355
2356 case LLCSAP_8021D:
2357 /*
2358 * I'm assuming the "Bridging PDU"s that go
2359 * over PPP are Spanning Tree Protocol
2360 * Bridging PDUs.
2361 */
2362 proto = PPP_BRPDU;
2363 break;
2364
2365 case LLCSAP_IPX:
2366 proto = PPP_IPX;
2367 break;
2368 }
2369 break;
2370
2371 case DLT_NULL:
2372 case DLT_LOOP:
2373 case DLT_ENC:
2374 /*
2375 * For DLT_NULL, the link-layer header is a 32-bit
2376 * word containing an AF_ value in *host* byte order,
2377 * and for DLT_ENC, the link-layer header begins
2378 * with a 32-bit work containing an AF_ value in
2379 * host byte order.
2380 *
2381 * In addition, if we're reading a saved capture file,
2382 * the host byte order in the capture may not be the
2383 * same as the host byte order on this machine.
2384 *
2385 * For DLT_LOOP, the link-layer header is a 32-bit
2386 * word containing an AF_ value in *network* byte order.
2387 *
2388 * XXX - AF_ values may, unfortunately, be platform-
2389 * dependent; for example, FreeBSD's AF_INET6 is 24
2390 * whilst NetBSD's and OpenBSD's is 26.
2391 *
2392 * This means that, when reading a capture file, just
2393 * checking for our AF_INET6 value won't work if the
2394 * capture file came from another OS.
2395 */
2396 switch (proto) {
2397
2398 case ETHERTYPE_IP:
2399 proto = AF_INET;
2400 break;
2401
2402 #ifdef INET6
2403 case ETHERTYPE_IPV6:
2404 proto = AF_INET6;
2405 break;
2406 #endif
2407
2408 default:
2409 /*
2410 * Not a type on which we support filtering.
2411 * XXX - support those that have AF_ values
2412 * #defined on this platform, at least?
2413 */
2414 return gen_false();
2415 }
2416
2417 if (linktype == DLT_NULL || linktype == DLT_ENC) {
2418 /*
2419 * The AF_ value is in host byte order, but
2420 * the BPF interpreter will convert it to
2421 * network byte order.
2422 *
2423 * If this is a save file, and it's from a
2424 * machine with the opposite byte order to
2425 * ours, we byte-swap the AF_ value.
2426 *
2427 * Then we run it through "htonl()", and
2428 * generate code to compare against the result.
2429 */
2430 if (bpf_pcap->sf.rfile != NULL &&
2431 bpf_pcap->sf.swapped)
2432 proto = SWAPLONG(proto);
2433 proto = htonl(proto);
2434 }
2435 return (gen_cmp(OR_LINK, 0, BPF_W, (bpf_int32)proto));
2436
2437 #ifdef HAVE_NET_PFVAR_H
2438 case DLT_PFLOG:
2439 /*
2440 * af field is host byte order in contrast to the rest of
2441 * the packet.
2442 */
2443 if (proto == ETHERTYPE_IP)
2444 return (gen_cmp(OR_LINK, offsetof(struct pfloghdr, af),
2445 BPF_B, (bpf_int32)AF_INET));
2446 #ifdef INET6
2447 else if (proto == ETHERTYPE_IPV6)
2448 return (gen_cmp(OR_LINK, offsetof(struct pfloghdr, af),
2449 BPF_B, (bpf_int32)AF_INET6));
2450 #endif /* INET6 */
2451 else
2452 return gen_false();
2453 /*NOTREACHED*/
2454 break;
2455 #endif /* HAVE_NET_PFVAR_H */
2456
2457 case DLT_ARCNET:
2458 case DLT_ARCNET_LINUX:
2459 /*
2460 * XXX should we check for first fragment if the protocol
2461 * uses PHDS?
2462 */
2463 switch (proto) {
2464
2465 default:
2466 return gen_false();
2467
2468 #ifdef INET6
2469 case ETHERTYPE_IPV6:
2470 return (gen_cmp(OR_LINK, off_linktype, BPF_B,
2471 (bpf_int32)ARCTYPE_INET6));
2472 #endif /* INET6 */
2473
2474 case ETHERTYPE_IP:
2475 b0 = gen_cmp(OR_LINK, off_linktype, BPF_B,
2476 (bpf_int32)ARCTYPE_IP);
2477 b1 = gen_cmp(OR_LINK, off_linktype, BPF_B,
2478 (bpf_int32)ARCTYPE_IP_OLD);
2479 gen_or(b0, b1);
2480 return (b1);
2481
2482 case ETHERTYPE_ARP:
2483 b0 = gen_cmp(OR_LINK, off_linktype, BPF_B,
2484 (bpf_int32)ARCTYPE_ARP);
2485 b1 = gen_cmp(OR_LINK, off_linktype, BPF_B,
2486 (bpf_int32)ARCTYPE_ARP_OLD);
2487 gen_or(b0, b1);
2488 return (b1);
2489
2490 case ETHERTYPE_REVARP:
2491 return (gen_cmp(OR_LINK, off_linktype, BPF_B,
2492 (bpf_int32)ARCTYPE_REVARP));
2493
2494 case ETHERTYPE_ATALK:
2495 return (gen_cmp(OR_LINK, off_linktype, BPF_B,
2496 (bpf_int32)ARCTYPE_ATALK));
2497 }
2498 /*NOTREACHED*/
2499 break;
2500
2501 case DLT_LTALK:
2502 switch (proto) {
2503 case ETHERTYPE_ATALK:
2504 return gen_true();
2505 default:
2506 return gen_false();
2507 }
2508 /*NOTREACHED*/
2509 break;
2510
2511 case DLT_FRELAY:
2512 /*
2513 * XXX - assumes a 2-byte Frame Relay header with
2514 * DLCI and flags. What if the address is longer?
2515 */
2516 switch (proto) {
2517
2518 case ETHERTYPE_IP:
2519 /*
2520 * Check for the special NLPID for IP.
2521 */
2522 return gen_cmp(OR_LINK, 2, BPF_H, (0x03<<8) | 0xcc);
2523
2524 #ifdef INET6
2525 case ETHERTYPE_IPV6:
2526 /*
2527 * Check for the special NLPID for IPv6.
2528 */
2529 return gen_cmp(OR_LINK, 2, BPF_H, (0x03<<8) | 0x8e);
2530 #endif
2531
2532 case LLCSAP_ISONS:
2533 /*
2534 * Check for several OSI protocols.
2535 *
2536 * Frame Relay packets typically have an OSI
2537 * NLPID at the beginning; we check for each
2538 * of them.
2539 *
2540 * What we check for is the NLPID and a frame
2541 * control field of UI, i.e. 0x03 followed
2542 * by the NLPID.
2543 */
2544 b0 = gen_cmp(OR_LINK, 2, BPF_H, (0x03<<8) | ISO8473_CLNP);
2545 b1 = gen_cmp(OR_LINK, 2, BPF_H, (0x03<<8) | ISO9542_ESIS);
2546 b2 = gen_cmp(OR_LINK, 2, BPF_H, (0x03<<8) | ISO10589_ISIS);
2547 gen_or(b1, b2);
2548 gen_or(b0, b2);
2549 return b2;
2550
2551 default:
2552 return gen_false();
2553 }
2554 /*NOTREACHED*/
2555 break;
2556
2557 case DLT_JUNIPER_MFR:
2558 case DLT_JUNIPER_MLFR:
2559 case DLT_JUNIPER_MLPPP:
2560 case DLT_JUNIPER_ATM1:
2561 case DLT_JUNIPER_ATM2:
2562 case DLT_JUNIPER_PPPOE:
2563 case DLT_JUNIPER_PPPOE_ATM:
2564 case DLT_JUNIPER_GGSN:
2565 case DLT_JUNIPER_ES:
2566 case DLT_JUNIPER_MONITOR:
2567 case DLT_JUNIPER_SERVICES:
2568 case DLT_JUNIPER_ETHER:
2569 case DLT_JUNIPER_PPP:
2570 case DLT_JUNIPER_FRELAY:
2571 case DLT_JUNIPER_CHDLC:
2572 case DLT_JUNIPER_VP:
2573 /* just lets verify the magic number for now -
2574 * on ATM we may have up to 6 different encapsulations on the wire
2575 * and need a lot of heuristics to figure out that the payload
2576 * might be;
2577 *
2578 * FIXME encapsulation specific BPF_ filters
2579 */
2580 return gen_mcmp(OR_LINK, 0, BPF_W, 0x4d474300, 0xffffff00); /* compare the magic number */
2581
2582 case DLT_LINUX_IRDA:
2583 bpf_error("IrDA link-layer type filtering not implemented");
2584
2585 case DLT_DOCSIS:
2586 bpf_error("DOCSIS link-layer type filtering not implemented");
2587
2588 case DLT_LINUX_LAPD:
2589 bpf_error("LAPD link-layer type filtering not implemented");
2590 }
2591
2592 /*
2593 * All the types that have no encapsulation should either be
2594 * handled as DLT_SLIP, DLT_SLIP_BSDOS, and DLT_RAW are, if
2595 * all packets are IP packets, or should be handled in some
2596 * special case, if none of them are (if some are and some
2597 * aren't, the lack of encapsulation is a problem, as we'd
2598 * have to find some other way of determining the packet type).
2599 *
2600 * Therefore, if "off_linktype" is -1, there's an error.
2601 */
2602 if (off_linktype == (u_int)-1)
2603 abort();
2604
2605 /*
2606 * Any type not handled above should always have an Ethernet
2607 * type at an offset of "off_linktype". (PPP is partially
2608 * handled above - the protocol type is mapped from the
2609 * Ethernet and LLC types we use internally to the corresponding
2610 * PPP type - but the PPP type is always specified by a value
2611 * at "off_linktype", so we don't have to do the code generation
2612 * above.)
2613 */
2614 return gen_cmp(OR_LINK, off_linktype, BPF_H, (bpf_int32)proto);
2615 }
2616
2617 /*
2618 * Check for an LLC SNAP packet with a given organization code and
2619 * protocol type; we check the entire contents of the 802.2 LLC and
2620 * snap headers, checking for DSAP and SSAP of SNAP and a control
2621 * field of 0x03 in the LLC header, and for the specified organization
2622 * code and protocol type in the SNAP header.
2623 */
2624 static struct block *
2625 gen_snap(orgcode, ptype, offset)
2626 bpf_u_int32 orgcode;
2627 bpf_u_int32 ptype;
2628 u_int offset;
2629 {
2630 u_char snapblock[8];
2631
2632 snapblock[0] = LLCSAP_SNAP; /* DSAP = SNAP */
2633 snapblock[1] = LLCSAP_SNAP; /* SSAP = SNAP */
2634 snapblock[2] = 0x03; /* control = UI */
2635 snapblock[3] = (orgcode >> 16); /* upper 8 bits of organization code */
2636 snapblock[4] = (orgcode >> 8); /* middle 8 bits of organization code */
2637 snapblock[5] = (orgcode >> 0); /* lower 8 bits of organization code */
2638 snapblock[6] = (ptype >> 8); /* upper 8 bits of protocol type */
2639 snapblock[7] = (ptype >> 0); /* lower 8 bits of protocol type */
2640 return gen_bcmp(OR_LINK, offset, 8, snapblock);
2641 }
2642
2643 /*
2644 * Generate code to match a particular packet type, for link-layer types
2645 * using 802.2 LLC headers.
2646 *
2647 * This is *NOT* used for Ethernet; "gen_ether_linktype()" is used
2648 * for that - it handles the D/I/X Ethernet vs. 802.3+802.2 issues.
2649 *
2650 * "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP
2651 * value, if <= ETHERMTU. We use that to determine whether to
2652 * match the DSAP or both DSAP and LSAP or to check the OUI and
2653 * protocol ID in a SNAP header.
2654 */
2655 static struct block *
2656 gen_llc_linktype(proto)
2657 int proto;
2658 {
2659 /*
2660 * XXX - handle token-ring variable-length header.
2661 */
2662 switch (proto) {
2663
2664 case LLCSAP_IP:
2665 case LLCSAP_ISONS:
2666 case LLCSAP_NETBEUI:
2667 /*
2668 * XXX - should we check both the DSAP and the
2669 * SSAP, like this, or should we check just the
2670 * DSAP, as we do for other types <= ETHERMTU
2671 * (i.e., other SAP values)?
2672 */
2673 return gen_cmp(OR_LINK, off_linktype, BPF_H, (bpf_u_int32)
2674 ((proto << 8) | proto));
2675
2676 case LLCSAP_IPX:
2677 /*
2678 * XXX - are there ever SNAP frames for IPX on
2679 * non-Ethernet 802.x networks?
2680 */
2681 return gen_cmp(OR_LINK, off_linktype, BPF_B,
2682 (bpf_int32)LLCSAP_IPX);
2683
2684 case ETHERTYPE_ATALK:
2685 /*
2686 * 802.2-encapsulated ETHERTYPE_ATALK packets are
2687 * SNAP packets with an organization code of
2688 * 0x080007 (Apple, for Appletalk) and a protocol
2689 * type of ETHERTYPE_ATALK (Appletalk).
2690 *
2691 * XXX - check for an organization code of
2692 * encapsulated Ethernet as well?
2693 */
2694 return gen_snap(0x080007, ETHERTYPE_ATALK, off_linktype);
2695
2696 default:
2697 /*
2698 * XXX - we don't have to check for IPX 802.3
2699 * here, but should we check for the IPX Ethertype?
2700 */
2701 if (proto <= ETHERMTU) {
2702 /*
2703 * This is an LLC SAP value, so check
2704 * the DSAP.
2705 */
2706 return gen_cmp(OR_LINK, off_linktype, BPF_B,
2707 (bpf_int32)proto);
2708 } else {
2709 /*
2710 * This is an Ethernet type; we assume that it's
2711 * unlikely that it'll appear in the right place
2712 * at random, and therefore check only the
2713 * location that would hold the Ethernet type
2714 * in a SNAP frame with an organization code of
2715 * 0x000000 (encapsulated Ethernet).
2716 *
2717 * XXX - if we were to check for the SNAP DSAP and
2718 * LSAP, as per XXX, and were also to check for an
2719 * organization code of 0x000000 (encapsulated
2720 * Ethernet), we'd do
2721 *
2722 * return gen_snap(0x000000, proto,
2723 * off_linktype);
2724 *
2725 * here; for now, we don't, as per the above.
2726 * I don't know whether it's worth the extra CPU
2727 * time to do the right check or not.
2728 */
2729 return gen_cmp(OR_LINK, off_linktype+6, BPF_H,
2730 (bpf_int32)proto);
2731 }
2732 }
2733 }
2734
2735 static struct block *
2736 gen_hostop(addr, mask, dir, proto, src_off, dst_off)
2737 bpf_u_int32 addr;
2738 bpf_u_int32 mask;
2739 int dir, proto;
2740 u_int src_off, dst_off;
2741 {
2742 struct block *b0, *b1;
2743 u_int offset;
2744
2745 switch (dir) {
2746
2747 case Q_SRC:
2748 offset = src_off;
2749 break;
2750
2751 case Q_DST:
2752 offset = dst_off;
2753 break;
2754
2755 case Q_AND:
2756 b0 = gen_hostop(addr, mask, Q_SRC, proto, src_off, dst_off);
2757 b1 = gen_hostop(addr, mask, Q_DST, proto, src_off, dst_off);
2758 gen_and(b0, b1);
2759 return b1;
2760
2761 case Q_OR:
2762 case Q_DEFAULT:
2763 b0 = gen_hostop(addr, mask, Q_SRC, proto, src_off, dst_off);
2764 b1 = gen_hostop(addr, mask, Q_DST, proto, src_off, dst_off);
2765 gen_or(b0, b1);
2766 return b1;
2767
2768 default:
2769 abort();
2770 }
2771 b0 = gen_linktype(proto);
2772 b1 = gen_mcmp(OR_NET, offset, BPF_W, (bpf_int32)addr, mask);
2773 gen_and(b0, b1);
2774 return b1;
2775 }
2776
2777 #ifdef INET6
2778 static struct block *
2779 gen_hostop6(addr, mask, dir, proto, src_off, dst_off)
2780 struct in6_addr *addr;
2781 struct in6_addr *mask;
2782 int dir, proto;
2783 u_int src_off, dst_off;
2784 {
2785 struct block *b0, *b1;
2786 u_int offset;
2787 u_int32_t *a, *m;
2788
2789 switch (dir) {
2790
2791 case Q_SRC:
2792 offset = src_off;
2793 break;
2794
2795 case Q_DST:
2796 offset = dst_off;
2797 break;
2798
2799 case Q_AND:
2800 b0 = gen_hostop6(addr, mask, Q_SRC, proto, src_off, dst_off);
2801 b1 = gen_hostop6(addr, mask, Q_DST, proto, src_off, dst_off);
2802 gen_and(b0, b1);
2803 return b1;
2804
2805 case Q_OR:
2806 case Q_DEFAULT:
2807 b0 = gen_hostop6(addr, mask, Q_SRC, proto, src_off, dst_off);
2808 b1 = gen_hostop6(addr, mask, Q_DST, proto, src_off, dst_off);
2809 gen_or(b0, b1);
2810 return b1;
2811
2812 default:
2813 abort();
2814 }
2815 /* this order is important */
2816 a = (u_int32_t *)addr;
2817 m = (u_int32_t *)mask;
2818 b1 = gen_mcmp(OR_NET, offset + 12, BPF_W, ntohl(a[3]), ntohl(m[3]));
2819 b0 = gen_mcmp(OR_NET, offset + 8, BPF_W, ntohl(a[2]), ntohl(m[2]));
2820 gen_and(b0, b1);
2821 b0 = gen_mcmp(OR_NET, offset + 4, BPF_W, ntohl(a[1]), ntohl(m[1]));
2822 gen_and(b0, b1);
2823 b0 = gen_mcmp(OR_NET, offset + 0, BPF_W, ntohl(a[0]), ntohl(m[0]));
2824 gen_and(b0, b1);
2825 b0 = gen_linktype(proto);
2826 gen_and(b0, b1);
2827 return b1;
2828 }
2829 #endif /*INET6*/
2830
2831 static struct block *
2832 gen_ehostop(eaddr, dir)
2833 register const u_char *eaddr;
2834 register int dir;
2835 {
2836 register struct block *b0, *b1;
2837
2838 switch (dir) {
2839 case Q_SRC:
2840 return gen_bcmp(OR_LINK, off_mac + 6, 6, eaddr);
2841
2842 case Q_DST:
2843 return gen_bcmp(OR_LINK, off_mac + 0, 6, eaddr);
2844
2845 case Q_AND:
2846 b0 = gen_ehostop(eaddr, Q_SRC);
2847 b1 = gen_ehostop(eaddr, Q_DST);
2848 gen_and(b0, b1);
2849 return b1;
2850
2851 case Q_DEFAULT:
2852 case Q_OR:
2853 b0 = gen_ehostop(eaddr, Q_SRC);
2854 b1 = gen_ehostop(eaddr, Q_DST);
2855 gen_or(b0, b1);
2856 return b1;
2857 }
2858 abort();
2859 /* NOTREACHED */
2860 }
2861
2862 /*
2863 * Like gen_ehostop, but for DLT_FDDI
2864 */
2865 static struct block *
2866 gen_fhostop(eaddr, dir)
2867 register const u_char *eaddr;
2868 register int dir;
2869 {
2870 struct block *b0, *b1;
2871
2872 switch (dir) {
2873 case Q_SRC:
2874 #ifdef PCAP_FDDIPAD
2875 return gen_bcmp(OR_LINK, 6 + 1 + pcap_fddipad, 6, eaddr);
2876 #else
2877 return gen_bcmp(OR_LINK, 6 + 1, 6, eaddr);
2878 #endif
2879
2880 case Q_DST:
2881 #ifdef PCAP_FDDIPAD
2882 return gen_bcmp(OR_LINK, 0 + 1 + pcap_fddipad, 6, eaddr);
2883 #else
2884 return gen_bcmp(OR_LINK, 0 + 1, 6, eaddr);
2885 #endif
2886
2887 case Q_AND:
2888 b0 = gen_fhostop(eaddr, Q_SRC);
2889 b1 = gen_fhostop(eaddr, Q_DST);
2890 gen_and(b0, b1);
2891 return b1;
2892
2893 case Q_DEFAULT:
2894 case Q_OR:
2895 b0 = gen_fhostop(eaddr, Q_SRC);
2896 b1 = gen_fhostop(eaddr, Q_DST);
2897 gen_or(b0, b1);
2898 return b1;
2899 }
2900 abort();
2901 /* NOTREACHED */
2902 }
2903
2904 /*
2905 * Like gen_ehostop, but for DLT_IEEE802 (Token Ring)
2906 */
2907 static struct block *
2908 gen_thostop(eaddr, dir)
2909 register const u_char *eaddr;
2910 register int dir;
2911 {
2912 register struct block *b0, *b1;
2913
2914 switch (dir) {
2915 case Q_SRC:
2916 return gen_bcmp(OR_LINK, 8, 6, eaddr);
2917
2918 case Q_DST:
2919 return gen_bcmp(OR_LINK, 2, 6, eaddr);
2920
2921 case Q_AND:
2922 b0 = gen_thostop(eaddr, Q_SRC);
2923 b1 = gen_thostop(eaddr, Q_DST);
2924 gen_and(b0, b1);
2925 return b1;
2926
2927 case Q_DEFAULT:
2928 case Q_OR:
2929 b0 = gen_thostop(eaddr, Q_SRC);
2930 b1 = gen_thostop(eaddr, Q_DST);
2931 gen_or(b0, b1);
2932 return b1;
2933 }
2934 abort();
2935 /* NOTREACHED */
2936 }
2937
2938 /*
2939 * Like gen_ehostop, but for DLT_IEEE802_11 (802.11 wireless LAN)
2940 */
2941 static struct block *
2942 gen_wlanhostop(eaddr, dir)
2943 register const u_char *eaddr;
2944 register int dir;
2945 {
2946 register struct block *b0, *b1, *b2;
2947 register struct slist *s;
2948
2949 switch (dir) {
2950 case Q_SRC:
2951 /*
2952 * Oh, yuk.
2953 *
2954 * For control frames, there is no SA.
2955 *
2956 * For management frames, SA is at an
2957 * offset of 10 from the beginning of
2958 * the packet.
2959 *
2960 * For data frames, SA is at an offset
2961 * of 10 from the beginning of the packet
2962 * if From DS is clear, at an offset of
2963 * 16 from the beginning of the packet
2964 * if From DS is set and To DS is clear,
2965 * and an offset of 24 from the beginning
2966 * of the packet if From DS is set and To DS
2967 * is set.
2968 */
2969
2970 /*
2971 * Generate the tests to be done for data frames
2972 * with From DS set.
2973 *
2974 * First, check for To DS set, i.e. check "link[1] & 0x01".
2975 */
2976 s = gen_load_a(OR_LINK, 1, BPF_B);
2977 b1 = new_block(JMP(BPF_JSET));
2978 b1->s.k = 0x01; /* To DS */
2979 b1->stmts = s;
2980
2981 /*
2982 * If To DS is set, the SA is at 24.
2983 */
2984 b0 = gen_bcmp(OR_LINK, 24, 6, eaddr);
2985 gen_and(b1, b0);
2986
2987 /*
2988 * Now, check for To DS not set, i.e. check
2989 * "!(link[1] & 0x01)".
2990 */
2991 s = gen_load_a(OR_LINK, 1, BPF_B);
2992 b2 = new_block(JMP(BPF_JSET));
2993 b2->s.k = 0x01; /* To DS */
2994 b2->stmts = s;
2995 gen_not(b2);
2996
2997 /*
2998 * If To DS is not set, the SA is at 16.
2999 */
3000 b1 = gen_bcmp(OR_LINK, 16, 6, eaddr);
3001 gen_and(b2, b1);
3002
3003 /*
3004 * Now OR together the last two checks. That gives
3005 * the complete set of checks for data frames with
3006 * From DS set.
3007 */
3008 gen_or(b1, b0);
3009
3010 /*
3011 * Now check for From DS being set, and AND that with
3012 * the ORed-together checks.
3013 */
3014 s = gen_load_a(OR_LINK, 1, BPF_B);
3015 b1 = new_block(JMP(BPF_JSET));
3016 b1->s.k = 0x02; /* From DS */
3017 b1->stmts = s;
3018 gen_and(b1, b0);
3019
3020 /*
3021 * Now check for data frames with From DS not set.
3022 */
3023 s = gen_load_a(OR_LINK, 1, BPF_B);
3024 b2 = new_block(JMP(BPF_JSET));
3025 b2->s.k = 0x02; /* From DS */
3026 b2->stmts = s;
3027 gen_not(b2);
3028
3029 /*
3030 * If From DS isn't set, the SA is at 10.
3031 */
3032 b1 = gen_bcmp(OR_LINK, 10, 6, eaddr);
3033 gen_and(b2, b1);
3034
3035 /*
3036 * Now OR together the checks for data frames with
3037 * From DS not set and for data frames with From DS
3038 * set; that gives the checks done for data frames.
3039 */
3040 gen_or(b1, b0);
3041
3042 /*
3043 * Now check for a data frame.
3044 * I.e, check "link[0] & 0x08".
3045 */
3046 gen_load_a(OR_LINK, 0, BPF_B);
3047 b1 = new_block(JMP(BPF_JSET));
3048 b1->s.k = 0x08;
3049 b1->stmts = s;
3050
3051 /*
3052 * AND that with the checks done for data frames.
3053 */
3054 gen_and(b1, b0);
3055
3056 /*
3057 * If the high-order bit of the type value is 0, this
3058 * is a management frame.
3059 * I.e, check "!(link[0] & 0x08)".
3060 */
3061 s = gen_load_a(OR_LINK, 0, BPF_B);
3062 b2 = new_block(JMP(BPF_JSET));
3063 b2->s.k = 0x08;
3064 b2->stmts = s;
3065 gen_not(b2);
3066
3067 /*
3068 * For management frames, the SA is at 10.
3069 */
3070 b1 = gen_bcmp(OR_LINK, 10, 6, eaddr);
3071 gen_and(b2, b1);
3072
3073 /*
3074 * OR that with the checks done for data frames.
3075 * That gives the checks done for management and
3076 * data frames.
3077 */
3078 gen_or(b1, b0);
3079
3080 /*
3081 * If the low-order bit of the type value is 1,
3082 * this is either a control frame or a frame
3083 * with a reserved type, and thus not a
3084 * frame with an SA.
3085 *
3086 * I.e., check "!(link[0] & 0x04)".
3087 */
3088 s = gen_load_a(OR_LINK, 0, BPF_B);
3089 b1 = new_block(JMP(BPF_JSET));
3090 b1->s.k = 0x04;
3091 b1->stmts = s;
3092 gen_not(b1);
3093
3094 /*
3095 * AND that with the checks for data and management
3096 * frames.
3097 */
3098 gen_and(b1, b0);
3099 return b0;
3100
3101 case Q_DST:
3102 /*
3103 * Oh, yuk.
3104 *
3105 * For control frames, there is no DA.
3106 *
3107 * For management frames, DA is at an
3108 * offset of 4 from the beginning of
3109 * the packet.
3110 *
3111 * For data frames, DA is at an offset
3112 * of 4 from the beginning of the packet
3113 * if To DS is clear and at an offset of
3114 * 16 from the beginning of the packet
3115 * if To DS is set.
3116 */
3117
3118 /*
3119 * Generate the tests to be done for data frames.
3120 *
3121 * First, check for To DS set, i.e. "link[1] & 0x01".
3122 */
3123 s = gen_load_a(OR_LINK, 1, BPF_B);
3124 b1 = new_block(JMP(BPF_JSET));
3125 b1->s.k = 0x01; /* To DS */
3126 b1->stmts = s;
3127
3128 /*
3129 * If To DS is set, the DA is at 16.
3130 */
3131 b0 = gen_bcmp(OR_LINK, 16, 6, eaddr);
3132 gen_and(b1, b0);
3133
3134 /*
3135 * Now, check for To DS not set, i.e. check
3136 * "!(link[1] & 0x01)".
3137 */
3138 s = gen_load_a(OR_LINK, 1, BPF_B);
3139 b2 = new_block(JMP(BPF_JSET));
3140 b2->s.k = 0x01; /* To DS */
3141 b2->stmts = s;
3142 gen_not(b2);
3143
3144 /*
3145 * If To DS is not set, the DA is at 4.
3146 */
3147 b1 = gen_bcmp(OR_LINK, 4, 6, eaddr);
3148 gen_and(b2, b1);
3149
3150 /*
3151 * Now OR together the last two checks. That gives
3152 * the complete set of checks for data frames.
3153 */
3154 gen_or(b1, b0);
3155
3156 /*
3157 * Now check for a data frame.
3158 * I.e, check "link[0] & 0x08".
3159 */
3160 s = gen_load_a(OR_LINK, 0, BPF_B);
3161 b1 = new_block(JMP(BPF_JSET));
3162 b1->s.k = 0x08;
3163 b1->stmts = s;
3164
3165 /*
3166 * AND that with the checks done for data frames.
3167 */
3168 gen_and(b1, b0);
3169
3170 /*
3171 * If the high-order bit of the type value is 0, this
3172 * is a management frame.
3173 * I.e, check "!(link[0] & 0x08)".
3174 */
3175 s = gen_load_a(OR_LINK, 0, BPF_B);
3176 b2 = new_block(JMP(BPF_JSET));
3177 b2->s.k = 0x08;
3178 b2->stmts = s;
3179 gen_not(b2);
3180
3181 /*
3182 * For management frames, the DA is at 4.
3183 */
3184 b1 = gen_bcmp(OR_LINK, 4, 6, eaddr);
3185 gen_and(b2, b1);
3186
3187 /*
3188 * OR that with the checks done for data frames.
3189 * That gives the checks done for management and
3190 * data frames.
3191 */
3192 gen_or(b1, b0);
3193
3194 /*
3195 * If the low-order bit of the type value is 1,
3196 * this is either a control frame or a frame
3197 * with a reserved type, and thus not a
3198 * frame with an SA.
3199 *
3200 * I.e., check "!(link[0] & 0x04)".
3201 */
3202 s = gen_load_a(OR_LINK, 0, BPF_B);
3203 b1 = new_block(JMP(BPF_JSET));
3204 b1->s.k = 0x04;
3205 b1->stmts = s;
3206 gen_not(b1);
3207
3208 /*
3209 * AND that with the checks for data and management
3210 * frames.
3211 */
3212 gen_and(b1, b0);
3213 return b0;
3214
3215 case Q_AND:
3216 b0 = gen_wlanhostop(eaddr, Q_SRC);
3217 b1 = gen_wlanhostop(eaddr, Q_DST);
3218 gen_and(b0, b1);
3219 return b1;
3220
3221 case Q_DEFAULT:
3222 case Q_OR:
3223 b0 = gen_wlanhostop(eaddr, Q_SRC);
3224 b1 = gen_wlanhostop(eaddr, Q_DST);
3225 gen_or(b0, b1);
3226 return b1;
3227 }
3228 abort();
3229 /* NOTREACHED */
3230 }
3231
3232 /*
3233 * Like gen_ehostop, but for RFC 2625 IP-over-Fibre-Channel.
3234 * (We assume that the addresses are IEEE 48-bit MAC addresses,
3235 * as the RFC states.)
3236 */
3237 static struct block *
3238 gen_ipfchostop(eaddr, dir)
3239 register const u_char *eaddr;
3240 register int dir;
3241 {
3242 register struct block *b0, *b1;
3243
3244 switch (dir) {
3245 case Q_SRC:
3246 return gen_bcmp(OR_LINK, 10, 6, eaddr);
3247
3248 case Q_DST:
3249 return gen_bcmp(OR_LINK, 2, 6, eaddr);
3250
3251 case Q_AND:
3252 b0 = gen_ipfchostop(eaddr, Q_SRC);
3253 b1 = gen_ipfchostop(eaddr, Q_DST);
3254 gen_and(b0, b1);
3255 return b1;
3256
3257 case Q_DEFAULT:
3258 case Q_OR:
3259 b0 = gen_ipfchostop(eaddr, Q_SRC);
3260 b1 = gen_ipfchostop(eaddr, Q_DST);
3261 gen_or(b0, b1);
3262 return b1;
3263 }
3264 abort();
3265 /* NOTREACHED */
3266 }
3267
3268 /*
3269 * This is quite tricky because there may be pad bytes in front of the
3270 * DECNET header, and then there are two possible data packet formats that
3271 * carry both src and dst addresses, plus 5 packet types in a format that
3272 * carries only the src node, plus 2 types that use a different format and
3273 * also carry just the src node.
3274 *
3275 * Yuck.
3276 *
3277 * Instead of doing those all right, we just look for data packets with
3278 * 0 or 1 bytes of padding. If you want to look at other packets, that
3279 * will require a lot more hacking.
3280 *
3281 * To add support for filtering on DECNET "areas" (network numbers)
3282 * one would want to add a "mask" argument to this routine. That would
3283 * make the filter even more inefficient, although one could be clever
3284 * and not generate masking instructions if the mask is 0xFFFF.
3285 */
3286 static struct block *
3287 gen_dnhostop(addr, dir)
3288 bpf_u_int32 addr;
3289 int dir;
3290 {
3291 struct block *b0, *b1, *b2, *tmp;
3292 u_int offset_lh; /* offset if long header is received */
3293 u_int offset_sh; /* offset if short header is received */
3294
3295 switch (dir) {
3296
3297 case Q_DST:
3298 offset_sh = 1; /* follows flags */
3299 offset_lh = 7; /* flgs,darea,dsubarea,HIORD */
3300 break;
3301
3302 case Q_SRC:
3303 offset_sh = 3; /* follows flags, dstnode */
3304 offset_lh = 15; /* flgs,darea,dsubarea,did,sarea,ssub,HIORD */
3305 break;
3306
3307 case Q_AND:
3308 /* Inefficient because we do our Calvinball dance twice */
3309 b0 = gen_dnhostop(addr, Q_SRC);
3310 b1 = gen_dnhostop(addr, Q_DST);
3311 gen_and(b0, b1);
3312 return b1;
3313
3314 case Q_OR:
3315 case Q_DEFAULT:
3316 /* Inefficient because we do our Calvinball dance twice */
3317 b0 = gen_dnhostop(addr, Q_SRC);
3318 b1 = gen_dnhostop(addr, Q_DST);
3319 gen_or(b0, b1);
3320 return b1;
3321
3322 case Q_ISO:
3323 bpf_error("ISO host filtering not implemented");
3324
3325 default:
3326 abort();
3327 }
3328 b0 = gen_linktype(ETHERTYPE_DN);
3329 /* Check for pad = 1, long header case */
3330 tmp = gen_mcmp(OR_NET, 2, BPF_H,
3331 (bpf_int32)ntohs(0x0681), (bpf_int32)ntohs(0x07FF));
3332 b1 = gen_cmp(OR_NET, 2 + 1 + offset_lh,
3333 BPF_H, (bpf_int32)ntohs((u_short)addr));
3334 gen_and(tmp, b1);
3335 /* Check for pad = 0, long header case */
3336 tmp = gen_mcmp(OR_NET, 2, BPF_B, (bpf_int32)0x06, (bpf_int32)0x7);
3337 b2 = gen_cmp(OR_NET, 2 + offset_lh, BPF_H, (bpf_int32)ntohs((u_short)addr));
3338 gen_and(tmp, b2);
3339 gen_or(b2, b1);
3340 /* Check for pad = 1, short header case */
3341 tmp = gen_mcmp(OR_NET, 2, BPF_H,
3342 (bpf_int32)ntohs(0x0281), (bpf_int32)ntohs(0x07FF));
3343 b2 = gen_cmp(OR_NET, 2 + 1 + offset_sh, BPF_H, (bpf_int32)ntohs((u_short)addr));
3344 gen_and(tmp, b2);
3345 gen_or(b2, b1);
3346 /* Check for pad = 0, short header case */
3347 tmp = gen_mcmp(OR_NET, 2, BPF_B, (bpf_int32)0x02, (bpf_int32)0x7);
3348 b2 = gen_cmp(OR_NET, 2 + offset_sh, BPF_H, (bpf_int32)ntohs((u_short)addr));
3349 gen_and(tmp, b2);
3350 gen_or(b2, b1);
3351
3352 /* Combine with test for linktype */
3353 gen_and(b0, b1);
3354 return b1;
3355 }
3356
3357 /*
3358 * Generate a check for IPv4 or IPv6 for MPLS-encapsulated packets;
3359 * test the bottom-of-stack bit, and then check the version number
3360 * field in the IP header.
3361 */
3362 static struct block *
3363 gen_mpls_linktype(proto)
3364 int proto;
3365 {
3366 struct block *b0, *b1;
3367
3368 switch (proto) {
3369
3370 case Q_IP:
3371 /* match the bottom-of-stack bit */
3372 b0 = gen_mcmp(OR_NET, -2, BPF_B, 0x01, 0x01);
3373 /* match the IPv4 version number */
3374 b1 = gen_mcmp(OR_NET, 0, BPF_B, 0x40, 0xf0);
3375 gen_and(b0, b1);
3376 return b1;
3377
3378 case Q_IPV6:
3379 /* match the bottom-of-stack bit */
3380 b0 = gen_mcmp(OR_NET, -2, BPF_B, 0x01, 0x01);
3381 /* match the IPv4 version number */
3382 b1 = gen_mcmp(OR_NET, 0, BPF_B, 0x60, 0xf0);
3383 gen_and(b0, b1);
3384 return b1;
3385
3386 default:
3387 abort();
3388 }
3389 }
3390
3391 static struct block *
3392 gen_host(addr, mask, proto, dir, type)
3393 bpf_u_int32 addr;
3394 bpf_u_int32 mask;
3395 int proto;
3396 int dir;
3397 int type;
3398 {
3399 struct block *b0, *b1;
3400 const char *typestr;
3401
3402 if (type == Q_NET)
3403 typestr = "net";
3404 else
3405 typestr = "host";
3406
3407 switch (proto) {
3408
3409 case Q_DEFAULT:
3410 b0 = gen_host(addr, mask, Q_IP, dir, type);
3411 /*
3412 * Only check for non-IPv4 addresses if we're not
3413 * checking MPLS-encapsulated packets.
3414 */
3415 if (label_stack_depth == 0) {
3416 b1 = gen_host(addr, mask, Q_ARP, dir, type);
3417 gen_or(b0, b1);
3418 b0 = gen_host(addr, mask, Q_RARP, dir, type);
3419 gen_or(b1, b0);
3420 }
3421 return b0;
3422
3423 case Q_IP:
3424 return gen_hostop(addr, mask, dir, ETHERTYPE_IP, 12, 16);
3425
3426 case Q_RARP:
3427 return gen_hostop(addr, mask, dir, ETHERTYPE_REVARP, 14, 24);
3428
3429 case Q_ARP:
3430 return gen_hostop(addr, mask, dir, ETHERTYPE_ARP, 14, 24);
3431
3432 case Q_TCP:
3433 bpf_error("'tcp' modifier applied to %s", typestr);
3434
3435 case Q_SCTP:
3436 bpf_error("'sctp' modifier applied to %s", typestr);
3437
3438 case Q_UDP:
3439 bpf_error("'udp' modifier applied to %s", typestr);
3440
3441 case Q_ICMP:
3442 bpf_error("'icmp' modifier applied to %s", typestr);
3443
3444 case Q_IGMP:
3445 bpf_error("'igmp' modifier applied to %s", typestr);
3446
3447 case Q_IGRP:
3448 bpf_error("'igrp' modifier applied to %s", typestr);
3449
3450 case Q_PIM:
3451 bpf_error("'pim' modifier applied to %s", typestr);
3452
3453 case Q_VRRP:
3454 bpf_error("'vrrp' modifier applied to %s", typestr);
3455
3456 case Q_ATALK:
3457 bpf_error("ATALK host filtering not implemented");
3458
3459 case Q_AARP:
3460 bpf_error("AARP host filtering not implemented");
3461
3462 case Q_DECNET:
3463 return gen_dnhostop(addr, dir);
3464
3465 case Q_SCA:
3466 bpf_error("SCA host filtering not implemented");
3467
3468 case Q_LAT:
3469 bpf_error("LAT host filtering not implemented");
3470
3471 case Q_MOPDL:
3472 bpf_error("MOPDL host filtering not implemented");
3473
3474 case Q_MOPRC:
3475 bpf_error("MOPRC host filtering not implemented");
3476
3477 #ifdef INET6
3478 case Q_IPV6:
3479 bpf_error("'ip6' modifier applied to ip host");
3480
3481 case Q_ICMPV6:
3482 bpf_error("'icmp6' modifier applied to %s", typestr);
3483 #endif /* INET6 */
3484
3485 case Q_AH:
3486 bpf_error("'ah' modifier applied to %s", typestr);
3487
3488 case Q_ESP:
3489 bpf_error("'esp' modifier applied to %s", typestr);
3490
3491 case Q_ISO:
3492 bpf_error("ISO host filtering not implemented");
3493
3494 case Q_ESIS:
3495 bpf_error("'esis' modifier applied to %s", typestr);
3496
3497 case Q_ISIS:
3498 bpf_error("'isis' modifier applied to %s", typestr);
3499
3500 case Q_CLNP:
3501 bpf_error("'clnp' modifier applied to %s", typestr);
3502
3503 case Q_STP:
3504 bpf_error("'stp' modifier applied to %s", typestr);
3505
3506 case Q_IPX:
3507 bpf_error("IPX host filtering not implemented");
3508
3509 case Q_NETBEUI:
3510 bpf_error("'netbeui' modifier applied to %s", typestr);
3511
3512 case Q_RADIO:
3513 bpf_error("'radio' modifier applied to %s", typestr);
3514
3515 default:
3516 abort();
3517 }
3518 /* NOTREACHED */
3519 }
3520
3521 #ifdef INET6
3522 static struct block *
3523 gen_host6(addr, mask, proto, dir, type)
3524 struct in6_addr *addr;
3525 struct in6_addr *mask;
3526 int proto;
3527 int dir;
3528 int type;
3529 {
3530 const char *typestr;
3531
3532 if (type == Q_NET)
3533 typestr = "net";
3534 else
3535 typestr = "host";
3536
3537 switch (proto) {
3538
3539 case Q_DEFAULT:
3540 return gen_host6(addr, mask, Q_IPV6, dir, type);
3541
3542 case Q_IP:
3543 bpf_error("'ip' modifier applied to ip6 %s", typestr);
3544
3545 case Q_RARP:
3546 bpf_error("'rarp' modifier applied to ip6 %s", typestr);
3547
3548 case Q_ARP:
3549 bpf_error("'arp' modifier applied to ip6 %s", typestr);
3550
3551 case Q_SCTP:
3552 bpf_error("'sctp' modifier applied to %s", typestr);
3553
3554 case Q_TCP:
3555 bpf_error("'tcp' modifier applied to %s", typestr);
3556
3557 case Q_UDP:
3558 bpf_error("'udp' modifier applied to %s", typestr);
3559
3560 case Q_ICMP:
3561 bpf_error("'icmp' modifier applied to %s", typestr);
3562
3563 case Q_IGMP:
3564 bpf_error("'igmp' modifier applied to %s", typestr);
3565
3566 case Q_IGRP:
3567 bpf_error("'igrp' modifier applied to %s", typestr);
3568
3569 case Q_PIM:
3570 bpf_error("'pim' modifier applied to %s", typestr);
3571
3572 case Q_VRRP:
3573 bpf_error("'vrrp' modifier applied to %s", typestr);
3574
3575 case Q_ATALK:
3576 bpf_error("ATALK host filtering not implemented");
3577
3578 case Q_AARP:
3579 bpf_error("AARP host filtering not implemented");
3580
3581 case Q_DECNET:
3582 bpf_error("'decnet' modifier applied to ip6 %s", typestr);
3583
3584 case Q_SCA:
3585 bpf_error("SCA host filtering not implemented");
3586
3587 case Q_LAT:
3588 bpf_error("LAT host filtering not implemented");
3589
3590 case Q_MOPDL:
3591 bpf_error("MOPDL host filtering not implemented");
3592
3593 case Q_MOPRC:
3594 bpf_error("MOPRC host filtering not implemented");
3595
3596 case Q_IPV6:
3597 return gen_hostop6(addr, mask, dir, ETHERTYPE_IPV6, 8, 24);
3598
3599 case Q_ICMPV6:
3600 bpf_error("'icmp6' modifier applied to %s", typestr);
3601
3602 case Q_AH:
3603 bpf_error("'ah' modifier applied to %s", typestr);
3604
3605 case Q_ESP:
3606 bpf_error("'esp' modifier applied to %s", typestr);
3607
3608 case Q_ISO:
3609 bpf_error("ISO host filtering not implemented");
3610
3611 case Q_ESIS:
3612 bpf_error("'esis' modifier applied to %s", typestr);
3613
3614 case Q_ISIS:
3615 bpf_error("'isis' modifier applied to %s", typestr);
3616
3617 case Q_CLNP:
3618 bpf_error("'clnp' modifier applied to %s", typestr);
3619
3620 case Q_STP:
3621 bpf_error("'stp' modifier applied to %s", typestr);
3622
3623 case Q_IPX:
3624 bpf_error("IPX host filtering not implemented");
3625
3626 case Q_NETBEUI:
3627 bpf_error("'netbeui' modifier applied to %s", typestr);
3628
3629 case Q_RADIO:
3630 bpf_error("'radio' modifier applied to %s", typestr);
3631
3632 default:
3633 abort();
3634 }
3635 /* NOTREACHED */
3636 }
3637 #endif /*INET6*/
3638
3639 #ifndef INET6
3640 static struct block *
3641 gen_gateway(eaddr, alist, proto, dir)
3642 const u_char *eaddr;
3643 bpf_u_int32 **alist;
3644 int proto;
3645 int dir;
3646 {
3647 struct block *b0, *b1, *tmp;
3648
3649 if (dir != 0)
3650 bpf_error("direction applied to 'gateway'");
3651
3652 switch (proto) {
3653 case Q_DEFAULT:
3654 case Q_IP:
3655 case Q_ARP:
3656 case Q_RARP:
3657 switch (linktype) {
3658 case DLT_EN10MB:
3659 b0 = gen_ehostop(eaddr, Q_OR);
3660 break;
3661 case DLT_FDDI:
3662 b0 = gen_fhostop(eaddr, Q_OR);
3663 break;
3664 case DLT_IEEE802:
3665 b0 = gen_thostop(eaddr, Q_OR);
3666 break;
3667 case DLT_IEEE802_11:
3668 case DLT_IEEE802_11_RADIO_AVS:
3669 case DLT_PPI:
3670 case DLT_IEEE802_11_RADIO:
3671 case DLT_PRISM_HEADER:
3672 b0 = gen_wlanhostop(eaddr, Q_OR);
3673 break;
3674 case DLT_SUNATM:
3675 if (is_lane) {
3676 /*
3677 * Check that the packet doesn't begin with an
3678 * LE Control marker. (We've already generated
3679 * a test for LANE.)
3680 */
3681 b1 = gen_cmp(OR_LINK, SUNATM_PKT_BEGIN_POS, BPF_H,
3682 0xFF00);
3683 gen_not(b1);
3684
3685 /*
3686 * Now check the MAC address.
3687 */
3688 b0 = gen_ehostop(eaddr, Q_OR);
3689 gen_and(b1, b0);
3690 }
3691 break;
3692 case DLT_IP_OVER_FC:
3693 b0 = gen_ipfchostop(eaddr, Q_OR);
3694 break;
3695 default:
3696 bpf_error(
3697 "'gateway' supported only on ethernet/FDDI/token ring/802.11/Fibre Channel");
3698 }
3699 b1 = gen_host(**alist++, 0xffffffff, proto, Q_OR, Q_HOST);
3700 while (*alist) {
3701 tmp = gen_host(**alist++, 0xffffffff, proto, Q_OR,
3702 Q_HOST);
3703 gen_or(b1, tmp);
3704 b1 = tmp;
3705 }
3706 gen_not(b1);
3707 gen_and(b0, b1);
3708 return b1;
3709 }
3710 bpf_error("illegal modifier of 'gateway'");
3711 /* NOTREACHED */
3712 }
3713 #endif
3714
3715 struct block *
3716 gen_proto_abbrev(proto)
3717 int proto;
3718 {
3719 struct block *b0;
3720 struct block *b1;
3721
3722 switch (proto) {
3723
3724 case Q_SCTP:
3725 b1 = gen_proto(IPPROTO_SCTP, Q_IP, Q_DEFAULT);
3726 #ifdef INET6
3727 b0 = gen_proto(IPPROTO_SCTP, Q_IPV6, Q_DEFAULT);
3728 gen_or(b0, b1);
3729 #endif
3730 break;
3731
3732 case Q_TCP:
3733 b1 = gen_proto(IPPROTO_TCP, Q_IP, Q_DEFAULT);
3734 #ifdef INET6
3735 b0 = gen_proto(IPPROTO_TCP, Q_IPV6, Q_DEFAULT);
3736 gen_or(b0, b1);
3737 #endif
3738 break;
3739
3740 case Q_UDP:
3741 b1 = gen_proto(IPPROTO_UDP, Q_IP, Q_DEFAULT);
3742 #ifdef INET6
3743 b0 = gen_proto(IPPROTO_UDP, Q_IPV6, Q_DEFAULT);
3744 gen_or(b0, b1);
3745 #endif
3746 break;
3747
3748 case Q_ICMP:
3749 b1 = gen_proto(IPPROTO_ICMP, Q_IP, Q_DEFAULT);
3750 break;
3751
3752 #ifndef IPPROTO_IGMP
3753 #define IPPROTO_IGMP 2
3754 #endif
3755
3756 case Q_IGMP:
3757 b1 = gen_proto(IPPROTO_IGMP, Q_IP, Q_DEFAULT);
3758 break;
3759
3760 #ifndef IPPROTO_IGRP
3761 #define IPPROTO_IGRP 9
3762 #endif
3763 case Q_IGRP:
3764 b1 = gen_proto(IPPROTO_IGRP, Q_IP, Q_DEFAULT);
3765 break;
3766
3767 #ifndef IPPROTO_PIM
3768 #define IPPROTO_PIM 103
3769 #endif
3770
3771 case Q_PIM:
3772 b1 = gen_proto(IPPROTO_PIM, Q_IP, Q_DEFAULT);
3773 #ifdef INET6
3774 b0 = gen_proto(IPPROTO_PIM, Q_IPV6, Q_DEFAULT);
3775 gen_or(b0, b1);
3776 #endif
3777 break;
3778
3779 #ifndef IPPROTO_VRRP
3780 #define IPPROTO_VRRP 112
3781 #endif
3782
3783 case Q_VRRP:
3784 b1 = gen_proto(IPPROTO_VRRP, Q_IP, Q_DEFAULT);
3785 break;
3786
3787 case Q_IP:
3788 b1 = gen_linktype(ETHERTYPE_IP);
3789 break;
3790
3791 case Q_ARP:
3792 b1 = gen_linktype(ETHERTYPE_ARP);
3793 break;
3794
3795 case Q_RARP:
3796 b1 = gen_linktype(ETHERTYPE_REVARP);
3797 break;
3798
3799 case Q_LINK:
3800 bpf_error("link layer applied in wrong context");
3801
3802 case Q_ATALK:
3803 b1 = gen_linktype(ETHERTYPE_ATALK);
3804 break;
3805
3806 case Q_AARP:
3807 b1 = gen_linktype(ETHERTYPE_AARP);
3808 break;
3809
3810 case Q_DECNET:
3811 b1 = gen_linktype(ETHERTYPE_DN);
3812 break;
3813
3814 case Q_SCA:
3815 b1 = gen_linktype(ETHERTYPE_SCA);
3816 break;
3817
3818 case Q_LAT:
3819 b1 = gen_linktype(ETHERTYPE_LAT);
3820 break;
3821
3822 case Q_MOPDL:
3823 b1 = gen_linktype(ETHERTYPE_MOPDL);
3824 break;
3825
3826 case Q_MOPRC:
3827 b1 = gen_linktype(ETHERTYPE_MOPRC);
3828 break;
3829
3830 #ifdef INET6
3831 case Q_IPV6:
3832 b1 = gen_linktype(ETHERTYPE_IPV6);
3833 break;
3834
3835 #ifndef IPPROTO_ICMPV6
3836 #define IPPROTO_ICMPV6 58
3837 #endif
3838 case Q_ICMPV6:
3839 b1 = gen_proto(IPPROTO_ICMPV6, Q_IPV6, Q_DEFAULT);
3840 break;
3841 #endif /* INET6 */
3842
3843 #ifndef IPPROTO_AH
3844 #define IPPROTO_AH 51
3845 #endif
3846 case Q_AH:
3847 b1 = gen_proto(IPPROTO_AH, Q_IP, Q_DEFAULT);
3848 #ifdef INET6
3849 b0 = gen_proto(IPPROTO_AH, Q_IPV6, Q_DEFAULT);
3850 gen_or(b0, b1);
3851 #endif
3852 break;
3853
3854 #ifndef IPPROTO_ESP
3855 #define IPPROTO_ESP 50
3856 #endif
3857 case Q_ESP:
3858 b1 = gen_proto(IPPROTO_ESP, Q_IP, Q_DEFAULT);
3859 #ifdef INET6
3860 b0 = gen_proto(IPPROTO_ESP, Q_IPV6, Q_DEFAULT);
3861 gen_or(b0, b1);
3862 #endif
3863 break;
3864
3865 case Q_ISO:
3866 b1 = gen_linktype(LLCSAP_ISONS);
3867 break;
3868
3869 case Q_ESIS:
3870 b1 = gen_proto(ISO9542_ESIS, Q_ISO, Q_DEFAULT);
3871 break;
3872
3873 case Q_ISIS:
3874 b1 = gen_proto(ISO10589_ISIS, Q_ISO, Q_DEFAULT);
3875 break;
3876
3877 case Q_ISIS_L1: /* all IS-IS Level1 PDU-Types */
3878 b0 = gen_proto(ISIS_L1_LAN_IIH, Q_ISIS, Q_DEFAULT);
3879 b1 = gen_proto(ISIS_PTP_IIH, Q_ISIS, Q_DEFAULT); /* FIXME extract the circuit-type bits */
3880 gen_or(b0, b1);
3881 b0 = gen_proto(ISIS_L1_LSP, Q_ISIS, Q_DEFAULT);
3882 gen_or(b0, b1);
3883 b0 = gen_proto(ISIS_L1_CSNP, Q_ISIS, Q_DEFAULT);
3884 gen_or(b0, b1);
3885 b0 = gen_proto(ISIS_L1_PSNP, Q_ISIS, Q_DEFAULT);
3886 gen_or(b0, b1);
3887 break;
3888
3889 case Q_ISIS_L2: /* all IS-IS Level2 PDU-Types */
3890 b0 = gen_proto(ISIS_L2_LAN_IIH, Q_ISIS, Q_DEFAULT);
3891 b1 = gen_proto(ISIS_PTP_IIH, Q_ISIS, Q_DEFAULT); /* FIXME extract the circuit-type bits */
3892 gen_or(b0, b1);
3893 b0 = gen_proto(ISIS_L2_LSP, Q_ISIS, Q_DEFAULT);
3894 gen_or(b0, b1);
3895 b0 = gen_proto(ISIS_L2_CSNP, Q_ISIS, Q_DEFAULT);
3896 gen_or(b0, b1);
3897 b0 = gen_proto(ISIS_L2_PSNP, Q_ISIS, Q_DEFAULT);
3898 gen_or(b0, b1);
3899 break;
3900
3901 case Q_ISIS_IIH: /* all IS-IS Hello PDU-Types */
3902 b0 = gen_proto(ISIS_L1_LAN_IIH, Q_ISIS, Q_DEFAULT);
3903 b1 = gen_proto(ISIS_L2_LAN_IIH, Q_ISIS, Q_DEFAULT);
3904 gen_or(b0, b1);
3905 b0 = gen_proto(ISIS_PTP_IIH, Q_ISIS, Q_DEFAULT);
3906 gen_or(b0, b1);
3907 break;
3908
3909 case Q_ISIS_LSP:
3910 b0 = gen_proto(ISIS_L1_LSP, Q_ISIS, Q_DEFAULT);
3911 b1 = gen_proto(ISIS_L2_LSP, Q_ISIS, Q_DEFAULT);
3912 gen_or(b0, b1);
3913 break;
3914
3915 case Q_ISIS_SNP:
3916 b0 = gen_proto(ISIS_L1_CSNP, Q_ISIS, Q_DEFAULT);
3917 b1 = gen_proto(ISIS_L2_CSNP, Q_ISIS, Q_DEFAULT);
3918 gen_or(b0, b1);
3919 b0 = gen_proto(ISIS_L1_PSNP, Q_ISIS, Q_DEFAULT);
3920 gen_or(b0, b1);
3921 b0 = gen_proto(ISIS_L2_PSNP, Q_ISIS, Q_DEFAULT);
3922 gen_or(b0, b1);
3923 break;
3924
3925 case Q_ISIS_CSNP:
3926 b0 = gen_proto(ISIS_L1_CSNP, Q_ISIS, Q_DEFAULT);
3927 b1 = gen_proto(ISIS_L2_CSNP, Q_ISIS, Q_DEFAULT);
3928 gen_or(b0, b1);
3929 break;
3930
3931 case Q_ISIS_PSNP:
3932 b0 = gen_proto(ISIS_L1_PSNP, Q_ISIS, Q_DEFAULT);
3933 b1 = gen_proto(ISIS_L2_PSNP, Q_ISIS, Q_DEFAULT);
3934 gen_or(b0, b1);
3935 break;
3936
3937 case Q_CLNP:
3938 b1 = gen_proto(ISO8473_CLNP, Q_ISO, Q_DEFAULT);
3939 break;
3940
3941 case Q_STP:
3942 b1 = gen_linktype(LLCSAP_8021D);
3943 break;
3944
3945 case Q_IPX:
3946 b1 = gen_linktype(LLCSAP_IPX);
3947 break;
3948
3949 case Q_NETBEUI:
3950 b1 = gen_linktype(LLCSAP_NETBEUI);
3951 break;
3952
3953 case Q_RADIO:
3954 bpf_error("'radio' is not a valid protocol type");
3955
3956 default:
3957 abort();
3958 }
3959 return b1;
3960 }
3961
3962 static struct block *
3963 gen_ipfrag()
3964 {
3965 struct slist *s;
3966 struct block *b;
3967
3968 /* not ip frag */
3969 s = gen_load_a(OR_NET, 6, BPF_H);
3970 b = new_block(JMP(BPF_JSET));
3971 b->s.k = 0x1fff;
3972 b->stmts = s;
3973 gen_not(b);
3974
3975 return b;
3976 }
3977
3978 /*
3979 * Generate a comparison to a port value in the transport-layer header
3980 * at the specified offset from the beginning of that header.
3981 *
3982 * XXX - this handles a variable-length prefix preceding the link-layer
3983 * header, such as the radiotap or AVS radio prefix, but doesn't handle
3984 * variable-length link-layer headers (such as Token Ring or 802.11
3985 * headers).
3986 */
3987 static struct block *
3988 gen_portatom(off, v)
3989 int off;
3990 bpf_int32 v;
3991 {
3992 return gen_cmp(OR_TRAN_IPV4, off, BPF_H, v);
3993 }
3994
3995 #ifdef INET6
3996 static struct block *
3997 gen_portatom6(off, v)
3998 int off;
3999 bpf_int32 v;
4000 {
4001 return gen_cmp(OR_TRAN_IPV6, off, BPF_H, v);
4002 }
4003 #endif/*INET6*/
4004
4005 struct block *
4006 gen_portop(port, proto, dir)
4007 int port, proto, dir;
4008 {
4009 struct block *b0, *b1, *tmp;
4010
4011 /* ip proto 'proto' */
4012 tmp = gen_cmp(OR_NET, 9, BPF_B, (bpf_int32)proto);
4013 b0 = gen_ipfrag();
4014 gen_and(tmp, b0);
4015
4016 switch (dir) {
4017 case Q_SRC:
4018 b1 = gen_portatom(0, (bpf_int32)port);
4019 break;
4020
4021 case Q_DST:
4022 b1 = gen_portatom(2, (bpf_int32)port);
4023 break;
4024
4025 case Q_OR:
4026 case Q_DEFAULT:
4027 tmp = gen_portatom(0, (bpf_int32)port);
4028 b1 = gen_portatom(2, (bpf_int32)port);
4029 gen_or(tmp, b1);
4030 break;
4031
4032 case Q_AND:
4033 tmp = gen_portatom(0, (bpf_int32)port);
4034 b1 = gen_portatom(2, (bpf_int32)port);
4035 gen_and(tmp, b1);
4036 break;
4037
4038 default:
4039 abort();
4040 }
4041 gen_and(b0, b1);
4042
4043 return b1;
4044 }
4045
4046 static struct block *
4047 gen_port(port, ip_proto, dir)
4048 int port;
4049 int ip_proto;
4050 int dir;
4051 {
4052 struct block *b0, *b1, *tmp;
4053
4054 /*
4055 * ether proto ip
4056 *
4057 * For FDDI, RFC 1188 says that SNAP encapsulation is used,
4058 * not LLC encapsulation with LLCSAP_IP.
4059 *
4060 * For IEEE 802 networks - which includes 802.5 token ring
4061 * (which is what DLT_IEEE802 means) and 802.11 - RFC 1042
4062 * says that SNAP encapsulation is used, not LLC encapsulation
4063 * with LLCSAP_IP.
4064 *
4065 * For LLC-encapsulated ATM/"Classical IP", RFC 1483 and
4066 * RFC 2225 say that SNAP encapsulation is used, not LLC
4067 * encapsulation with LLCSAP_IP.
4068 *
4069 * So we always check for ETHERTYPE_IP.
4070 */
4071 b0 = gen_linktype(ETHERTYPE_IP);
4072
4073 switch (ip_proto) {
4074 case IPPROTO_UDP:
4075 case IPPROTO_TCP:
4076 case IPPROTO_SCTP:
4077 b1 = gen_portop(port, ip_proto, dir);
4078 break;
4079
4080 case PROTO_UNDEF:
4081 tmp = gen_portop(port, IPPROTO_TCP, dir);
4082 b1 = gen_portop(port, IPPROTO_UDP, dir);
4083 gen_or(tmp, b1);
4084 tmp = gen_portop(port, IPPROTO_SCTP, dir);
4085 gen_or(tmp, b1);
4086 break;
4087
4088 default:
4089 abort();
4090 }
4091 gen_and(b0, b1);
4092 return b1;
4093 }
4094
4095 #ifdef INET6
4096 struct block *
4097 gen_portop6(port, proto, dir)
4098 int port, proto, dir;
4099 {
4100 struct block *b0, *b1, *tmp;
4101
4102 /* ip6 proto 'proto' */
4103 b0 = gen_cmp(OR_NET, 6, BPF_B, (bpf_int32)proto);
4104
4105 switch (dir) {
4106 case Q_SRC:
4107 b1 = gen_portatom6(0, (bpf_int32)port);
4108 break;
4109
4110 case Q_DST:
4111 b1 = gen_portatom6(2, (bpf_int32)port);
4112 break;
4113
4114 case Q_OR:
4115 case Q_DEFAULT:
4116 tmp = gen_portatom6(0, (bpf_int32)port);
4117 b1 = gen_portatom6(2, (bpf_int32)port);
4118 gen_or(tmp, b1);
4119 break;
4120
4121 case Q_AND:
4122 tmp = gen_portatom6(0, (bpf_int32)port);
4123 b1 = gen_portatom6(2, (bpf_int32)port);
4124 gen_and(tmp, b1);
4125 break;
4126
4127 default:
4128 abort();
4129 }
4130 gen_and(b0, b1);
4131
4132 return b1;
4133 }
4134
4135 static struct block *
4136 gen_port6(port, ip_proto, dir)
4137 int port;
4138 int ip_proto;
4139 int dir;
4140 {
4141 struct block *b0, *b1, *tmp;
4142
4143 /* link proto ip6 */
4144 b0 = gen_linktype(ETHERTYPE_IPV6);
4145
4146 switch (ip_proto) {
4147 case IPPROTO_UDP:
4148 case IPPROTO_TCP:
4149 case IPPROTO_SCTP:
4150 b1 = gen_portop6(port, ip_proto, dir);
4151 break;
4152
4153 case PROTO_UNDEF:
4154 tmp = gen_portop6(port, IPPROTO_TCP, dir);
4155 b1 = gen_portop6(port, IPPROTO_UDP, dir);
4156 gen_or(tmp, b1);
4157 tmp = gen_portop6(port, IPPROTO_SCTP, dir);
4158 gen_or(tmp, b1);
4159 break;
4160
4161 default:
4162 abort();
4163 }
4164 gen_and(b0, b1);
4165 return b1;
4166 }
4167 #endif /* INET6 */
4168
4169 /* gen_portrange code */
4170 static struct block *
4171 gen_portrangeatom(off, v1, v2)
4172 int off;
4173 bpf_int32 v1, v2;
4174 {
4175 struct block *b1, *b2;
4176
4177 if (v1 > v2) {
4178 /*
4179 * Reverse the order of the ports, so v1 is the lower one.
4180 */
4181 bpf_int32 vtemp;
4182
4183 vtemp = v1;
4184 v1 = v2;
4185 v2 = vtemp;
4186 }
4187
4188 b1 = gen_cmp_ge(OR_TRAN_IPV4, off, BPF_H, v1);
4189 b2 = gen_cmp_le(OR_TRAN_IPV4, off, BPF_H, v2);
4190
4191 gen_and(b1, b2);
4192
4193 return b2;
4194 }
4195
4196 struct block *
4197 gen_portrangeop(port1, port2, proto, dir)
4198 int port1, port2;
4199 int proto;
4200 int dir;
4201 {
4202 struct block *b0, *b1, *tmp;
4203
4204 /* ip proto 'proto' */
4205 tmp = gen_cmp(OR_NET, 9, BPF_B, (bpf_int32)proto);
4206 b0 = gen_ipfrag();
4207 gen_and(tmp, b0);
4208
4209 switch (dir) {
4210 case Q_SRC:
4211 b1 = gen_portrangeatom(0, (bpf_int32)port1, (bpf_int32)port2);
4212 break;
4213
4214 case Q_DST:
4215 b1 = gen_portrangeatom(2, (bpf_int32)port1, (bpf_int32)port2);
4216 break;
4217
4218 case Q_OR:
4219 case Q_DEFAULT:
4220 tmp = gen_portrangeatom(0, (bpf_int32)port1, (bpf_int32)port2);
4221 b1 = gen_portrangeatom(2, (bpf_int32)port1, (bpf_int32)port2);
4222 gen_or(tmp, b1);
4223 break;
4224
4225 case Q_AND:
4226 tmp = gen_portrangeatom(0, (bpf_int32)port1, (bpf_int32)port2);
4227 b1 = gen_portrangeatom(2, (bpf_int32)port1, (bpf_int32)port2);
4228 gen_and(tmp, b1);
4229 break;
4230
4231 default:
4232 abort();
4233 }
4234 gen_and(b0, b1);
4235
4236 return b1;
4237 }
4238
4239 static struct block *
4240 gen_portrange(port1, port2, ip_proto, dir)
4241 int port1, port2;
4242 int ip_proto;
4243 int dir;
4244 {
4245 struct block *b0, *b1, *tmp;
4246
4247 /* link proto ip */
4248 b0 = gen_linktype(ETHERTYPE_IP);
4249
4250 switch (ip_proto) {
4251 case IPPROTO_UDP:
4252 case IPPROTO_TCP:
4253 case IPPROTO_SCTP:
4254 b1 = gen_portrangeop(port1, port2, ip_proto, dir);
4255 break;
4256
4257 case PROTO_UNDEF:
4258 tmp = gen_portrangeop(port1, port2, IPPROTO_TCP, dir);
4259 b1 = gen_portrangeop(port1, port2, IPPROTO_UDP, dir);
4260 gen_or(tmp, b1);
4261 tmp = gen_portrangeop(port1, port2, IPPROTO_SCTP, dir);
4262 gen_or(tmp, b1);
4263 break;
4264
4265 default:
4266 abort();
4267 }
4268 gen_and(b0, b1);
4269 return b1;
4270 }
4271
4272 #ifdef INET6
4273 static struct block *
4274 gen_portrangeatom6(off, v1, v2)
4275 int off;
4276 bpf_int32 v1, v2;
4277 {
4278 struct block *b1, *b2;
4279
4280 if (v1 > v2) {
4281 /*
4282 * Reverse the order of the ports, so v1 is the lower one.
4283 */
4284 bpf_int32 vtemp;
4285
4286 vtemp = v1;
4287 v1 = v2;
4288 v2 = vtemp;
4289 }
4290
4291 b1 = gen_cmp_ge(OR_TRAN_IPV6, off, BPF_H, v1);
4292 b2 = gen_cmp_le(OR_TRAN_IPV6, off, BPF_H, v2);
4293
4294 gen_and(b1, b2);
4295
4296 return b2;
4297 }
4298
4299 struct block *
4300 gen_portrangeop6(port1, port2, proto, dir)
4301 int port1, port2;
4302 int proto;
4303 int dir;
4304 {
4305 struct block *b0, *b1, *tmp;
4306
4307 /* ip6 proto 'proto' */
4308 b0 = gen_cmp(OR_NET, 6, BPF_B, (bpf_int32)proto);
4309
4310 switch (dir) {
4311 case Q_SRC:
4312 b1 = gen_portrangeatom6(0, (bpf_int32)port1, (bpf_int32)port2);
4313 break;
4314
4315 case Q_DST:
4316 b1 = gen_portrangeatom6(2, (bpf_int32)port1, (bpf_int32)port2);
4317 break;
4318
4319 case Q_OR:
4320 case Q_DEFAULT:
4321 tmp = gen_portrangeatom6(0, (bpf_int32)port1, (bpf_int32)port2);
4322 b1 = gen_portrangeatom6(2, (bpf_int32)port1, (bpf_int32)port2);
4323 gen_or(tmp, b1);
4324 break;
4325
4326 case Q_AND:
4327 tmp = gen_portrangeatom6(0, (bpf_int32)port1, (bpf_int32)port2);
4328 b1 = gen_portrangeatom6(2, (bpf_int32)port1, (bpf_int32)port2);
4329 gen_and(tmp, b1);
4330 break;
4331
4332 default:
4333 abort();
4334 }
4335 gen_and(b0, b1);
4336
4337 return b1;
4338 }
4339
4340 static struct block *
4341 gen_portrange6(port1, port2, ip_proto, dir)
4342 int port1, port2;
4343 int ip_proto;
4344 int dir;
4345 {
4346 struct block *b0, *b1, *tmp;
4347
4348 /* link proto ip6 */
4349 b0 = gen_linktype(ETHERTYPE_IPV6);
4350
4351 switch (ip_proto) {
4352 case IPPROTO_UDP:
4353 case IPPROTO_TCP:
4354 case IPPROTO_SCTP:
4355 b1 = gen_portrangeop6(port1, port2, ip_proto, dir);
4356 break;
4357
4358 case PROTO_UNDEF:
4359 tmp = gen_portrangeop6(port1, port2, IPPROTO_TCP, dir);
4360 b1 = gen_portrangeop6(port1, port2, IPPROTO_UDP, dir);
4361 gen_or(tmp, b1);
4362 tmp = gen_portrangeop6(port1, port2, IPPROTO_SCTP, dir);
4363 gen_or(tmp, b1);
4364 break;
4365
4366 default:
4367 abort();
4368 }
4369 gen_and(b0, b1);
4370 return b1;
4371 }
4372 #endif /* INET6 */
4373
4374 static int
4375 lookup_proto(name, proto)
4376 register const char *name;
4377 register int proto;
4378 {
4379 register int v;
4380
4381 switch (proto) {
4382
4383 case Q_DEFAULT:
4384 case Q_IP:
4385 case Q_IPV6:
4386 v = pcap_nametoproto(name);
4387 if (v == PROTO_UNDEF)
4388 bpf_error("unknown ip proto '%s'", name);
4389 break;
4390
4391 case Q_LINK:
4392 /* XXX should look up h/w protocol type based on linktype */
4393 v = pcap_nametoeproto(name);
4394 if (v == PROTO_UNDEF) {
4395 v = pcap_nametollc(name);
4396 if (v == PROTO_UNDEF)
4397 bpf_error("unknown ether proto '%s'", name);
4398 }
4399 break;
4400
4401 case Q_ISO:
4402 if (strcmp(name, "esis") == 0)
4403 v = ISO9542_ESIS;
4404 else if (strcmp(name, "isis") == 0)
4405 v = ISO10589_ISIS;
4406 else if (strcmp(name, "clnp") == 0)
4407 v = ISO8473_CLNP;
4408 else
4409 bpf_error("unknown osi proto '%s'", name);
4410 break;
4411
4412 default:
4413 v = PROTO_UNDEF;
4414 break;
4415 }
4416 return v;
4417 }
4418
4419 #if 0
4420 struct stmt *
4421 gen_joinsp(s, n)
4422 struct stmt **s;
4423 int n;
4424 {
4425 return NULL;
4426 }
4427 #endif
4428
4429 static struct block *
4430 gen_protochain(v, proto, dir)
4431 int v;
4432 int proto;
4433 int dir;
4434 {
4435 #ifdef NO_PROTOCHAIN
4436 return gen_proto(v, proto, dir);
4437 #else
4438 struct block *b0, *b;
4439 struct slist *s[100];
4440 int fix2, fix3, fix4, fix5;
4441 int ahcheck, again, end;
4442 int i, max;
4443 int reg2 = alloc_reg();
4444
4445 memset(s, 0, sizeof(s));
4446 fix2 = fix3 = fix4 = fix5 = 0;
4447
4448 switch (proto) {
4449 case Q_IP:
4450 case Q_IPV6:
4451 break;
4452 case Q_DEFAULT:
4453 b0 = gen_protochain(v, Q_IP, dir);
4454 b = gen_protochain(v, Q_IPV6, dir);
4455 gen_or(b0, b);
4456 return b;
4457 default:
4458 bpf_error("bad protocol applied for 'protochain'");
4459 /*NOTREACHED*/
4460 }
4461
4462 /*
4463 * We don't handle variable-length radiotap here headers yet.
4464 * We might want to add BPF instructions to do the protochain
4465 * work, to simplify that and, on platforms that have a BPF
4466 * interpreter with the new instructions, let the filtering
4467 * be done in the kernel. (We already require a modified BPF
4468 * engine to do the protochain stuff, to support backward
4469 * branches, and backward branch support is unlikely to appear
4470 * in kernel BPF engines.)
4471 */
4472 if (linktype == DLT_IEEE802_11_RADIO)
4473 bpf_error("'protochain' not supported with radiotap headers");
4474
4475 if (linktype == DLT_PPI)
4476 bpf_error("'protochain' not supported with PPI headers");
4477
4478 no_optimize = 1; /*this code is not compatible with optimzer yet */
4479
4480 /*
4481 * s[0] is a dummy entry to protect other BPF insn from damage
4482 * by s[fix] = foo with uninitialized variable "fix". It is somewhat
4483 * hard to find interdependency made by jump table fixup.
4484 */
4485 i = 0;
4486 s[i] = new_stmt(0); /*dummy*/
4487 i++;
4488
4489 switch (proto) {
4490 case Q_IP:
4491 b0 = gen_linktype(ETHERTYPE_IP);
4492
4493 /* A = ip->ip_p */
4494 s[i] = new_stmt(BPF_LD|BPF_ABS|BPF_B);
4495 s[i]->s.k = off_ll + off_nl + 9;
4496 i++;
4497 /* X = ip->ip_hl << 2 */
4498 s[i] = new_stmt(BPF_LDX|BPF_MSH|BPF_B);
4499 s[i]->s.k = off_ll + off_nl;
4500 i++;
4501 break;
4502 #ifdef INET6
4503 case Q_IPV6:
4504 b0 = gen_linktype(ETHERTYPE_IPV6);
4505
4506 /* A = ip6->ip_nxt */
4507 s[i] = new_stmt(BPF_LD|BPF_ABS|BPF_B);
4508 s[i]->s.k = off_ll + off_nl + 6;
4509 i++;
4510 /* X = sizeof(struct ip6_hdr) */
4511 s[i] = new_stmt(BPF_LDX|BPF_IMM);
4512 s[i]->s.k = 40;
4513 i++;
4514 break;
4515 #endif
4516 default:
4517 bpf_error("unsupported proto to gen_protochain");
4518 /*NOTREACHED*/
4519 }
4520
4521 /* again: if (A == v) goto end; else fall through; */
4522 again = i;
4523 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K);
4524 s[i]->s.k = v;
4525 s[i]->s.jt = NULL; /*later*/
4526 s[i]->s.jf = NULL; /*update in next stmt*/
4527 fix5 = i;
4528 i++;
4529
4530 #ifndef IPPROTO_NONE
4531 #define IPPROTO_NONE 59
4532 #endif
4533 /* if (A == IPPROTO_NONE) goto end */
4534 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K);
4535 s[i]->s.jt = NULL; /*later*/
4536 s[i]->s.jf = NULL; /*update in next stmt*/
4537 s[i]->s.k = IPPROTO_NONE;
4538 s[fix5]->s.jf = s[i];
4539 fix2 = i;
4540 i++;
4541
4542 #ifdef INET6
4543 if (proto == Q_IPV6) {
4544 int v6start, v6end, v6advance, j;
4545
4546 v6start = i;
4547 /* if (A == IPPROTO_HOPOPTS) goto v6advance */
4548 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K);
4549 s[i]->s.jt = NULL; /*later*/
4550 s[i]->s.jf = NULL; /*update in next stmt*/
4551 s[i]->s.k = IPPROTO_HOPOPTS;
4552 s[fix2]->s.jf = s[i];
4553 i++;
4554 /* if (A == IPPROTO_DSTOPTS) goto v6advance */
4555 s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K);
4556 s[i]->s.jt = NULL; /*later*/
4557 s[i]->s.jf = NULL; /*update in next stmt*/
4558 s[i]->s.k = IPPROTO_DSTOPTS;
4559 i++;
4560 /* if (A == IPPROTO_ROUTING) goto v6advance */
4561 s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K);
4562 s[i]->s.jt = NULL; /*later*/
4563 s[i]->s.jf = NULL; /*update in next stmt*/
4564 s[i]->s.k = IPPROTO_ROUTING;
4565 i++;
4566 /* if (A == IPPROTO_FRAGMENT) goto v6advance; else goto ahcheck; */
4567 s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K);
4568 s[i]->s.jt = NULL; /*later*/
4569 s[i]->s.jf = NULL; /*later*/
4570 s[i]->s.k = IPPROTO_FRAGMENT;
4571 fix3 = i;
4572 v6end = i;
4573 i++;
4574
4575 /* v6advance: */
4576 v6advance = i;
4577
4578 /*
4579 * in short,
4580 * A = P[X];
4581 * X = X + (P[X + 1] + 1) * 8;
4582 */
4583 /* A = X */
4584 s[i] = new_stmt(BPF_MISC|BPF_TXA);
4585 i++;
4586 /* A = P[X + packet head] */
4587 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B);
4588 s[i]->s.k = off_ll + off_nl;
4589 i++;
4590 /* MEM[reg2] = A */
4591 s[i] = new_stmt(BPF_ST);
4592 s[i]->s.k = reg2;
4593 i++;
4594 /* A = X */
4595 s[i] = new_stmt(BPF_MISC|BPF_TXA);
4596 i++;
4597 /* A += 1 */
4598 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K);
4599 s[i]->s.k = 1;
4600 i++;
4601 /* X = A */
4602 s[i] = new_stmt(BPF_MISC|BPF_TAX);
4603 i++;
4604 /* A = P[X + packet head]; */
4605 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B);
4606 s[i]->s.k = off_ll + off_nl;
4607 i++;
4608 /* A += 1 */
4609 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K);
4610 s[i]->s.k = 1;
4611 i++;
4612 /* A *= 8 */
4613 s[i] = new_stmt(BPF_ALU|BPF_MUL|BPF_K);
4614 s[i]->s.k = 8;
4615 i++;
4616 /* X = A; */
4617 s[i] = new_stmt(BPF_MISC|BPF_TAX);
4618 i++;
4619 /* A = MEM[reg2] */
4620 s[i] = new_stmt(BPF_LD|BPF_MEM);
4621 s[i]->s.k = reg2;
4622 i++;
4623
4624 /* goto again; (must use BPF_JA for backward jump) */
4625 s[i] = new_stmt(BPF_JMP|BPF_JA);
4626 s[i]->s.k = again - i - 1;
4627 s[i - 1]->s.jf = s[i];
4628 i++;
4629
4630 /* fixup */
4631 for (j = v6start; j <= v6end; j++)
4632 s[j]->s.jt = s[v6advance];
4633 } else
4634 #endif
4635 {
4636 /* nop */
4637 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K);
4638 s[i]->s.k = 0;
4639 s[fix2]->s.jf = s[i];
4640 i++;
4641 }
4642
4643 /* ahcheck: */
4644 ahcheck = i;
4645 /* if (A == IPPROTO_AH) then fall through; else goto end; */
4646 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K);
4647 s[i]->s.jt = NULL; /*later*/
4648 s[i]->s.jf = NULL; /*later*/
4649 s[i]->s.k = IPPROTO_AH;
4650 if (fix3)
4651 s[fix3]->s.jf = s[ahcheck];
4652 fix4 = i;
4653 i++;
4654
4655 /*
4656 * in short,
4657 * A = P[X];
4658 * X = X + (P[X + 1] + 2) * 4;
4659 */
4660 /* A = X */
4661 s[i - 1]->s.jt = s[i] = new_stmt(BPF_MISC|BPF_TXA);
4662 i++;
4663 /* A = P[X + packet head]; */
4664 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B);
4665 s[i]->s.k = off_ll + off_nl;
4666 i++;
4667 /* MEM[reg2] = A */
4668 s[i] = new_stmt(BPF_ST);
4669 s[i]->s.k = reg2;
4670 i++;
4671 /* A = X */
4672 s[i - 1]->s.jt = s[i] = new_stmt(BPF_MISC|BPF_TXA);
4673 i++;
4674 /* A += 1 */
4675 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K);
4676 s[i]->s.k = 1;
4677 i++;
4678 /* X = A */
4679 s[i] = new_stmt(BPF_MISC|BPF_TAX);
4680 i++;
4681 /* A = P[X + packet head] */
4682 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B);
4683 s[i]->s.k = off_ll + off_nl;
4684 i++;
4685 /* A += 2 */
4686 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K);
4687 s[i]->s.k = 2;
4688 i++;
4689 /* A *= 4 */
4690 s[i] = new_stmt(BPF_ALU|BPF_MUL|BPF_K);
4691 s[i]->s.k = 4;
4692 i++;
4693 /* X = A; */
4694 s[i] = new_stmt(BPF_MISC|BPF_TAX);
4695 i++;
4696 /* A = MEM[reg2] */
4697 s[i] = new_stmt(BPF_LD|BPF_MEM);
4698 s[i]->s.k = reg2;
4699 i++;
4700
4701 /* goto again; (must use BPF_JA for backward jump) */
4702 s[i] = new_stmt(BPF_JMP|BPF_JA);
4703 s[i]->s.k = again - i - 1;
4704 i++;
4705
4706 /* end: nop */
4707 end = i;
4708 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K);
4709 s[i]->s.k = 0;
4710 s[fix2]->s.jt = s[end];
4711 s[fix4]->s.jf = s[end];
4712 s[fix5]->s.jt = s[end];
4713 i++;
4714
4715 /*
4716 * make slist chain
4717 */
4718 max = i;
4719 for (i = 0; i < max - 1; i++)
4720 s[i]->next = s[i + 1];
4721 s[max - 1]->next = NULL;
4722
4723 /*
4724 * emit final check
4725 */
4726 b = new_block(JMP(BPF_JEQ));
4727 b->stmts = s[1]; /*remember, s[0] is dummy*/
4728 b->s.k = v;
4729
4730 free_reg(reg2);
4731
4732 gen_and(b0, b);
4733 return b;
4734 #endif
4735 }
4736
4737
4738 /*
4739 * Generate code that checks whether the packet is a packet for protocol
4740 * <proto> and whether the type field in that protocol's header has
4741 * the value <v>, e.g. if <proto> is Q_IP, it checks whether it's an
4742 * IP packet and checks the protocol number in the IP header against <v>.
4743 *
4744 * If <proto> is Q_DEFAULT, i.e. just "proto" was specified, it checks
4745 * against Q_IP and Q_IPV6.
4746 */
4747 static struct block *
4748 gen_proto(v, proto, dir)
4749 int v;
4750 int proto;
4751 int dir;
4752 {
4753 struct block *b0, *b1;
4754
4755 if (dir != Q_DEFAULT)
4756 bpf_error("direction applied to 'proto'");
4757
4758 switch (proto) {
4759 case Q_DEFAULT:
4760 #ifdef INET6
4761 b0 = gen_proto(v, Q_IP, dir);
4762 b1 = gen_proto(v, Q_IPV6, dir);
4763 gen_or(b0, b1);
4764 return b1;
4765 #else
4766 /*FALLTHROUGH*/
4767 #endif
4768 case Q_IP:
4769 /*
4770 * For FDDI, RFC 1188 says that SNAP encapsulation is used,
4771 * not LLC encapsulation with LLCSAP_IP.
4772 *
4773 * For IEEE 802 networks - which includes 802.5 token ring
4774 * (which is what DLT_IEEE802 means) and 802.11 - RFC 1042
4775 * says that SNAP encapsulation is used, not LLC encapsulation
4776 * with LLCSAP_IP.
4777 *
4778 * For LLC-encapsulated ATM/"Classical IP", RFC 1483 and
4779 * RFC 2225 say that SNAP encapsulation is used, not LLC
4780 * encapsulation with LLCSAP_IP.
4781 *
4782 * So we always check for ETHERTYPE_IP.
4783 */
4784 b0 = gen_linktype(ETHERTYPE_IP);
4785 #ifndef CHASE_CHAIN
4786 b1 = gen_cmp(OR_NET, 9, BPF_B, (bpf_int32)v);
4787 #else
4788 b1 = gen_protochain(v, Q_IP);
4789 #endif
4790 gen_and(b0, b1);
4791 return b1;
4792
4793 case Q_ISO:
4794 switch (linktype) {
4795
4796 case DLT_FRELAY:
4797 /*
4798 * Frame Relay packets typically have an OSI
4799 * NLPID at the beginning; "gen_linktype(LLCSAP_ISONS)"
4800 * generates code to check for all the OSI
4801 * NLPIDs, so calling it and then adding a check
4802 * for the particular NLPID for which we're
4803 * looking is bogus, as we can just check for
4804 * the NLPID.
4805 *
4806 * What we check for is the NLPID and a frame
4807 * control field value of UI, i.e. 0x03 followed
4808 * by the NLPID.
4809 *
4810 * XXX - assumes a 2-byte Frame Relay header with
4811 * DLCI and flags. What if the address is longer?
4812 *
4813 * XXX - what about SNAP-encapsulated frames?
4814 */
4815 return gen_cmp(OR_LINK, 2, BPF_H, (0x03<<8) | v);
4816 /*NOTREACHED*/
4817 break;
4818
4819 case DLT_C_HDLC:
4820 /*
4821 * Cisco uses an Ethertype lookalike - for OSI,
4822 * it's 0xfefe.
4823 */
4824 b0 = gen_linktype(LLCSAP_ISONS<<8 | LLCSAP_ISONS);
4825 /* OSI in C-HDLC is stuffed with a fudge byte */
4826 b1 = gen_cmp(OR_NET_NOSNAP, 1, BPF_B, (long)v);
4827 gen_and(b0, b1);
4828 return b1;
4829
4830 default:
4831 b0 = gen_linktype(LLCSAP_ISONS);
4832 b1 = gen_cmp(OR_NET_NOSNAP, 0, BPF_B, (long)v);
4833 gen_and(b0, b1);
4834 return b1;
4835 }
4836
4837 case Q_ISIS:
4838 b0 = gen_proto(ISO10589_ISIS, Q_ISO, Q_DEFAULT);
4839 /*
4840 * 4 is the offset of the PDU type relative to the IS-IS
4841 * header.
4842 */
4843 b1 = gen_cmp(OR_NET_NOSNAP, 4, BPF_B, (long)v);
4844 gen_and(b0, b1);
4845 return b1;
4846
4847 case Q_ARP:
4848 bpf_error("arp does not encapsulate another protocol");
4849 /* NOTREACHED */
4850
4851 case Q_RARP:
4852 bpf_error("rarp does not encapsulate another protocol");
4853 /* NOTREACHED */
4854
4855 case Q_ATALK:
4856 bpf_error("atalk encapsulation is not specifiable");
4857 /* NOTREACHED */
4858
4859 case Q_DECNET:
4860 bpf_error("decnet encapsulation is not specifiable");
4861 /* NOTREACHED */
4862
4863 case Q_SCA:
4864 bpf_error("sca does not encapsulate another protocol");
4865 /* NOTREACHED */
4866
4867 case Q_LAT:
4868 bpf_error("lat does not encapsulate another protocol");
4869 /* NOTREACHED */
4870
4871 case Q_MOPRC:
4872 bpf_error("moprc does not encapsulate another protocol");
4873 /* NOTREACHED */
4874
4875 case Q_MOPDL:
4876 bpf_error("mopdl does not encapsulate another protocol");
4877 /* NOTREACHED */
4878
4879 case Q_LINK:
4880 return gen_linktype(v);
4881
4882 case Q_UDP:
4883 bpf_error("'udp proto' is bogus");
4884 /* NOTREACHED */
4885
4886 case Q_TCP:
4887 bpf_error("'tcp proto' is bogus");
4888 /* NOTREACHED */
4889
4890 case Q_SCTP:
4891 bpf_error("'sctp proto' is bogus");
4892 /* NOTREACHED */
4893
4894 case Q_ICMP:
4895 bpf_error("'icmp proto' is bogus");
4896 /* NOTREACHED */
4897
4898 case Q_IGMP:
4899 bpf_error("'igmp proto' is bogus");
4900 /* NOTREACHED */
4901
4902 case Q_IGRP:
4903 bpf_error("'igrp proto' is bogus");
4904 /* NOTREACHED */
4905
4906 case Q_PIM:
4907 bpf_error("'pim proto' is bogus");
4908 /* NOTREACHED */
4909
4910 case Q_VRRP:
4911 bpf_error("'vrrp proto' is bogus");
4912 /* NOTREACHED */
4913
4914 #ifdef INET6
4915 case Q_IPV6:
4916 b0 = gen_linktype(ETHERTYPE_IPV6);
4917 #ifndef CHASE_CHAIN
4918 b1 = gen_cmp(OR_NET, 6, BPF_B, (bpf_int32)v);
4919 #else
4920 b1 = gen_protochain(v, Q_IPV6);
4921 #endif
4922 gen_and(b0, b1);
4923 return b1;
4924
4925 case Q_ICMPV6:
4926 bpf_error("'icmp6 proto' is bogus");
4927 #endif /* INET6 */
4928
4929 case Q_AH:
4930 bpf_error("'ah proto' is bogus");
4931
4932 case Q_ESP:
4933 bpf_error("'ah proto' is bogus");
4934
4935 case Q_STP:
4936 bpf_error("'stp proto' is bogus");
4937
4938 case Q_IPX:
4939 bpf_error("'ipx proto' is bogus");
4940
4941 case Q_NETBEUI:
4942 bpf_error("'netbeui proto' is bogus");
4943
4944 case Q_RADIO:
4945 bpf_error("'radio proto' is bogus");
4946
4947 default:
4948 abort();
4949 /* NOTREACHED */
4950 }
4951 /* NOTREACHED */
4952 }
4953
4954 struct block *
4955 gen_scode(name, q)
4956 register const char *name;
4957 struct qual q;
4958 {
4959 int proto = q.proto;
4960 int dir = q.dir;
4961 int tproto;
4962 u_char *eaddr;
4963 bpf_u_int32 mask, addr;
4964 #ifndef INET6
4965 bpf_u_int32 **alist;
4966 #else
4967 int tproto6;
4968 struct sockaddr_in *sin4;
4969 struct sockaddr_in6 *sin6;
4970 struct addrinfo *res, *res0;
4971 struct in6_addr mask128;
4972 #endif /*INET6*/
4973 struct block *b, *tmp;
4974 int port, real_proto;
4975 int port1, port2;
4976
4977 switch (q.addr) {
4978
4979 case Q_NET:
4980 addr = pcap_nametonetaddr(name);
4981 if (addr == 0)
4982 bpf_error("unknown network '%s'", name);
4983 /* Left justify network addr and calculate its network mask */
4984 mask = 0xffffffff;
4985 while (addr && (addr & 0xff000000) == 0) {
4986 addr <<= 8;
4987 mask <<= 8;
4988 }
4989 return gen_host(addr, mask, proto, dir, q.addr);
4990
4991 case Q_DEFAULT:
4992 case Q_HOST:
4993 if (proto == Q_LINK) {
4994 switch (linktype) {
4995
4996 case DLT_EN10MB:
4997 eaddr = pcap_ether_hostton(name);
4998 if (eaddr == NULL)
4999 bpf_error(
5000 "unknown ether host '%s'", name);
5001 b = gen_ehostop(eaddr, dir);
5002 free(eaddr);
5003 return b;
5004
5005 case DLT_FDDI:
5006 eaddr = pcap_ether_hostton(name);
5007 if (eaddr == NULL)
5008 bpf_error(
5009 "unknown FDDI host '%s'", name);
5010 b = gen_fhostop(eaddr, dir);
5011 free(eaddr);
5012 return b;
5013
5014 case DLT_IEEE802:
5015 eaddr = pcap_ether_hostton(name);
5016 if (eaddr == NULL)
5017 bpf_error(
5018 "unknown token ring host '%s'", name);
5019 b = gen_thostop(eaddr, dir);
5020 free(eaddr);
5021 return b;
5022
5023 case DLT_IEEE802_11:
5024 case DLT_IEEE802_11_RADIO_AVS:
5025 case DLT_IEEE802_11_RADIO:
5026 case DLT_PRISM_HEADER:
5027 case DLT_PPI:
5028 eaddr = pcap_ether_hostton(name);
5029 if (eaddr == NULL)
5030 bpf_error(
5031 "unknown 802.11 host '%s'", name);
5032 b = gen_wlanhostop(eaddr, dir);
5033 free(eaddr);
5034 return b;
5035
5036 case DLT_IP_OVER_FC:
5037 eaddr = pcap_ether_hostton(name);
5038 if (eaddr == NULL)
5039 bpf_error(
5040 "unknown Fibre Channel host '%s'", name);
5041 b = gen_ipfchostop(eaddr, dir);
5042 free(eaddr);
5043 return b;
5044
5045 case DLT_SUNATM:
5046 if (!is_lane)
5047 break;
5048
5049 /*
5050 * Check that the packet doesn't begin
5051 * with an LE Control marker. (We've
5052 * already generated a test for LANE.)
5053 */
5054 tmp = gen_cmp(OR_LINK, SUNATM_PKT_BEGIN_POS,
5055 BPF_H, 0xFF00);
5056 gen_not(tmp);
5057
5058 eaddr = pcap_ether_hostton(name);
5059 if (eaddr == NULL)
5060 bpf_error(
5061 "unknown ether host '%s'", name);
5062 b = gen_ehostop(eaddr, dir);
5063 gen_and(tmp, b);
5064 free(eaddr);
5065 return b;
5066 }
5067
5068 bpf_error("only ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel supports link-level host name");
5069 } else if (proto == Q_DECNET) {
5070 unsigned short dn_addr = __pcap_nametodnaddr(name);
5071 /*
5072 * I don't think DECNET hosts can be multihomed, so
5073 * there is no need to build up a list of addresses
5074 */
5075 return (gen_host(dn_addr, 0, proto, dir, q.addr));
5076 } else {
5077 #ifndef INET6
5078 alist = pcap_nametoaddr(name);
5079 if (alist == NULL || *alist == NULL)
5080 bpf_error("unknown host '%s'", name);
5081 tproto = proto;
5082 if (off_linktype == (u_int)-1 && tproto == Q_DEFAULT)
5083 tproto = Q_IP;
5084 b = gen_host(**alist++, 0xffffffff, tproto, dir, q.addr);
5085 while (*alist) {
5086 tmp = gen_host(**alist++, 0xffffffff,
5087 tproto, dir, q.addr);
5088 gen_or(b, tmp);
5089 b = tmp;
5090 }
5091 return b;
5092 #else
5093 memset(&mask128, 0xff, sizeof(mask128));
5094 res0 = res = pcap_nametoaddrinfo(name);
5095 if (res == NULL)
5096 bpf_error("unknown host '%s'", name);
5097 b = tmp = NULL;
5098 tproto = tproto6 = proto;
5099 if (off_linktype == -1 && tproto == Q_DEFAULT) {
5100 tproto = Q_IP;
5101 tproto6 = Q_IPV6;
5102 }
5103 for (res = res0; res; res = res->ai_next) {
5104 switch (res->ai_family) {
5105 case AF_INET:
5106 if (tproto == Q_IPV6)
5107 continue;
5108
5109 sin4 = (struct sockaddr_in *)
5110 res->ai_addr;
5111 tmp = gen_host(ntohl(sin4->sin_addr.s_addr),
5112 0xffffffff, tproto, dir, q.addr);
5113 break;
5114 case AF_INET6:
5115 if (tproto6 == Q_IP)
5116 continue;
5117
5118 sin6 = (struct sockaddr_in6 *)
5119 res->ai_addr;
5120 tmp = gen_host6(&sin6->sin6_addr,
5121 &mask128, tproto6, dir, q.addr);
5122 break;
5123 default:
5124 continue;
5125 }
5126 if (b)
5127 gen_or(b, tmp);
5128 b = tmp;
5129 }
5130 freeaddrinfo(res0);
5131 if (b == NULL) {
5132 bpf_error("unknown host '%s'%s", name,
5133 (proto == Q_DEFAULT)
5134 ? ""
5135 : " for specified address family");
5136 }
5137 return b;
5138 #endif /*INET6*/
5139 }
5140
5141 case Q_PORT:
5142 if (proto != Q_DEFAULT &&
5143 proto != Q_UDP && proto != Q_TCP && proto != Q_SCTP)
5144 bpf_error("illegal qualifier of 'port'");
5145 if (pcap_nametoport(name, &port, &real_proto) == 0)
5146 bpf_error("unknown port '%s'", name);
5147 if (proto == Q_UDP) {
5148 if (real_proto == IPPROTO_TCP)
5149 bpf_error("port '%s' is tcp", name);
5150 else if (real_proto == IPPROTO_SCTP)
5151 bpf_error("port '%s' is sctp", name);
5152 else
5153 /* override PROTO_UNDEF */
5154 real_proto = IPPROTO_UDP;
5155 }
5156 if (proto == Q_TCP) {
5157 if (real_proto == IPPROTO_UDP)
5158 bpf_error("port '%s' is udp", name);
5159
5160 else if (real_proto == IPPROTO_SCTP)
5161 bpf_error("port '%s' is sctp", name);
5162 else
5163 /* override PROTO_UNDEF */
5164 real_proto = IPPROTO_TCP;
5165 }
5166 if (proto == Q_SCTP) {
5167 if (real_proto == IPPROTO_UDP)
5168 bpf_error("port '%s' is udp", name);
5169
5170 else if (real_proto == IPPROTO_TCP)
5171 bpf_error("port '%s' is tcp", name);
5172 else
5173 /* override PROTO_UNDEF */
5174 real_proto = IPPROTO_SCTP;
5175 }
5176 #ifndef INET6
5177 return gen_port(port, real_proto, dir);
5178 #else
5179 b = gen_port(port, real_proto, dir);
5180 gen_or(gen_port6(port, real_proto, dir), b);
5181 return b;
5182 #endif /* INET6 */
5183
5184 case Q_PORTRANGE:
5185 if (proto != Q_DEFAULT &&
5186 proto != Q_UDP && proto != Q_TCP && proto != Q_SCTP)
5187 bpf_error("illegal qualifier of 'portrange'");
5188 if (pcap_nametoportrange(name, &port1, &port2, &real_proto) == 0)
5189 bpf_error("unknown port in range '%s'", name);
5190 if (proto == Q_UDP) {
5191 if (real_proto == IPPROTO_TCP)
5192 bpf_error("port in range '%s' is tcp", name);
5193 else if (real_proto == IPPROTO_SCTP)
5194 bpf_error("port in range '%s' is sctp", name);
5195 else
5196 /* override PROTO_UNDEF */
5197 real_proto = IPPROTO_UDP;
5198 }
5199 if (proto == Q_TCP) {
5200 if (real_proto == IPPROTO_UDP)
5201 bpf_error("port in range '%s' is udp", name);
5202 else if (real_proto == IPPROTO_SCTP)
5203 bpf_error("port in range '%s' is sctp", name);
5204 else
5205 /* override PROTO_UNDEF */
5206 real_proto = IPPROTO_TCP;
5207 }
5208 if (proto == Q_SCTP) {
5209 if (real_proto == IPPROTO_UDP)
5210 bpf_error("port in range '%s' is udp", name);
5211 else if (real_proto == IPPROTO_TCP)
5212 bpf_error("port in range '%s' is tcp", name);
5213 else
5214 /* override PROTO_UNDEF */
5215 real_proto = IPPROTO_SCTP;
5216 }
5217 #ifndef INET6
5218 return gen_portrange(port1, port2, real_proto, dir);
5219 #else
5220 b = gen_portrange(port1, port2, real_proto, dir);
5221 gen_or(gen_portrange6(port1, port2, real_proto, dir), b);
5222 return b;
5223 #endif /* INET6 */
5224
5225 case Q_GATEWAY:
5226 #ifndef INET6
5227 eaddr = pcap_ether_hostton(name);
5228 if (eaddr == NULL)
5229 bpf_error("unknown ether host: %s", name);
5230
5231 alist = pcap_nametoaddr(name);
5232 if (alist == NULL || *alist == NULL)
5233 bpf_error("unknown host '%s'", name);
5234 b = gen_gateway(eaddr, alist, proto, dir);
5235 free(eaddr);
5236 return b;
5237 #else
5238 bpf_error("'gateway' not supported in this configuration");
5239 #endif /*INET6*/
5240
5241 case Q_PROTO:
5242 real_proto = lookup_proto(name, proto);
5243 if (real_proto >= 0)
5244 return gen_proto(real_proto, proto, dir);
5245 else
5246 bpf_error("unknown protocol: %s", name);
5247
5248 case Q_PROTOCHAIN:
5249 real_proto = lookup_proto(name, proto);
5250 if (real_proto >= 0)
5251 return gen_protochain(real_proto, proto, dir);
5252 else
5253 bpf_error("unknown protocol: %s", name);
5254
5255
5256 case Q_UNDEF:
5257 syntax();
5258 /* NOTREACHED */
5259 }
5260 abort();
5261 /* NOTREACHED */
5262 }
5263
5264 struct block *
5265 gen_mcode(s1, s2, masklen, q)
5266 register const char *s1, *s2;
5267 register int masklen;
5268 struct qual q;
5269 {
5270 register int nlen, mlen;
5271 bpf_u_int32 n, m;
5272
5273 nlen = __pcap_atoin(s1, &n);
5274 /* Promote short ipaddr */
5275 n <<= 32 - nlen;
5276
5277 if (s2 != NULL) {
5278 mlen = __pcap_atoin(s2, &m);
5279 /* Promote short ipaddr */
5280 m <<= 32 - mlen;
5281 if ((n & ~m) != 0)
5282 bpf_error("non-network bits set in \"%s mask %s\"",
5283 s1, s2);
5284 } else {
5285 /* Convert mask len to mask */
5286 if (masklen > 32)
5287 bpf_error("mask length must be <= 32");
5288 if (masklen == 0) {
5289 /*
5290 * X << 32 is not guaranteed by C to be 0; it's
5291 * undefined.
5292 */
5293 m = 0;
5294 } else
5295 m = 0xffffffff << (32 - masklen);
5296 if ((n & ~m) != 0)
5297 bpf_error("non-network bits set in \"%s/%d\"",
5298 s1, masklen);
5299 }
5300
5301 switch (q.addr) {
5302
5303 case Q_NET:
5304 return gen_host(n, m, q.proto, q.dir, q.addr);
5305
5306 default:
5307 bpf_error("Mask syntax for networks only");
5308 /* NOTREACHED */
5309 }
5310 /* NOTREACHED */
5311 return NULL;
5312 }
5313
5314 struct block *
5315 gen_ncode(s, v, q)
5316 register const char *s;
5317 bpf_u_int32 v;
5318 struct qual q;
5319 {
5320 bpf_u_int32 mask;
5321 int proto = q.proto;
5322 int dir = q.dir;
5323 register int vlen;
5324
5325 if (s == NULL)
5326 vlen = 32;
5327 else if (q.proto == Q_DECNET)
5328 vlen = __pcap_atodn(s, &v);
5329 else
5330 vlen = __pcap_atoin(s, &v);
5331
5332 switch (q.addr) {
5333
5334 case Q_DEFAULT:
5335 case Q_HOST:
5336 case Q_NET:
5337 if (proto == Q_DECNET)
5338 return gen_host(v, 0, proto, dir, q.addr);
5339 else if (proto == Q_LINK) {
5340 bpf_error("illegal link layer address");
5341 } else {
5342 mask = 0xffffffff;
5343 if (s == NULL && q.addr == Q_NET) {
5344 /* Promote short net number */
5345 while (v && (v & 0xff000000) == 0) {
5346 v <<= 8;
5347 mask <<= 8;
5348 }
5349 } else {
5350 /* Promote short ipaddr */
5351 v <<= 32 - vlen;
5352 mask <<= 32 - vlen;
5353 }
5354 return gen_host(v, mask, proto, dir, q.addr);
5355 }
5356
5357 case Q_PORT:
5358 if (proto == Q_UDP)
5359 proto = IPPROTO_UDP;
5360 else if (proto == Q_TCP)
5361 proto = IPPROTO_TCP;
5362 else if (proto == Q_SCTP)
5363 proto = IPPROTO_SCTP;
5364 else if (proto == Q_DEFAULT)
5365 proto = PROTO_UNDEF;
5366 else
5367 bpf_error("illegal qualifier of 'port'");
5368
5369 #ifndef INET6
5370 return gen_port((int)v, proto, dir);
5371 #else
5372 {
5373 struct block *b;
5374 b = gen_port((int)v, proto, dir);
5375 gen_or(gen_port6((int)v, proto, dir), b);
5376 return b;
5377 }
5378 #endif /* INET6 */
5379
5380 case Q_PORTRANGE:
5381 if (proto == Q_UDP)
5382 proto = IPPROTO_UDP;
5383 else if (proto == Q_TCP)
5384 proto = IPPROTO_TCP;
5385 else if (proto == Q_SCTP)
5386 proto = IPPROTO_SCTP;
5387 else if (proto == Q_DEFAULT)
5388 proto = PROTO_UNDEF;
5389 else
5390 bpf_error("illegal qualifier of 'portrange'");
5391
5392 #ifndef INET6
5393 return gen_portrange((int)v, (int)v, proto, dir);
5394 #else
5395 {
5396 struct block *b;
5397 b = gen_portrange((int)v, (int)v, proto, dir);
5398 gen_or(gen_portrange6((int)v, (int)v, proto, dir), b);
5399 return b;
5400 }
5401 #endif /* INET6 */
5402
5403 case Q_GATEWAY:
5404 bpf_error("'gateway' requires a name");
5405 /* NOTREACHED */
5406
5407 case Q_PROTO:
5408 return gen_proto((int)v, proto, dir);
5409
5410 case Q_PROTOCHAIN:
5411 return gen_protochain((int)v, proto, dir);
5412
5413 case Q_UNDEF:
5414 syntax();
5415 /* NOTREACHED */
5416
5417 default:
5418 abort();
5419 /* NOTREACHED */
5420 }
5421 /* NOTREACHED */
5422 }
5423
5424 #ifdef INET6
5425 struct block *
5426 gen_mcode6(s1, s2, masklen, q)
5427 register const char *s1, *s2;
5428 register int masklen;
5429 struct qual q;
5430 {
5431 struct addrinfo *res;
5432 struct in6_addr *addr;
5433 struct in6_addr mask;
5434 struct block *b;
5435 u_int32_t *a, *m;
5436
5437 if (s2)
5438 bpf_error("no mask %s supported", s2);
5439
5440 res = pcap_nametoaddrinfo(s1);
5441 if (!res)
5442 bpf_error("invalid ip6 address %s", s1);
5443 if (res->ai_next)
5444 bpf_error("%s resolved to multiple address", s1);
5445 addr = &((struct sockaddr_in6 *)res->ai_addr)->sin6_addr;
5446
5447 if (sizeof(mask) * 8 < masklen)
5448 bpf_error("mask length must be <= %u", (unsigned int)(sizeof(mask) * 8));
5449 memset(&mask, 0, sizeof(mask));
5450 memset(&mask, 0xff, masklen / 8);
5451 if (masklen % 8) {
5452 mask.s6_addr[masklen / 8] =
5453 (0xff << (8 - masklen % 8)) & 0xff;
5454 }
5455
5456 a = (u_int32_t *)addr;
5457 m = (u_int32_t *)&mask;
5458 if ((a[0] & ~m[0]) || (a[1] & ~m[1])
5459 || (a[2] & ~m[2]) || (a[3] & ~m[3])) {
5460 bpf_error("non-network bits set in \"%s/%d\"", s1, masklen);
5461 }
5462
5463 switch (q.addr) {
5464
5465 case Q_DEFAULT:
5466 case Q_HOST:
5467 if (masklen != 128)
5468 bpf_error("Mask syntax for networks only");
5469 /* FALLTHROUGH */
5470
5471 case Q_NET:
5472 b = gen_host6(addr, &mask, q.proto, q.dir, q.addr);
5473 freeaddrinfo(res);
5474 return b;
5475
5476 default:
5477 bpf_error("invalid qualifier against IPv6 address");
5478 /* NOTREACHED */
5479 }
5480 return NULL;
5481 }
5482 #endif /*INET6*/
5483
5484 struct block *
5485 gen_ecode(eaddr, q)
5486 register const u_char *eaddr;
5487 struct qual q;
5488 {
5489 struct block *b, *tmp;
5490
5491 if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) && q.proto == Q_LINK) {
5492 switch (linktype) {
5493 case DLT_EN10MB:
5494 return gen_ehostop(eaddr, (int)q.dir);
5495 case DLT_FDDI:
5496 return gen_fhostop(eaddr, (int)q.dir);
5497 case DLT_IEEE802:
5498 return gen_thostop(eaddr, (int)q.dir);
5499 case DLT_IEEE802_11:
5500 case DLT_IEEE802_11_RADIO_AVS:
5501 case DLT_IEEE802_11_RADIO:
5502 case DLT_PRISM_HEADER:
5503 case DLT_PPI:
5504 return gen_wlanhostop(eaddr, (int)q.dir);
5505 case DLT_SUNATM:
5506 if (is_lane) {
5507 /*
5508 * Check that the packet doesn't begin with an
5509 * LE Control marker. (We've already generated
5510 * a test for LANE.)
5511 */
5512 tmp = gen_cmp(OR_LINK, SUNATM_PKT_BEGIN_POS, BPF_H,
5513 0xFF00);
5514 gen_not(tmp);
5515
5516 /*
5517 * Now check the MAC address.
5518 */
5519 b = gen_ehostop(eaddr, (int)q.dir);
5520 gen_and(tmp, b);
5521 return b;
5522 }
5523 break;
5524 case DLT_IP_OVER_FC:
5525 return gen_ipfchostop(eaddr, (int)q.dir);
5526 default:
5527 bpf_error("ethernet addresses supported only on ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel");
5528 break;
5529 }
5530 }
5531 bpf_error("ethernet address used in non-ether expression");
5532 /* NOTREACHED */
5533 return NULL;
5534 }
5535
5536 void
5537 sappend(s0, s1)
5538 struct slist *s0, *s1;
5539 {
5540 /*
5541 * This is definitely not the best way to do this, but the
5542 * lists will rarely get long.
5543 */
5544 while (s0->next)
5545 s0 = s0->next;
5546 s0->next = s1;
5547 }
5548
5549 static struct slist *
5550 xfer_to_x(a)
5551 struct arth *a;
5552 {
5553 struct slist *s;
5554
5555 s = new_stmt(BPF_LDX|BPF_MEM);
5556 s->s.k = a->regno;
5557 return s;
5558 }
5559
5560 static struct slist *
5561 xfer_to_a(a)
5562 struct arth *a;
5563 {
5564 struct slist *s;
5565
5566 s = new_stmt(BPF_LD|BPF_MEM);
5567 s->s.k = a->regno;
5568 return s;
5569 }
5570
5571 /*
5572 * Modify "index" to use the value stored into its register as an
5573 * offset relative to the beginning of the header for the protocol
5574 * "proto", and allocate a register and put an item "size" bytes long
5575 * (1, 2, or 4) at that offset into that register, making it the register
5576 * for "index".
5577 */
5578 struct arth *
5579 gen_load(proto, inst, size)
5580 int proto;
5581 struct arth *inst;
5582 int size;
5583 {
5584 struct slist *s, *tmp;
5585 struct block *b;
5586 int regno = alloc_reg();
5587
5588 free_reg(inst->regno);
5589 switch (size) {
5590
5591 default:
5592 bpf_error("data size must be 1, 2, or 4");
5593
5594 case 1:
5595 size = BPF_B;
5596 break;
5597
5598 case 2:
5599 size = BPF_H;
5600 break;
5601
5602 case 4:
5603 size = BPF_W;
5604 break;
5605 }
5606 switch (proto) {
5607 default:
5608 bpf_error("unsupported index operation");
5609
5610 case Q_RADIO:
5611 /*
5612 * The offset is relative to the beginning of the packet
5613 * data, if we have a radio header. (If we don't, this
5614 * is an error.)
5615 */
5616 if (linktype != DLT_IEEE802_11_RADIO_AVS &&
5617 linktype != DLT_IEEE802_11_RADIO &&
5618 linktype != DLT_PRISM_HEADER)
5619 bpf_error("radio information not present in capture");
5620
5621 /*
5622 * Load into the X register the offset computed into the
5623 * register specifed by "index".
5624 */
5625 s = xfer_to_x(inst);
5626
5627 /*
5628 * Load the item at that offset.
5629 */
5630 tmp = new_stmt(BPF_LD|BPF_IND|size);
5631 sappend(s, tmp);
5632 sappend(inst->s, s);
5633 break;
5634
5635 case Q_LINK:
5636 /*
5637 * The offset is relative to the beginning of
5638 * the link-layer header.
5639 *
5640 * XXX - what about ATM LANE? Should the index be
5641 * relative to the beginning of the AAL5 frame, so
5642 * that 0 refers to the beginning of the LE Control
5643 * field, or relative to the beginning of the LAN
5644 * frame, so that 0 refers, for Ethernet LANE, to
5645 * the beginning of the destination address?
5646 */
5647 s = gen_llprefixlen();
5648
5649 /*
5650 * If "s" is non-null, it has code to arrange that the
5651 * X register contains the length of the prefix preceding
5652 * the link-layer header. Add to it the offset computed
5653 * into the register specified by "index", and move that
5654 * into the X register. Otherwise, just load into the X
5655 * register the offset computed into the register specifed
5656 * by "index".
5657 */
5658 if (s != NULL) {
5659 sappend(s, xfer_to_a(inst));
5660 sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X));
5661 sappend(s, new_stmt(BPF_MISC|BPF_TAX));
5662 } else
5663 s = xfer_to_x(inst);
5664
5665 /*
5666 * Load the item at the sum of the offset we've put in the
5667 * X register and the offset of the start of the link
5668 * layer header (which is 0 if the radio header is
5669 * variable-length; that header length is what we put
5670 * into the X register and then added to the index).
5671 */
5672 tmp = new_stmt(BPF_LD|BPF_IND|size);
5673 tmp->s.k = off_ll;
5674 sappend(s, tmp);
5675 sappend(inst->s, s);
5676 break;
5677
5678 case Q_IP:
5679 case Q_ARP:
5680 case Q_RARP:
5681 case Q_ATALK:
5682 case Q_DECNET:
5683 case Q_SCA:
5684 case Q_LAT:
5685 case Q_MOPRC:
5686 case Q_MOPDL:
5687 #ifdef INET6
5688 case Q_IPV6:
5689 #endif
5690 /*
5691 * The offset is relative to the beginning of
5692 * the network-layer header.
5693 * XXX - are there any cases where we want
5694 * off_nl_nosnap?
5695 */
5696 s = gen_llprefixlen();
5697
5698 /*
5699 * If "s" is non-null, it has code to arrange that the
5700 * X register contains the length of the prefix preceding
5701 * the link-layer header. Add to it the offset computed
5702 * into the register specified by "index", and move that
5703 * into the X register. Otherwise, just load into the X
5704 * register the offset computed into the register specifed
5705 * by "index".
5706 */
5707 if (s != NULL) {
5708 sappend(s, xfer_to_a(inst));
5709 sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X));
5710 sappend(s, new_stmt(BPF_MISC|BPF_TAX));
5711 } else
5712 s = xfer_to_x(inst);
5713
5714 /*
5715 * Load the item at the sum of the offset we've put in the
5716 * X register, the offset of the start of the network
5717 * layer header, and the offset of the start of the link
5718 * layer header (which is 0 if the radio header is
5719 * variable-length; that header length is what we put
5720 * into the X register and then added to the index).
5721 */
5722 tmp = new_stmt(BPF_LD|BPF_IND|size);
5723 tmp->s.k = off_ll + off_nl;
5724 sappend(s, tmp);
5725 sappend(inst->s, s);
5726
5727 /*
5728 * Do the computation only if the packet contains
5729 * the protocol in question.
5730 */
5731 b = gen_proto_abbrev(proto);
5732 if (inst->b)
5733 gen_and(inst->b, b);
5734 inst->b = b;
5735 break;
5736
5737 case Q_SCTP:
5738 case Q_TCP:
5739 case Q_UDP:
5740 case Q_ICMP:
5741 case Q_IGMP:
5742 case Q_IGRP:
5743 case Q_PIM:
5744 case Q_VRRP:
5745 /*
5746 * The offset is relative to the beginning of
5747 * the transport-layer header.
5748 *
5749 * Load the X register with the length of the IPv4 header
5750 * (plus the offset of the link-layer header, if it's
5751 * a variable-length header), in bytes.
5752 *
5753 * XXX - are there any cases where we want
5754 * off_nl_nosnap?
5755 * XXX - we should, if we're built with
5756 * IPv6 support, generate code to load either
5757 * IPv4, IPv6, or both, as appropriate.
5758 */
5759 s = gen_loadx_iphdrlen();
5760
5761 /*
5762 * The X register now contains the sum of the length
5763 * of any variable-length header preceding the link-layer
5764 * header and the length of the network-layer header.
5765 * Load into the A register the offset relative to
5766 * the beginning of the transport layer header,
5767 * add the X register to that, move that to the
5768 * X register, and load with an offset from the
5769 * X register equal to the offset of the network
5770 * layer header relative to the beginning of
5771 * the link-layer header plus the length of any
5772 * fixed-length header preceding the link-layer
5773 * header.
5774 */
5775 sappend(s, xfer_to_a(inst));
5776 sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X));
5777 sappend(s, new_stmt(BPF_MISC|BPF_TAX));
5778 sappend(s, tmp = new_stmt(BPF_LD|BPF_IND|size));
5779 tmp->s.k = off_ll + off_nl;
5780 sappend(inst->s, s);
5781
5782 /*
5783 * Do the computation only if the packet contains
5784 * the protocol in question - which is true only
5785 * if this is an IP datagram and is the first or
5786 * only fragment of that datagram.
5787 */
5788 gen_and(gen_proto_abbrev(proto), b = gen_ipfrag());
5789 if (inst->b)
5790 gen_and(inst->b, b);
5791 #ifdef INET6
5792 gen_and(gen_proto_abbrev(Q_IP), b);
5793 #endif
5794 inst->b = b;
5795 break;
5796 #ifdef INET6
5797 case Q_ICMPV6:
5798 bpf_error("IPv6 upper-layer protocol is not supported by proto[x]");
5799 /*NOTREACHED*/
5800 #endif
5801 }
5802 inst->regno = regno;
5803 s = new_stmt(BPF_ST);
5804 s->s.k = regno;
5805 sappend(inst->s, s);
5806
5807 return inst;
5808 }
5809
5810 struct block *
5811 gen_relation(code, a0, a1, reversed)
5812 int code;
5813 struct arth *a0, *a1;
5814 int reversed;
5815 {
5816 struct slist *s0, *s1, *s2;
5817 struct block *b, *tmp;
5818
5819 s0 = xfer_to_x(a1);
5820 s1 = xfer_to_a(a0);
5821 if (code == BPF_JEQ) {
5822 s2 = new_stmt(BPF_ALU|BPF_SUB|BPF_X);
5823 b = new_block(JMP(code));
5824 sappend(s1, s2);
5825 }
5826 else
5827 b = new_block(BPF_JMP|code|BPF_X);
5828 if (reversed)
5829 gen_not(b);
5830
5831 sappend(s0, s1);
5832 sappend(a1->s, s0);
5833 sappend(a0->s, a1->s);
5834
5835 b->stmts = a0->s;
5836
5837 free_reg(a0->regno);
5838 free_reg(a1->regno);
5839
5840 /* 'and' together protocol checks */
5841 if (a0->b) {
5842 if (a1->b) {
5843 gen_and(a0->b, tmp = a1->b);
5844 }
5845 else
5846 tmp = a0->b;
5847 } else
5848 tmp = a1->b;
5849
5850 if (tmp)
5851 gen_and(tmp, b);
5852
5853 return b;
5854 }
5855
5856 struct arth *
5857 gen_loadlen()
5858 {
5859 int regno = alloc_reg();
5860 struct arth *a = (struct arth *)newchunk(sizeof(*a));
5861 struct slist *s;
5862
5863 s = new_stmt(BPF_LD|BPF_LEN);
5864 s->next = new_stmt(BPF_ST);
5865 s->next->s.k = regno;
5866 a->s = s;
5867 a->regno = regno;
5868
5869 return a;
5870 }
5871
5872 struct arth *
5873 gen_loadi(val)
5874 int val;
5875 {
5876 struct arth *a;
5877 struct slist *s;
5878 int reg;
5879
5880 a = (struct arth *)newchunk(sizeof(*a));
5881
5882 reg = alloc_reg();
5883
5884 s = new_stmt(BPF_LD|BPF_IMM);
5885 s->s.k = val;
5886 s->next = new_stmt(BPF_ST);
5887 s->next->s.k = reg;
5888 a->s = s;
5889 a->regno = reg;
5890
5891 return a;
5892 }
5893
5894 struct arth *
5895 gen_neg(a)
5896 struct arth *a;
5897 {
5898 struct slist *s;
5899
5900 s = xfer_to_a(a);
5901 sappend(a->s, s);
5902 s = new_stmt(BPF_ALU|BPF_NEG);
5903 s->s.k = 0;
5904 sappend(a->s, s);
5905 s = new_stmt(BPF_ST);
5906 s->s.k = a->regno;
5907 sappend(a->s, s);
5908
5909 return a;
5910 }
5911
5912 struct arth *
5913 gen_arth(code, a0, a1)
5914 int code;
5915 struct arth *a0, *a1;
5916 {
5917 struct slist *s0, *s1, *s2;
5918
5919 s0 = xfer_to_x(a1);
5920 s1 = xfer_to_a(a0);
5921 s2 = new_stmt(BPF_ALU|BPF_X|code);
5922
5923 sappend(s1, s2);
5924 sappend(s0, s1);
5925 sappend(a1->s, s0);
5926 sappend(a0->s, a1->s);
5927
5928 free_reg(a0->regno);
5929 free_reg(a1->regno);
5930
5931 s0 = new_stmt(BPF_ST);
5932 a0->regno = s0->s.k = alloc_reg();
5933 sappend(a0->s, s0);
5934
5935 return a0;
5936 }
5937
5938 /*
5939 * Here we handle simple allocation of the scratch registers.
5940 * If too many registers are alloc'd, the allocator punts.
5941 */
5942 static int regused[BPF_MEMWORDS];
5943 static int curreg;
5944
5945 /*
5946 * Return the next free register.
5947 */
5948 static int
5949 alloc_reg()
5950 {
5951 int n = BPF_MEMWORDS;
5952
5953 while (--n >= 0) {
5954 if (regused[curreg])
5955 curreg = (curreg + 1) % BPF_MEMWORDS;
5956 else {
5957 regused[curreg] = 1;
5958 return curreg;
5959 }
5960 }
5961 bpf_error("too many registers needed to evaluate expression");
5962 /* NOTREACHED */
5963 return 0;
5964 }
5965
5966 /*
5967 * Return a register to the table so it can
5968 * be used later.
5969 */
5970 static void
5971 free_reg(n)
5972 int n;
5973 {
5974 regused[n] = 0;
5975 }
5976
5977 static struct block *
5978 gen_len(jmp, n)
5979 int jmp, n;
5980 {
5981 struct slist *s;
5982 struct block *b;
5983
5984 s = new_stmt(BPF_LD|BPF_LEN);
5985 b = new_block(JMP(jmp));
5986 b->stmts = s;
5987 b->s.k = n;
5988
5989 return b;
5990 }
5991
5992 struct block *
5993 gen_greater(n)
5994 int n;
5995 {
5996 return gen_len(BPF_JGE, n);
5997 }
5998
5999 /*
6000 * Actually, this is less than or equal.
6001 */
6002 struct block *
6003 gen_less(n)
6004 int n;
6005 {
6006 struct block *b;
6007
6008 b = gen_len(BPF_JGT, n);
6009 gen_not(b);
6010
6011 return b;
6012 }
6013
6014 /*
6015 * This is for "byte {idx} {op} {val}"; "idx" is treated as relative to
6016 * the beginning of the link-layer header.
6017 * XXX - that means you can't test values in the radiotap header, but
6018 * as that header is difficult if not impossible to parse generally
6019 * without a loop, that might not be a severe problem. A new keyword
6020 * "radio" could be added for that, although what you'd really want
6021 * would be a way of testing particular radio header values, which
6022 * would generate code appropriate to the radio header in question.
6023 */
6024 struct block *
6025 gen_byteop(op, idx, val)
6026 int op, idx, val;
6027 {
6028 struct block *b;
6029 struct slist *s;
6030
6031 switch (op) {
6032 default:
6033 abort();
6034
6035 case '=':
6036 return gen_cmp(OR_LINK, (u_int)idx, BPF_B, (bpf_int32)val);
6037
6038 case '<':
6039 b = gen_cmp_lt(OR_LINK, (u_int)idx, BPF_B, (bpf_int32)val);
6040 return b;
6041
6042 case '>':
6043 b = gen_cmp_gt(OR_LINK, (u_int)idx, BPF_B, (bpf_int32)val);
6044 return b;
6045
6046 case '|':
6047 s = new_stmt(BPF_ALU|BPF_OR|BPF_K);
6048 break;
6049
6050 case '&':
6051 s = new_stmt(BPF_ALU|BPF_AND|BPF_K);
6052 break;
6053 }
6054 s->s.k = val;
6055 b = new_block(JMP(BPF_JEQ));
6056 b->stmts = s;
6057 gen_not(b);
6058
6059 return b;
6060 }
6061
6062 static u_char abroadcast[] = { 0x0 };
6063
6064 struct block *
6065 gen_broadcast(proto)
6066 int proto;
6067 {
6068 bpf_u_int32 hostmask;
6069 struct block *b0, *b1, *b2;
6070 static u_char ebroadcast[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
6071
6072 switch (proto) {
6073
6074 case Q_DEFAULT:
6075 case Q_LINK:
6076 switch (linktype) {
6077 case DLT_ARCNET:
6078 case DLT_ARCNET_LINUX:
6079 return gen_ahostop(abroadcast, Q_DST);
6080 case DLT_EN10MB:
6081 return gen_ehostop(ebroadcast, Q_DST);
6082 case DLT_FDDI:
6083 return gen_fhostop(ebroadcast, Q_DST);
6084 case DLT_IEEE802:
6085 return gen_thostop(ebroadcast, Q_DST);
6086 case DLT_IEEE802_11:
6087 case DLT_IEEE802_11_RADIO_AVS:
6088 case DLT_IEEE802_11_RADIO:
6089 case DLT_PPI:
6090 case DLT_PRISM_HEADER:
6091 return gen_wlanhostop(ebroadcast, Q_DST);
6092 case DLT_IP_OVER_FC:
6093 return gen_ipfchostop(ebroadcast, Q_DST);
6094 case DLT_SUNATM:
6095 if (is_lane) {
6096 /*
6097 * Check that the packet doesn't begin with an
6098 * LE Control marker. (We've already generated
6099 * a test for LANE.)
6100 */
6101 b1 = gen_cmp(OR_LINK, SUNATM_PKT_BEGIN_POS, BPF_H,
6102 0xFF00);
6103 gen_not(b1);
6104
6105 /*
6106 * Now check the MAC address.
6107 */
6108 b0 = gen_ehostop(ebroadcast, Q_DST);
6109 gen_and(b1, b0);
6110 return b0;
6111 }
6112 break;
6113 default:
6114 bpf_error("not a broadcast link");
6115 }
6116 break;
6117
6118 case Q_IP:
6119 b0 = gen_linktype(ETHERTYPE_IP);
6120 hostmask = ~netmask;
6121 b1 = gen_mcmp(OR_NET, 16, BPF_W, (bpf_int32)0, hostmask);
6122 b2 = gen_mcmp(OR_NET, 16, BPF_W,
6123 (bpf_int32)(~0 & hostmask), hostmask);
6124 gen_or(b1, b2);
6125 gen_and(b0, b2);
6126 return b2;
6127 }
6128 bpf_error("only link-layer/IP broadcast filters supported");
6129 /* NOTREACHED */
6130 return NULL;
6131 }
6132
6133 /*
6134 * Generate code to test the low-order bit of a MAC address (that's
6135 * the bottom bit of the *first* byte).
6136 */
6137 static struct block *
6138 gen_mac_multicast(offset)
6139 int offset;
6140 {
6141 register struct block *b0;
6142 register struct slist *s;
6143
6144 /* link[offset] & 1 != 0 */
6145 s = gen_load_a(OR_LINK, offset, BPF_B);
6146 b0 = new_block(JMP(BPF_JSET));
6147 b0->s.k = 1;
6148 b0->stmts = s;
6149 return b0;
6150 }
6151
6152 struct block *
6153 gen_multicast(proto)
6154 int proto;
6155 {
6156 register struct block *b0, *b1, *b2;
6157 register struct slist *s;
6158
6159 switch (proto) {
6160
6161 case Q_DEFAULT:
6162 case Q_LINK:
6163 switch (linktype) {
6164 case DLT_ARCNET:
6165 case DLT_ARCNET_LINUX:
6166 /* all ARCnet multicasts use the same address */
6167 return gen_ahostop(abroadcast, Q_DST);
6168 case DLT_EN10MB:
6169 /* ether[0] & 1 != 0 */
6170 return gen_mac_multicast(0);
6171 case DLT_FDDI:
6172 /*
6173 * XXX TEST THIS: MIGHT NOT PORT PROPERLY XXX
6174 *
6175 * XXX - was that referring to bit-order issues?
6176 */
6177 /* fddi[1] & 1 != 0 */
6178 return gen_mac_multicast(1);
6179 case DLT_IEEE802:
6180 /* tr[2] & 1 != 0 */
6181 return gen_mac_multicast(2);
6182 case DLT_IEEE802_11:
6183 case DLT_IEEE802_11_RADIO_AVS:
6184 case DLT_PPI:
6185 case DLT_IEEE802_11_RADIO:
6186 case DLT_PRISM_HEADER:
6187 /*
6188 * Oh, yuk.
6189 *
6190 * For control frames, there is no DA.
6191 *
6192 * For management frames, DA is at an
6193 * offset of 4 from the beginning of
6194 * the packet.
6195 *
6196 * For data frames, DA is at an offset
6197 * of 4 from the beginning of the packet
6198 * if To DS is clear and at an offset of
6199 * 16 from the beginning of the packet
6200 * if To DS is set.
6201 */
6202
6203 /*
6204 * Generate the tests to be done for data frames.
6205 *
6206 * First, check for To DS set, i.e. "link[1] & 0x01".
6207 */
6208 s = gen_load_a(OR_LINK, 1, BPF_B);
6209 b1 = new_block(JMP(BPF_JSET));
6210 b1->s.k = 0x01; /* To DS */
6211 b1->stmts = s;
6212
6213 /*
6214 * If To DS is set, the DA is at 16.
6215 */
6216 b0 = gen_mac_multicast(16);
6217 gen_and(b1, b0);
6218
6219 /*
6220 * Now, check for To DS not set, i.e. check
6221 * "!(link[1] & 0x01)".
6222 */
6223 s = gen_load_a(OR_LINK, 1, BPF_B);
6224 b2 = new_block(JMP(BPF_JSET));
6225 b2->s.k = 0x01; /* To DS */
6226 b2->stmts = s;
6227 gen_not(b2);
6228
6229 /*
6230 * If To DS is not set, the DA is at 4.
6231 */
6232 b1 = gen_mac_multicast(4);
6233 gen_and(b2, b1);
6234
6235 /*
6236 * Now OR together the last two checks. That gives
6237 * the complete set of checks for data frames.
6238 */
6239 gen_or(b1, b0);
6240
6241 /*
6242 * Now check for a data frame.
6243 * I.e, check "link[0] & 0x08".
6244 */
6245 s = gen_load_a(OR_LINK, 0, BPF_B);
6246 b1 = new_block(JMP(BPF_JSET));
6247 b1->s.k = 0x08;
6248 b1->stmts = s;
6249
6250 /*
6251 * AND that with the checks done for data frames.
6252 */
6253 gen_and(b1, b0);
6254
6255 /*
6256 * If the high-order bit of the type value is 0, this
6257 * is a management frame.
6258 * I.e, check "!(link[0] & 0x08)".
6259 */
6260 s = gen_load_a(OR_LINK, 0, BPF_B);
6261 b2 = new_block(JMP(BPF_JSET));
6262 b2->s.k = 0x08;
6263 b2->stmts = s;
6264 gen_not(b2);
6265
6266 /*
6267 * For management frames, the DA is at 4.
6268 */
6269 b1 = gen_mac_multicast(4);
6270 gen_and(b2, b1);
6271
6272 /*
6273 * OR that with the checks done for data frames.
6274 * That gives the checks done for management and
6275 * data frames.
6276 */
6277 gen_or(b1, b0);
6278
6279 /*
6280 * If the low-order bit of the type value is 1,
6281 * this is either a control frame or a frame
6282 * with a reserved type, and thus not a
6283 * frame with an SA.
6284 *
6285 * I.e., check "!(link[0] & 0x04)".
6286 */
6287 s = gen_load_a(OR_LINK, 0, BPF_B);
6288 b1 = new_block(JMP(BPF_JSET));
6289 b1->s.k = 0x04;
6290 b1->stmts = s;
6291 gen_not(b1);
6292
6293 /*
6294 * AND that with the checks for data and management
6295 * frames.
6296 */
6297 gen_and(b1, b0);
6298 return b0;
6299 case DLT_IP_OVER_FC:
6300 b0 = gen_mac_multicast(2);
6301 return b0;
6302 case DLT_SUNATM:
6303 if (is_lane) {
6304 /*
6305 * Check that the packet doesn't begin with an
6306 * LE Control marker. (We've already generated
6307 * a test for LANE.)
6308 */
6309 b1 = gen_cmp(OR_LINK, SUNATM_PKT_BEGIN_POS, BPF_H,
6310 0xFF00);
6311 gen_not(b1);
6312
6313 /* ether[off_mac] & 1 != 0 */
6314 b0 = gen_mac_multicast(off_mac);
6315 gen_and(b1, b0);
6316 return b0;
6317 }
6318 break;
6319 default:
6320 break;
6321 }
6322 /* Link not known to support multicasts */
6323 break;
6324
6325 case Q_IP:
6326 b0 = gen_linktype(ETHERTYPE_IP);
6327 b1 = gen_cmp_ge(OR_NET, 16, BPF_B, (bpf_int32)224);
6328 gen_and(b0, b1);
6329 return b1;
6330
6331 #ifdef INET6
6332 case Q_IPV6:
6333 b0 = gen_linktype(ETHERTYPE_IPV6);
6334 b1 = gen_cmp(OR_NET, 24, BPF_B, (bpf_int32)255);
6335 gen_and(b0, b1);
6336 return b1;
6337 #endif /* INET6 */
6338 }
6339 bpf_error("link-layer multicast filters supported only on ethernet/FDDI/token ring/ARCNET/802.11/ATM LANE/Fibre Channel");
6340 /* NOTREACHED */
6341 return NULL;
6342 }
6343
6344 /*
6345 * generate command for inbound/outbound. It's here so we can
6346 * make it link-type specific. 'dir' = 0 implies "inbound",
6347 * = 1 implies "outbound".
6348 */
6349 struct block *
6350 gen_inbound(dir)
6351 int dir;
6352 {
6353 register struct block *b0;
6354
6355 /*
6356 * Only some data link types support inbound/outbound qualifiers.
6357 */
6358 switch (linktype) {
6359 case DLT_SLIP:
6360 b0 = gen_relation(BPF_JEQ,
6361 gen_load(Q_LINK, gen_loadi(0), 1),
6362 gen_loadi(0),
6363 dir);
6364 break;
6365
6366 case DLT_LINUX_SLL:
6367 if (dir) {
6368 /*
6369 * Match packets sent by this machine.
6370 */
6371 b0 = gen_cmp(OR_LINK, 0, BPF_H, LINUX_SLL_OUTGOING);
6372 } else {
6373 /*
6374 * Match packets sent to this machine.
6375 * (No broadcast or multicast packets, or
6376 * packets sent to some other machine and
6377 * received promiscuously.)
6378 *
6379 * XXX - packets sent to other machines probably
6380 * shouldn't be matched, but what about broadcast
6381 * or multicast packets we received?
6382 */
6383 b0 = gen_cmp(OR_LINK, 0, BPF_H, LINUX_SLL_HOST);
6384 }
6385 break;
6386
6387 #ifdef HAVE_NET_PFVAR_H
6388 case DLT_PFLOG:
6389 b0 = gen_cmp(OR_LINK, offsetof(struct pfloghdr, dir), BPF_B,
6390 (bpf_int32)((dir == 0) ? PF_IN : PF_OUT));
6391 break;
6392 #endif
6393
6394 case DLT_PPP_PPPD:
6395 if (dir) {
6396 /* match outgoing packets */
6397 b0 = gen_cmp(OR_LINK, 0, BPF_B, PPP_PPPD_OUT);
6398 } else {
6399 /* match incoming packets */
6400 b0 = gen_cmp(OR_LINK, 0, BPF_B, PPP_PPPD_IN);
6401 }
6402 break;
6403
6404 case DLT_JUNIPER_MFR:
6405 case DLT_JUNIPER_MLFR:
6406 case DLT_JUNIPER_MLPPP:
6407 case DLT_JUNIPER_ATM1:
6408 case DLT_JUNIPER_ATM2:
6409 case DLT_JUNIPER_PPPOE:
6410 case DLT_JUNIPER_PPPOE_ATM:
6411 case DLT_JUNIPER_GGSN:
6412 case DLT_JUNIPER_ES:
6413 case DLT_JUNIPER_MONITOR:
6414 case DLT_JUNIPER_SERVICES:
6415 case DLT_JUNIPER_ETHER:
6416 case DLT_JUNIPER_PPP:
6417 case DLT_JUNIPER_FRELAY:
6418 case DLT_JUNIPER_CHDLC:
6419 case DLT_JUNIPER_VP:
6420 /* juniper flags (including direction) are stored
6421 * the byte after the 3-byte magic number */
6422 if (dir) {
6423 /* match outgoing packets */
6424 b0 = gen_mcmp(OR_LINK, 3, BPF_B, 0, 0x01);
6425 } else {
6426 /* match incoming packets */
6427 b0 = gen_mcmp(OR_LINK, 3, BPF_B, 1, 0x01);
6428 }
6429 break;
6430
6431 default:
6432 bpf_error("inbound/outbound not supported on linktype %d",
6433 linktype);
6434 b0 = NULL;
6435 /* NOTREACHED */
6436 }
6437 return (b0);
6438 }
6439
6440 #ifdef HAVE_NET_PFVAR_H
6441 /* PF firewall log matched interface */
6442 struct block *
6443 gen_pf_ifname(const char *ifname)
6444 {
6445 struct block *b0;
6446 u_int len, off;
6447
6448 if (linktype == DLT_PFLOG) {
6449 len = sizeof(((struct pfloghdr *)0)->ifname);
6450 off = offsetof(struct pfloghdr, ifname);
6451 } else {
6452 bpf_error("ifname not supported on linktype 0x%x", linktype);
6453 /* NOTREACHED */
6454 }
6455 if (strlen(ifname) >= len) {
6456 bpf_error("ifname interface names can only be %d characters",
6457 len-1);
6458 /* NOTREACHED */
6459 }
6460 b0 = gen_bcmp(OR_LINK, off, strlen(ifname), (const u_char *)ifname);
6461 return (b0);
6462 }
6463
6464 /* PF firewall log ruleset name */
6465 struct block *
6466 gen_pf_ruleset(char *ruleset)
6467 {
6468 struct block *b0;
6469
6470 if (linktype != DLT_PFLOG) {
6471 bpf_error("ruleset not supported on linktype 0x%x", linktype);
6472 /* NOTREACHED */
6473 }
6474 if (strlen(ruleset) >= sizeof(((struct pfloghdr *)0)->ruleset)) {
6475 bpf_error("ruleset names can only be %ld characters",
6476 (long)(sizeof(((struct pfloghdr *)0)->ruleset) - 1));
6477 /* NOTREACHED */
6478 }
6479 b0 = gen_bcmp(OR_LINK, offsetof(struct pfloghdr, ruleset),
6480 strlen(ruleset), (const u_char *)ruleset);
6481 return (b0);
6482 }
6483
6484 /* PF firewall log rule number */
6485 struct block *
6486 gen_pf_rnr(int rnr)
6487 {
6488 struct block *b0;
6489
6490 if (linktype == DLT_PFLOG) {
6491 b0 = gen_cmp(OR_LINK, offsetof(struct pfloghdr, rulenr), BPF_W,
6492 (bpf_int32)rnr);
6493 } else {
6494 bpf_error("rnr not supported on linktype 0x%x", linktype);
6495 /* NOTREACHED */
6496 }
6497
6498 return (b0);
6499 }
6500
6501 /* PF firewall log sub-rule number */
6502 struct block *
6503 gen_pf_srnr(int srnr)
6504 {
6505 struct block *b0;
6506
6507 if (linktype != DLT_PFLOG) {
6508 bpf_error("srnr not supported on linktype 0x%x", linktype);
6509 /* NOTREACHED */
6510 }
6511
6512 b0 = gen_cmp(OR_LINK, offsetof(struct pfloghdr, subrulenr), BPF_W,
6513 (bpf_int32)srnr);
6514 return (b0);
6515 }
6516
6517 /* PF firewall log reason code */
6518 struct block *
6519 gen_pf_reason(int reason)
6520 {
6521 struct block *b0;
6522
6523 if (linktype == DLT_PFLOG) {
6524 b0 = gen_cmp(OR_LINK, offsetof(struct pfloghdr, reason), BPF_B,
6525 (bpf_int32)reason);
6526 } else {
6527 bpf_error("reason not supported on linktype 0x%x", linktype);
6528 /* NOTREACHED */
6529 }
6530
6531 return (b0);
6532 }
6533
6534 /* PF firewall log action */
6535 struct block *
6536 gen_pf_action(int action)
6537 {
6538 struct block *b0;
6539
6540 if (linktype == DLT_PFLOG) {
6541 b0 = gen_cmp(OR_LINK, offsetof(struct pfloghdr, action), BPF_B,
6542 (bpf_int32)action);
6543 } else {
6544 bpf_error("action not supported on linktype 0x%x", linktype);
6545 /* NOTREACHED */
6546 }
6547
6548 return (b0);
6549 }
6550 #else /* !HAVE_NET_PFVAR_H */
6551 struct block *
6552 gen_pf_ifname(const char *ifname)
6553 {
6554 bpf_error("libpcap was compiled without pf support");
6555 /* NOTREACHED */
6556 return (NULL);
6557 }
6558
6559 struct block *
6560 gen_pf_ruleset(char *ruleset)
6561 {
6562 bpf_error("libpcap was compiled on a machine without pf support");
6563 /* NOTREACHED */
6564 return (NULL);
6565 }
6566
6567 struct block *
6568 gen_pf_rnr(int rnr)
6569 {
6570 bpf_error("libpcap was compiled on a machine without pf support");
6571 /* NOTREACHED */
6572 return (NULL);
6573 }
6574
6575 struct block *
6576 gen_pf_srnr(int srnr)
6577 {
6578 bpf_error("libpcap was compiled on a machine without pf support");
6579 /* NOTREACHED */
6580 return (NULL);
6581 }
6582
6583 struct block *
6584 gen_pf_reason(int reason)
6585 {
6586 bpf_error("libpcap was compiled on a machine without pf support");
6587 /* NOTREACHED */
6588 return (NULL);
6589 }
6590
6591 struct block *
6592 gen_pf_action(int action)
6593 {
6594 bpf_error("libpcap was compiled on a machine without pf support");
6595 /* NOTREACHED */
6596 return (NULL);
6597 }
6598 #endif /* HAVE_NET_PFVAR_H */
6599
6600 struct block *
6601 gen_acode(eaddr, q)
6602 register const u_char *eaddr;
6603 struct qual q;
6604 {
6605 if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) && q.proto == Q_LINK) {
6606 if (linktype == DLT_ARCNET || linktype == DLT_ARCNET_LINUX)
6607 return gen_ahostop(eaddr, (int)q.dir);
6608 }
6609 bpf_error("ARCnet address used in non-arc expression");
6610 /* NOTREACHED */
6611 return NULL;
6612 }
6613
6614 static struct block *
6615 gen_ahostop(eaddr, dir)
6616 register const u_char *eaddr;
6617 register int dir;
6618 {
6619 register struct block *b0, *b1;
6620
6621 switch (dir) {
6622 /* src comes first, different from Ethernet */
6623 case Q_SRC:
6624 return gen_bcmp(OR_LINK, 0, 1, eaddr);
6625
6626 case Q_DST:
6627 return gen_bcmp(OR_LINK, 1, 1, eaddr);
6628
6629 case Q_AND:
6630 b0 = gen_ahostop(eaddr, Q_SRC);
6631 b1 = gen_ahostop(eaddr, Q_DST);
6632 gen_and(b0, b1);
6633 return b1;
6634
6635 case Q_DEFAULT:
6636 case Q_OR:
6637 b0 = gen_ahostop(eaddr, Q_SRC);
6638 b1 = gen_ahostop(eaddr, Q_DST);
6639 gen_or(b0, b1);
6640 return b1;
6641 }
6642 abort();
6643 /* NOTREACHED */
6644 }
6645
6646 /*
6647 * support IEEE 802.1Q VLAN trunk over ethernet
6648 */
6649 struct block *
6650 gen_vlan(vlan_num)
6651 int vlan_num;
6652 {
6653 struct block *b0, *b1;
6654
6655 /* can't check for VLAN-encapsulated packets inside MPLS */
6656 if (label_stack_depth > 0)
6657 bpf_error("no VLAN match after MPLS");
6658
6659 /*
6660 * Change the offsets to point to the type and data fields within
6661 * the VLAN packet. Just increment the offsets, so that we
6662 * can support a hierarchy, e.g. "vlan 300 && vlan 200" to
6663 * capture VLAN 200 encapsulated within VLAN 100.
6664 *
6665 * XXX - this is a bit of a kludge. If we were to split the
6666 * compiler into a parser that parses an expression and
6667 * generates an expression tree, and a code generator that
6668 * takes an expression tree (which could come from our
6669 * parser or from some other parser) and generates BPF code,
6670 * we could perhaps make the offsets parameters of routines
6671 * and, in the handler for an "AND" node, pass to subnodes
6672 * other than the VLAN node the adjusted offsets.
6673 *
6674 * This would mean that "vlan" would, instead of changing the
6675 * behavior of *all* tests after it, change only the behavior
6676 * of tests ANDed with it. That would change the documented
6677 * semantics of "vlan", which might break some expressions.
6678 * However, it would mean that "(vlan and ip) or ip" would check
6679 * both for VLAN-encapsulated IP and IP-over-Ethernet, rather than
6680 * checking only for VLAN-encapsulated IP, so that could still
6681 * be considered worth doing; it wouldn't break expressions
6682 * that are of the form "vlan and ..." or "vlan N and ...",
6683 * which I suspect are the most common expressions involving
6684 * "vlan". "vlan or ..." doesn't necessarily do what the user
6685 * would really want, now, as all the "or ..." tests would
6686 * be done assuming a VLAN, even though the "or" could be viewed
6687 * as meaning "or, if this isn't a VLAN packet...".
6688 */
6689 orig_linktype = off_linktype; /* save original values */
6690 orig_nl = off_nl;
6691
6692 switch (linktype) {
6693
6694 case DLT_EN10MB:
6695 off_linktype += 4;
6696 off_nl_nosnap += 4;
6697 off_nl += 4;
6698 break;
6699
6700 default:
6701 bpf_error("no VLAN support for data link type %d",
6702 linktype);
6703 /*NOTREACHED*/
6704 }
6705
6706 /* check for VLAN */
6707 b0 = gen_cmp(OR_LINK, orig_linktype, BPF_H, (bpf_int32)ETHERTYPE_8021Q);
6708
6709 /* If a specific VLAN is requested, check VLAN id */
6710 if (vlan_num >= 0) {
6711 b1 = gen_mcmp(OR_LINK, orig_nl, BPF_H, (bpf_int32)vlan_num,
6712 0x0fff);
6713 gen_and(b0, b1);
6714 b0 = b1;
6715 }
6716
6717 return (b0);
6718 }
6719
6720 /*
6721 * support for MPLS
6722 */
6723 struct block *
6724 gen_mpls(label_num)
6725 int label_num;
6726 {
6727 struct block *b0,*b1;
6728
6729 /*
6730 * Change the offsets to point to the type and data fields within
6731 * the MPLS packet. Just increment the offsets, so that we
6732 * can support a hierarchy, e.g. "mpls 100000 && mpls 1024" to
6733 * capture packets with an outer label of 100000 and an inner
6734 * label of 1024.
6735 *
6736 * XXX - this is a bit of a kludge. See comments in gen_vlan().
6737 */
6738 orig_nl = off_nl;
6739
6740 if (label_stack_depth > 0) {
6741 /* just match the bottom-of-stack bit clear */
6742 b0 = gen_mcmp(OR_LINK, orig_nl-2, BPF_B, 0, 0x01);
6743 } else {
6744 /*
6745 * Indicate that we're checking MPLS-encapsulated headers,
6746 * to make sure higher level code generators don't try to
6747 * match against IP-related protocols such as Q_ARP, Q_RARP
6748 * etc.
6749 */
6750 switch (linktype) {
6751
6752 case DLT_C_HDLC: /* fall through */
6753 case DLT_EN10MB:
6754 b0 = gen_linktype(ETHERTYPE_MPLS);
6755 break;
6756
6757 case DLT_PPP:
6758 b0 = gen_linktype(PPP_MPLS_UCAST);
6759 break;
6760
6761 /* FIXME add other DLT_s ...
6762 * for Frame-Relay/and ATM this may get messy due to SNAP headers
6763 * leave it for now */
6764
6765 default:
6766 bpf_error("no MPLS support for data link type %d",
6767 linktype);
6768 b0 = NULL;
6769 /*NOTREACHED*/
6770 break;
6771 }
6772 }
6773
6774 /* If a specific MPLS label is requested, check it */
6775 if (label_num >= 0) {
6776 label_num = label_num << 12; /* label is shifted 12 bits on the wire */
6777 b1 = gen_mcmp(OR_LINK, orig_nl, BPF_W, (bpf_int32)label_num,
6778 0xfffff000); /* only compare the first 20 bits */
6779 gen_and(b0, b1);
6780 b0 = b1;
6781 }
6782
6783 off_nl_nosnap += 4;
6784 off_nl += 4;
6785 label_stack_depth++;
6786 return (b0);
6787 }
6788
6789 /*
6790 * Support PPPOE discovery and session.
6791 */
6792 struct block *
6793 gen_pppoed()
6794 {
6795 /* check for PPPoE discovery */
6796 return gen_linktype((bpf_int32)ETHERTYPE_PPPOED);
6797 }
6798
6799 struct block *
6800 gen_pppoes()
6801 {
6802 struct block *b0;
6803
6804 /*
6805 * Test against the PPPoE session link-layer type.
6806 */
6807 b0 = gen_linktype((bpf_int32)ETHERTYPE_PPPOES);
6808
6809 /*
6810 * Change the offsets to point to the type and data fields within
6811 * the PPP packet.
6812 *
6813 * XXX - this is a bit of a kludge. If we were to split the
6814 * compiler into a parser that parses an expression and
6815 * generates an expression tree, and a code generator that
6816 * takes an expression tree (which could come from our
6817 * parser or from some other parser) and generates BPF code,
6818 * we could perhaps make the offsets parameters of routines
6819 * and, in the handler for an "AND" node, pass to subnodes
6820 * other than the PPPoE node the adjusted offsets.
6821 *
6822 * This would mean that "pppoes" would, instead of changing the
6823 * behavior of *all* tests after it, change only the behavior
6824 * of tests ANDed with it. That would change the documented
6825 * semantics of "pppoes", which might break some expressions.
6826 * However, it would mean that "(pppoes and ip) or ip" would check
6827 * both for VLAN-encapsulated IP and IP-over-Ethernet, rather than
6828 * checking only for VLAN-encapsulated IP, so that could still
6829 * be considered worth doing; it wouldn't break expressions
6830 * that are of the form "pppoes and ..." which I suspect are the
6831 * most common expressions involving "pppoes". "pppoes or ..."
6832 * doesn't necessarily do what the user would really want, now,
6833 * as all the "or ..." tests would be done assuming PPPoE, even
6834 * though the "or" could be viewed as meaning "or, if this isn't
6835 * a PPPoE packet...".
6836 */
6837 orig_linktype = off_linktype; /* save original values */
6838 orig_nl = off_nl;
6839
6840 /*
6841 * The "network-layer" protocol is PPPoE, which has a 6-byte
6842 * PPPoE header, followed by PPP payload, so we set the
6843 * offsets to the network layer offset plus 6 bytes for
6844 * the PPPoE header plus the values appropriate for PPP when
6845 * encapsulated in Ethernet (which means there's no HDLC
6846 * encapsulation).
6847 */
6848 off_linktype = orig_nl + 6;
6849 off_nl = orig_nl + 6 + 2;
6850 off_nl_nosnap = orig_nl + 6 + 2;
6851
6852 /*
6853 * Set the link-layer type to PPP, as all subsequent tests will
6854 * be on the encapsulated PPP header.
6855 */
6856 linktype = DLT_PPP;
6857
6858 return b0;
6859 }
6860
6861 struct block *
6862 gen_atmfield_code(atmfield, jvalue, jtype, reverse)
6863 int atmfield;
6864 bpf_int32 jvalue;
6865 bpf_u_int32 jtype;
6866 int reverse;
6867 {
6868 struct block *b0;
6869
6870 switch (atmfield) {
6871
6872 case A_VPI:
6873 if (!is_atm)
6874 bpf_error("'vpi' supported only on raw ATM");
6875 if (off_vpi == (u_int)-1)
6876 abort();
6877 b0 = gen_ncmp(OR_LINK, off_vpi, BPF_B, 0xffffffff, jtype,
6878 reverse, jvalue);
6879 break;
6880
6881 case A_VCI:
6882 if (!is_atm)
6883 bpf_error("'vci' supported only on raw ATM");
6884 if (off_vci == (u_int)-1)
6885 abort();
6886 b0 = gen_ncmp(OR_LINK, off_vci, BPF_H, 0xffffffff, jtype,
6887 reverse, jvalue);
6888 break;
6889
6890 case A_PROTOTYPE:
6891 if (off_proto == (u_int)-1)
6892 abort(); /* XXX - this isn't on FreeBSD */
6893 b0 = gen_ncmp(OR_LINK, off_proto, BPF_B, 0x0f, jtype,
6894 reverse, jvalue);
6895 break;
6896
6897 case A_MSGTYPE:
6898 if (off_payload == (u_int)-1)
6899 abort();
6900 b0 = gen_ncmp(OR_LINK, off_payload + MSG_TYPE_POS, BPF_B,
6901 0xffffffff, jtype, reverse, jvalue);
6902 break;
6903
6904 case A_CALLREFTYPE:
6905 if (!is_atm)
6906 bpf_error("'callref' supported only on raw ATM");
6907 if (off_proto == (u_int)-1)
6908 abort();
6909 b0 = gen_ncmp(OR_LINK, off_proto, BPF_B, 0xffffffff,
6910 jtype, reverse, jvalue);
6911 break;
6912
6913 default:
6914 abort();
6915 }
6916 return b0;
6917 }
6918
6919 struct block *
6920 gen_atmtype_abbrev(type)
6921 int type;
6922 {
6923 struct block *b0, *b1;
6924
6925 switch (type) {
6926
6927 case A_METAC:
6928 /* Get all packets in Meta signalling Circuit */
6929 if (!is_atm)
6930 bpf_error("'metac' supported only on raw ATM");
6931 b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0);
6932 b1 = gen_atmfield_code(A_VCI, 1, BPF_JEQ, 0);
6933 gen_and(b0, b1);
6934 break;
6935
6936 case A_BCC:
6937 /* Get all packets in Broadcast Circuit*/
6938 if (!is_atm)
6939 bpf_error("'bcc' supported only on raw ATM");
6940 b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0);
6941 b1 = gen_atmfield_code(A_VCI, 2, BPF_JEQ, 0);
6942 gen_and(b0, b1);
6943 break;
6944
6945 case A_OAMF4SC:
6946 /* Get all cells in Segment OAM F4 circuit*/
6947 if (!is_atm)
6948 bpf_error("'oam4sc' supported only on raw ATM");
6949 b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0);
6950 b1 = gen_atmfield_code(A_VCI, 3, BPF_JEQ, 0);
6951 gen_and(b0, b1);
6952 break;
6953
6954 case A_OAMF4EC:
6955 /* Get all cells in End-to-End OAM F4 Circuit*/
6956 if (!is_atm)
6957 bpf_error("'oam4ec' supported only on raw ATM");
6958 b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0);
6959 b1 = gen_atmfield_code(A_VCI, 4, BPF_JEQ, 0);
6960 gen_and(b0, b1);
6961 break;
6962
6963 case A_SC:
6964 /* Get all packets in connection Signalling Circuit */
6965 if (!is_atm)
6966 bpf_error("'sc' supported only on raw ATM");
6967 b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0);
6968 b1 = gen_atmfield_code(A_VCI, 5, BPF_JEQ, 0);
6969 gen_and(b0, b1);
6970 break;
6971
6972 case A_ILMIC:
6973 /* Get all packets in ILMI Circuit */
6974 if (!is_atm)
6975 bpf_error("'ilmic' supported only on raw ATM");
6976 b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0);
6977 b1 = gen_atmfield_code(A_VCI, 16, BPF_JEQ, 0);
6978 gen_and(b0, b1);
6979 break;
6980
6981 case A_LANE:
6982 /* Get all LANE packets */
6983 if (!is_atm)
6984 bpf_error("'lane' supported only on raw ATM");
6985 b1 = gen_atmfield_code(A_PROTOTYPE, PT_LANE, BPF_JEQ, 0);
6986
6987 /*
6988 * Arrange that all subsequent tests assume LANE
6989 * rather than LLC-encapsulated packets, and set
6990 * the offsets appropriately for LANE-encapsulated
6991 * Ethernet.
6992 *
6993 * "off_mac" is the offset of the Ethernet header,
6994 * which is 2 bytes past the ATM pseudo-header
6995 * (skipping the pseudo-header and 2-byte LE Client
6996 * field). The other offsets are Ethernet offsets
6997 * relative to "off_mac".
6998 */
6999 is_lane = 1;
7000 off_mac = off_payload + 2; /* MAC header */
7001 off_linktype = off_mac + 12;
7002 off_nl = off_mac + 14; /* Ethernet II */
7003 off_nl_nosnap = off_mac + 17; /* 802.3+802.2 */
7004 break;
7005
7006 case A_LLC:
7007 /* Get all LLC-encapsulated packets */
7008 if (!is_atm)
7009 bpf_error("'llc' supported only on raw ATM");
7010 b1 = gen_atmfield_code(A_PROTOTYPE, PT_LLC, BPF_JEQ, 0);
7011 is_lane = 0;
7012 break;
7013
7014 default:
7015 abort();
7016 }
7017 return b1;
7018 }
7019
7020 /*
7021 * Filtering for MTP2 messages based on li value
7022 * FISU, length is null
7023 * LSSU, length is 1 or 2
7024 * MSU, length is 3 or more
7025 */
7026 struct block *
7027 gen_mtp2type_abbrev(type)
7028 int type;
7029 {
7030 struct block *b0, *b1;
7031
7032 switch (type) {
7033
7034 case M_FISU:
7035 if ( (linktype != DLT_MTP2) &&
7036 (linktype != DLT_MTP2_WITH_PHDR) )
7037 bpf_error("'fisu' supported only on MTP2");
7038 /* gen_ncmp(offrel, offset, size, mask, jtype, reverse, value) */
7039 b0 = gen_ncmp(OR_PACKET, off_li, BPF_B, 0x3f, BPF_JEQ, 0, 0);
7040 break;
7041
7042 case M_LSSU:
7043 if ( (linktype != DLT_MTP2) &&
7044 (linktype != DLT_MTP2_WITH_PHDR) )
7045 bpf_error("'lssu' supported only on MTP2");
7046 b0 = gen_ncmp(OR_PACKET, off_li, BPF_B, 0x3f, BPF_JGT, 1, 2);
7047 b1 = gen_ncmp(OR_PACKET, off_li, BPF_B, 0x3f, BPF_JGT, 0, 0);
7048 gen_and(b1, b0);
7049 break;
7050
7051 case M_MSU:
7052 if ( (linktype != DLT_MTP2) &&
7053 (linktype != DLT_MTP2_WITH_PHDR) )
7054 bpf_error("'msu' supported only on MTP2");
7055 b0 = gen_ncmp(OR_PACKET, off_li, BPF_B, 0x3f, BPF_JGT, 0, 2);
7056 break;
7057
7058 default:
7059 abort();
7060 }
7061 return b0;
7062 }
7063
7064 struct block *
7065 gen_mtp3field_code(mtp3field, jvalue, jtype, reverse)
7066 int mtp3field;
7067 bpf_u_int32 jvalue;
7068 bpf_u_int32 jtype;
7069 int reverse;
7070 {
7071 struct block *b0;
7072 bpf_u_int32 val1 , val2 , val3;
7073
7074 switch (mtp3field) {
7075
7076 case M_SIO:
7077 if (off_sio == (u_int)-1)
7078 bpf_error("'sio' supported only on SS7");
7079 /* sio coded on 1 byte so max value 255 */
7080 if(jvalue > 255)
7081 bpf_error("sio value %u too big; max value = 255",
7082 jvalue);
7083 b0 = gen_ncmp(OR_PACKET, off_sio, BPF_B, 0xffffffff,
7084 (u_int)jtype, reverse, (u_int)jvalue);
7085 break;
7086
7087 case M_OPC:
7088 if (off_opc == (u_int)-1)
7089 bpf_error("'opc' supported only on SS7");
7090 /* opc coded on 14 bits so max value 16383 */
7091 if (jvalue > 16383)
7092 bpf_error("opc value %u too big; max value = 16383",
7093 jvalue);
7094 /* the following instructions are made to convert jvalue
7095 * to the form used to write opc in an ss7 message*/
7096 val1 = jvalue & 0x00003c00;
7097 val1 = val1 >>10;
7098 val2 = jvalue & 0x000003fc;
7099 val2 = val2 <<6;
7100 val3 = jvalue & 0x00000003;
7101 val3 = val3 <<22;
7102 jvalue = val1 + val2 + val3;
7103 b0 = gen_ncmp(OR_PACKET, off_opc, BPF_W, 0x00c0ff0f,
7104 (u_int)jtype, reverse, (u_int)jvalue);
7105 break;
7106
7107 case M_DPC:
7108 if (off_dpc == (u_int)-1)
7109 bpf_error("'dpc' supported only on SS7");
7110 /* dpc coded on 14 bits so max value 16383 */
7111 if (jvalue > 16383)
7112 bpf_error("dpc value %u too big; max value = 16383",
7113 jvalue);
7114 /* the following instructions are made to convert jvalue
7115 * to the forme used to write dpc in an ss7 message*/
7116 val1 = jvalue & 0x000000ff;
7117 val1 = val1 << 24;
7118 val2 = jvalue & 0x00003f00;
7119 val2 = val2 << 8;
7120 jvalue = val1 + val2;
7121 b0 = gen_ncmp(OR_PACKET, off_dpc, BPF_W, 0xff3f0000,
7122 (u_int)jtype, reverse, (u_int)jvalue);
7123 break;
7124
7125 case M_SLS:
7126 if (off_sls == (u_int)-1)
7127 bpf_error("'sls' supported only on SS7");
7128 /* sls coded on 4 bits so max value 15 */
7129 if (jvalue > 15)
7130 bpf_error("sls value %u too big; max value = 15",
7131 jvalue);
7132 /* the following instruction is made to convert jvalue
7133 * to the forme used to write sls in an ss7 message*/
7134 jvalue = jvalue << 4;
7135 b0 = gen_ncmp(OR_PACKET, off_sls, BPF_B, 0xf0,
7136 (u_int)jtype,reverse, (u_int)jvalue);
7137 break;
7138
7139 default:
7140 abort();
7141 }
7142 return b0;
7143 }
7144
7145 static struct block *
7146 gen_msg_abbrev(type)
7147 int type;
7148 {
7149 struct block *b1;
7150
7151 /*
7152 * Q.2931 signalling protocol messages for handling virtual circuits
7153 * establishment and teardown
7154 */
7155 switch (type) {
7156
7157 case A_SETUP:
7158 b1 = gen_atmfield_code(A_MSGTYPE, SETUP, BPF_JEQ, 0);
7159 break;
7160
7161 case A_CALLPROCEED:
7162 b1 = gen_atmfield_code(A_MSGTYPE, CALL_PROCEED, BPF_JEQ, 0);
7163 break;
7164
7165 case A_CONNECT:
7166 b1 = gen_atmfield_code(A_MSGTYPE, CONNECT, BPF_JEQ, 0);
7167 break;
7168
7169 case A_CONNECTACK:
7170 b1 = gen_atmfield_code(A_MSGTYPE, CONNECT_ACK, BPF_JEQ, 0);
7171 break;
7172
7173 case A_RELEASE:
7174 b1 = gen_atmfield_code(A_MSGTYPE, RELEASE, BPF_JEQ, 0);
7175 break;
7176
7177 case A_RELEASE_DONE:
7178 b1 = gen_atmfield_code(A_MSGTYPE, RELEASE_DONE, BPF_JEQ, 0);
7179 break;
7180
7181 default:
7182 abort();
7183 }
7184 return b1;
7185 }
7186
7187 struct block *
7188 gen_atmmulti_abbrev(type)
7189 int type;
7190 {
7191 struct block *b0, *b1;
7192
7193 switch (type) {
7194
7195 case A_OAM:
7196 if (!is_atm)
7197 bpf_error("'oam' supported only on raw ATM");
7198 b1 = gen_atmmulti_abbrev(A_OAMF4);
7199 break;
7200
7201 case A_OAMF4:
7202 if (!is_atm)
7203 bpf_error("'oamf4' supported only on raw ATM");
7204 /* OAM F4 type */
7205 b0 = gen_atmfield_code(A_VCI, 3, BPF_JEQ, 0);
7206 b1 = gen_atmfield_code(A_VCI, 4, BPF_JEQ, 0);
7207 gen_or(b0, b1);
7208 b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0);
7209 gen_and(b0, b1);
7210 break;
7211
7212 case A_CONNECTMSG:
7213 /*
7214 * Get Q.2931 signalling messages for switched
7215 * virtual connection
7216 */
7217 if (!is_atm)
7218 bpf_error("'connectmsg' supported only on raw ATM");
7219 b0 = gen_msg_abbrev(A_SETUP);
7220 b1 = gen_msg_abbrev(A_CALLPROCEED);
7221 gen_or(b0, b1);
7222 b0 = gen_msg_abbrev(A_CONNECT);
7223 gen_or(b0, b1);
7224 b0 = gen_msg_abbrev(A_CONNECTACK);
7225 gen_or(b0, b1);
7226 b0 = gen_msg_abbrev(A_RELEASE);
7227 gen_or(b0, b1);
7228 b0 = gen_msg_abbrev(A_RELEASE_DONE);
7229 gen_or(b0, b1);
7230 b0 = gen_atmtype_abbrev(A_SC);
7231 gen_and(b0, b1);
7232 break;
7233
7234 case A_METACONNECT:
7235 if (!is_atm)
7236 bpf_error("'metaconnect' supported only on raw ATM");
7237 b0 = gen_msg_abbrev(A_SETUP);
7238 b1 = gen_msg_abbrev(A_CALLPROCEED);
7239 gen_or(b0, b1);
7240 b0 = gen_msg_abbrev(A_CONNECT);
7241 gen_or(b0, b1);
7242 b0 = gen_msg_abbrev(A_RELEASE);
7243 gen_or(b0, b1);
7244 b0 = gen_msg_abbrev(A_RELEASE_DONE);
7245 gen_or(b0, b1);
7246 b0 = gen_atmtype_abbrev(A_METAC);
7247 gen_and(b0, b1);
7248 break;
7249
7250 default:
7251 abort();
7252 }
7253 return b1;
7254 }
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