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[dragonfly.git] / contrib / libpcap-0.9 / gencode.c
blobeb260b93edbb881cd358212734688e08bb294cbc
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 #ifndef lint
23 static const char rcsid[] _U_ =
24 "@(#) $Header: /tcpdump/master/libpcap/gencode.c,v 1.221.2.53 2007/09/12 19:17:24 guy Exp $ (LBL)";
25 #endif
26
27 #ifdef HAVE_CONFIG_H
28 #include "config.h"
29 #endif
30
31 #ifdef WIN32
32 #include <pcap-stdinc.h>
33 #else /* WIN32 */
34 #include <sys/types.h>
35 #include <sys/socket.h>
36 #endif /* WIN32 */
37
38 /*
39 * XXX - why was this included even on UNIX?
40 */
41 #ifdef __MINGW32__
42 #include "IP6_misc.h"
43 #endif
44
45 #ifndef WIN32
46
47 #ifdef __NetBSD__
48 #include <sys/param.h>
49 #endif
50
51 #include <netinet/in.h>
52
53 #endif /* WIN32 */
54
55 #include <stdlib.h>
56 #include <string.h>
57 #include <memory.h>
58 #include <setjmp.h>
59 #include <stdarg.h>
60
61 #ifdef MSDOS
62 #include "pcap-dos.h"
63 #endif
64
65 #include "pcap-int.h"
66
67 #include "ethertype.h"
68 #include "nlpid.h"
69 #include "llc.h"
70 #include "gencode.h"
71 #include "atmuni31.h"
72 #include "sunatmpos.h"
73 #include "ppp.h"
74 #include "sll.h"
75 #include "arcnet.h"
76 #ifdef HAVE_NET_PFVAR_H
77 #include <sys/socket.h>
78 #include <net/if.h>
79 #include <net/if_var.h>
80 #include <net/pf/pfvar.h>
81 #include <net/pf/if_pflog.h>
82 #endif
83 #ifndef offsetof
84 #define offsetof(s, e) ((size_t)&((s *)0)->e)
85 #endif
86 #ifdef INET6
87 #ifndef WIN32
88 #include <netdb.h> /* for "struct addrinfo" */
89 #endif /* WIN32 */
90 #endif /*INET6*/
91 #include <pcap-namedb.h>
92
93 #include <netproto/802_11/ieee80211.h>
94 #include <netproto/802_11/ieee80211_radiotap.h>
95
96 #define ETHERMTU 1500
97
98 #ifndef IPPROTO_SCTP
99 #define IPPROTO_SCTP 132
100 #endif
101
102 #ifdef HAVE_OS_PROTO_H
103 #include "os-proto.h"
104 #endif
105
106 #define JMP(c) ((c)|BPF_JMP|BPF_K)
107
108 /* Locals */
109 static jmp_buf top_ctx;
110 static pcap_t *bpf_pcap;
111
112 #ifdef WIN32
113 /* Hack for updating VLAN, MPLS, and PPPoE offsets. */
114 static u_int orig_linktype = (u_int)-1, orig_nl = (u_int)-1, label_stack_depth = (u_int)-1;
115 #else
116 static u_int orig_linktype = -1U, orig_nl = -1U, label_stack_depth = -1U;
117 #endif
118
119 /* XXX */
120 #ifdef PCAP_FDDIPAD
121 static int pcap_fddipad;
122 #endif
123
124 /* VARARGS */
125 void
126 bpf_error(const char *fmt, ...)
127 {
128 va_list ap;
129
130 va_start(ap, fmt);
131 if (bpf_pcap != NULL)
132 (void)vsnprintf(pcap_geterr(bpf_pcap), PCAP_ERRBUF_SIZE,
133 fmt, ap);
134 va_end(ap);
135 longjmp(top_ctx, 1);
136 /* NOTREACHED */
137 }
138
139 static void init_linktype(pcap_t *);
140
141 static int alloc_reg(void);
142 static void free_reg(int);
143
144 static struct block *root;
145
146 /*
147 * Value passed to gen_load_a() to indicate what the offset argument
148 * is relative to.
149 */
150 enum e_offrel {
151 OR_PACKET, /* relative to the beginning of the packet */
152 OR_LINK, /* relative to the link-layer header */
153 OR_NET, /* relative to the network-layer header */
154 OR_NET_NOSNAP, /* relative to the network-layer header, with no SNAP header at the link layer */
155 OR_TRAN_IPV4, /* relative to the transport-layer header, with IPv4 network layer */
156 OR_TRAN_IPV6 /* relative to the transport-layer header, with IPv6 network layer */
157 };
158
159 /*
160 * We divy out chunks of memory rather than call malloc each time so
161 * we don't have to worry about leaking memory. It's probably
162 * not a big deal if all this memory was wasted but if this ever
163 * goes into a library that would probably not be a good idea.
164 *
165 * XXX - this *is* in a library....
166 */
167 #define NCHUNKS 16
168 #define CHUNK0SIZE 1024
169 struct chunk {
170 u_int n_left;
171 void *m;
172 };
173
174 static struct chunk chunks[NCHUNKS];
175 static int cur_chunk;
176
177 static void *newchunk(u_int);
178 static void freechunks(void);
179 static inline struct block *new_block(int);
180 static inline struct slist *new_stmt(int);
181 static struct block *gen_retblk(int);
182 static inline void syntax(void);
183
184 static void backpatch(struct block *, struct block *);
185 static void merge(struct block *, struct block *);
186 static struct block *gen_cmp(enum e_offrel, u_int, u_int, bpf_int32);
187 static struct block *gen_cmp_gt(enum e_offrel, u_int, u_int, bpf_int32);
188 static struct block *gen_cmp_ge(enum e_offrel, u_int, u_int, bpf_int32);
189 static struct block *gen_cmp_lt(enum e_offrel, u_int, u_int, bpf_int32);
190 static struct block *gen_cmp_le(enum e_offrel, u_int, u_int, bpf_int32);
191 static struct block *gen_mcmp(enum e_offrel, u_int, u_int, bpf_int32,
192 bpf_u_int32);
193 static struct block *gen_bcmp(enum e_offrel, u_int, u_int, const u_char *);
194 static struct block *gen_ncmp(enum e_offrel, bpf_u_int32, bpf_u_int32,
195 bpf_u_int32, bpf_u_int32, int, bpf_int32);
196 static struct slist *gen_load_llrel(u_int, u_int);
197 static struct slist *gen_load_a(enum e_offrel, u_int, u_int);
198 static struct slist *gen_loadx_iphdrlen(void);
199 static struct block *gen_uncond(int);
200 static inline struct block *gen_true(void);
201 static inline struct block *gen_false(void);
202 static struct block *gen_ether_linktype(int);
203 static struct block *gen_linux_sll_linktype(int);
204 static void insert_radiotap_load_llprefixlen(struct block *);
205 static void insert_ppi_load_llprefixlen(struct block *);
206 static void insert_load_llprefixlen(struct block *);
207 static struct slist *gen_llprefixlen(void);
208 static struct block *gen_linktype(int);
209 static struct block *gen_snap(bpf_u_int32, bpf_u_int32, u_int);
210 static struct block *gen_llc_linktype(int);
211 static struct block *gen_hostop(bpf_u_int32, bpf_u_int32, int, int, u_int, u_int);
212 #ifdef INET6
213 static struct block *gen_hostop6(struct in6_addr *, struct in6_addr *, int, int, u_int, u_int);
214 #endif
215 static struct block *gen_ahostop(const u_char *, int);
216 static struct block *gen_ehostop(const u_char *, int);
217 static struct block *gen_fhostop(const u_char *, int);
218 static struct block *gen_thostop(const u_char *, int);
219 static struct block *gen_wlanhostop(const u_char *, int);
220 static struct block *gen_ipfchostop(const u_char *, int);
221 static struct block *gen_dnhostop(bpf_u_int32, int);
222 static struct block *gen_mpls_linktype(int);
223 static struct block *gen_host(bpf_u_int32, bpf_u_int32, int, int, int);
224 #ifdef INET6
225 static struct block *gen_host6(struct in6_addr *, struct in6_addr *, int, int, int);
226 #endif
227 #ifndef INET6
228 static struct block *gen_gateway(const u_char *, bpf_u_int32 **, int, int);
229 #endif
230 static struct block *gen_ipfrag(void);
231 static struct block *gen_portatom(int, bpf_int32);
232 static struct block *gen_portrangeatom(int, bpf_int32, bpf_int32);
233 #ifdef INET6
234 static struct block *gen_portatom6(int, bpf_int32);
235 static struct block *gen_portrangeatom6(int, bpf_int32, bpf_int32);
236 #endif
237 struct block *gen_portop(int, int, int);
238 static struct block *gen_port(int, int, int);
239 struct block *gen_portrangeop(int, int, int, int);
240 static struct block *gen_portrange(int, int, int, int);
241 #ifdef INET6
242 struct block *gen_portop6(int, int, int);
243 static struct block *gen_port6(int, int, int);
244 struct block *gen_portrangeop6(int, int, int, int);
245 static struct block *gen_portrange6(int, int, int, int);
246 #endif
247 static int lookup_proto(const char *, int);
248 static struct block *gen_protochain(int, int, int);
249 static struct block *gen_proto(int, int, int);
250 static struct slist *xfer_to_x(struct arth *);
251 static struct slist *xfer_to_a(struct arth *);
252 static struct block *gen_mac_multicast(int);
253 static struct block *gen_len(int, int);
254
255 static struct block *gen_ppi_dlt_check(void);
256 static struct block *gen_msg_abbrev(int type);
257
258 static void *
259 newchunk(n)
260 u_int n;
261 {
262 struct chunk *cp;
263 int k;
264 size_t size;
265
266 #ifndef __NetBSD__
267 /* XXX Round up to nearest long. */
268 n = (n + sizeof(long) - 1) & ~(sizeof(long) - 1);
269 #else
270 /* XXX Round up to structure boundary. */
271 n = ALIGN(n);
272 #endif
273
274 cp = &chunks[cur_chunk];
275 if (n > cp->n_left) {
276 ++cp, k = ++cur_chunk;
277 if (k >= NCHUNKS)
278 bpf_error("out of memory");
279 size = CHUNK0SIZE << k;
280 cp->m = (void *)malloc(size);
281 if (cp->m == NULL)
282 bpf_error("out of memory");
283 memset((char *)cp->m, 0, size);
284 cp->n_left = size;
285 if (n > size)
286 bpf_error("out of memory");
287 }
288 cp->n_left -= n;
289 return (void *)((char *)cp->m + cp->n_left);
290 }
291
292 static void
293 freechunks()
294 {
295 int i;
296
297 cur_chunk = 0;
298 for (i = 0; i < NCHUNKS; ++i)
299 if (chunks[i].m != NULL) {
300 free(chunks[i].m);
301 chunks[i].m = NULL;
302 }
303 }
304
305 /*
306 * A strdup whose allocations are freed after code generation is over.
307 */
308 char *
309 sdup(s)
310 register const char *s;
311 {
312 int n = strlen(s) + 1;
313 char *cp = newchunk(n);
314
315 strlcpy(cp, s, n);
316 return (cp);
317 }
318
319 static inline struct block *
320 new_block(code)
321 int code;
322 {
323 struct block *p;
324
325 p = (struct block *)newchunk(sizeof(*p));
326 p->s.code = code;
327 p->head = p;
328
329 return p;
330 }
331
332 static inline struct slist *
333 new_stmt(code)
334 int code;
335 {
336 struct slist *p;
337
338 p = (struct slist *)newchunk(sizeof(*p));
339 p->s.code = code;
340
341 return p;
342 }
343
344 static struct block *
345 gen_retblk(v)
346 int v;
347 {
348 struct block *b = new_block(BPF_RET|BPF_K);
349
350 b->s.k = v;
351 return b;
352 }
353
354 static inline void
355 syntax()
356 {
357 bpf_error("syntax error in filter expression");
358 }
359
360 static bpf_u_int32 netmask;
361 static int snaplen;
362 int no_optimize;
363
364 int
365 pcap_compile(pcap_t *p, struct bpf_program *program,
366 const char *buf, int optimize, bpf_u_int32 mask)
367 {
368 extern int n_errors;
369 const char * volatile xbuf = buf;
370 int len;
371
372 no_optimize = 0;
373 n_errors = 0;
374 root = NULL;
375 bpf_pcap = p;
376 if (setjmp(top_ctx)) {
377 lex_cleanup();
378 freechunks();
379 return (-1);
380 }
381
382 netmask = mask;
383
384 snaplen = pcap_snapshot(p);
385 if (snaplen == 0) {
386 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
387 "snaplen of 0 rejects all packets");
388 return -1;
389 }
390
391 lex_init(xbuf ? xbuf : "");
392 init_linktype(p);
393 (void)pcap_parse();
394
395 if (n_errors)
396 syntax();
397
398 if (root == NULL)
399 root = gen_retblk(snaplen);
400
401 if (optimize && !no_optimize) {
402 bpf_optimize(&root);
403 if (root == NULL ||
404 (root->s.code == (BPF_RET|BPF_K) && root->s.k == 0))
405 bpf_error("expression rejects all packets");
406 }
407 program->bf_insns = icode_to_fcode(root, &len);
408 program->bf_len = len;
409
410 lex_cleanup();
411 freechunks();
412 return (0);
413 }
414
415 /*
416 * entry point for using the compiler with no pcap open
417 * pass in all the stuff that is needed explicitly instead.
418 */
419 int
420 pcap_compile_nopcap(int snaplen_arg, int linktype_arg,
421 struct bpf_program *program,
422 const char *buf, int optimize, bpf_u_int32 mask)
423 {
424 pcap_t *p;
425 int ret;
426
427 p = pcap_open_dead(linktype_arg, snaplen_arg);
428 if (p == NULL)
429 return (-1);
430 ret = pcap_compile(p, program, buf, optimize, mask);
431 pcap_close(p);
432 return (ret);
433 }
434
435 /*
436 * Clean up a "struct bpf_program" by freeing all the memory allocated
437 * in it.
438 */
439 void
440 pcap_freecode(struct bpf_program *program)
441 {
442 program->bf_len = 0;
443 if (program->bf_insns != NULL) {
444 free((char *)program->bf_insns);
445 program->bf_insns = NULL;
446 }
447 }
448
449 /*
450 * Backpatch the blocks in 'list' to 'target'. The 'sense' field indicates
451 * which of the jt and jf fields has been resolved and which is a pointer
452 * back to another unresolved block (or nil). At least one of the fields
453 * in each block is already resolved.
454 */
455 static void
456 backpatch(list, target)
457 struct block *list, *target;
458 {
459 struct block *next;
460
461 while (list) {
462 if (!list->sense) {
463 next = JT(list);
464 JT(list) = target;
465 } else {
466 next = JF(list);
467 JF(list) = target;
468 }
469 list = next;
470 }
471 }
472
473 /*
474 * Merge the lists in b0 and b1, using the 'sense' field to indicate
475 * which of jt and jf is the link.
476 */
477 static void
478 merge(b0, b1)
479 struct block *b0, *b1;
480 {
481 register struct block **p = &b0;
482
483 /* Find end of list. */
484 while (*p)
485 p = !((*p)->sense) ? &JT(*p) : &JF(*p);
486
487 /* Concatenate the lists. */
488 *p = b1;
489 }
490
491
492 void
493 finish_parse(p)
494 struct block *p;
495 {
496 struct block *ppi_dlt_check;
497
498 ppi_dlt_check = gen_ppi_dlt_check();
499
500 if (ppi_dlt_check != NULL)
501 {
502 gen_and(ppi_dlt_check, p);
503 }
504
505 backpatch(p, gen_retblk(snaplen));
506 p->sense = !p->sense;
507 backpatch(p, gen_retblk(0));
508 root = p->head;
509
510 /*
511 * Insert before the statements of the first (root) block any
512 * statements needed to load the lengths of any variable-length
513 * headers into registers.
514 *
515 * XXX - a fancier strategy would be to insert those before the
516 * statements of all blocks that use those lengths and that
517 * have no predecessors that use them, so that we only compute
518 * the lengths if we need them. There might be even better
519 * approaches than that. However, as we're currently only
520 * handling variable-length radiotap headers, and as all
521 * filtering expressions other than raw link[M:N] tests
522 * require the length of that header, doing more for that
523 * header length isn't really worth the effort.
524 */
525
526 insert_load_llprefixlen(root);
527 }
528
529 void
530 gen_and(b0, b1)
531 struct block *b0, *b1;
532 {
533 backpatch(b0, b1->head);
534 b0->sense = !b0->sense;
535 b1->sense = !b1->sense;
536 merge(b1, b0);
537 b1->sense = !b1->sense;
538 b1->head = b0->head;
539 }
540
541 void
542 gen_or(b0, b1)
543 struct block *b0, *b1;
544 {
545 b0->sense = !b0->sense;
546 backpatch(b0, b1->head);
547 b0->sense = !b0->sense;
548 merge(b1, b0);
549 b1->head = b0->head;
550 }
551
552 void
553 gen_not(b)
554 struct block *b;
555 {
556 b->sense = !b->sense;
557 }
558
559 static struct block *
560 gen_cmp(offrel, offset, size, v)
561 enum e_offrel offrel;
562 u_int offset, size;
563 bpf_int32 v;
564 {
565 return gen_ncmp(offrel, offset, size, 0xffffffff, BPF_JEQ, 0, v);
566 }
567
568 static struct block *
569 gen_cmp_gt(offrel, offset, size, v)
570 enum e_offrel offrel;
571 u_int offset, size;
572 bpf_int32 v;
573 {
574 return gen_ncmp(offrel, offset, size, 0xffffffff, BPF_JGT, 0, v);
575 }
576
577 static struct block *
578 gen_cmp_ge(offrel, offset, size, v)
579 enum e_offrel offrel;
580 u_int offset, size;
581 bpf_int32 v;
582 {
583 return gen_ncmp(offrel, offset, size, 0xffffffff, BPF_JGE, 0, v);
584 }
585
586 static struct block *
587 gen_cmp_lt(offrel, offset, size, v)
588 enum e_offrel offrel;
589 u_int offset, size;
590 bpf_int32 v;
591 {
592 return gen_ncmp(offrel, offset, size, 0xffffffff, BPF_JGE, 1, v);
593 }
594
595 static struct block *
596 gen_cmp_le(offrel, offset, size, v)
597 enum e_offrel offrel;
598 u_int offset, size;
599 bpf_int32 v;
600 {
601 return gen_ncmp(offrel, offset, size, 0xffffffff, BPF_JGT, 1, v);
602 }
603
604 static struct block *
605 gen_mcmp(offrel, offset, size, v, mask)
606 enum e_offrel offrel;
607 u_int offset, size;
608 bpf_int32 v;
609 bpf_u_int32 mask;
610 {
611 return gen_ncmp(offrel, offset, size, mask, BPF_JEQ, 0, v);
612 }
613
614 static struct block *
615 gen_bcmp(offrel, offset, size, v)
616 enum e_offrel offrel;
617 register u_int offset, size;
618 register const u_char *v;
619 {
620 register struct block *b, *tmp;
621
622 b = NULL;
623 while (size >= 4) {
624 register const u_char *p = &v[size - 4];
625 bpf_int32 w = ((bpf_int32)p[0] << 24) |
626 ((bpf_int32)p[1] << 16) | ((bpf_int32)p[2] << 8) | p[3];
627
628 tmp = gen_cmp(offrel, offset + size - 4, BPF_W, w);
629 if (b != NULL)
630 gen_and(b, tmp);
631 b = tmp;
632 size -= 4;
633 }
634 while (size >= 2) {
635 register const u_char *p = &v[size - 2];
636 bpf_int32 w = ((bpf_int32)p[0] << 8) | p[1];
637
638 tmp = gen_cmp(offrel, offset + size - 2, BPF_H, w);
639 if (b != NULL)
640 gen_and(b, tmp);
641 b = tmp;
642 size -= 2;
643 }
644 if (size > 0) {
645 tmp = gen_cmp(offrel, offset, BPF_B, (bpf_int32)v[0]);
646 if (b != NULL)
647 gen_and(b, tmp);
648 b = tmp;
649 }
650 return b;
651 }
652
653 /*
654 * AND the field of size "size" at offset "offset" relative to the header
655 * specified by "offrel" with "mask", and compare it with the value "v"
656 * with the test specified by "jtype"; if "reverse" is true, the test
657 * should test the opposite of "jtype".
658 */
659 static struct block *
660 gen_ncmp(offrel, offset, size, mask, jtype, reverse, v)
661 enum e_offrel offrel;
662 bpf_int32 v;
663 bpf_u_int32 offset, size, mask, jtype;
664 int reverse;
665 {
666 struct slist *s, *s2;
667 struct block *b;
668
669 s = gen_load_a(offrel, offset, size);
670
671 if (mask != 0xffffffff) {
672 s2 = new_stmt(BPF_ALU|BPF_AND|BPF_K);
673 s2->s.k = mask;
674 sappend(s, s2);
675 }
676
677 b = new_block(JMP(jtype));
678 b->stmts = s;
679 b->s.k = v;
680 if (reverse && (jtype == BPF_JGT || jtype == BPF_JGE))
681 gen_not(b);
682 return b;
683 }
684
685 /*
686 * Various code constructs need to know the layout of the data link
687 * layer. These variables give the necessary offsets from the beginning
688 * of the packet data.
689 *
690 * If the link layer has variable_length headers, the offsets are offsets
691 * from the end of the link-link-layer header, and "reg_ll_size" is
692 * the register number for a register containing the length of the
693 * link-layer header. Otherwise, "reg_ll_size" is -1.
694 */
695 static int reg_ll_size;
696
697 /*
698 * This is the offset of the beginning of the link-layer header from
699 * the beginning of the raw packet data.
700 *
701 * It's usually 0, except for 802.11 with a fixed-length radio header.
702 * (For 802.11 with a variable-length radio header, we have to generate
703 * code to compute that offset; off_ll is 0 in that case.)
704 */
705 static u_int off_ll;
706
707 /*
708 * This is the offset of the beginning of the MAC-layer header.
709 * It's usually 0, except for ATM LANE, where it's the offset, relative
710 * to the beginning of the raw packet data, of the Ethernet header.
711 */
712 static u_int off_mac;
713
714 /*
715 * "off_linktype" is the offset to information in the link-layer header
716 * giving the packet type. This offset is relative to the beginning
717 * of the link-layer header (i.e., it doesn't include off_ll).
718 *
719 * For Ethernet, it's the offset of the Ethernet type field.
720 *
721 * For link-layer types that always use 802.2 headers, it's the
722 * offset of the LLC header.
723 *
724 * For PPP, it's the offset of the PPP type field.
725 *
726 * For Cisco HDLC, it's the offset of the CHDLC type field.
727 *
728 * For BSD loopback, it's the offset of the AF_ value.
729 *
730 * For Linux cooked sockets, it's the offset of the type field.
731 *
732 * It's set to -1 for no encapsulation, in which case, IP is assumed.
733 */
734 static u_int off_linktype;
735
736 /*
737 * TRUE if the link layer includes an ATM pseudo-header.
738 */
739 static int is_atm = 0;
740
741 /*
742 * TRUE if "lane" appeared in the filter; it causes us to generate
743 * code that assumes LANE rather than LLC-encapsulated traffic in SunATM.
744 */
745 static int is_lane = 0;
746
747 /*
748 * These are offsets for the ATM pseudo-header.
749 */
750 static u_int off_vpi;
751 static u_int off_vci;
752 static u_int off_proto;
753
754 /*
755 * These are offsets for the MTP2 fields.
756 */
757 static u_int off_li;
758
759 /*
760 * These are offsets for the MTP3 fields.
761 */
762 static u_int off_sio;
763 static u_int off_opc;
764 static u_int off_dpc;
765 static u_int off_sls;
766
767 /*
768 * This is the offset of the first byte after the ATM pseudo_header,
769 * or -1 if there is no ATM pseudo-header.
770 */
771 static u_int off_payload;
772
773 /*
774 * These are offsets to the beginning of the network-layer header.
775 * They are relative to the beginning of the link-layer header (i.e.,
776 * they don't include off_ll).
777 *
778 * If the link layer never uses 802.2 LLC:
779 *
780 * "off_nl" and "off_nl_nosnap" are the same.
781 *
782 * If the link layer always uses 802.2 LLC:
783 *
784 * "off_nl" is the offset if there's a SNAP header following
785 * the 802.2 header;
786 *
787 * "off_nl_nosnap" is the offset if there's no SNAP header.
788 *
789 * If the link layer is Ethernet:
790 *
791 * "off_nl" is the offset if the packet is an Ethernet II packet
792 * (we assume no 802.3+802.2+SNAP);
793 *
794 * "off_nl_nosnap" is the offset if the packet is an 802.3 packet
795 * with an 802.2 header following it.
796 */
797 static u_int off_nl;
798 static u_int off_nl_nosnap;
799
800 static int linktype;
801
802 static void
803 init_linktype(p)
804 pcap_t *p;
805 {
806 linktype = pcap_datalink(p);
807 #ifdef PCAP_FDDIPAD
808 pcap_fddipad = p->fddipad;
809 #endif
810
811 /*
812 * Assume it's not raw ATM with a pseudo-header, for now.
813 */
814 off_mac = 0;
815 is_atm = 0;
816 is_lane = 0;
817 off_vpi = -1;
818 off_vci = -1;
819 off_proto = -1;
820 off_payload = -1;
821
822 /*
823 * And assume we're not doing SS7.
824 */
825 off_li = -1;
826 off_sio = -1;
827 off_opc = -1;
828 off_dpc = -1;
829 off_sls = -1;
830
831 /*
832 * Also assume it's not 802.11 with a fixed-length radio header.
833 */
834 off_ll = 0;
835
836 orig_linktype = -1;
837 orig_nl = -1;
838 label_stack_depth = 0;
839
840 reg_ll_size = -1;
841
842 switch (linktype) {
843
844 case DLT_ARCNET:
845 off_linktype = 2;
846 off_nl = 6; /* XXX in reality, variable! */
847 off_nl_nosnap = 6; /* no 802.2 LLC */
848 return;
849
850 case DLT_ARCNET_LINUX:
851 off_linktype = 4;
852 off_nl = 8; /* XXX in reality, variable! */
853 off_nl_nosnap = 8; /* no 802.2 LLC */
854 return;
855
856 case DLT_EN10MB:
857 off_linktype = 12;
858 off_nl = 14; /* Ethernet II */
859 off_nl_nosnap = 17; /* 802.3+802.2 */
860 return;
861
862 case DLT_SLIP:
863 /*
864 * SLIP doesn't have a link level type. The 16 byte
865 * header is hacked into our SLIP driver.
866 */
867 off_linktype = -1;
868 off_nl = 16;
869 off_nl_nosnap = 16; /* no 802.2 LLC */
870 return;
871
872 case DLT_SLIP_BSDOS:
873 /* XXX this may be the same as the DLT_PPP_BSDOS case */
874 off_linktype = -1;
875 /* XXX end */
876 off_nl = 24;
877 off_nl_nosnap = 24; /* no 802.2 LLC */
878 return;
879
880 case DLT_NULL:
881 case DLT_LOOP:
882 off_linktype = 0;
883 off_nl = 4;
884 off_nl_nosnap = 4; /* no 802.2 LLC */
885 return;
886
887 case DLT_ENC:
888 off_linktype = 0;
889 off_nl = 12;
890 off_nl_nosnap = 12; /* no 802.2 LLC */
891 return;
892
893 case DLT_PPP:
894 case DLT_PPP_PPPD:
895 case DLT_C_HDLC: /* BSD/OS Cisco HDLC */
896 case DLT_PPP_SERIAL: /* NetBSD sync/async serial PPP */
897 off_linktype = 2;
898 off_nl = 4;
899 off_nl_nosnap = 4; /* no 802.2 LLC */
900 return;
901
902 case DLT_PPP_ETHER:
903 /*
904 * This does no include the Ethernet header, and
905 * only covers session state.
906 */
907 off_linktype = 6;
908 off_nl = 8;
909 off_nl_nosnap = 8; /* no 802.2 LLC */
910 return;
911
912 case DLT_PPP_BSDOS:
913 off_linktype = 5;
914 off_nl = 24;
915 off_nl_nosnap = 24; /* no 802.2 LLC */
916 return;
917
918 case DLT_FDDI:
919 /*
920 * FDDI doesn't really have a link-level type field.
921 * We set "off_linktype" to the offset of the LLC header.
922 *
923 * To check for Ethernet types, we assume that SSAP = SNAP
924 * is being used and pick out the encapsulated Ethernet type.
925 * XXX - should we generate code to check for SNAP?
926 */
927 off_linktype = 13;
928 #ifdef PCAP_FDDIPAD
929 off_linktype += pcap_fddipad;
930 #endif
931 off_nl = 21; /* FDDI+802.2+SNAP */
932 off_nl_nosnap = 16; /* FDDI+802.2 */
933 #ifdef PCAP_FDDIPAD
934 off_nl += pcap_fddipad;
935 off_nl_nosnap += pcap_fddipad;
936 #endif
937 return;
938
939 case DLT_IEEE802:
940 /*
941 * Token Ring doesn't really have a link-level type field.
942 * We set "off_linktype" to the offset of the LLC header.
943 *
944 * To check for Ethernet types, we assume that SSAP = SNAP
945 * is being used and pick out the encapsulated Ethernet type.
946 * XXX - should we generate code to check for SNAP?
947 *
948 * XXX - the header is actually variable-length.
949 * Some various Linux patched versions gave 38
950 * as "off_linktype" and 40 as "off_nl"; however,
951 * if a token ring packet has *no* routing
952 * information, i.e. is not source-routed, the correct
953 * values are 20 and 22, as they are in the vanilla code.
954 *
955 * A packet is source-routed iff the uppermost bit
956 * of the first byte of the source address, at an
957 * offset of 8, has the uppermost bit set. If the
958 * packet is source-routed, the total number of bytes
959 * of routing information is 2 plus bits 0x1F00 of
960 * the 16-bit value at an offset of 14 (shifted right
961 * 8 - figure out which byte that is).
962 */
963 off_linktype = 14;
964 off_nl = 22; /* Token Ring+802.2+SNAP */
965 off_nl_nosnap = 17; /* Token Ring+802.2 */
966 return;
967
968 case DLT_IEEE802_11:
969 /*
970 * 802.11 doesn't really have a link-level type field.
971 * We set "off_linktype" to the offset of the LLC header.
972 *
973 * To check for Ethernet types, we assume that SSAP = SNAP
974 * is being used and pick out the encapsulated Ethernet type.
975 * XXX - should we generate code to check for SNAP?
976 *
977 * XXX - the header is actually variable-length. We
978 * assume a 24-byte link-layer header, as appears in
979 * data frames in networks with no bridges. If the
980 * fromds and tods 802.11 header bits are both set,
981 * it's actually supposed to be 30 bytes.
982 */
983 off_linktype = 24;
984 off_nl = 32; /* 802.11+802.2+SNAP */
985 off_nl_nosnap = 27; /* 802.11+802.2 */
986 return;
987
988 case DLT_PRISM_HEADER:
989 /*
990 * Same as 802.11, but with an additional header before
991 * the 802.11 header, containing a bunch of additional
992 * information including radio-level information.
993 *
994 * The header is 144 bytes long.
995 *
996 * XXX - same variable-length header problem; at least
997 * the Prism header is fixed-length.
998 */
999 off_ll = 144;
1000 off_linktype = 24;
1001 off_nl = 32; /* Prism+802.11+802.2+SNAP */
1002 off_nl_nosnap = 27; /* Prism+802.11+802.2 */
1003 return;
1004
1005 case DLT_IEEE802_11_RADIO_AVS:
1006 /*
1007 * Same as 802.11, but with an additional header before
1008 * the 802.11 header, containing a bunch of additional
1009 * information including radio-level information.
1010 *
1011 * The header is 64 bytes long, at least in its
1012 * current incarnation.
1013 *
1014 * XXX - same variable-length header problem, only
1015 * more so; this header is also variable-length,
1016 * with the length being the 32-bit big-endian
1017 * number at an offset of 4 from the beginning
1018 * of the radio header. We should handle that the
1019 * same way we handle the length at the beginning
1020 * of the radiotap header.
1021 *
1022 * XXX - in Linux, do any drivers that supply an AVS
1023 * header supply a link-layer type other than
1024 * ARPHRD_IEEE80211_PRISM? If so, we should map that
1025 * to DLT_IEEE802_11_RADIO_AVS; if not, or if there are
1026 * any drivers that supply an AVS header but supply
1027 * an ARPHRD value of ARPHRD_IEEE80211_PRISM, we'll
1028 * have to check the header in the generated code to
1029 * determine whether it's Prism or AVS.
1030 */
1031 off_ll = 64;
1032 off_linktype = 24;
1033 off_nl = 32; /* Radio+802.11+802.2+SNAP */
1034 off_nl_nosnap = 27; /* Radio+802.11+802.2 */
1035 return;
1036
1037
1038 /*
1039 * At the moment we treat PPI as normal Radiotap encoded
1040 * packets. The difference is in the function that generates
1041 * the code at the beginning to compute the header length.
1042 * Since this code generator of PPI supports bare 802.11
1043 * encapsulation only (i.e. the encapsulated DLT should be
1044 * DLT_IEEE802_11) we generate code to check for this too.
1045 */
1046 case DLT_PPI:
1047 case DLT_IEEE802_11_RADIO:
1048 /*
1049 * Same as 802.11, but with an additional header before
1050 * the 802.11 header, containing a bunch of additional
1051 * information including radio-level information.
1052 *
1053 * The radiotap header is variable length, and we
1054 * generate code to compute its length and store it
1055 * in a register. These offsets are relative to the
1056 * beginning of the 802.11 header.
1057 */
1058 off_linktype = 24;
1059 off_nl = 32; /* 802.11+802.2+SNAP */
1060 off_nl_nosnap = 27; /* 802.11+802.2 */
1061 return;
1062
1063 case DLT_ATM_RFC1483:
1064 case DLT_ATM_CLIP: /* Linux ATM defines this */
1065 /*
1066 * assume routed, non-ISO PDUs
1067 * (i.e., LLC = 0xAA-AA-03, OUT = 0x00-00-00)
1068 *
1069 * XXX - what about ISO PDUs, e.g. CLNP, ISIS, ESIS,
1070 * or PPP with the PPP NLPID (e.g., PPPoA)? The
1071 * latter would presumably be treated the way PPPoE
1072 * should be, so you can do "pppoe and udp port 2049"
1073 * or "pppoa and tcp port 80" and have it check for
1074 * PPPo{A,E} and a PPP protocol of IP and....
1075 */
1076 off_linktype = 0;
1077 off_nl = 8; /* 802.2+SNAP */
1078 off_nl_nosnap = 3; /* 802.2 */
1079 return;
1080
1081 case DLT_SUNATM:
1082 /*
1083 * Full Frontal ATM; you get AALn PDUs with an ATM
1084 * pseudo-header.
1085 */
1086 is_atm = 1;
1087 off_vpi = SUNATM_VPI_POS;
1088 off_vci = SUNATM_VCI_POS;
1089 off_proto = PROTO_POS;
1090 off_mac = -1; /* LLC-encapsulated, so no MAC-layer header */
1091 off_payload = SUNATM_PKT_BEGIN_POS;
1092 off_linktype = off_payload;
1093 off_nl = off_payload+8; /* 802.2+SNAP */
1094 off_nl_nosnap = off_payload+3; /* 802.2 */
1095 return;
1096
1097 case DLT_RAW:
1098 off_linktype = -1;
1099 off_nl = 0;
1100 off_nl_nosnap = 0; /* no 802.2 LLC */
1101 return;
1102
1103 case DLT_LINUX_SLL: /* fake header for Linux cooked socket */
1104 off_linktype = 14;
1105 off_nl = 16;
1106 off_nl_nosnap = 16; /* no 802.2 LLC */
1107 return;
1108
1109 case DLT_LTALK:
1110 /*
1111 * LocalTalk does have a 1-byte type field in the LLAP header,
1112 * but really it just indicates whether there is a "short" or
1113 * "long" DDP packet following.
1114 */
1115 off_linktype = -1;
1116 off_nl = 0;
1117 off_nl_nosnap = 0; /* no 802.2 LLC */
1118 return;
1119
1120 case DLT_IP_OVER_FC:
1121 /*
1122 * RFC 2625 IP-over-Fibre-Channel doesn't really have a
1123 * link-level type field. We set "off_linktype" to the
1124 * offset of the LLC header.
1125 *
1126 * To check for Ethernet types, we assume that SSAP = SNAP
1127 * is being used and pick out the encapsulated Ethernet type.
1128 * XXX - should we generate code to check for SNAP? RFC
1129 * 2625 says SNAP should be used.
1130 */
1131 off_linktype = 16;
1132 off_nl = 24; /* IPFC+802.2+SNAP */
1133 off_nl_nosnap = 19; /* IPFC+802.2 */
1134 return;
1135
1136 case DLT_FRELAY:
1137 /*
1138 * XXX - we should set this to handle SNAP-encapsulated
1139 * frames (NLPID of 0x80).
1140 */
1141 off_linktype = -1;
1142 off_nl = 0;
1143 off_nl_nosnap = 0; /* no 802.2 LLC */
1144 return;
1145
1146 /*
1147 * the only BPF-interesting FRF.16 frames are non-control frames;
1148 * Frame Relay has a variable length link-layer
1149 * so lets start with offset 4 for now and increments later on (FIXME);
1150 */
1151 case DLT_MFR:
1152 off_linktype = -1;
1153 off_nl = 4;
1154 off_nl_nosnap = 0; /* XXX - for now -> no 802.2 LLC */
1155 return;
1156
1157 case DLT_APPLE_IP_OVER_IEEE1394:
1158 off_linktype = 16;
1159 off_nl = 18;
1160 off_nl_nosnap = 18; /* no 802.2 LLC */
1161 return;
1162
1163 case DLT_LINUX_IRDA:
1164 /*
1165 * Currently, only raw "link[N:M]" filtering is supported.
1166 */
1167 off_linktype = -1;
1168 off_nl = -1;
1169 off_nl_nosnap = -1;
1170 return;
1171
1172 case DLT_DOCSIS:
1173 /*
1174 * Currently, only raw "link[N:M]" filtering is supported.
1175 */
1176 off_linktype = -1;
1177 off_nl = -1;
1178 off_nl_nosnap = -1;
1179 return;
1180
1181 case DLT_SYMANTEC_FIREWALL:
1182 off_linktype = 6;
1183 off_nl = 44; /* Ethernet II */
1184 off_nl_nosnap = 44; /* XXX - what does it do with 802.3 packets? */
1185 return;
1186
1187 #ifdef HAVE_NET_PFVAR_H
1188 case DLT_PFLOG:
1189 off_linktype = 0;
1190 off_nl = PFLOG_HDRLEN;
1191 off_nl_nosnap = PFLOG_HDRLEN; /* no 802.2 LLC */
1192 return;
1193 #endif
1194
1195 case DLT_JUNIPER_MFR:
1196 case DLT_JUNIPER_MLFR:
1197 case DLT_JUNIPER_MLPPP:
1198 case DLT_JUNIPER_PPP:
1199 case DLT_JUNIPER_CHDLC:
1200 case DLT_JUNIPER_FRELAY:
1201 off_linktype = 4;
1202 off_nl = 4;
1203 off_nl_nosnap = -1; /* no 802.2 LLC */
1204 return;
1205
1206 case DLT_JUNIPER_ATM1:
1207 off_linktype = 4; /* in reality variable between 4-8 */
1208 off_nl = 4;
1209 off_nl_nosnap = 14;
1210 return;
1211
1212 case DLT_JUNIPER_ATM2:
1213 off_linktype = 8; /* in reality variable between 8-12 */
1214 off_nl = 8;
1215 off_nl_nosnap = 18;
1216 return;
1217
1218 /* frames captured on a Juniper PPPoE service PIC
1219 * contain raw ethernet frames */
1220 case DLT_JUNIPER_PPPOE:
1221 case DLT_JUNIPER_ETHER:
1222 off_linktype = 16;
1223 off_nl = 18; /* Ethernet II */
1224 off_nl_nosnap = 21; /* 802.3+802.2 */
1225 return;
1226
1227 case DLT_JUNIPER_PPPOE_ATM:
1228 off_linktype = 4;
1229 off_nl = 6;
1230 off_nl_nosnap = -1; /* no 802.2 LLC */
1231 return;
1232
1233 case DLT_JUNIPER_GGSN:
1234 off_linktype = 6;
1235 off_nl = 12;
1236 off_nl_nosnap = -1; /* no 802.2 LLC */
1237 return;
1238
1239 case DLT_JUNIPER_ES:
1240 off_linktype = 6;
1241 off_nl = -1; /* not really a network layer but raw IP adresses */
1242 off_nl_nosnap = -1; /* no 802.2 LLC */
1243 return;
1244
1245 case DLT_JUNIPER_MONITOR:
1246 off_linktype = 12;
1247 off_nl = 12; /* raw IP/IP6 header */
1248 off_nl_nosnap = -1; /* no 802.2 LLC */
1249 return;
1250
1251 case DLT_JUNIPER_SERVICES:
1252 off_linktype = 12;
1253 off_nl = -1; /* L3 proto location dep. on cookie type */
1254 off_nl_nosnap = -1; /* no 802.2 LLC */
1255 return;
1256
1257 case DLT_JUNIPER_VP:
1258 off_linktype = 18;
1259 off_nl = -1;
1260 off_nl_nosnap = -1;
1261 return;
1262
1263 case DLT_MTP2:
1264 off_li = 2;
1265 off_sio = 3;
1266 off_opc = 4;
1267 off_dpc = 4;
1268 off_sls = 7;
1269 off_linktype = -1;
1270 off_nl = -1;
1271 off_nl_nosnap = -1;
1272 return;
1273
1274 case DLT_MTP2_WITH_PHDR:
1275 off_li = 6;
1276 off_sio = 7;
1277 off_opc = 8;
1278 off_dpc = 8;
1279 off_sls = 11;
1280 off_linktype = -1;
1281 off_nl = -1;
1282 off_nl_nosnap = -1;
1283 return;
1284
1285 #ifdef DLT_PFSYNC
1286 case DLT_PFSYNC:
1287 off_linktype = -1;
1288 off_nl = 4;
1289 off_nl_nosnap = 4;
1290 return;
1291 #endif
1292
1293 case DLT_LINUX_LAPD:
1294 /*
1295 * Currently, only raw "link[N:M]" filtering is supported.
1296 */
1297 off_linktype = -1;
1298 off_nl = -1;
1299 off_nl_nosnap = -1;
1300 return;
1301
1302 case DLT_USB:
1303 /*
1304 * Currently, only raw "link[N:M]" filtering is supported.
1305 */
1306 off_linktype = -1;
1307 off_nl = -1;
1308 off_nl_nosnap = -1;
1309 return;
1310
1311 case DLT_BLUETOOTH_HCI_H4:
1312 /*
1313 * Currently, only raw "link[N:M]" filtering is supported.
1314 */
1315 off_linktype = -1;
1316 off_nl = -1;
1317 off_nl_nosnap = -1;
1318 return;
1319 }
1320 bpf_error("unknown data link type %d", linktype);
1321 /* NOTREACHED */
1322 }
1323
1324 /*
1325 * Load a value relative to the beginning of the link-layer header.
1326 * The link-layer header doesn't necessarily begin at the beginning
1327 * of the packet data; there might be a variable-length prefix containing
1328 * radio information.
1329 */
1330 static struct slist *
1331 gen_load_llrel(offset, size)
1332 u_int offset, size;
1333 {
1334 struct slist *s, *s2;
1335
1336 s = gen_llprefixlen();
1337
1338 /*
1339 * If "s" is non-null, it has code to arrange that the X register
1340 * contains the length of the prefix preceding the link-layer
1341 * header.
1342 *
1343 * Otherwise, the length of the prefix preceding the link-layer
1344 * header is "off_ll".
1345 */
1346 if (s != NULL) {
1347 /*
1348 * There's a variable-length prefix preceding the
1349 * link-layer header. "s" points to a list of statements
1350 * that put the length of that prefix into the X register.
1351 * do an indirect load, to use the X register as an offset.
1352 */
1353 s2 = new_stmt(BPF_LD|BPF_IND|size);
1354 s2->s.k = offset;
1355 sappend(s, s2);
1356 } else {
1357 /*
1358 * There is no variable-length header preceding the
1359 * link-layer header; add in off_ll, which, if there's
1360 * a fixed-length header preceding the link-layer header,
1361 * is the length of that header.
1362 */
1363 s = new_stmt(BPF_LD|BPF_ABS|size);
1364 s->s.k = offset + off_ll;
1365 }
1366 return s;
1367 }
1368
1369
1370 /*
1371 * Load a value relative to the beginning of the specified header.
1372 */
1373 static struct slist *
1374 gen_load_a(offrel, offset, size)
1375 enum e_offrel offrel;
1376 u_int offset, size;
1377 {
1378 struct slist *s, *s2;
1379
1380 switch (offrel) {
1381
1382 case OR_PACKET:
1383 s = new_stmt(BPF_LD|BPF_ABS|size);
1384 s->s.k = offset;
1385 break;
1386
1387 case OR_LINK:
1388 s = gen_load_llrel(offset, size);
1389 break;
1390
1391 case OR_NET:
1392 s = gen_load_llrel(off_nl + offset, size);
1393 break;
1394
1395 case OR_NET_NOSNAP:
1396 s = gen_load_llrel(off_nl_nosnap + offset, size);
1397 break;
1398
1399 case OR_TRAN_IPV4:
1400 /*
1401 * Load the X register with the length of the IPv4 header
1402 * (plus the offset of the link-layer header, if it's
1403 * preceded by a variable-length header such as a radio
1404 * header), in bytes.
1405 */
1406 s = gen_loadx_iphdrlen();
1407
1408 /*
1409 * Load the item at {offset of the link-layer header} +
1410 * {offset, relative to the start of the link-layer
1411 * header, of the IPv4 header} + {length of the IPv4 header} +
1412 * {specified offset}.
1413 *
1414 * (If the link-layer is variable-length, it's included
1415 * in the value in the X register, and off_ll is 0.)
1416 */
1417 s2 = new_stmt(BPF_LD|BPF_IND|size);
1418 s2->s.k = off_ll + off_nl + offset;
1419 sappend(s, s2);
1420 break;
1421
1422 case OR_TRAN_IPV6:
1423 s = gen_load_llrel(off_nl + 40 + offset, size);
1424 break;
1425
1426 default:
1427 abort();
1428 return NULL;
1429 }
1430 return s;
1431 }
1432
1433 /*
1434 * Generate code to load into the X register the sum of the length of
1435 * the IPv4 header and any variable-length header preceding the link-layer
1436 * header.
1437 */
1438 static struct slist *
1439 gen_loadx_iphdrlen()
1440 {
1441 struct slist *s, *s2;
1442
1443 s = gen_llprefixlen();
1444 if (s != NULL) {
1445 /*
1446 * There's a variable-length prefix preceding the
1447 * link-layer header. "s" points to a list of statements
1448 * that put the length of that prefix into the X register.
1449 * The 4*([k]&0xf) addressing mode can't be used, as we
1450 * don't have a constant offset, so we have to load the
1451 * value in question into the A register and add to it
1452 * the value from the X register.
1453 */
1454 s2 = new_stmt(BPF_LD|BPF_IND|BPF_B);
1455 s2->s.k = off_nl;
1456 sappend(s, s2);
1457 s2 = new_stmt(BPF_ALU|BPF_AND|BPF_K);
1458 s2->s.k = 0xf;
1459 sappend(s, s2);
1460 s2 = new_stmt(BPF_ALU|BPF_LSH|BPF_K);
1461 s2->s.k = 2;
1462 sappend(s, s2);
1463
1464 /*
1465 * The A register now contains the length of the
1466 * IP header. We need to add to it the length
1467 * of the prefix preceding the link-layer
1468 * header, which is still in the X register, and
1469 * move the result into the X register.
1470 */
1471 sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X));
1472 sappend(s, new_stmt(BPF_MISC|BPF_TAX));
1473 } else {
1474 /*
1475 * There is no variable-length header preceding the
1476 * link-layer header; add in off_ll, which, if there's
1477 * a fixed-length header preceding the link-layer header,
1478 * is the length of that header.
1479 */
1480 s = new_stmt(BPF_LDX|BPF_MSH|BPF_B);
1481 s->s.k = off_ll + off_nl;
1482 }
1483 return s;
1484 }
1485
1486 static struct block *
1487 gen_uncond(rsense)
1488 int rsense;
1489 {
1490 struct block *b;
1491 struct slist *s;
1492
1493 s = new_stmt(BPF_LD|BPF_IMM);
1494 s->s.k = !rsense;
1495 b = new_block(JMP(BPF_JEQ));
1496 b->stmts = s;
1497
1498 return b;
1499 }
1500
1501 static inline struct block *
1502 gen_true()
1503 {
1504 return gen_uncond(1);
1505 }
1506
1507 static inline struct block *
1508 gen_false()
1509 {
1510 return gen_uncond(0);
1511 }
1512
1513 /*
1514 * Byte-swap a 32-bit number.
1515 * ("htonl()" or "ntohl()" won't work - we want to byte-swap even on
1516 * big-endian platforms.)
1517 */
1518 #define SWAPLONG(y) \
1519 ((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff))
1520
1521 /*
1522 * Generate code to match a particular packet type.
1523 *
1524 * "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP
1525 * value, if <= ETHERMTU. We use that to determine whether to
1526 * match the type/length field or to check the type/length field for
1527 * a value <= ETHERMTU to see whether it's a type field and then do
1528 * the appropriate test.
1529 */
1530 static struct block *
1531 gen_ether_linktype(proto)
1532 register int proto;
1533 {
1534 struct block *b0, *b1;
1535
1536 switch (proto) {
1537
1538 case LLCSAP_ISONS:
1539 case LLCSAP_IP:
1540 case LLCSAP_NETBEUI:
1541 /*
1542 * OSI protocols and NetBEUI always use 802.2 encapsulation,
1543 * so we check the DSAP and SSAP.
1544 *
1545 * LLCSAP_IP checks for IP-over-802.2, rather
1546 * than IP-over-Ethernet or IP-over-SNAP.
1547 *
1548 * XXX - should we check both the DSAP and the
1549 * SSAP, like this, or should we check just the
1550 * DSAP, as we do for other types <= ETHERMTU
1551 * (i.e., other SAP values)?
1552 */
1553 b0 = gen_cmp_gt(OR_LINK, off_linktype, BPF_H, ETHERMTU);
1554 gen_not(b0);
1555 b1 = gen_cmp(OR_LINK, off_linktype + 2, BPF_H, (bpf_int32)
1556 ((proto << 8) | proto));
1557 gen_and(b0, b1);
1558 return b1;
1559
1560 case LLCSAP_IPX:
1561 /*
1562 * Check for;
1563 *
1564 * Ethernet_II frames, which are Ethernet
1565 * frames with a frame type of ETHERTYPE_IPX;
1566 *
1567 * Ethernet_802.3 frames, which are 802.3
1568 * frames (i.e., the type/length field is
1569 * a length field, <= ETHERMTU, rather than
1570 * a type field) with the first two bytes
1571 * after the Ethernet/802.3 header being
1572 * 0xFFFF;
1573 *
1574 * Ethernet_802.2 frames, which are 802.3
1575 * frames with an 802.2 LLC header and
1576 * with the IPX LSAP as the DSAP in the LLC
1577 * header;
1578 *
1579 * Ethernet_SNAP frames, which are 802.3
1580 * frames with an LLC header and a SNAP
1581 * header and with an OUI of 0x000000
1582 * (encapsulated Ethernet) and a protocol
1583 * ID of ETHERTYPE_IPX in the SNAP header.
1584 *
1585 * XXX - should we generate the same code both
1586 * for tests for LLCSAP_IPX and for ETHERTYPE_IPX?
1587 */
1588
1589 /*
1590 * This generates code to check both for the
1591 * IPX LSAP (Ethernet_802.2) and for Ethernet_802.3.
1592 */
1593 b0 = gen_cmp(OR_LINK, off_linktype + 2, BPF_B,
1594 (bpf_int32)LLCSAP_IPX);
1595 b1 = gen_cmp(OR_LINK, off_linktype + 2, BPF_H,
1596 (bpf_int32)0xFFFF);
1597 gen_or(b0, b1);
1598
1599 /*
1600 * Now we add code to check for SNAP frames with
1601 * ETHERTYPE_IPX, i.e. Ethernet_SNAP.
1602 */
1603 b0 = gen_snap(0x000000, ETHERTYPE_IPX, 14);
1604 gen_or(b0, b1);
1605
1606 /*
1607 * Now we generate code to check for 802.3
1608 * frames in general.
1609 */
1610 b0 = gen_cmp_gt(OR_LINK, off_linktype, BPF_H, ETHERMTU);
1611 gen_not(b0);
1612
1613 /*
1614 * Now add the check for 802.3 frames before the
1615 * check for Ethernet_802.2 and Ethernet_802.3,
1616 * as those checks should only be done on 802.3
1617 * frames, not on Ethernet frames.
1618 */
1619 gen_and(b0, b1);
1620
1621 /*
1622 * Now add the check for Ethernet_II frames, and
1623 * do that before checking for the other frame
1624 * types.
1625 */
1626 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H,
1627 (bpf_int32)ETHERTYPE_IPX);
1628 gen_or(b0, b1);
1629 return b1;
1630
1631 case ETHERTYPE_ATALK:
1632 case ETHERTYPE_AARP:
1633 /*
1634 * EtherTalk (AppleTalk protocols on Ethernet link
1635 * layer) may use 802.2 encapsulation.
1636 */
1637
1638 /*
1639 * Check for 802.2 encapsulation (EtherTalk phase 2?);
1640 * we check for an Ethernet type field less than
1641 * 1500, which means it's an 802.3 length field.
1642 */
1643 b0 = gen_cmp_gt(OR_LINK, off_linktype, BPF_H, ETHERMTU);
1644 gen_not(b0);
1645
1646 /*
1647 * 802.2-encapsulated ETHERTYPE_ATALK packets are
1648 * SNAP packets with an organization code of
1649 * 0x080007 (Apple, for Appletalk) and a protocol
1650 * type of ETHERTYPE_ATALK (Appletalk).
1651 *
1652 * 802.2-encapsulated ETHERTYPE_AARP packets are
1653 * SNAP packets with an organization code of
1654 * 0x000000 (encapsulated Ethernet) and a protocol
1655 * type of ETHERTYPE_AARP (Appletalk ARP).
1656 */
1657 if (proto == ETHERTYPE_ATALK)
1658 b1 = gen_snap(0x080007, ETHERTYPE_ATALK, 14);
1659 else /* proto == ETHERTYPE_AARP */
1660 b1 = gen_snap(0x000000, ETHERTYPE_AARP, 14);
1661 gen_and(b0, b1);
1662
1663 /*
1664 * Check for Ethernet encapsulation (Ethertalk
1665 * phase 1?); we just check for the Ethernet
1666 * protocol type.
1667 */
1668 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, (bpf_int32)proto);
1669
1670 gen_or(b0, b1);
1671 return b1;
1672
1673 default:
1674 if (proto <= ETHERMTU) {
1675 /*
1676 * This is an LLC SAP value, so the frames
1677 * that match would be 802.2 frames.
1678 * Check that the frame is an 802.2 frame
1679 * (i.e., that the length/type field is
1680 * a length field, <= ETHERMTU) and
1681 * then check the DSAP.
1682 */
1683 b0 = gen_cmp_gt(OR_LINK, off_linktype, BPF_H, ETHERMTU);
1684 gen_not(b0);
1685 b1 = gen_cmp(OR_LINK, off_linktype + 2, BPF_B,
1686 (bpf_int32)proto);
1687 gen_and(b0, b1);
1688 return b1;
1689 } else {
1690 /*
1691 * This is an Ethernet type, so compare
1692 * the length/type field with it (if
1693 * the frame is an 802.2 frame, the length
1694 * field will be <= ETHERMTU, and, as
1695 * "proto" is > ETHERMTU, this test
1696 * will fail and the frame won't match,
1697 * which is what we want).
1698 */
1699 return gen_cmp(OR_LINK, off_linktype, BPF_H,
1700 (bpf_int32)proto);
1701 }
1702 }
1703 }
1704
1705 /*
1706 * Generate code to match a particular packet type.
1707 *
1708 * "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP
1709 * value, if <= ETHERMTU. We use that to determine whether to
1710 * match the type field or to check the type field for the special
1711 * LINUX_SLL_P_802_2 value and then do the appropriate test.
1712 */
1713 static struct block *
1714 gen_linux_sll_linktype(proto)
1715 register int proto;
1716 {
1717 struct block *b0, *b1;
1718
1719 switch (proto) {
1720
1721 case LLCSAP_ISONS:
1722 case LLCSAP_IP:
1723 case LLCSAP_NETBEUI:
1724 /*
1725 * OSI protocols and NetBEUI always use 802.2 encapsulation,
1726 * so we check the DSAP and SSAP.
1727 *
1728 * LLCSAP_IP checks for IP-over-802.2, rather
1729 * than IP-over-Ethernet or IP-over-SNAP.
1730 *
1731 * XXX - should we check both the DSAP and the
1732 * SSAP, like this, or should we check just the
1733 * DSAP, as we do for other types <= ETHERMTU
1734 * (i.e., other SAP values)?
1735 */
1736 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, LINUX_SLL_P_802_2);
1737 b1 = gen_cmp(OR_LINK, off_linktype + 2, BPF_H, (bpf_int32)
1738 ((proto << 8) | proto));
1739 gen_and(b0, b1);
1740 return b1;
1741
1742 case LLCSAP_IPX:
1743 /*
1744 * Ethernet_II frames, which are Ethernet
1745 * frames with a frame type of ETHERTYPE_IPX;
1746 *
1747 * Ethernet_802.3 frames, which have a frame
1748 * type of LINUX_SLL_P_802_3;
1749 *
1750 * Ethernet_802.2 frames, which are 802.3
1751 * frames with an 802.2 LLC header (i.e, have
1752 * a frame type of LINUX_SLL_P_802_2) and
1753 * with the IPX LSAP as the DSAP in the LLC
1754 * header;
1755 *
1756 * Ethernet_SNAP frames, which are 802.3
1757 * frames with an LLC header and a SNAP
1758 * header and with an OUI of 0x000000
1759 * (encapsulated Ethernet) and a protocol
1760 * ID of ETHERTYPE_IPX in the SNAP header.
1761 *
1762 * First, do the checks on LINUX_SLL_P_802_2
1763 * frames; generate the check for either
1764 * Ethernet_802.2 or Ethernet_SNAP frames, and
1765 * then put a check for LINUX_SLL_P_802_2 frames
1766 * before it.
1767 */
1768 b0 = gen_cmp(OR_LINK, off_linktype + 2, BPF_B,
1769 (bpf_int32)LLCSAP_IPX);
1770 b1 = gen_snap(0x000000, ETHERTYPE_IPX,
1771 off_linktype + 2);
1772 gen_or(b0, b1);
1773 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, LINUX_SLL_P_802_2);
1774 gen_and(b0, b1);
1775
1776 /*
1777 * Now check for 802.3 frames and OR that with
1778 * the previous test.
1779 */
1780 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, LINUX_SLL_P_802_3);
1781 gen_or(b0, b1);
1782
1783 /*
1784 * Now add the check for Ethernet_II frames, and
1785 * do that before checking for the other frame
1786 * types.
1787 */
1788 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H,
1789 (bpf_int32)ETHERTYPE_IPX);
1790 gen_or(b0, b1);
1791 return b1;
1792
1793 case ETHERTYPE_ATALK:
1794 case ETHERTYPE_AARP:
1795 /*
1796 * EtherTalk (AppleTalk protocols on Ethernet link
1797 * layer) may use 802.2 encapsulation.
1798 */
1799
1800 /*
1801 * Check for 802.2 encapsulation (EtherTalk phase 2?);
1802 * we check for the 802.2 protocol type in the
1803 * "Ethernet type" field.
1804 */
1805 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, LINUX_SLL_P_802_2);
1806
1807 /*
1808 * 802.2-encapsulated ETHERTYPE_ATALK packets are
1809 * SNAP packets with an organization code of
1810 * 0x080007 (Apple, for Appletalk) and a protocol
1811 * type of ETHERTYPE_ATALK (Appletalk).
1812 *
1813 * 802.2-encapsulated ETHERTYPE_AARP packets are
1814 * SNAP packets with an organization code of
1815 * 0x000000 (encapsulated Ethernet) and a protocol
1816 * type of ETHERTYPE_AARP (Appletalk ARP).
1817 */
1818 if (proto == ETHERTYPE_ATALK)
1819 b1 = gen_snap(0x080007, ETHERTYPE_ATALK,
1820 off_linktype + 2);
1821 else /* proto == ETHERTYPE_AARP */
1822 b1 = gen_snap(0x000000, ETHERTYPE_AARP,
1823 off_linktype + 2);
1824 gen_and(b0, b1);
1825
1826 /*
1827 * Check for Ethernet encapsulation (Ethertalk
1828 * phase 1?); we just check for the Ethernet
1829 * protocol type.
1830 */
1831 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, (bpf_int32)proto);
1832
1833 gen_or(b0, b1);
1834 return b1;
1835
1836 default:
1837 if (proto <= ETHERMTU) {
1838 /*
1839 * This is an LLC SAP value, so the frames
1840 * that match would be 802.2 frames.
1841 * Check for the 802.2 protocol type
1842 * in the "Ethernet type" field, and
1843 * then check the DSAP.
1844 */
1845 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H,
1846 LINUX_SLL_P_802_2);
1847 b1 = gen_cmp(OR_LINK, off_linktype + 2, BPF_B,
1848 (bpf_int32)proto);
1849 gen_and(b0, b1);
1850 return b1;
1851 } else {
1852 /*
1853 * This is an Ethernet type, so compare
1854 * the length/type field with it (if
1855 * the frame is an 802.2 frame, the length
1856 * field will be <= ETHERMTU, and, as
1857 * "proto" is > ETHERMTU, this test
1858 * will fail and the frame won't match,
1859 * which is what we want).
1860 */
1861 return gen_cmp(OR_LINK, off_linktype, BPF_H,
1862 (bpf_int32)proto);
1863 }
1864 }
1865 }
1866
1867 static void
1868 insert_radiotap_load_llprefixlen(b)
1869 struct block *b;
1870 {
1871 struct slist *s1, *s2;
1872
1873 /*
1874 * Prepend to the statements in this block code to load the
1875 * length of the radiotap header into the register assigned
1876 * to hold that length, if one has been assigned.
1877 */
1878 if (reg_ll_size != -1) {
1879 /*
1880 * The 2 bytes at offsets of 2 and 3 from the beginning
1881 * of the radiotap header are the length of the radiotap
1882 * header; unfortunately, it's little-endian, so we have
1883 * to load it a byte at a time and construct the value.
1884 */
1885
1886 /*
1887 * Load the high-order byte, at an offset of 3, shift it
1888 * left a byte, and put the result in the X register.
1889 */
1890 s1 = new_stmt(BPF_LD|BPF_B|BPF_ABS);
1891 s1->s.k = 3;
1892 s2 = new_stmt(BPF_ALU|BPF_LSH|BPF_K);
1893 sappend(s1, s2);
1894 s2->s.k = 8;
1895 s2 = new_stmt(BPF_MISC|BPF_TAX);
1896 sappend(s1, s2);
1897
1898 /*
1899 * Load the next byte, at an offset of 2, and OR the
1900 * value from the X register into it.
1901 */
1902 s2 = new_stmt(BPF_LD|BPF_B|BPF_ABS);
1903 sappend(s1, s2);
1904 s2->s.k = 2;
1905 s2 = new_stmt(BPF_ALU|BPF_OR|BPF_X);
1906 sappend(s1, s2);
1907
1908 /*
1909 * Now allocate a register to hold that value and store
1910 * it.
1911 */
1912 s2 = new_stmt(BPF_ST);
1913 s2->s.k = reg_ll_size;
1914 sappend(s1, s2);
1915
1916 /*
1917 * Now move it into the X register.
1918 */
1919 s2 = new_stmt(BPF_MISC|BPF_TAX);
1920 sappend(s1, s2);
1921
1922 /*
1923 * Now append all the existing statements in this
1924 * block to these statements.
1925 */
1926 sappend(s1, b->stmts);
1927 b->stmts = s1;
1928 }
1929 }
1930
1931 /*
1932 * At the moment we treat PPI as normal Radiotap encoded
1933 * packets. The difference is in the function that generates
1934 * the code at the beginning to compute the header length.
1935 * Since this code generator of PPI supports bare 802.11
1936 * encapsulation only (i.e. the encapsulated DLT should be
1937 * DLT_IEEE802_11) we generate code to check for this too.
1938 */
1939 static void
1940 insert_ppi_load_llprefixlen(b)
1941 struct block *b;
1942 {
1943 struct slist *s1, *s2;
1944
1945 /*
1946 * Prepend to the statements in this block code to load the
1947 * length of the radiotap header into the register assigned
1948 * to hold that length, if one has been assigned.
1949 */
1950 if (reg_ll_size != -1) {
1951 /*
1952 * The 2 bytes at offsets of 2 and 3 from the beginning
1953 * of the radiotap header are the length of the radiotap
1954 * header; unfortunately, it's little-endian, so we have
1955 * to load it a byte at a time and construct the value.
1956 */
1957
1958 /*
1959 * Load the high-order byte, at an offset of 3, shift it
1960 * left a byte, and put the result in the X register.
1961 */
1962 s1 = new_stmt(BPF_LD|BPF_B|BPF_ABS);
1963 s1->s.k = 3;
1964 s2 = new_stmt(BPF_ALU|BPF_LSH|BPF_K);
1965 sappend(s1, s2);
1966 s2->s.k = 8;
1967 s2 = new_stmt(BPF_MISC|BPF_TAX);
1968 sappend(s1, s2);
1969
1970 /*
1971 * Load the next byte, at an offset of 2, and OR the
1972 * value from the X register into it.
1973 */
1974 s2 = new_stmt(BPF_LD|BPF_B|BPF_ABS);
1975 sappend(s1, s2);
1976 s2->s.k = 2;
1977 s2 = new_stmt(BPF_ALU|BPF_OR|BPF_X);
1978 sappend(s1, s2);
1979
1980 /*
1981 * Now allocate a register to hold that value and store
1982 * it.
1983 */
1984 s2 = new_stmt(BPF_ST);
1985 s2->s.k = reg_ll_size;
1986 sappend(s1, s2);
1987
1988 /*
1989 * Now move it into the X register.
1990 */
1991 s2 = new_stmt(BPF_MISC|BPF_TAX);
1992 sappend(s1, s2);
1993
1994 /*
1995 * Now append all the existing statements in this
1996 * block to these statements.
1997 */
1998 sappend(s1, b->stmts);
1999 b->stmts = s1;
2000
2001 }
2002 }
2003
2004 static struct block *
2005 gen_ppi_dlt_check(void)
2006 {
2007 struct slist *s_load_dlt;
2008 struct block *b;
2009
2010 if (linktype == DLT_PPI)
2011 {
2012 /* Create the statements that check for the DLT
2013 */
2014 s_load_dlt = new_stmt(BPF_LD|BPF_W|BPF_ABS);
2015 s_load_dlt->s.k = 4;
2016
2017 b = new_block(JMP(BPF_JEQ));
2018
2019 b->stmts = s_load_dlt;
2020 b->s.k = SWAPLONG(DLT_IEEE802_11);
2021 }
2022 else
2023 {
2024 b = NULL;
2025 }
2026
2027 return b;
2028 }
2029
2030 static void
2031 insert_load_llprefixlen(b)
2032 struct block *b;
2033 {
2034 switch (linktype) {
2035
2036 /*
2037 * At the moment we treat PPI as normal Radiotap encoded
2038 * packets. The difference is in the function that generates
2039 * the code at the beginning to compute the header length.
2040 * Since this code generator of PPI supports bare 802.11
2041 * encapsulation only (i.e. the encapsulated DLT should be
2042 * DLT_IEEE802_11) we generate code to check for this too.
2043 */
2044 case DLT_PPI:
2045 insert_ppi_load_llprefixlen(b);
2046 break;
2047
2048 case DLT_IEEE802_11_RADIO:
2049 insert_radiotap_load_llprefixlen(b);
2050 break;
2051 }
2052 }
2053
2054
2055 static struct slist *
2056 gen_radiotap_llprefixlen(void)
2057 {
2058 struct slist *s;
2059
2060 if (reg_ll_size == -1) {
2061 /*
2062 * We haven't yet assigned a register for the length
2063 * of the radiotap header; allocate one.
2064 */
2065 reg_ll_size = alloc_reg();
2066 }
2067
2068 /*
2069 * Load the register containing the radiotap length
2070 * into the X register.
2071 */
2072 s = new_stmt(BPF_LDX|BPF_MEM);
2073 s->s.k = reg_ll_size;
2074 return s;
2075 }
2076
2077 /*
2078 * At the moment we treat PPI as normal Radiotap encoded
2079 * packets. The difference is in the function that generates
2080 * the code at the beginning to compute the header length.
2081 * Since this code generator of PPI supports bare 802.11
2082 * encapsulation only (i.e. the encapsulated DLT should be
2083 * DLT_IEEE802_11) we generate code to check for this too.
2084 */
2085 static struct slist *
2086 gen_ppi_llprefixlen(void)
2087 {
2088 struct slist *s;
2089
2090 if (reg_ll_size == -1) {
2091 /*
2092 * We haven't yet assigned a register for the length
2093 * of the radiotap header; allocate one.
2094 */
2095 reg_ll_size = alloc_reg();
2096 }
2097
2098 /*
2099 * Load the register containing the radiotap length
2100 * into the X register.
2101 */
2102 s = new_stmt(BPF_LDX|BPF_MEM);
2103 s->s.k = reg_ll_size;
2104 return s;
2105 }
2106
2107
2108
2109 /*
2110 * Generate code to compute the link-layer header length, if necessary,
2111 * putting it into the X register, and to return either a pointer to a
2112 * "struct slist" for the list of statements in that code, or NULL if
2113 * no code is necessary.
2114 */
2115 static struct slist *
2116 gen_llprefixlen(void)
2117 {
2118 switch (linktype) {
2119
2120 case DLT_PPI:
2121 return gen_ppi_llprefixlen();
2122
2123
2124 case DLT_IEEE802_11_RADIO:
2125 return gen_radiotap_llprefixlen();
2126
2127 default:
2128 return NULL;
2129 }
2130 }
2131
2132 /*
2133 * Generate code to match a particular packet type by matching the
2134 * link-layer type field or fields in the 802.2 LLC header.
2135 *
2136 * "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP
2137 * value, if <= ETHERMTU.
2138 */
2139 static struct block *
2140 gen_linktype(proto)
2141 register int proto;
2142 {
2143 struct block *b0, *b1, *b2;
2144
2145 /* are we checking MPLS-encapsulated packets? */
2146 if (label_stack_depth > 0) {
2147 switch (proto) {
2148 case ETHERTYPE_IP:
2149 case PPP_IP:
2150 /* FIXME add other L3 proto IDs */
2151 return gen_mpls_linktype(Q_IP);
2152
2153 case ETHERTYPE_IPV6:
2154 case PPP_IPV6:
2155 /* FIXME add other L3 proto IDs */
2156 return gen_mpls_linktype(Q_IPV6);
2157
2158 default:
2159 bpf_error("unsupported protocol over mpls");
2160 /* NOTREACHED */
2161 }
2162 }
2163
2164 switch (linktype) {
2165
2166 case DLT_EN10MB:
2167 return gen_ether_linktype(proto);
2168 /*NOTREACHED*/
2169 break;
2170
2171 case DLT_C_HDLC:
2172 switch (proto) {
2173
2174 case LLCSAP_ISONS:
2175 proto = (proto << 8 | LLCSAP_ISONS);
2176 /* fall through */
2177
2178 default:
2179 return gen_cmp(OR_LINK, off_linktype, BPF_H,
2180 (bpf_int32)proto);
2181 /*NOTREACHED*/
2182 break;
2183 }
2184 break;
2185
2186 case DLT_PPI:
2187 case DLT_FDDI:
2188 case DLT_IEEE802:
2189 case DLT_IEEE802_11:
2190 case DLT_IEEE802_11_RADIO_AVS:
2191 case DLT_IEEE802_11_RADIO:
2192 case DLT_PRISM_HEADER:
2193 case DLT_ATM_RFC1483:
2194 case DLT_ATM_CLIP:
2195 case DLT_IP_OVER_FC:
2196 return gen_llc_linktype(proto);
2197 /*NOTREACHED*/
2198 break;
2199
2200 case DLT_SUNATM:
2201 /*
2202 * If "is_lane" is set, check for a LANE-encapsulated
2203 * version of this protocol, otherwise check for an
2204 * LLC-encapsulated version of this protocol.
2205 *
2206 * We assume LANE means Ethernet, not Token Ring.
2207 */
2208 if (is_lane) {
2209 /*
2210 * Check that the packet doesn't begin with an
2211 * LE Control marker. (We've already generated
2212 * a test for LANE.)
2213 */
2214 b0 = gen_cmp(OR_LINK, SUNATM_PKT_BEGIN_POS, BPF_H,
2215 0xFF00);
2216 gen_not(b0);
2217
2218 /*
2219 * Now generate an Ethernet test.
2220 */
2221 b1 = gen_ether_linktype(proto);
2222 gen_and(b0, b1);
2223 return b1;
2224 } else {
2225 /*
2226 * Check for LLC encapsulation and then check the
2227 * protocol.
2228 */
2229 b0 = gen_atmfield_code(A_PROTOTYPE, PT_LLC, BPF_JEQ, 0);
2230 b1 = gen_llc_linktype(proto);
2231 gen_and(b0, b1);
2232 return b1;
2233 }
2234 /*NOTREACHED*/
2235 break;
2236
2237 case DLT_LINUX_SLL:
2238 return gen_linux_sll_linktype(proto);
2239 /*NOTREACHED*/
2240 break;
2241
2242 case DLT_SLIP:
2243 case DLT_SLIP_BSDOS:
2244 case DLT_RAW:
2245 /*
2246 * These types don't provide any type field; packets
2247 * are always IPv4 or IPv6.
2248 *
2249 * XXX - for IPv4, check for a version number of 4, and,
2250 * for IPv6, check for a version number of 6?
2251 */
2252 switch (proto) {
2253
2254 case ETHERTYPE_IP:
2255 /* Check for a version number of 4. */
2256 return gen_mcmp(OR_LINK, 0, BPF_B, 0x40, 0xF0);
2257 #ifdef INET6
2258 case ETHERTYPE_IPV6:
2259 /* Check for a version number of 6. */
2260 return gen_mcmp(OR_LINK, 0, BPF_B, 0x60, 0xF0);
2261 #endif
2262
2263 default:
2264 return gen_false(); /* always false */
2265 }
2266 /*NOTREACHED*/
2267 break;
2268
2269 case DLT_PPP:
2270 case DLT_PPP_PPPD:
2271 case DLT_PPP_SERIAL:
2272 case DLT_PPP_ETHER:
2273 /*
2274 * We use Ethernet protocol types inside libpcap;
2275 * map them to the corresponding PPP protocol types.
2276 */
2277 switch (proto) {
2278
2279 case ETHERTYPE_IP:
2280 proto = PPP_IP;
2281 break;
2282
2283 #ifdef INET6
2284 case ETHERTYPE_IPV6:
2285 proto = PPP_IPV6;
2286 break;
2287 #endif
2288
2289 case ETHERTYPE_DN:
2290 proto = PPP_DECNET;
2291 break;
2292
2293 case ETHERTYPE_ATALK:
2294 proto = PPP_APPLE;
2295 break;
2296
2297 case ETHERTYPE_NS:
2298 proto = PPP_NS;
2299 break;
2300
2301 case LLCSAP_ISONS:
2302 proto = PPP_OSI;
2303 break;
2304
2305 case LLCSAP_8021D:
2306 /*
2307 * I'm assuming the "Bridging PDU"s that go
2308 * over PPP are Spanning Tree Protocol
2309 * Bridging PDUs.
2310 */
2311 proto = PPP_BRPDU;
2312 break;
2313
2314 case LLCSAP_IPX:
2315 proto = PPP_IPX;
2316 break;
2317 }
2318 break;
2319
2320 case DLT_PPP_BSDOS:
2321 /*
2322 * We use Ethernet protocol types inside libpcap;
2323 * map them to the corresponding PPP protocol types.
2324 */
2325 switch (proto) {
2326
2327 case ETHERTYPE_IP:
2328 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, PPP_IP);
2329 b1 = gen_cmp(OR_LINK, off_linktype, BPF_H, PPP_VJC);
2330 gen_or(b0, b1);
2331 b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, PPP_VJNC);
2332 gen_or(b1, b0);
2333 return b0;
2334
2335 #ifdef INET6
2336 case ETHERTYPE_IPV6:
2337 proto = PPP_IPV6;
2338 /* more to go? */
2339 break;
2340 #endif
2341
2342 case ETHERTYPE_DN:
2343 proto = PPP_DECNET;
2344 break;
2345
2346 case ETHERTYPE_ATALK:
2347 proto = PPP_APPLE;
2348 break;
2349
2350 case ETHERTYPE_NS:
2351 proto = PPP_NS;
2352 break;
2353
2354 case LLCSAP_ISONS:
2355 proto = PPP_OSI;
2356 break;
2357
2358 case LLCSAP_8021D:
2359 /*
2360 * I'm assuming the "Bridging PDU"s that go
2361 * over PPP are Spanning Tree Protocol
2362 * Bridging PDUs.
2363 */
2364 proto = PPP_BRPDU;
2365 break;
2366
2367 case LLCSAP_IPX:
2368 proto = PPP_IPX;
2369 break;
2370 }
2371 break;
2372
2373 case DLT_NULL:
2374 case DLT_LOOP:
2375 case DLT_ENC:
2376 /*
2377 * For DLT_NULL, the link-layer header is a 32-bit
2378 * word containing an AF_ value in *host* byte order,
2379 * and for DLT_ENC, the link-layer header begins
2380 * with a 32-bit work containing an AF_ value in
2381 * host byte order.
2382 *
2383 * In addition, if we're reading a saved capture file,
2384 * the host byte order in the capture may not be the
2385 * same as the host byte order on this machine.
2386 *
2387 * For DLT_LOOP, the link-layer header is a 32-bit
2388 * word containing an AF_ value in *network* byte order.
2389 *
2390 * XXX - AF_ values may, unfortunately, be platform-
2391 * dependent; for example, FreeBSD's AF_INET6 is 24
2392 * whilst NetBSD's and OpenBSD's is 26.
2393 *
2394 * This means that, when reading a capture file, just
2395 * checking for our AF_INET6 value won't work if the
2396 * capture file came from another OS.
2397 */
2398 switch (proto) {
2399
2400 case ETHERTYPE_IP:
2401 proto = AF_INET;
2402 break;
2403
2404 #ifdef INET6
2405 case ETHERTYPE_IPV6:
2406 proto = AF_INET6;
2407 break;
2408 #endif
2409
2410 default:
2411 /*
2412 * Not a type on which we support filtering.
2413 * XXX - support those that have AF_ values
2414 * #defined on this platform, at least?
2415 */
2416 return gen_false();
2417 }
2418
2419 if (linktype == DLT_NULL || linktype == DLT_ENC) {
2420 /*
2421 * The AF_ value is in host byte order, but
2422 * the BPF interpreter will convert it to
2423 * network byte order.
2424 *
2425 * If this is a save file, and it's from a
2426 * machine with the opposite byte order to
2427 * ours, we byte-swap the AF_ value.
2428 *
2429 * Then we run it through "htonl()", and
2430 * generate code to compare against the result.
2431 */
2432 if (bpf_pcap->sf.rfile != NULL &&
2433 bpf_pcap->sf.swapped)
2434 proto = SWAPLONG(proto);
2435 proto = htonl(proto);
2436 }
2437 return (gen_cmp(OR_LINK, 0, BPF_W, (bpf_int32)proto));
2438
2439 #ifdef HAVE_NET_PFVAR_H
2440 case DLT_PFLOG:
2441 /*
2442 * af field is host byte order in contrast to the rest of
2443 * the packet.
2444 */
2445 if (proto == ETHERTYPE_IP)
2446 return (gen_cmp(OR_LINK, offsetof(struct pfloghdr, af),
2447 BPF_B, (bpf_int32)AF_INET));
2448 #ifdef INET6
2449 else if (proto == ETHERTYPE_IPV6)
2450 return (gen_cmp(OR_LINK, offsetof(struct pfloghdr, af),
2451 BPF_B, (bpf_int32)AF_INET6));
2452 #endif /* INET6 */
2453 else
2454 return gen_false();
2455 /*NOTREACHED*/
2456 break;
2457 #endif /* HAVE_NET_PFVAR_H */
2458
2459 case DLT_ARCNET:
2460 case DLT_ARCNET_LINUX:
2461 /*
2462 * XXX should we check for first fragment if the protocol
2463 * uses PHDS?
2464 */
2465 switch (proto) {
2466
2467 default:
2468 return gen_false();
2469
2470 #ifdef INET6
2471 case ETHERTYPE_IPV6:
2472 return (gen_cmp(OR_LINK, off_linktype, BPF_B,
2473 (bpf_int32)ARCTYPE_INET6));
2474 #endif /* INET6 */
2475
2476 case ETHERTYPE_IP:
2477 b0 = gen_cmp(OR_LINK, off_linktype, BPF_B,
2478 (bpf_int32)ARCTYPE_IP);
2479 b1 = gen_cmp(OR_LINK, off_linktype, BPF_B,
2480 (bpf_int32)ARCTYPE_IP_OLD);
2481 gen_or(b0, b1);
2482 return (b1);
2483
2484 case ETHERTYPE_ARP:
2485 b0 = gen_cmp(OR_LINK, off_linktype, BPF_B,
2486 (bpf_int32)ARCTYPE_ARP);
2487 b1 = gen_cmp(OR_LINK, off_linktype, BPF_B,
2488 (bpf_int32)ARCTYPE_ARP_OLD);
2489 gen_or(b0, b1);
2490 return (b1);
2491
2492 case ETHERTYPE_REVARP:
2493 return (gen_cmp(OR_LINK, off_linktype, BPF_B,
2494 (bpf_int32)ARCTYPE_REVARP));
2495
2496 case ETHERTYPE_ATALK:
2497 return (gen_cmp(OR_LINK, off_linktype, BPF_B,
2498 (bpf_int32)ARCTYPE_ATALK));
2499 }
2500 /*NOTREACHED*/
2501 break;
2502
2503 case DLT_LTALK:
2504 switch (proto) {
2505 case ETHERTYPE_ATALK:
2506 return gen_true();
2507 default:
2508 return gen_false();
2509 }
2510 /*NOTREACHED*/
2511 break;
2512
2513 case DLT_FRELAY:
2514 /*
2515 * XXX - assumes a 2-byte Frame Relay header with
2516 * DLCI and flags. What if the address is longer?
2517 */
2518 switch (proto) {
2519
2520 case ETHERTYPE_IP:
2521 /*
2522 * Check for the special NLPID for IP.
2523 */
2524 return gen_cmp(OR_LINK, 2, BPF_H, (0x03<<8) | 0xcc);
2525
2526 #ifdef INET6
2527 case ETHERTYPE_IPV6:
2528 /*
2529 * Check for the special NLPID for IPv6.
2530 */
2531 return gen_cmp(OR_LINK, 2, BPF_H, (0x03<<8) | 0x8e);
2532 #endif
2533
2534 case LLCSAP_ISONS:
2535 /*
2536 * Check for several OSI protocols.
2537 *
2538 * Frame Relay packets typically have an OSI
2539 * NLPID at the beginning; we check for each
2540 * of them.
2541 *
2542 * What we check for is the NLPID and a frame
2543 * control field of UI, i.e. 0x03 followed
2544 * by the NLPID.
2545 */
2546 b0 = gen_cmp(OR_LINK, 2, BPF_H, (0x03<<8) | ISO8473_CLNP);
2547 b1 = gen_cmp(OR_LINK, 2, BPF_H, (0x03<<8) | ISO9542_ESIS);
2548 b2 = gen_cmp(OR_LINK, 2, BPF_H, (0x03<<8) | ISO10589_ISIS);
2549 gen_or(b1, b2);
2550 gen_or(b0, b2);
2551 return b2;
2552
2553 default:
2554 return gen_false();
2555 }
2556 /*NOTREACHED*/
2557 break;
2558
2559 case DLT_JUNIPER_MFR:
2560 case DLT_JUNIPER_MLFR:
2561 case DLT_JUNIPER_MLPPP:
2562 case DLT_JUNIPER_ATM1:
2563 case DLT_JUNIPER_ATM2:
2564 case DLT_JUNIPER_PPPOE:
2565 case DLT_JUNIPER_PPPOE_ATM:
2566 case DLT_JUNIPER_GGSN:
2567 case DLT_JUNIPER_ES:
2568 case DLT_JUNIPER_MONITOR:
2569 case DLT_JUNIPER_SERVICES:
2570 case DLT_JUNIPER_ETHER:
2571 case DLT_JUNIPER_PPP:
2572 case DLT_JUNIPER_FRELAY:
2573 case DLT_JUNIPER_CHDLC:
2574 case DLT_JUNIPER_VP:
2575 /* just lets verify the magic number for now -
2576 * on ATM we may have up to 6 different encapsulations on the wire
2577 * and need a lot of heuristics to figure out that the payload
2578 * might be;
2579 *
2580 * FIXME encapsulation specific BPF_ filters
2581 */
2582 return gen_mcmp(OR_LINK, 0, BPF_W, 0x4d474300, 0xffffff00); /* compare the magic number */
2583
2584 case DLT_LINUX_IRDA:
2585 bpf_error("IrDA link-layer type filtering not implemented");
2586
2587 case DLT_DOCSIS:
2588 bpf_error("DOCSIS link-layer type filtering not implemented");
2589
2590 case DLT_LINUX_LAPD:
2591 bpf_error("LAPD link-layer type filtering not implemented");
2592 }
2593
2594 /*
2595 * All the types that have no encapsulation should either be
2596 * handled as DLT_SLIP, DLT_SLIP_BSDOS, and DLT_RAW are, if
2597 * all packets are IP packets, or should be handled in some
2598 * special case, if none of them are (if some are and some
2599 * aren't, the lack of encapsulation is a problem, as we'd
2600 * have to find some other way of determining the packet type).
2601 *
2602 * Therefore, if "off_linktype" is -1, there's an error.
2603 */
2604 if (off_linktype == (u_int)-1)
2605 abort();
2606
2607 /*
2608 * Any type not handled above should always have an Ethernet
2609 * type at an offset of "off_linktype". (PPP is partially
2610 * handled above - the protocol type is mapped from the
2611 * Ethernet and LLC types we use internally to the corresponding
2612 * PPP type - but the PPP type is always specified by a value
2613 * at "off_linktype", so we don't have to do the code generation
2614 * above.)
2615 */
2616 return gen_cmp(OR_LINK, off_linktype, BPF_H, (bpf_int32)proto);
2617 }
2618
2619 /*
2620 * Check for an LLC SNAP packet with a given organization code and
2621 * protocol type; we check the entire contents of the 802.2 LLC and
2622 * snap headers, checking for DSAP and SSAP of SNAP and a control
2623 * field of 0x03 in the LLC header, and for the specified organization
2624 * code and protocol type in the SNAP header.
2625 */
2626 static struct block *
2627 gen_snap(orgcode, ptype, offset)
2628 bpf_u_int32 orgcode;
2629 bpf_u_int32 ptype;
2630 u_int offset;
2631 {
2632 u_char snapblock[8];
2633
2634 snapblock[0] = LLCSAP_SNAP; /* DSAP = SNAP */
2635 snapblock[1] = LLCSAP_SNAP; /* SSAP = SNAP */
2636 snapblock[2] = 0x03; /* control = UI */
2637 snapblock[3] = (orgcode >> 16); /* upper 8 bits of organization code */
2638 snapblock[4] = (orgcode >> 8); /* middle 8 bits of organization code */
2639 snapblock[5] = (orgcode >> 0); /* lower 8 bits of organization code */
2640 snapblock[6] = (ptype >> 8); /* upper 8 bits of protocol type */
2641 snapblock[7] = (ptype >> 0); /* lower 8 bits of protocol type */
2642 return gen_bcmp(OR_LINK, offset, 8, snapblock);
2643 }
2644
2645 /*
2646 * Generate code to match a particular packet type, for link-layer types
2647 * using 802.2 LLC headers.
2648 *
2649 * This is *NOT* used for Ethernet; "gen_ether_linktype()" is used
2650 * for that - it handles the D/I/X Ethernet vs. 802.3+802.2 issues.
2651 *
2652 * "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP
2653 * value, if <= ETHERMTU. We use that to determine whether to
2654 * match the DSAP or both DSAP and LSAP or to check the OUI and
2655 * protocol ID in a SNAP header.
2656 */
2657 static struct block *
2658 gen_llc_linktype(proto)
2659 int proto;
2660 {
2661 /*
2662 * XXX - handle token-ring variable-length header.
2663 */
2664 switch (proto) {
2665
2666 case LLCSAP_IP:
2667 case LLCSAP_ISONS:
2668 case LLCSAP_NETBEUI:
2669 /*
2670 * XXX - should we check both the DSAP and the
2671 * SSAP, like this, or should we check just the
2672 * DSAP, as we do for other types <= ETHERMTU
2673 * (i.e., other SAP values)?
2674 */
2675 return gen_cmp(OR_LINK, off_linktype, BPF_H, (bpf_u_int32)
2676 ((proto << 8) | proto));
2677
2678 case LLCSAP_IPX:
2679 /*
2680 * XXX - are there ever SNAP frames for IPX on
2681 * non-Ethernet 802.x networks?
2682 */
2683 return gen_cmp(OR_LINK, off_linktype, BPF_B,
2684 (bpf_int32)LLCSAP_IPX);
2685
2686 case ETHERTYPE_ATALK:
2687 /*
2688 * 802.2-encapsulated ETHERTYPE_ATALK packets are
2689 * SNAP packets with an organization code of
2690 * 0x080007 (Apple, for Appletalk) and a protocol
2691 * type of ETHERTYPE_ATALK (Appletalk).
2692 *
2693 * XXX - check for an organization code of
2694 * encapsulated Ethernet as well?
2695 */
2696 return gen_snap(0x080007, ETHERTYPE_ATALK, off_linktype);
2697
2698 default:
2699 /*
2700 * XXX - we don't have to check for IPX 802.3
2701 * here, but should we check for the IPX Ethertype?
2702 */
2703 if (proto <= ETHERMTU) {
2704 /*
2705 * This is an LLC SAP value, so check
2706 * the DSAP.
2707 */
2708 return gen_cmp(OR_LINK, off_linktype, BPF_B,
2709 (bpf_int32)proto);
2710 } else {
2711 /*
2712 * This is an Ethernet type; we assume that it's
2713 * unlikely that it'll appear in the right place
2714 * at random, and therefore check only the
2715 * location that would hold the Ethernet type
2716 * in a SNAP frame with an organization code of
2717 * 0x000000 (encapsulated Ethernet).
2718 *
2719 * XXX - if we were to check for the SNAP DSAP and
2720 * LSAP, as per XXX, and were also to check for an
2721 * organization code of 0x000000 (encapsulated
2722 * Ethernet), we'd do
2723 *
2724 * return gen_snap(0x000000, proto,
2725 * off_linktype);
2726 *
2727 * here; for now, we don't, as per the above.
2728 * I don't know whether it's worth the extra CPU
2729 * time to do the right check or not.
2730 */
2731 return gen_cmp(OR_LINK, off_linktype+6, BPF_H,
2732 (bpf_int32)proto);
2733 }
2734 }
2735 }
2736
2737 static struct block *
2738 gen_hostop(addr, mask, dir, proto, src_off, dst_off)
2739 bpf_u_int32 addr;
2740 bpf_u_int32 mask;
2741 int dir, proto;
2742 u_int src_off, dst_off;
2743 {
2744 struct block *b0, *b1;
2745 u_int offset;
2746
2747 switch (dir) {
2748
2749 case Q_SRC:
2750 offset = src_off;
2751 break;
2752
2753 case Q_DST:
2754 offset = dst_off;
2755 break;
2756
2757 case Q_AND:
2758 b0 = gen_hostop(addr, mask, Q_SRC, proto, src_off, dst_off);
2759 b1 = gen_hostop(addr, mask, Q_DST, proto, src_off, dst_off);
2760 gen_and(b0, b1);
2761 return b1;
2762
2763 case Q_OR:
2764 case Q_DEFAULT:
2765 b0 = gen_hostop(addr, mask, Q_SRC, proto, src_off, dst_off);
2766 b1 = gen_hostop(addr, mask, Q_DST, proto, src_off, dst_off);
2767 gen_or(b0, b1);
2768 return b1;
2769
2770 default:
2771 abort();
2772 }
2773 b0 = gen_linktype(proto);
2774 b1 = gen_mcmp(OR_NET, offset, BPF_W, (bpf_int32)addr, mask);
2775 gen_and(b0, b1);
2776 return b1;
2777 }
2778
2779 #ifdef INET6
2780 static struct block *
2781 gen_hostop6(addr, mask, dir, proto, src_off, dst_off)
2782 struct in6_addr *addr;
2783 struct in6_addr *mask;
2784 int dir, proto;
2785 u_int src_off, dst_off;
2786 {
2787 struct block *b0, *b1;
2788 u_int offset;
2789 u_int32_t *a, *m;
2790
2791 switch (dir) {
2792
2793 case Q_SRC:
2794 offset = src_off;
2795 break;
2796
2797 case Q_DST:
2798 offset = dst_off;
2799 break;
2800
2801 case Q_AND:
2802 b0 = gen_hostop6(addr, mask, Q_SRC, proto, src_off, dst_off);
2803 b1 = gen_hostop6(addr, mask, Q_DST, proto, src_off, dst_off);
2804 gen_and(b0, b1);
2805 return b1;
2806
2807 case Q_OR:
2808 case Q_DEFAULT:
2809 b0 = gen_hostop6(addr, mask, Q_SRC, proto, src_off, dst_off);
2810 b1 = gen_hostop6(addr, mask, Q_DST, proto, src_off, dst_off);
2811 gen_or(b0, b1);
2812 return b1;
2813
2814 default:
2815 abort();
2816 }
2817 /* this order is important */
2818 a = (u_int32_t *)addr;
2819 m = (u_int32_t *)mask;
2820 b1 = gen_mcmp(OR_NET, offset + 12, BPF_W, ntohl(a[3]), ntohl(m[3]));
2821 b0 = gen_mcmp(OR_NET, offset + 8, BPF_W, ntohl(a[2]), ntohl(m[2]));
2822 gen_and(b0, b1);
2823 b0 = gen_mcmp(OR_NET, offset + 4, BPF_W, ntohl(a[1]), ntohl(m[1]));
2824 gen_and(b0, b1);
2825 b0 = gen_mcmp(OR_NET, offset + 0, BPF_W, ntohl(a[0]), ntohl(m[0]));
2826 gen_and(b0, b1);
2827 b0 = gen_linktype(proto);
2828 gen_and(b0, b1);
2829 return b1;
2830 }
2831 #endif /*INET6*/
2832
2833 static struct block *
2834 gen_ehostop(eaddr, dir)
2835 register const u_char *eaddr;
2836 register int dir;
2837 {
2838 register struct block *b0, *b1;
2839
2840 switch (dir) {
2841 case Q_SRC:
2842 return gen_bcmp(OR_LINK, off_mac + 6, 6, eaddr);
2843
2844 case Q_DST:
2845 return gen_bcmp(OR_LINK, off_mac + 0, 6, eaddr);
2846
2847 case Q_AND:
2848 b0 = gen_ehostop(eaddr, Q_SRC);
2849 b1 = gen_ehostop(eaddr, Q_DST);
2850 gen_and(b0, b1);
2851 return b1;
2852
2853 case Q_DEFAULT:
2854 case Q_OR:
2855 b0 = gen_ehostop(eaddr, Q_SRC);
2856 b1 = gen_ehostop(eaddr, Q_DST);
2857 gen_or(b0, b1);
2858 return b1;
2859 }
2860 abort();
2861 /* NOTREACHED */
2862 }
2863
2864 /*
2865 * Like gen_ehostop, but for DLT_FDDI
2866 */
2867 static struct block *
2868 gen_fhostop(eaddr, dir)
2869 register const u_char *eaddr;
2870 register int dir;
2871 {
2872 struct block *b0, *b1;
2873
2874 switch (dir) {
2875 case Q_SRC:
2876 #ifdef PCAP_FDDIPAD
2877 return gen_bcmp(OR_LINK, 6 + 1 + pcap_fddipad, 6, eaddr);
2878 #else
2879 return gen_bcmp(OR_LINK, 6 + 1, 6, eaddr);
2880 #endif
2881
2882 case Q_DST:
2883 #ifdef PCAP_FDDIPAD
2884 return gen_bcmp(OR_LINK, 0 + 1 + pcap_fddipad, 6, eaddr);
2885 #else
2886 return gen_bcmp(OR_LINK, 0 + 1, 6, eaddr);
2887 #endif
2888
2889 case Q_AND:
2890 b0 = gen_fhostop(eaddr, Q_SRC);
2891 b1 = gen_fhostop(eaddr, Q_DST);
2892 gen_and(b0, b1);
2893 return b1;
2894
2895 case Q_DEFAULT:
2896 case Q_OR:
2897 b0 = gen_fhostop(eaddr, Q_SRC);
2898 b1 = gen_fhostop(eaddr, Q_DST);
2899 gen_or(b0, b1);
2900 return b1;
2901 }
2902 abort();
2903 /* NOTREACHED */
2904 }
2905
2906 /*
2907 * Like gen_ehostop, but for DLT_IEEE802 (Token Ring)
2908 */
2909 static struct block *
2910 gen_thostop(eaddr, dir)
2911 register const u_char *eaddr;
2912 register int dir;
2913 {
2914 register struct block *b0, *b1;
2915
2916 switch (dir) {
2917 case Q_SRC:
2918 return gen_bcmp(OR_LINK, 8, 6, eaddr);
2919
2920 case Q_DST:
2921 return gen_bcmp(OR_LINK, 2, 6, eaddr);
2922
2923 case Q_AND:
2924 b0 = gen_thostop(eaddr, Q_SRC);
2925 b1 = gen_thostop(eaddr, Q_DST);
2926 gen_and(b0, b1);
2927 return b1;
2928
2929 case Q_DEFAULT:
2930 case Q_OR:
2931 b0 = gen_thostop(eaddr, Q_SRC);
2932 b1 = gen_thostop(eaddr, Q_DST);
2933 gen_or(b0, b1);
2934 return b1;
2935 }
2936 abort();
2937 /* NOTREACHED */
2938 }
2939
2940 /*
2941 * Like gen_ehostop, but for DLT_IEEE802_11 (802.11 wireless LAN)
2942 */
2943 static struct block *
2944 gen_wlanhostop(eaddr, dir)
2945 register const u_char *eaddr;
2946 register int dir;
2947 {
2948 register struct block *b0, *b1, *b2;
2949 register struct slist *s;
2950
2951 switch (dir) {
2952 case Q_SRC:
2953 /*
2954 * Oh, yuk.
2955 *
2956 * For control frames, there is no SA.
2957 *
2958 * For management frames, SA is at an
2959 * offset of 10 from the beginning of
2960 * the packet.
2961 *
2962 * For data frames, SA is at an offset
2963 * of 10 from the beginning of the packet
2964 * if From DS is clear, at an offset of
2965 * 16 from the beginning of the packet
2966 * if From DS is set and To DS is clear,
2967 * and an offset of 24 from the beginning
2968 * of the packet if From DS is set and To DS
2969 * is set.
2970 */
2971
2972 /*
2973 * Generate the tests to be done for data frames
2974 * with From DS set.
2975 *
2976 * First, check for To DS set, i.e. check "link[1] & 0x01".
2977 */
2978 s = gen_load_a(OR_LINK, 1, BPF_B);
2979 b1 = new_block(JMP(BPF_JSET));
2980 b1->s.k = 0x01; /* To DS */
2981 b1->stmts = s;
2982
2983 /*
2984 * If To DS is set, the SA is at 24.
2985 */
2986 b0 = gen_bcmp(OR_LINK, 24, 6, eaddr);
2987 gen_and(b1, b0);
2988
2989 /*
2990 * Now, check for To DS not set, i.e. check
2991 * "!(link[1] & 0x01)".
2992 */
2993 s = gen_load_a(OR_LINK, 1, BPF_B);
2994 b2 = new_block(JMP(BPF_JSET));
2995 b2->s.k = 0x01; /* To DS */
2996 b2->stmts = s;
2997 gen_not(b2);
2998
2999 /*
3000 * If To DS is not set, the SA is at 16.
3001 */
3002 b1 = gen_bcmp(OR_LINK, 16, 6, eaddr);
3003 gen_and(b2, b1);
3004
3005 /*
3006 * Now OR together the last two checks. That gives
3007 * the complete set of checks for data frames with
3008 * From DS set.
3009 */
3010 gen_or(b1, b0);
3011
3012 /*
3013 * Now check for From DS being set, and AND that with
3014 * the ORed-together checks.
3015 */
3016 s = gen_load_a(OR_LINK, 1, BPF_B);
3017 b1 = new_block(JMP(BPF_JSET));
3018 b1->s.k = 0x02; /* From DS */
3019 b1->stmts = s;
3020 gen_and(b1, b0);
3021
3022 /*
3023 * Now check for data frames with From DS not set.
3024 */
3025 s = gen_load_a(OR_LINK, 1, BPF_B);
3026 b2 = new_block(JMP(BPF_JSET));
3027 b2->s.k = 0x02; /* From DS */
3028 b2->stmts = s;
3029 gen_not(b2);
3030
3031 /*
3032 * If From DS isn't set, the SA is at 10.
3033 */
3034 b1 = gen_bcmp(OR_LINK, 10, 6, eaddr);
3035 gen_and(b2, b1);
3036
3037 /*
3038 * Now OR together the checks for data frames with
3039 * From DS not set and for data frames with From DS
3040 * set; that gives the checks done for data frames.
3041 */
3042 gen_or(b1, b0);
3043
3044 /*
3045 * Now check for a data frame.
3046 * I.e, check "link[0] & 0x08".
3047 */
3048 gen_load_a(OR_LINK, 0, BPF_B);
3049 b1 = new_block(JMP(BPF_JSET));
3050 b1->s.k = 0x08;
3051 b1->stmts = s;
3052
3053 /*
3054 * AND that with the checks done for data frames.
3055 */
3056 gen_and(b1, b0);
3057
3058 /*
3059 * If the high-order bit of the type value is 0, this
3060 * is a management frame.
3061 * I.e, check "!(link[0] & 0x08)".
3062 */
3063 s = gen_load_a(OR_LINK, 0, BPF_B);
3064 b2 = new_block(JMP(BPF_JSET));
3065 b2->s.k = 0x08;
3066 b2->stmts = s;
3067 gen_not(b2);
3068
3069 /*
3070 * For management frames, the SA is at 10.
3071 */
3072 b1 = gen_bcmp(OR_LINK, 10, 6, eaddr);
3073 gen_and(b2, b1);
3074
3075 /*
3076 * OR that with the checks done for data frames.
3077 * That gives the checks done for management and
3078 * data frames.
3079 */
3080 gen_or(b1, b0);
3081
3082 /*
3083 * If the low-order bit of the type value is 1,
3084 * this is either a control frame or a frame
3085 * with a reserved type, and thus not a
3086 * frame with an SA.
3087 *
3088 * I.e., check "!(link[0] & 0x04)".
3089 */
3090 s = gen_load_a(OR_LINK, 0, BPF_B);
3091 b1 = new_block(JMP(BPF_JSET));
3092 b1->s.k = 0x04;
3093 b1->stmts = s;
3094 gen_not(b1);
3095
3096 /*
3097 * AND that with the checks for data and management
3098 * frames.
3099 */
3100 gen_and(b1, b0);
3101 return b0;
3102
3103 case Q_DST:
3104 /*
3105 * Oh, yuk.
3106 *
3107 * For control frames, there is no DA.
3108 *
3109 * For management frames, DA is at an
3110 * offset of 4 from the beginning of
3111 * the packet.
3112 *
3113 * For data frames, DA is at an offset
3114 * of 4 from the beginning of the packet
3115 * if To DS is clear and at an offset of
3116 * 16 from the beginning of the packet
3117 * if To DS is set.
3118 */
3119
3120 /*
3121 * Generate the tests to be done for data frames.
3122 *
3123 * First, check for To DS set, i.e. "link[1] & 0x01".
3124 */
3125 s = gen_load_a(OR_LINK, 1, BPF_B);
3126 b1 = new_block(JMP(BPF_JSET));
3127 b1->s.k = 0x01; /* To DS */
3128 b1->stmts = s;
3129
3130 /*
3131 * If To DS is set, the DA is at 16.
3132 */
3133 b0 = gen_bcmp(OR_LINK, 16, 6, eaddr);
3134 gen_and(b1, b0);
3135
3136 /*
3137 * Now, check for To DS not set, i.e. check
3138 * "!(link[1] & 0x01)".
3139 */
3140 s = gen_load_a(OR_LINK, 1, BPF_B);
3141 b2 = new_block(JMP(BPF_JSET));
3142 b2->s.k = 0x01; /* To DS */
3143 b2->stmts = s;
3144 gen_not(b2);
3145
3146 /*
3147 * If To DS is not set, the DA is at 4.
3148 */
3149 b1 = gen_bcmp(OR_LINK, 4, 6, eaddr);
3150 gen_and(b2, b1);
3151
3152 /*
3153 * Now OR together the last two checks. That gives
3154 * the complete set of checks for data frames.
3155 */
3156 gen_or(b1, b0);
3157
3158 /*
3159 * Now check for a data frame.
3160 * I.e, check "link[0] & 0x08".
3161 */
3162 s = gen_load_a(OR_LINK, 0, BPF_B);
3163 b1 = new_block(JMP(BPF_JSET));
3164 b1->s.k = 0x08;
3165 b1->stmts = s;
3166
3167 /*
3168 * AND that with the checks done for data frames.
3169 */
3170 gen_and(b1, b0);
3171
3172 /*
3173 * If the high-order bit of the type value is 0, this
3174 * is a management frame.
3175 * I.e, check "!(link[0] & 0x08)".
3176 */
3177 s = gen_load_a(OR_LINK, 0, BPF_B);
3178 b2 = new_block(JMP(BPF_JSET));
3179 b2->s.k = 0x08;
3180 b2->stmts = s;
3181 gen_not(b2);
3182
3183 /*
3184 * For management frames, the DA is at 4.
3185 */
3186 b1 = gen_bcmp(OR_LINK, 4, 6, eaddr);
3187 gen_and(b2, b1);
3188
3189 /*
3190 * OR that with the checks done for data frames.
3191 * That gives the checks done for management and
3192 * data frames.
3193 */
3194 gen_or(b1, b0);
3195
3196 /*
3197 * If the low-order bit of the type value is 1,
3198 * this is either a control frame or a frame
3199 * with a reserved type, and thus not a
3200 * frame with an SA.
3201 *
3202 * I.e., check "!(link[0] & 0x04)".
3203 */
3204 s = gen_load_a(OR_LINK, 0, BPF_B);
3205 b1 = new_block(JMP(BPF_JSET));
3206 b1->s.k = 0x04;
3207 b1->stmts = s;
3208 gen_not(b1);
3209
3210 /*
3211 * AND that with the checks for data and management
3212 * frames.
3213 */
3214 gen_and(b1, b0);
3215 return b0;
3216
3217 case Q_AND:
3218 b0 = gen_wlanhostop(eaddr, Q_SRC);
3219 b1 = gen_wlanhostop(eaddr, Q_DST);
3220 gen_and(b0, b1);
3221 return b1;
3222
3223 case Q_DEFAULT:
3224 case Q_OR:
3225 b0 = gen_wlanhostop(eaddr, Q_SRC);
3226 b1 = gen_wlanhostop(eaddr, Q_DST);
3227 gen_or(b0, b1);
3228 return b1;
3229 }
3230 abort();
3231 /* NOTREACHED */
3232 }
3233
3234 /*
3235 * Like gen_ehostop, but for RFC 2625 IP-over-Fibre-Channel.
3236 * (We assume that the addresses are IEEE 48-bit MAC addresses,
3237 * as the RFC states.)
3238 */
3239 static struct block *
3240 gen_ipfchostop(eaddr, dir)
3241 register const u_char *eaddr;
3242 register int dir;
3243 {
3244 register struct block *b0, *b1;
3245
3246 switch (dir) {
3247 case Q_SRC:
3248 return gen_bcmp(OR_LINK, 10, 6, eaddr);
3249
3250 case Q_DST:
3251 return gen_bcmp(OR_LINK, 2, 6, eaddr);
3252
3253 case Q_AND:
3254 b0 = gen_ipfchostop(eaddr, Q_SRC);
3255 b1 = gen_ipfchostop(eaddr, Q_DST);
3256 gen_and(b0, b1);
3257 return b1;
3258
3259 case Q_DEFAULT:
3260 case Q_OR:
3261 b0 = gen_ipfchostop(eaddr, Q_SRC);
3262 b1 = gen_ipfchostop(eaddr, Q_DST);
3263 gen_or(b0, b1);
3264 return b1;
3265 }
3266 abort();
3267 /* NOTREACHED */
3268 }
3269
3270 /*
3271 * This is quite tricky because there may be pad bytes in front of the
3272 * DECNET header, and then there are two possible data packet formats that
3273 * carry both src and dst addresses, plus 5 packet types in a format that
3274 * carries only the src node, plus 2 types that use a different format and
3275 * also carry just the src node.
3276 *
3277 * Yuck.
3278 *
3279 * Instead of doing those all right, we just look for data packets with
3280 * 0 or 1 bytes of padding. If you want to look at other packets, that
3281 * will require a lot more hacking.
3282 *
3283 * To add support for filtering on DECNET "areas" (network numbers)
3284 * one would want to add a "mask" argument to this routine. That would
3285 * make the filter even more inefficient, although one could be clever
3286 * and not generate masking instructions if the mask is 0xFFFF.
3287 */
3288 static struct block *
3289 gen_dnhostop(addr, dir)
3290 bpf_u_int32 addr;
3291 int dir;
3292 {
3293 struct block *b0, *b1, *b2, *tmp;
3294 u_int offset_lh; /* offset if long header is received */
3295 u_int offset_sh; /* offset if short header is received */
3296
3297 switch (dir) {
3298
3299 case Q_DST:
3300 offset_sh = 1; /* follows flags */
3301 offset_lh = 7; /* flgs,darea,dsubarea,HIORD */
3302 break;
3303
3304 case Q_SRC:
3305 offset_sh = 3; /* follows flags, dstnode */
3306 offset_lh = 15; /* flgs,darea,dsubarea,did,sarea,ssub,HIORD */
3307 break;
3308
3309 case Q_AND:
3310 /* Inefficient because we do our Calvinball dance twice */
3311 b0 = gen_dnhostop(addr, Q_SRC);
3312 b1 = gen_dnhostop(addr, Q_DST);
3313 gen_and(b0, b1);
3314 return b1;
3315
3316 case Q_OR:
3317 case Q_DEFAULT:
3318 /* Inefficient because we do our Calvinball dance twice */
3319 b0 = gen_dnhostop(addr, Q_SRC);
3320 b1 = gen_dnhostop(addr, Q_DST);
3321 gen_or(b0, b1);
3322 return b1;
3323
3324 case Q_ISO:
3325 bpf_error("ISO host filtering not implemented");
3326
3327 default:
3328 abort();
3329 }
3330 b0 = gen_linktype(ETHERTYPE_DN);
3331 /* Check for pad = 1, long header case */
3332 tmp = gen_mcmp(OR_NET, 2, BPF_H,
3333 (bpf_int32)ntohs(0x0681), (bpf_int32)ntohs(0x07FF));
3334 b1 = gen_cmp(OR_NET, 2 + 1 + offset_lh,
3335 BPF_H, (bpf_int32)ntohs((u_short)addr));
3336 gen_and(tmp, b1);
3337 /* Check for pad = 0, long header case */
3338 tmp = gen_mcmp(OR_NET, 2, BPF_B, (bpf_int32)0x06, (bpf_int32)0x7);
3339 b2 = gen_cmp(OR_NET, 2 + offset_lh, BPF_H, (bpf_int32)ntohs((u_short)addr));
3340 gen_and(tmp, b2);
3341 gen_or(b2, b1);
3342 /* Check for pad = 1, short header case */
3343 tmp = gen_mcmp(OR_NET, 2, BPF_H,
3344 (bpf_int32)ntohs(0x0281), (bpf_int32)ntohs(0x07FF));
3345 b2 = gen_cmp(OR_NET, 2 + 1 + offset_sh, BPF_H, (bpf_int32)ntohs((u_short)addr));
3346 gen_and(tmp, b2);
3347 gen_or(b2, b1);
3348 /* Check for pad = 0, short header case */
3349 tmp = gen_mcmp(OR_NET, 2, BPF_B, (bpf_int32)0x02, (bpf_int32)0x7);
3350 b2 = gen_cmp(OR_NET, 2 + offset_sh, BPF_H, (bpf_int32)ntohs((u_short)addr));
3351 gen_and(tmp, b2);
3352 gen_or(b2, b1);
3353
3354 /* Combine with test for linktype */
3355 gen_and(b0, b1);
3356 return b1;
3357 }
3358
3359 /*
3360 * Generate a check for IPv4 or IPv6 for MPLS-encapsulated packets;
3361 * test the bottom-of-stack bit, and then check the version number
3362 * field in the IP header.
3363 */
3364 static struct block *
3365 gen_mpls_linktype(proto)
3366 int proto;
3367 {
3368 struct block *b0, *b1;
3369
3370 switch (proto) {
3371
3372 case Q_IP:
3373 /* match the bottom-of-stack bit */
3374 b0 = gen_mcmp(OR_NET, -2, BPF_B, 0x01, 0x01);
3375 /* match the IPv4 version number */
3376 b1 = gen_mcmp(OR_NET, 0, BPF_B, 0x40, 0xf0);
3377 gen_and(b0, b1);
3378 return b1;
3379
3380 case Q_IPV6:
3381 /* match the bottom-of-stack bit */
3382 b0 = gen_mcmp(OR_NET, -2, BPF_B, 0x01, 0x01);
3383 /* match the IPv4 version number */
3384 b1 = gen_mcmp(OR_NET, 0, BPF_B, 0x60, 0xf0);
3385 gen_and(b0, b1);
3386 return b1;
3387
3388 default:
3389 abort();
3390 }
3391 }
3392
3393 static struct block *
3394 gen_host(addr, mask, proto, dir, type)
3395 bpf_u_int32 addr;
3396 bpf_u_int32 mask;
3397 int proto;
3398 int dir;
3399 int type;
3400 {
3401 struct block *b0, *b1;
3402 const char *typestr;
3403
3404 if (type == Q_NET)
3405 typestr = "net";
3406 else
3407 typestr = "host";
3408
3409 switch (proto) {
3410
3411 case Q_DEFAULT:
3412 b0 = gen_host(addr, mask, Q_IP, dir, type);
3413 /*
3414 * Only check for non-IPv4 addresses if we're not
3415 * checking MPLS-encapsulated packets.
3416 */
3417 if (label_stack_depth == 0) {
3418 b1 = gen_host(addr, mask, Q_ARP, dir, type);
3419 gen_or(b0, b1);
3420 b0 = gen_host(addr, mask, Q_RARP, dir, type);
3421 gen_or(b1, b0);
3422 }
3423 return b0;
3424
3425 case Q_IP:
3426 return gen_hostop(addr, mask, dir, ETHERTYPE_IP, 12, 16);
3427
3428 case Q_RARP:
3429 return gen_hostop(addr, mask, dir, ETHERTYPE_REVARP, 14, 24);
3430
3431 case Q_ARP:
3432 return gen_hostop(addr, mask, dir, ETHERTYPE_ARP, 14, 24);
3433
3434 case Q_TCP:
3435 bpf_error("'tcp' modifier applied to %s", typestr);
3436
3437 case Q_SCTP:
3438 bpf_error("'sctp' modifier applied to %s", typestr);
3439
3440 case Q_UDP:
3441 bpf_error("'udp' modifier applied to %s", typestr);
3442
3443 case Q_ICMP:
3444 bpf_error("'icmp' modifier applied to %s", typestr);
3445
3446 case Q_IGMP:
3447 bpf_error("'igmp' modifier applied to %s", typestr);
3448
3449 case Q_IGRP:
3450 bpf_error("'igrp' modifier applied to %s", typestr);
3451
3452 case Q_PIM:
3453 bpf_error("'pim' modifier applied to %s", typestr);
3454
3455 case Q_VRRP:
3456 bpf_error("'vrrp' modifier applied to %s", typestr);
3457
3458 case Q_ATALK:
3459 bpf_error("ATALK host filtering not implemented");
3460
3461 case Q_AARP:
3462 bpf_error("AARP host filtering not implemented");
3463
3464 case Q_DECNET:
3465 return gen_dnhostop(addr, dir);
3466
3467 case Q_SCA:
3468 bpf_error("SCA host filtering not implemented");
3469
3470 case Q_LAT:
3471 bpf_error("LAT host filtering not implemented");
3472
3473 case Q_MOPDL:
3474 bpf_error("MOPDL host filtering not implemented");
3475
3476 case Q_MOPRC:
3477 bpf_error("MOPRC host filtering not implemented");
3478
3479 #ifdef INET6
3480 case Q_IPV6:
3481 bpf_error("'ip6' modifier applied to ip host");
3482
3483 case Q_ICMPV6:
3484 bpf_error("'icmp6' modifier applied to %s", typestr);
3485 #endif /* INET6 */
3486
3487 case Q_AH:
3488 bpf_error("'ah' modifier applied to %s", typestr);
3489
3490 case Q_ESP:
3491 bpf_error("'esp' modifier applied to %s", typestr);
3492
3493 case Q_ISO:
3494 bpf_error("ISO host filtering not implemented");
3495
3496 case Q_ESIS:
3497 bpf_error("'esis' modifier applied to %s", typestr);
3498
3499 case Q_ISIS:
3500 bpf_error("'isis' modifier applied to %s", typestr);
3501
3502 case Q_CLNP:
3503 bpf_error("'clnp' modifier applied to %s", typestr);
3504
3505 case Q_STP:
3506 bpf_error("'stp' modifier applied to %s", typestr);
3507
3508 case Q_IPX:
3509 bpf_error("IPX host filtering not implemented");
3510
3511 case Q_NETBEUI:
3512 bpf_error("'netbeui' modifier applied to %s", typestr);
3513
3514 case Q_RADIO:
3515 bpf_error("'radio' modifier applied to %s", typestr);
3516
3517 default:
3518 abort();
3519 }
3520 /* NOTREACHED */
3521 }
3522
3523 #ifdef INET6
3524 static struct block *
3525 gen_host6(addr, mask, proto, dir, type)
3526 struct in6_addr *addr;
3527 struct in6_addr *mask;
3528 int proto;
3529 int dir;
3530 int type;
3531 {
3532 const char *typestr;
3533
3534 if (type == Q_NET)
3535 typestr = "net";
3536 else
3537 typestr = "host";
3538
3539 switch (proto) {
3540
3541 case Q_DEFAULT:
3542 return gen_host6(addr, mask, Q_IPV6, dir, type);
3543
3544 case Q_IP:
3545 bpf_error("'ip' modifier applied to ip6 %s", typestr);
3546
3547 case Q_RARP:
3548 bpf_error("'rarp' modifier applied to ip6 %s", typestr);
3549
3550 case Q_ARP:
3551 bpf_error("'arp' modifier applied to ip6 %s", typestr);
3552
3553 case Q_SCTP:
3554 bpf_error("'sctp' modifier applied to %s", typestr);
3555
3556 case Q_TCP:
3557 bpf_error("'tcp' modifier applied to %s", typestr);
3558
3559 case Q_UDP:
3560 bpf_error("'udp' modifier applied to %s", typestr);
3561
3562 case Q_ICMP:
3563 bpf_error("'icmp' modifier applied to %s", typestr);
3564
3565 case Q_IGMP:
3566 bpf_error("'igmp' modifier applied to %s", typestr);
3567
3568 case Q_IGRP:
3569 bpf_error("'igrp' modifier applied to %s", typestr);
3570
3571 case Q_PIM:
3572 bpf_error("'pim' modifier applied to %s", typestr);
3573
3574 case Q_VRRP:
3575 bpf_error("'vrrp' modifier applied to %s", typestr);
3576
3577 case Q_ATALK:
3578 bpf_error("ATALK host filtering not implemented");
3579
3580 case Q_AARP:
3581 bpf_error("AARP host filtering not implemented");
3582
3583 case Q_DECNET:
3584 bpf_error("'decnet' modifier applied to ip6 %s", typestr);
3585
3586 case Q_SCA:
3587 bpf_error("SCA host filtering not implemented");
3588
3589 case Q_LAT:
3590 bpf_error("LAT host filtering not implemented");
3591
3592 case Q_MOPDL:
3593 bpf_error("MOPDL host filtering not implemented");
3594
3595 case Q_MOPRC:
3596 bpf_error("MOPRC host filtering not implemented");
3597
3598 case Q_IPV6:
3599 return gen_hostop6(addr, mask, dir, ETHERTYPE_IPV6, 8, 24);
3600
3601 case Q_ICMPV6:
3602 bpf_error("'icmp6' modifier applied to %s", typestr);
3603
3604 case Q_AH:
3605 bpf_error("'ah' modifier applied to %s", typestr);
3606
3607 case Q_ESP:
3608 bpf_error("'esp' modifier applied to %s", typestr);
3609
3610 case Q_ISO:
3611 bpf_error("ISO host filtering not implemented");
3612
3613 case Q_ESIS:
3614 bpf_error("'esis' modifier applied to %s", typestr);
3615
3616 case Q_ISIS:
3617 bpf_error("'isis' modifier applied to %s", typestr);
3618
3619 case Q_CLNP:
3620 bpf_error("'clnp' modifier applied to %s", typestr);
3621
3622 case Q_STP:
3623 bpf_error("'stp' modifier applied to %s", typestr);
3624
3625 case Q_IPX:
3626 bpf_error("IPX host filtering not implemented");
3627
3628 case Q_NETBEUI:
3629 bpf_error("'netbeui' modifier applied to %s", typestr);
3630
3631 case Q_RADIO:
3632 bpf_error("'radio' modifier applied to %s", typestr);
3633
3634 default:
3635 abort();
3636 }
3637 /* NOTREACHED */
3638 }
3639 #endif /*INET6*/
3640
3641 #ifndef INET6
3642 static struct block *
3643 gen_gateway(eaddr, alist, proto, dir)
3644 const u_char *eaddr;
3645 bpf_u_int32 **alist;
3646 int proto;
3647 int dir;
3648 {
3649 struct block *b0, *b1, *tmp;
3650
3651 if (dir != 0)
3652 bpf_error("direction applied to 'gateway'");
3653
3654 switch (proto) {
3655 case Q_DEFAULT:
3656 case Q_IP:
3657 case Q_ARP:
3658 case Q_RARP:
3659 switch (linktype) {
3660 case DLT_EN10MB:
3661 b0 = gen_ehostop(eaddr, Q_OR);
3662 break;
3663 case DLT_FDDI:
3664 b0 = gen_fhostop(eaddr, Q_OR);
3665 break;
3666 case DLT_IEEE802:
3667 b0 = gen_thostop(eaddr, Q_OR);
3668 break;
3669 case DLT_IEEE802_11:
3670 case DLT_IEEE802_11_RADIO_AVS:
3671 case DLT_PPI:
3672 case DLT_IEEE802_11_RADIO:
3673 case DLT_PRISM_HEADER:
3674 b0 = gen_wlanhostop(eaddr, Q_OR);
3675 break;
3676 case DLT_SUNATM:
3677 if (is_lane) {
3678 /*
3679 * Check that the packet doesn't begin with an
3680 * LE Control marker. (We've already generated
3681 * a test for LANE.)
3682 */
3683 b1 = gen_cmp(OR_LINK, SUNATM_PKT_BEGIN_POS, BPF_H,
3684 0xFF00);
3685 gen_not(b1);
3686
3687 /*
3688 * Now check the MAC address.
3689 */
3690 b0 = gen_ehostop(eaddr, Q_OR);
3691 gen_and(b1, b0);
3692 }
3693 break;
3694 case DLT_IP_OVER_FC:
3695 b0 = gen_ipfchostop(eaddr, Q_OR);
3696 break;
3697 default:
3698 bpf_error(
3699 "'gateway' supported only on ethernet/FDDI/token ring/802.11/Fibre Channel");
3700 }
3701 b1 = gen_host(**alist++, 0xffffffff, proto, Q_OR, Q_HOST);
3702 while (*alist) {
3703 tmp = gen_host(**alist++, 0xffffffff, proto, Q_OR,
3704 Q_HOST);
3705 gen_or(b1, tmp);
3706 b1 = tmp;
3707 }
3708 gen_not(b1);
3709 gen_and(b0, b1);
3710 return b1;
3711 }
3712 bpf_error("illegal modifier of 'gateway'");
3713 /* NOTREACHED */
3714 }
3715 #endif
3716
3717 struct block *
3718 gen_proto_abbrev(proto)
3719 int proto;
3720 {
3721 struct block *b0;
3722 struct block *b1;
3723
3724 switch (proto) {
3725
3726 case Q_SCTP:
3727 b1 = gen_proto(IPPROTO_SCTP, Q_IP, Q_DEFAULT);
3728 #ifdef INET6
3729 b0 = gen_proto(IPPROTO_SCTP, Q_IPV6, Q_DEFAULT);
3730 gen_or(b0, b1);
3731 #endif
3732 break;
3733
3734 case Q_TCP:
3735 b1 = gen_proto(IPPROTO_TCP, Q_IP, Q_DEFAULT);
3736 #ifdef INET6
3737 b0 = gen_proto(IPPROTO_TCP, Q_IPV6, Q_DEFAULT);
3738 gen_or(b0, b1);
3739 #endif
3740 break;
3741
3742 case Q_UDP:
3743 b1 = gen_proto(IPPROTO_UDP, Q_IP, Q_DEFAULT);
3744 #ifdef INET6
3745 b0 = gen_proto(IPPROTO_UDP, Q_IPV6, Q_DEFAULT);
3746 gen_or(b0, b1);
3747 #endif
3748 break;
3749
3750 case Q_ICMP:
3751 b1 = gen_proto(IPPROTO_ICMP, Q_IP, Q_DEFAULT);
3752 break;
3753
3754 #ifndef IPPROTO_IGMP
3755 #define IPPROTO_IGMP 2
3756 #endif
3757
3758 case Q_IGMP:
3759 b1 = gen_proto(IPPROTO_IGMP, Q_IP, Q_DEFAULT);
3760 break;
3761
3762 #ifndef IPPROTO_IGRP
3763 #define IPPROTO_IGRP 9
3764 #endif
3765 case Q_IGRP:
3766 b1 = gen_proto(IPPROTO_IGRP, Q_IP, Q_DEFAULT);
3767 break;
3768
3769 #ifndef IPPROTO_PIM
3770 #define IPPROTO_PIM 103
3771 #endif
3772
3773 case Q_PIM:
3774 b1 = gen_proto(IPPROTO_PIM, Q_IP, Q_DEFAULT);
3775 #ifdef INET6
3776 b0 = gen_proto(IPPROTO_PIM, Q_IPV6, Q_DEFAULT);
3777 gen_or(b0, b1);
3778 #endif
3779 break;
3780
3781 #ifndef IPPROTO_VRRP
3782 #define IPPROTO_VRRP 112
3783 #endif
3784
3785 case Q_VRRP:
3786 b1 = gen_proto(IPPROTO_VRRP, Q_IP, Q_DEFAULT);
3787 break;
3788
3789 case Q_IP:
3790 b1 = gen_linktype(ETHERTYPE_IP);
3791 break;
3792
3793 case Q_ARP:
3794 b1 = gen_linktype(ETHERTYPE_ARP);
3795 break;
3796
3797 case Q_RARP:
3798 b1 = gen_linktype(ETHERTYPE_REVARP);
3799 break;
3800
3801 case Q_LINK:
3802 bpf_error("link layer applied in wrong context");
3803
3804 case Q_ATALK:
3805 b1 = gen_linktype(ETHERTYPE_ATALK);
3806 break;
3807
3808 case Q_AARP:
3809 b1 = gen_linktype(ETHERTYPE_AARP);
3810 break;
3811
3812 case Q_DECNET:
3813 b1 = gen_linktype(ETHERTYPE_DN);
3814 break;
3815
3816 case Q_SCA:
3817 b1 = gen_linktype(ETHERTYPE_SCA);
3818 break;
3819
3820 case Q_LAT:
3821 b1 = gen_linktype(ETHERTYPE_LAT);
3822 break;
3823
3824 case Q_MOPDL:
3825 b1 = gen_linktype(ETHERTYPE_MOPDL);
3826 break;
3827
3828 case Q_MOPRC:
3829 b1 = gen_linktype(ETHERTYPE_MOPRC);
3830 break;
3831
3832 #ifdef INET6
3833 case Q_IPV6:
3834 b1 = gen_linktype(ETHERTYPE_IPV6);
3835 break;
3836
3837 #ifndef IPPROTO_ICMPV6
3838 #define IPPROTO_ICMPV6 58
3839 #endif
3840 case Q_ICMPV6:
3841 b1 = gen_proto(IPPROTO_ICMPV6, Q_IPV6, Q_DEFAULT);
3842 break;
3843 #endif /* INET6 */
3844
3845 #ifndef IPPROTO_AH
3846 #define IPPROTO_AH 51
3847 #endif
3848 case Q_AH:
3849 b1 = gen_proto(IPPROTO_AH, Q_IP, Q_DEFAULT);
3850 #ifdef INET6
3851 b0 = gen_proto(IPPROTO_AH, Q_IPV6, Q_DEFAULT);
3852 gen_or(b0, b1);
3853 #endif
3854 break;
3855
3856 #ifndef IPPROTO_ESP
3857 #define IPPROTO_ESP 50
3858 #endif
3859 case Q_ESP:
3860 b1 = gen_proto(IPPROTO_ESP, Q_IP, Q_DEFAULT);
3861 #ifdef INET6
3862 b0 = gen_proto(IPPROTO_ESP, Q_IPV6, Q_DEFAULT);
3863 gen_or(b0, b1);
3864 #endif
3865 break;
3866
3867 case Q_ISO:
3868 b1 = gen_linktype(LLCSAP_ISONS);
3869 break;
3870
3871 case Q_ESIS:
3872 b1 = gen_proto(ISO9542_ESIS, Q_ISO, Q_DEFAULT);
3873 break;
3874
3875 case Q_ISIS:
3876 b1 = gen_proto(ISO10589_ISIS, Q_ISO, Q_DEFAULT);
3877 break;
3878
3879 case Q_ISIS_L1: /* all IS-IS Level1 PDU-Types */
3880 b0 = gen_proto(ISIS_L1_LAN_IIH, Q_ISIS, Q_DEFAULT);
3881 b1 = gen_proto(ISIS_PTP_IIH, Q_ISIS, Q_DEFAULT); /* FIXME extract the circuit-type bits */
3882 gen_or(b0, b1);
3883 b0 = gen_proto(ISIS_L1_LSP, Q_ISIS, Q_DEFAULT);
3884 gen_or(b0, b1);
3885 b0 = gen_proto(ISIS_L1_CSNP, Q_ISIS, Q_DEFAULT);
3886 gen_or(b0, b1);
3887 b0 = gen_proto(ISIS_L1_PSNP, Q_ISIS, Q_DEFAULT);
3888 gen_or(b0, b1);
3889 break;
3890
3891 case Q_ISIS_L2: /* all IS-IS Level2 PDU-Types */
3892 b0 = gen_proto(ISIS_L2_LAN_IIH, Q_ISIS, Q_DEFAULT);
3893 b1 = gen_proto(ISIS_PTP_IIH, Q_ISIS, Q_DEFAULT); /* FIXME extract the circuit-type bits */
3894 gen_or(b0, b1);
3895 b0 = gen_proto(ISIS_L2_LSP, Q_ISIS, Q_DEFAULT);
3896 gen_or(b0, b1);
3897 b0 = gen_proto(ISIS_L2_CSNP, Q_ISIS, Q_DEFAULT);
3898 gen_or(b0, b1);
3899 b0 = gen_proto(ISIS_L2_PSNP, Q_ISIS, Q_DEFAULT);
3900 gen_or(b0, b1);
3901 break;
3902
3903 case Q_ISIS_IIH: /* all IS-IS Hello PDU-Types */
3904 b0 = gen_proto(ISIS_L1_LAN_IIH, Q_ISIS, Q_DEFAULT);
3905 b1 = gen_proto(ISIS_L2_LAN_IIH, Q_ISIS, Q_DEFAULT);
3906 gen_or(b0, b1);
3907 b0 = gen_proto(ISIS_PTP_IIH, Q_ISIS, Q_DEFAULT);
3908 gen_or(b0, b1);
3909 break;
3910
3911 case Q_ISIS_LSP:
3912 b0 = gen_proto(ISIS_L1_LSP, Q_ISIS, Q_DEFAULT);
3913 b1 = gen_proto(ISIS_L2_LSP, Q_ISIS, Q_DEFAULT);
3914 gen_or(b0, b1);
3915 break;
3916
3917 case Q_ISIS_SNP:
3918 b0 = gen_proto(ISIS_L1_CSNP, Q_ISIS, Q_DEFAULT);
3919 b1 = gen_proto(ISIS_L2_CSNP, Q_ISIS, Q_DEFAULT);
3920 gen_or(b0, b1);
3921 b0 = gen_proto(ISIS_L1_PSNP, Q_ISIS, Q_DEFAULT);
3922 gen_or(b0, b1);
3923 b0 = gen_proto(ISIS_L2_PSNP, Q_ISIS, Q_DEFAULT);
3924 gen_or(b0, b1);
3925 break;
3926
3927 case Q_ISIS_CSNP:
3928 b0 = gen_proto(ISIS_L1_CSNP, Q_ISIS, Q_DEFAULT);
3929 b1 = gen_proto(ISIS_L2_CSNP, Q_ISIS, Q_DEFAULT);
3930 gen_or(b0, b1);
3931 break;
3932
3933 case Q_ISIS_PSNP:
3934 b0 = gen_proto(ISIS_L1_PSNP, Q_ISIS, Q_DEFAULT);
3935 b1 = gen_proto(ISIS_L2_PSNP, Q_ISIS, Q_DEFAULT);
3936 gen_or(b0, b1);
3937 break;
3938
3939 case Q_CLNP:
3940 b1 = gen_proto(ISO8473_CLNP, Q_ISO, Q_DEFAULT);
3941 break;
3942
3943 case Q_STP:
3944 b1 = gen_linktype(LLCSAP_8021D);
3945 break;
3946
3947 case Q_IPX:
3948 b1 = gen_linktype(LLCSAP_IPX);
3949 break;
3950
3951 case Q_NETBEUI:
3952 b1 = gen_linktype(LLCSAP_NETBEUI);
3953 break;
3954
3955 case Q_RADIO:
3956 bpf_error("'radio' is not a valid protocol type");
3957
3958 default:
3959 abort();
3960 }
3961 return b1;
3962 }
3963
3964 static struct block *
3965 gen_ipfrag()
3966 {
3967 struct slist *s;
3968 struct block *b;
3969
3970 /* not ip frag */
3971 s = gen_load_a(OR_NET, 6, BPF_H);
3972 b = new_block(JMP(BPF_JSET));
3973 b->s.k = 0x1fff;
3974 b->stmts = s;
3975 gen_not(b);
3976
3977 return b;
3978 }
3979
3980 /*
3981 * Generate a comparison to a port value in the transport-layer header
3982 * at the specified offset from the beginning of that header.
3983 *
3984 * XXX - this handles a variable-length prefix preceding the link-layer
3985 * header, such as the radiotap or AVS radio prefix, but doesn't handle
3986 * variable-length link-layer headers (such as Token Ring or 802.11
3987 * headers).
3988 */
3989 static struct block *
3990 gen_portatom(off, v)
3991 int off;
3992 bpf_int32 v;
3993 {
3994 return gen_cmp(OR_TRAN_IPV4, off, BPF_H, v);
3995 }
3996
3997 #ifdef INET6
3998 static struct block *
3999 gen_portatom6(off, v)
4000 int off;
4001 bpf_int32 v;
4002 {
4003 return gen_cmp(OR_TRAN_IPV6, off, BPF_H, v);
4004 }
4005 #endif/*INET6*/
4006
4007 struct block *
4008 gen_portop(port, proto, dir)
4009 int port, proto, dir;
4010 {
4011 struct block *b0, *b1, *tmp;
4012
4013 /* ip proto 'proto' */
4014 tmp = gen_cmp(OR_NET, 9, BPF_B, (bpf_int32)proto);
4015 b0 = gen_ipfrag();
4016 gen_and(tmp, b0);
4017
4018 switch (dir) {
4019 case Q_SRC:
4020 b1 = gen_portatom(0, (bpf_int32)port);
4021 break;
4022
4023 case Q_DST:
4024 b1 = gen_portatom(2, (bpf_int32)port);
4025 break;
4026
4027 case Q_OR:
4028 case Q_DEFAULT:
4029 tmp = gen_portatom(0, (bpf_int32)port);
4030 b1 = gen_portatom(2, (bpf_int32)port);
4031 gen_or(tmp, b1);
4032 break;
4033
4034 case Q_AND:
4035 tmp = gen_portatom(0, (bpf_int32)port);
4036 b1 = gen_portatom(2, (bpf_int32)port);
4037 gen_and(tmp, b1);
4038 break;
4039
4040 default:
4041 abort();
4042 }
4043 gen_and(b0, b1);
4044
4045 return b1;
4046 }
4047
4048 static struct block *
4049 gen_port(port, ip_proto, dir)
4050 int port;
4051 int ip_proto;
4052 int dir;
4053 {
4054 struct block *b0, *b1, *tmp;
4055
4056 /*
4057 * ether proto ip
4058 *
4059 * For FDDI, RFC 1188 says that SNAP encapsulation is used,
4060 * not LLC encapsulation with LLCSAP_IP.
4061 *
4062 * For IEEE 802 networks - which includes 802.5 token ring
4063 * (which is what DLT_IEEE802 means) and 802.11 - RFC 1042
4064 * says that SNAP encapsulation is used, not LLC encapsulation
4065 * with LLCSAP_IP.
4066 *
4067 * For LLC-encapsulated ATM/"Classical IP", RFC 1483 and
4068 * RFC 2225 say that SNAP encapsulation is used, not LLC
4069 * encapsulation with LLCSAP_IP.
4070 *
4071 * So we always check for ETHERTYPE_IP.
4072 */
4073 b0 = gen_linktype(ETHERTYPE_IP);
4074
4075 switch (ip_proto) {
4076 case IPPROTO_UDP:
4077 case IPPROTO_TCP:
4078 case IPPROTO_SCTP:
4079 b1 = gen_portop(port, ip_proto, dir);
4080 break;
4081
4082 case PROTO_UNDEF:
4083 tmp = gen_portop(port, IPPROTO_TCP, dir);
4084 b1 = gen_portop(port, IPPROTO_UDP, dir);
4085 gen_or(tmp, b1);
4086 tmp = gen_portop(port, IPPROTO_SCTP, dir);
4087 gen_or(tmp, b1);
4088 break;
4089
4090 default:
4091 abort();
4092 }
4093 gen_and(b0, b1);
4094 return b1;
4095 }
4096
4097 #ifdef INET6
4098 struct block *
4099 gen_portop6(port, proto, dir)
4100 int port, proto, dir;
4101 {
4102 struct block *b0, *b1, *tmp;
4103
4104 /* ip6 proto 'proto' */
4105 b0 = gen_cmp(OR_NET, 6, BPF_B, (bpf_int32)proto);
4106
4107 switch (dir) {
4108 case Q_SRC:
4109 b1 = gen_portatom6(0, (bpf_int32)port);
4110 break;
4111
4112 case Q_DST:
4113 b1 = gen_portatom6(2, (bpf_int32)port);
4114 break;
4115
4116 case Q_OR:
4117 case Q_DEFAULT:
4118 tmp = gen_portatom6(0, (bpf_int32)port);
4119 b1 = gen_portatom6(2, (bpf_int32)port);
4120 gen_or(tmp, b1);
4121 break;
4122
4123 case Q_AND:
4124 tmp = gen_portatom6(0, (bpf_int32)port);
4125 b1 = gen_portatom6(2, (bpf_int32)port);
4126 gen_and(tmp, b1);
4127 break;
4128
4129 default:
4130 abort();
4131 }
4132 gen_and(b0, b1);
4133
4134 return b1;
4135 }
4136
4137 static struct block *
4138 gen_port6(port, ip_proto, dir)
4139 int port;
4140 int ip_proto;
4141 int dir;
4142 {
4143 struct block *b0, *b1, *tmp;
4144
4145 /* link proto ip6 */
4146 b0 = gen_linktype(ETHERTYPE_IPV6);
4147
4148 switch (ip_proto) {
4149 case IPPROTO_UDP:
4150 case IPPROTO_TCP:
4151 case IPPROTO_SCTP:
4152 b1 = gen_portop6(port, ip_proto, dir);
4153 break;
4154
4155 case PROTO_UNDEF:
4156 tmp = gen_portop6(port, IPPROTO_TCP, dir);
4157 b1 = gen_portop6(port, IPPROTO_UDP, dir);
4158 gen_or(tmp, b1);
4159 tmp = gen_portop6(port, IPPROTO_SCTP, dir);
4160 gen_or(tmp, b1);
4161 break;
4162
4163 default:
4164 abort();
4165 }
4166 gen_and(b0, b1);
4167 return b1;
4168 }
4169 #endif /* INET6 */
4170
4171 /* gen_portrange code */
4172 static struct block *
4173 gen_portrangeatom(off, v1, v2)
4174 int off;
4175 bpf_int32 v1, v2;
4176 {
4177 struct block *b1, *b2;
4178
4179 if (v1 > v2) {
4180 /*
4181 * Reverse the order of the ports, so v1 is the lower one.
4182 */
4183 bpf_int32 vtemp;
4184
4185 vtemp = v1;
4186 v1 = v2;
4187 v2 = vtemp;
4188 }
4189
4190 b1 = gen_cmp_ge(OR_TRAN_IPV4, off, BPF_H, v1);
4191 b2 = gen_cmp_le(OR_TRAN_IPV4, off, BPF_H, v2);
4192
4193 gen_and(b1, b2);
4194
4195 return b2;
4196 }
4197
4198 struct block *
4199 gen_portrangeop(port1, port2, proto, dir)
4200 int port1, port2;
4201 int proto;
4202 int dir;
4203 {
4204 struct block *b0, *b1, *tmp;
4205
4206 /* ip proto 'proto' */
4207 tmp = gen_cmp(OR_NET, 9, BPF_B, (bpf_int32)proto);
4208 b0 = gen_ipfrag();
4209 gen_and(tmp, b0);
4210
4211 switch (dir) {
4212 case Q_SRC:
4213 b1 = gen_portrangeatom(0, (bpf_int32)port1, (bpf_int32)port2);
4214 break;
4215
4216 case Q_DST:
4217 b1 = gen_portrangeatom(2, (bpf_int32)port1, (bpf_int32)port2);
4218 break;
4219
4220 case Q_OR:
4221 case Q_DEFAULT:
4222 tmp = gen_portrangeatom(0, (bpf_int32)port1, (bpf_int32)port2);
4223 b1 = gen_portrangeatom(2, (bpf_int32)port1, (bpf_int32)port2);
4224 gen_or(tmp, b1);
4225 break;
4226
4227 case Q_AND:
4228 tmp = gen_portrangeatom(0, (bpf_int32)port1, (bpf_int32)port2);
4229 b1 = gen_portrangeatom(2, (bpf_int32)port1, (bpf_int32)port2);
4230 gen_and(tmp, b1);
4231 break;
4232
4233 default:
4234 abort();
4235 }
4236 gen_and(b0, b1);
4237
4238 return b1;
4239 }
4240
4241 static struct block *
4242 gen_portrange(port1, port2, ip_proto, dir)
4243 int port1, port2;
4244 int ip_proto;
4245 int dir;
4246 {
4247 struct block *b0, *b1, *tmp;
4248
4249 /* link proto ip */
4250 b0 = gen_linktype(ETHERTYPE_IP);
4251
4252 switch (ip_proto) {
4253 case IPPROTO_UDP:
4254 case IPPROTO_TCP:
4255 case IPPROTO_SCTP:
4256 b1 = gen_portrangeop(port1, port2, ip_proto, dir);
4257 break;
4258
4259 case PROTO_UNDEF:
4260 tmp = gen_portrangeop(port1, port2, IPPROTO_TCP, dir);
4261 b1 = gen_portrangeop(port1, port2, IPPROTO_UDP, dir);
4262 gen_or(tmp, b1);
4263 tmp = gen_portrangeop(port1, port2, IPPROTO_SCTP, dir);
4264 gen_or(tmp, b1);
4265 break;
4266
4267 default:
4268 abort();
4269 }
4270 gen_and(b0, b1);
4271 return b1;
4272 }
4273
4274 #ifdef INET6
4275 static struct block *
4276 gen_portrangeatom6(off, v1, v2)
4277 int off;
4278 bpf_int32 v1, v2;
4279 {
4280 struct block *b1, *b2;
4281
4282 if (v1 > v2) {
4283 /*
4284 * Reverse the order of the ports, so v1 is the lower one.
4285 */
4286 bpf_int32 vtemp;
4287
4288 vtemp = v1;
4289 v1 = v2;
4290 v2 = vtemp;
4291 }
4292
4293 b1 = gen_cmp_ge(OR_TRAN_IPV6, off, BPF_H, v1);
4294 b2 = gen_cmp_le(OR_TRAN_IPV6, off, BPF_H, v2);
4295
4296 gen_and(b1, b2);
4297
4298 return b2;
4299 }
4300
4301 struct block *
4302 gen_portrangeop6(port1, port2, proto, dir)
4303 int port1, port2;
4304 int proto;
4305 int dir;
4306 {
4307 struct block *b0, *b1, *tmp;
4308
4309 /* ip6 proto 'proto' */
4310 b0 = gen_cmp(OR_NET, 6, BPF_B, (bpf_int32)proto);
4311
4312 switch (dir) {
4313 case Q_SRC:
4314 b1 = gen_portrangeatom6(0, (bpf_int32)port1, (bpf_int32)port2);
4315 break;
4316
4317 case Q_DST:
4318 b1 = gen_portrangeatom6(2, (bpf_int32)port1, (bpf_int32)port2);
4319 break;
4320
4321 case Q_OR:
4322 case Q_DEFAULT:
4323 tmp = gen_portrangeatom6(0, (bpf_int32)port1, (bpf_int32)port2);
4324 b1 = gen_portrangeatom6(2, (bpf_int32)port1, (bpf_int32)port2);
4325 gen_or(tmp, b1);
4326 break;
4327
4328 case Q_AND:
4329 tmp = gen_portrangeatom6(0, (bpf_int32)port1, (bpf_int32)port2);
4330 b1 = gen_portrangeatom6(2, (bpf_int32)port1, (bpf_int32)port2);
4331 gen_and(tmp, b1);
4332 break;
4333
4334 default:
4335 abort();
4336 }
4337 gen_and(b0, b1);
4338
4339 return b1;
4340 }
4341
4342 static struct block *
4343 gen_portrange6(port1, port2, ip_proto, dir)
4344 int port1, port2;
4345 int ip_proto;
4346 int dir;
4347 {
4348 struct block *b0, *b1, *tmp;
4349
4350 /* link proto ip6 */
4351 b0 = gen_linktype(ETHERTYPE_IPV6);
4352
4353 switch (ip_proto) {
4354 case IPPROTO_UDP:
4355 case IPPROTO_TCP:
4356 case IPPROTO_SCTP:
4357 b1 = gen_portrangeop6(port1, port2, ip_proto, dir);
4358 break;
4359
4360 case PROTO_UNDEF:
4361 tmp = gen_portrangeop6(port1, port2, IPPROTO_TCP, dir);
4362 b1 = gen_portrangeop6(port1, port2, IPPROTO_UDP, dir);
4363 gen_or(tmp, b1);
4364 tmp = gen_portrangeop6(port1, port2, IPPROTO_SCTP, dir);
4365 gen_or(tmp, b1);
4366 break;
4367
4368 default:
4369 abort();
4370 }
4371 gen_and(b0, b1);
4372 return b1;
4373 }
4374 #endif /* INET6 */
4375
4376 static int
4377 lookup_proto(name, proto)
4378 register const char *name;
4379 register int proto;
4380 {
4381 register int v;
4382
4383 switch (proto) {
4384
4385 case Q_DEFAULT:
4386 case Q_IP:
4387 case Q_IPV6:
4388 v = pcap_nametoproto(name);
4389 if (v == PROTO_UNDEF)
4390 bpf_error("unknown ip proto '%s'", name);
4391 break;
4392
4393 case Q_LINK:
4394 /* XXX should look up h/w protocol type based on linktype */
4395 v = pcap_nametoeproto(name);
4396 if (v == PROTO_UNDEF) {
4397 v = pcap_nametollc(name);
4398 if (v == PROTO_UNDEF)
4399 bpf_error("unknown ether proto '%s'", name);
4400 }
4401 break;
4402
4403 case Q_ISO:
4404 if (strcmp(name, "esis") == 0)
4405 v = ISO9542_ESIS;
4406 else if (strcmp(name, "isis") == 0)
4407 v = ISO10589_ISIS;
4408 else if (strcmp(name, "clnp") == 0)
4409 v = ISO8473_CLNP;
4410 else
4411 bpf_error("unknown osi proto '%s'", name);
4412 break;
4413
4414 default:
4415 v = PROTO_UNDEF;
4416 break;
4417 }
4418 return v;
4419 }
4420
4421 #if 0
4422 struct stmt *
4423 gen_joinsp(s, n)
4424 struct stmt **s;
4425 int n;
4426 {
4427 return NULL;
4428 }
4429 #endif
4430
4431 static struct block *
4432 gen_protochain(v, proto, dir)
4433 int v;
4434 int proto;
4435 int dir;
4436 {
4437 #ifdef NO_PROTOCHAIN
4438 return gen_proto(v, proto, dir);
4439 #else
4440 struct block *b0, *b;
4441 struct slist *s[100];
4442 int fix2, fix3, fix4, fix5;
4443 int ahcheck, again, end;
4444 int i, max;
4445 int reg2 = alloc_reg();
4446
4447 memset(s, 0, sizeof(s));
4448 fix2 = fix3 = fix4 = fix5 = 0;
4449
4450 switch (proto) {
4451 case Q_IP:
4452 case Q_IPV6:
4453 break;
4454 case Q_DEFAULT:
4455 b0 = gen_protochain(v, Q_IP, dir);
4456 b = gen_protochain(v, Q_IPV6, dir);
4457 gen_or(b0, b);
4458 return b;
4459 default:
4460 bpf_error("bad protocol applied for 'protochain'");
4461 /*NOTREACHED*/
4462 }
4463
4464 /*
4465 * We don't handle variable-length radiotap here headers yet.
4466 * We might want to add BPF instructions to do the protochain
4467 * work, to simplify that and, on platforms that have a BPF
4468 * interpreter with the new instructions, let the filtering
4469 * be done in the kernel. (We already require a modified BPF
4470 * engine to do the protochain stuff, to support backward
4471 * branches, and backward branch support is unlikely to appear
4472 * in kernel BPF engines.)
4473 */
4474 if (linktype == DLT_IEEE802_11_RADIO)
4475 bpf_error("'protochain' not supported with radiotap headers");
4476
4477 if (linktype == DLT_PPI)
4478 bpf_error("'protochain' not supported with PPI headers");
4479
4480 no_optimize = 1; /*this code is not compatible with optimzer yet */
4481
4482 /*
4483 * s[0] is a dummy entry to protect other BPF insn from damage
4484 * by s[fix] = foo with uninitialized variable "fix". It is somewhat
4485 * hard to find interdependency made by jump table fixup.
4486 */
4487 i = 0;
4488 s[i] = new_stmt(0); /*dummy*/
4489 i++;
4490
4491 switch (proto) {
4492 case Q_IP:
4493 b0 = gen_linktype(ETHERTYPE_IP);
4494
4495 /* A = ip->ip_p */
4496 s[i] = new_stmt(BPF_LD|BPF_ABS|BPF_B);
4497 s[i]->s.k = off_ll + off_nl + 9;
4498 i++;
4499 /* X = ip->ip_hl << 2 */
4500 s[i] = new_stmt(BPF_LDX|BPF_MSH|BPF_B);
4501 s[i]->s.k = off_ll + off_nl;
4502 i++;
4503 break;
4504 #ifdef INET6
4505 case Q_IPV6:
4506 b0 = gen_linktype(ETHERTYPE_IPV6);
4507
4508 /* A = ip6->ip_nxt */
4509 s[i] = new_stmt(BPF_LD|BPF_ABS|BPF_B);
4510 s[i]->s.k = off_ll + off_nl + 6;
4511 i++;
4512 /* X = sizeof(struct ip6_hdr) */
4513 s[i] = new_stmt(BPF_LDX|BPF_IMM);
4514 s[i]->s.k = 40;
4515 i++;
4516 break;
4517 #endif
4518 default:
4519 bpf_error("unsupported proto to gen_protochain");
4520 /*NOTREACHED*/
4521 }
4522
4523 /* again: if (A == v) goto end; else fall through; */
4524 again = i;
4525 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K);
4526 s[i]->s.k = v;
4527 s[i]->s.jt = NULL; /*later*/
4528 s[i]->s.jf = NULL; /*update in next stmt*/
4529 fix5 = i;
4530 i++;
4531
4532 #ifndef IPPROTO_NONE
4533 #define IPPROTO_NONE 59
4534 #endif
4535 /* if (A == IPPROTO_NONE) goto end */
4536 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K);
4537 s[i]->s.jt = NULL; /*later*/
4538 s[i]->s.jf = NULL; /*update in next stmt*/
4539 s[i]->s.k = IPPROTO_NONE;
4540 s[fix5]->s.jf = s[i];
4541 fix2 = i;
4542 i++;
4543
4544 #ifdef INET6
4545 if (proto == Q_IPV6) {
4546 int v6start, v6end, v6advance, j;
4547
4548 v6start = i;
4549 /* if (A == IPPROTO_HOPOPTS) goto v6advance */
4550 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K);
4551 s[i]->s.jt = NULL; /*later*/
4552 s[i]->s.jf = NULL; /*update in next stmt*/
4553 s[i]->s.k = IPPROTO_HOPOPTS;
4554 s[fix2]->s.jf = s[i];
4555 i++;
4556 /* if (A == IPPROTO_DSTOPTS) goto v6advance */
4557 s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K);
4558 s[i]->s.jt = NULL; /*later*/
4559 s[i]->s.jf = NULL; /*update in next stmt*/
4560 s[i]->s.k = IPPROTO_DSTOPTS;
4561 i++;
4562 /* if (A == IPPROTO_ROUTING) goto v6advance */
4563 s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K);
4564 s[i]->s.jt = NULL; /*later*/
4565 s[i]->s.jf = NULL; /*update in next stmt*/
4566 s[i]->s.k = IPPROTO_ROUTING;
4567 i++;
4568 /* if (A == IPPROTO_FRAGMENT) goto v6advance; else goto ahcheck; */
4569 s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K);
4570 s[i]->s.jt = NULL; /*later*/
4571 s[i]->s.jf = NULL; /*later*/
4572 s[i]->s.k = IPPROTO_FRAGMENT;
4573 fix3 = i;
4574 v6end = i;
4575 i++;
4576
4577 /* v6advance: */
4578 v6advance = i;
4579
4580 /*
4581 * in short,
4582 * A = P[X];
4583 * X = X + (P[X + 1] + 1) * 8;
4584 */
4585 /* A = X */
4586 s[i] = new_stmt(BPF_MISC|BPF_TXA);
4587 i++;
4588 /* A = P[X + packet head] */
4589 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B);
4590 s[i]->s.k = off_ll + off_nl;
4591 i++;
4592 /* MEM[reg2] = A */
4593 s[i] = new_stmt(BPF_ST);
4594 s[i]->s.k = reg2;
4595 i++;
4596 /* A = X */
4597 s[i] = new_stmt(BPF_MISC|BPF_TXA);
4598 i++;
4599 /* A += 1 */
4600 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K);
4601 s[i]->s.k = 1;
4602 i++;
4603 /* X = A */
4604 s[i] = new_stmt(BPF_MISC|BPF_TAX);
4605 i++;
4606 /* A = P[X + packet head]; */
4607 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B);
4608 s[i]->s.k = off_ll + off_nl;
4609 i++;
4610 /* A += 1 */
4611 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K);
4612 s[i]->s.k = 1;
4613 i++;
4614 /* A *= 8 */
4615 s[i] = new_stmt(BPF_ALU|BPF_MUL|BPF_K);
4616 s[i]->s.k = 8;
4617 i++;
4618 /* X = A; */
4619 s[i] = new_stmt(BPF_MISC|BPF_TAX);
4620 i++;
4621 /* A = MEM[reg2] */
4622 s[i] = new_stmt(BPF_LD|BPF_MEM);
4623 s[i]->s.k = reg2;
4624 i++;
4625
4626 /* goto again; (must use BPF_JA for backward jump) */
4627 s[i] = new_stmt(BPF_JMP|BPF_JA);
4628 s[i]->s.k = again - i - 1;
4629 s[i - 1]->s.jf = s[i];
4630 i++;
4631
4632 /* fixup */
4633 for (j = v6start; j <= v6end; j++)
4634 s[j]->s.jt = s[v6advance];
4635 } else
4636 #endif
4637 {
4638 /* nop */
4639 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K);
4640 s[i]->s.k = 0;
4641 s[fix2]->s.jf = s[i];
4642 i++;
4643 }
4644
4645 /* ahcheck: */
4646 ahcheck = i;
4647 /* if (A == IPPROTO_AH) then fall through; else goto end; */
4648 s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K);
4649 s[i]->s.jt = NULL; /*later*/
4650 s[i]->s.jf = NULL; /*later*/
4651 s[i]->s.k = IPPROTO_AH;
4652 if (fix3)
4653 s[fix3]->s.jf = s[ahcheck];
4654 fix4 = i;
4655 i++;
4656
4657 /*
4658 * in short,
4659 * A = P[X];
4660 * X = X + (P[X + 1] + 2) * 4;
4661 */
4662 /* A = X */
4663 s[i - 1]->s.jt = s[i] = new_stmt(BPF_MISC|BPF_TXA);
4664 i++;
4665 /* A = P[X + packet head]; */
4666 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B);
4667 s[i]->s.k = off_ll + off_nl;
4668 i++;
4669 /* MEM[reg2] = A */
4670 s[i] = new_stmt(BPF_ST);
4671 s[i]->s.k = reg2;
4672 i++;
4673 /* A = X */
4674 s[i - 1]->s.jt = s[i] = new_stmt(BPF_MISC|BPF_TXA);
4675 i++;
4676 /* A += 1 */
4677 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K);
4678 s[i]->s.k = 1;
4679 i++;
4680 /* X = A */
4681 s[i] = new_stmt(BPF_MISC|BPF_TAX);
4682 i++;
4683 /* A = P[X + packet head] */
4684 s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B);
4685 s[i]->s.k = off_ll + off_nl;
4686 i++;
4687 /* A += 2 */
4688 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K);
4689 s[i]->s.k = 2;
4690 i++;
4691 /* A *= 4 */
4692 s[i] = new_stmt(BPF_ALU|BPF_MUL|BPF_K);
4693 s[i]->s.k = 4;
4694 i++;
4695 /* X = A; */
4696 s[i] = new_stmt(BPF_MISC|BPF_TAX);
4697 i++;
4698 /* A = MEM[reg2] */
4699 s[i] = new_stmt(BPF_LD|BPF_MEM);
4700 s[i]->s.k = reg2;
4701 i++;
4702
4703 /* goto again; (must use BPF_JA for backward jump) */
4704 s[i] = new_stmt(BPF_JMP|BPF_JA);
4705 s[i]->s.k = again - i - 1;
4706 i++;
4707
4708 /* end: nop */
4709 end = i;
4710 s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K);
4711 s[i]->s.k = 0;
4712 s[fix2]->s.jt = s[end];
4713 s[fix4]->s.jf = s[end];
4714 s[fix5]->s.jt = s[end];
4715 i++;
4716
4717 /*
4718 * make slist chain
4719 */
4720 max = i;
4721 for (i = 0; i < max - 1; i++)
4722 s[i]->next = s[i + 1];
4723 s[max - 1]->next = NULL;
4724
4725 /*
4726 * emit final check
4727 */
4728 b = new_block(JMP(BPF_JEQ));
4729 b->stmts = s[1]; /*remember, s[0] is dummy*/
4730 b->s.k = v;
4731
4732 free_reg(reg2);
4733
4734 gen_and(b0, b);
4735 return b;
4736 #endif
4737 }
4738
4739
4740 /*
4741 * Generate code that checks whether the packet is a packet for protocol
4742 * <proto> and whether the type field in that protocol's header has
4743 * the value <v>, e.g. if <proto> is Q_IP, it checks whether it's an
4744 * IP packet and checks the protocol number in the IP header against <v>.
4745 *
4746 * If <proto> is Q_DEFAULT, i.e. just "proto" was specified, it checks
4747 * against Q_IP and Q_IPV6.
4748 */
4749 static struct block *
4750 gen_proto(v, proto, dir)
4751 int v;
4752 int proto;
4753 int dir;
4754 {
4755 struct block *b0, *b1;
4756
4757 if (dir != Q_DEFAULT)
4758 bpf_error("direction applied to 'proto'");
4759
4760 switch (proto) {
4761 case Q_DEFAULT:
4762 #ifdef INET6
4763 b0 = gen_proto(v, Q_IP, dir);
4764 b1 = gen_proto(v, Q_IPV6, dir);
4765 gen_or(b0, b1);
4766 return b1;
4767 #else
4768 /*FALLTHROUGH*/
4769 #endif
4770 case Q_IP:
4771 /*
4772 * For FDDI, RFC 1188 says that SNAP encapsulation is used,
4773 * not LLC encapsulation with LLCSAP_IP.
4774 *
4775 * For IEEE 802 networks - which includes 802.5 token ring
4776 * (which is what DLT_IEEE802 means) and 802.11 - RFC 1042
4777 * says that SNAP encapsulation is used, not LLC encapsulation
4778 * with LLCSAP_IP.
4779 *
4780 * For LLC-encapsulated ATM/"Classical IP", RFC 1483 and
4781 * RFC 2225 say that SNAP encapsulation is used, not LLC
4782 * encapsulation with LLCSAP_IP.
4783 *
4784 * So we always check for ETHERTYPE_IP.
4785 */
4786 b0 = gen_linktype(ETHERTYPE_IP);
4787 #ifndef CHASE_CHAIN
4788 b1 = gen_cmp(OR_NET, 9, BPF_B, (bpf_int32)v);
4789 #else
4790 b1 = gen_protochain(v, Q_IP);
4791 #endif
4792 gen_and(b0, b1);
4793 return b1;
4794
4795 case Q_ISO:
4796 switch (linktype) {
4797
4798 case DLT_FRELAY:
4799 /*
4800 * Frame Relay packets typically have an OSI
4801 * NLPID at the beginning; "gen_linktype(LLCSAP_ISONS)"
4802 * generates code to check for all the OSI
4803 * NLPIDs, so calling it and then adding a check
4804 * for the particular NLPID for which we're
4805 * looking is bogus, as we can just check for
4806 * the NLPID.
4807 *
4808 * What we check for is the NLPID and a frame
4809 * control field value of UI, i.e. 0x03 followed
4810 * by the NLPID.
4811 *
4812 * XXX - assumes a 2-byte Frame Relay header with
4813 * DLCI and flags. What if the address is longer?
4814 *
4815 * XXX - what about SNAP-encapsulated frames?
4816 */
4817 return gen_cmp(OR_LINK, 2, BPF_H, (0x03<<8) | v);
4818 /*NOTREACHED*/
4819 break;
4820
4821 case DLT_C_HDLC:
4822 /*
4823 * Cisco uses an Ethertype lookalike - for OSI,
4824 * it's 0xfefe.
4825 */
4826 b0 = gen_linktype(LLCSAP_ISONS<<8 | LLCSAP_ISONS);
4827 /* OSI in C-HDLC is stuffed with a fudge byte */
4828 b1 = gen_cmp(OR_NET_NOSNAP, 1, BPF_B, (long)v);
4829 gen_and(b0, b1);
4830 return b1;
4831
4832 default:
4833 b0 = gen_linktype(LLCSAP_ISONS);
4834 b1 = gen_cmp(OR_NET_NOSNAP, 0, BPF_B, (long)v);
4835 gen_and(b0, b1);
4836 return b1;
4837 }
4838
4839 case Q_ISIS:
4840 b0 = gen_proto(ISO10589_ISIS, Q_ISO, Q_DEFAULT);
4841 /*
4842 * 4 is the offset of the PDU type relative to the IS-IS
4843 * header.
4844 */
4845 b1 = gen_cmp(OR_NET_NOSNAP, 4, BPF_B, (long)v);
4846 gen_and(b0, b1);
4847 return b1;
4848
4849 case Q_ARP:
4850 bpf_error("arp does not encapsulate another protocol");
4851 /* NOTREACHED */
4852
4853 case Q_RARP:
4854 bpf_error("rarp does not encapsulate another protocol");
4855 /* NOTREACHED */
4856
4857 case Q_ATALK:
4858 bpf_error("atalk encapsulation is not specifiable");
4859 /* NOTREACHED */
4860
4861 case Q_DECNET:
4862 bpf_error("decnet encapsulation is not specifiable");
4863 /* NOTREACHED */
4864
4865 case Q_SCA:
4866 bpf_error("sca does not encapsulate another protocol");
4867 /* NOTREACHED */
4868
4869 case Q_LAT:
4870 bpf_error("lat does not encapsulate another protocol");
4871 /* NOTREACHED */
4872
4873 case Q_MOPRC:
4874 bpf_error("moprc does not encapsulate another protocol");
4875 /* NOTREACHED */
4876
4877 case Q_MOPDL:
4878 bpf_error("mopdl does not encapsulate another protocol");
4879 /* NOTREACHED */
4880
4881 case Q_LINK:
4882 return gen_linktype(v);
4883
4884 case Q_UDP:
4885 bpf_error("'udp proto' is bogus");
4886 /* NOTREACHED */
4887
4888 case Q_TCP:
4889 bpf_error("'tcp proto' is bogus");
4890 /* NOTREACHED */
4891
4892 case Q_SCTP:
4893 bpf_error("'sctp proto' is bogus");
4894 /* NOTREACHED */
4895
4896 case Q_ICMP:
4897 bpf_error("'icmp proto' is bogus");
4898 /* NOTREACHED */
4899
4900 case Q_IGMP:
4901 bpf_error("'igmp proto' is bogus");
4902 /* NOTREACHED */
4903
4904 case Q_IGRP:
4905 bpf_error("'igrp proto' is bogus");
4906 /* NOTREACHED */
4907
4908 case Q_PIM:
4909 bpf_error("'pim proto' is bogus");
4910 /* NOTREACHED */
4911
4912 case Q_VRRP:
4913 bpf_error("'vrrp proto' is bogus");
4914 /* NOTREACHED */
4915
4916 #ifdef INET6
4917 case Q_IPV6:
4918 b0 = gen_linktype(ETHERTYPE_IPV6);
4919 #ifndef CHASE_CHAIN
4920 b1 = gen_cmp(OR_NET, 6, BPF_B, (bpf_int32)v);
4921 #else
4922 b1 = gen_protochain(v, Q_IPV6);
4923 #endif
4924 gen_and(b0, b1);
4925 return b1;
4926
4927 case Q_ICMPV6:
4928 bpf_error("'icmp6 proto' is bogus");
4929 #endif /* INET6 */
4930
4931 case Q_AH:
4932 bpf_error("'ah proto' is bogus");
4933
4934 case Q_ESP:
4935 bpf_error("'ah proto' is bogus");
4936
4937 case Q_STP:
4938 bpf_error("'stp proto' is bogus");
4939
4940 case Q_IPX:
4941 bpf_error("'ipx proto' is bogus");
4942
4943 case Q_NETBEUI:
4944 bpf_error("'netbeui proto' is bogus");
4945
4946 case Q_RADIO:
4947 bpf_error("'radio proto' is bogus");
4948
4949 default:
4950 abort();
4951 /* NOTREACHED */
4952 }
4953 /* NOTREACHED */
4954 }
4955
4956 struct block *
4957 gen_scode(name, q)
4958 register const char *name;
4959 struct qual q;
4960 {
4961 int proto = q.proto;
4962 int dir = q.dir;
4963 int tproto;
4964 u_char *eaddr;
4965 bpf_u_int32 mask, addr;
4966 #ifndef INET6
4967 bpf_u_int32 **alist;
4968 #else
4969 int tproto6;
4970 struct sockaddr_in *sin4;
4971 struct sockaddr_in6 *sin6;
4972 struct addrinfo *res, *res0;
4973 struct in6_addr mask128;
4974 #endif /*INET6*/
4975 struct block *b, *tmp;
4976 int port, real_proto;
4977 int port1, port2;
4978
4979 switch (q.addr) {
4980
4981 case Q_NET:
4982 addr = pcap_nametonetaddr(name);
4983 if (addr == 0)
4984 bpf_error("unknown network '%s'", name);
4985 /* Left justify network addr and calculate its network mask */
4986 mask = 0xffffffff;
4987 while (addr && (addr & 0xff000000) == 0) {
4988 addr <<= 8;
4989 mask <<= 8;
4990 }
4991 return gen_host(addr, mask, proto, dir, q.addr);
4992
4993 case Q_DEFAULT:
4994 case Q_HOST:
4995 if (proto == Q_LINK) {
4996 switch (linktype) {
4997
4998 case DLT_EN10MB:
4999 eaddr = pcap_ether_hostton(name);
5000 if (eaddr == NULL)
5001 bpf_error(
5002 "unknown ether host '%s'", name);
5003 b = gen_ehostop(eaddr, dir);
5004 free(eaddr);
5005 return b;
5006
5007 case DLT_FDDI:
5008 eaddr = pcap_ether_hostton(name);
5009 if (eaddr == NULL)
5010 bpf_error(
5011 "unknown FDDI host '%s'", name);
5012 b = gen_fhostop(eaddr, dir);
5013 free(eaddr);
5014 return b;
5015
5016 case DLT_IEEE802:
5017 eaddr = pcap_ether_hostton(name);
5018 if (eaddr == NULL)
5019 bpf_error(
5020 "unknown token ring host '%s'", name);
5021 b = gen_thostop(eaddr, dir);
5022 free(eaddr);
5023 return b;
5024
5025 case DLT_IEEE802_11:
5026 case DLT_IEEE802_11_RADIO_AVS:
5027 case DLT_IEEE802_11_RADIO:
5028 case DLT_PRISM_HEADER:
5029 case DLT_PPI:
5030 eaddr = pcap_ether_hostton(name);
5031 if (eaddr == NULL)
5032 bpf_error(
5033 "unknown 802.11 host '%s'", name);
5034 b = gen_wlanhostop(eaddr, dir);
5035 free(eaddr);
5036 return b;
5037
5038 case DLT_IP_OVER_FC:
5039 eaddr = pcap_ether_hostton(name);
5040 if (eaddr == NULL)
5041 bpf_error(
5042 "unknown Fibre Channel host '%s'", name);
5043 b = gen_ipfchostop(eaddr, dir);
5044 free(eaddr);
5045 return b;
5046
5047 case DLT_SUNATM:
5048 if (!is_lane)
5049 break;
5050
5051 /*
5052 * Check that the packet doesn't begin
5053 * with an LE Control marker. (We've
5054 * already generated a test for LANE.)
5055 */
5056 tmp = gen_cmp(OR_LINK, SUNATM_PKT_BEGIN_POS,
5057 BPF_H, 0xFF00);
5058 gen_not(tmp);
5059
5060 eaddr = pcap_ether_hostton(name);
5061 if (eaddr == NULL)
5062 bpf_error(
5063 "unknown ether host '%s'", name);
5064 b = gen_ehostop(eaddr, dir);
5065 gen_and(tmp, b);
5066 free(eaddr);
5067 return b;
5068 }
5069
5070 bpf_error("only ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel supports link-level host name");
5071 } else if (proto == Q_DECNET) {
5072 unsigned short dn_addr = __pcap_nametodnaddr(name);
5073 /*
5074 * I don't think DECNET hosts can be multihomed, so
5075 * there is no need to build up a list of addresses
5076 */
5077 return (gen_host(dn_addr, 0, proto, dir, q.addr));
5078 } else {
5079 #ifndef INET6
5080 alist = pcap_nametoaddr(name);
5081 if (alist == NULL || *alist == NULL)
5082 bpf_error("unknown host '%s'", name);
5083 tproto = proto;
5084 if (off_linktype == (u_int)-1 && tproto == Q_DEFAULT)
5085 tproto = Q_IP;
5086 b = gen_host(**alist++, 0xffffffff, tproto, dir, q.addr);
5087 while (*alist) {
5088 tmp = gen_host(**alist++, 0xffffffff,
5089 tproto, dir, q.addr);
5090 gen_or(b, tmp);
5091 b = tmp;
5092 }
5093 return b;
5094 #else
5095 memset(&mask128, 0xff, sizeof(mask128));
5096 res0 = res = pcap_nametoaddrinfo(name);
5097 if (res == NULL)
5098 bpf_error("unknown host '%s'", name);
5099 b = tmp = NULL;
5100 tproto = tproto6 = proto;
5101 if (off_linktype == -1 && tproto == Q_DEFAULT) {
5102 tproto = Q_IP;
5103 tproto6 = Q_IPV6;
5104 }
5105 for (res = res0; res; res = res->ai_next) {
5106 switch (res->ai_family) {
5107 case AF_INET:
5108 if (tproto == Q_IPV6)
5109 continue;
5110
5111 sin4 = (struct sockaddr_in *)
5112 res->ai_addr;
5113 tmp = gen_host(ntohl(sin4->sin_addr.s_addr),
5114 0xffffffff, tproto, dir, q.addr);
5115 break;
5116 case AF_INET6:
5117 if (tproto6 == Q_IP)
5118 continue;
5119
5120 sin6 = (struct sockaddr_in6 *)
5121 res->ai_addr;
5122 tmp = gen_host6(&sin6->sin6_addr,
5123 &mask128, tproto6, dir, q.addr);
5124 break;
5125 default:
5126 continue;
5127 }
5128 if (b)
5129 gen_or(b, tmp);
5130 b = tmp;
5131 }
5132 freeaddrinfo(res0);
5133 if (b == NULL) {
5134 bpf_error("unknown host '%s'%s", name,
5135 (proto == Q_DEFAULT)
5136 ? ""
5137 : " for specified address family");
5138 }
5139 return b;
5140 #endif /*INET6*/
5141 }
5142
5143 case Q_PORT:
5144 if (proto != Q_DEFAULT &&
5145 proto != Q_UDP && proto != Q_TCP && proto != Q_SCTP)
5146 bpf_error("illegal qualifier of 'port'");
5147 if (pcap_nametoport(name, &port, &real_proto) == 0)
5148 bpf_error("unknown port '%s'", name);
5149 if (proto == Q_UDP) {
5150 if (real_proto == IPPROTO_TCP)
5151 bpf_error("port '%s' is tcp", name);
5152 else if (real_proto == IPPROTO_SCTP)
5153 bpf_error("port '%s' is sctp", name);
5154 else
5155 /* override PROTO_UNDEF */
5156 real_proto = IPPROTO_UDP;
5157 }
5158 if (proto == Q_TCP) {
5159 if (real_proto == IPPROTO_UDP)
5160 bpf_error("port '%s' is udp", name);
5161
5162 else if (real_proto == IPPROTO_SCTP)
5163 bpf_error("port '%s' is sctp", name);
5164 else
5165 /* override PROTO_UNDEF */
5166 real_proto = IPPROTO_TCP;
5167 }
5168 if (proto == Q_SCTP) {
5169 if (real_proto == IPPROTO_UDP)
5170 bpf_error("port '%s' is udp", name);
5171
5172 else if (real_proto == IPPROTO_TCP)
5173 bpf_error("port '%s' is tcp", name);
5174 else
5175 /* override PROTO_UNDEF */
5176 real_proto = IPPROTO_SCTP;
5177 }
5178 #ifndef INET6
5179 return gen_port(port, real_proto, dir);
5180 #else
5181 b = gen_port(port, real_proto, dir);
5182 gen_or(gen_port6(port, real_proto, dir), b);
5183 return b;
5184 #endif /* INET6 */
5185
5186 case Q_PORTRANGE:
5187 if (proto != Q_DEFAULT &&
5188 proto != Q_UDP && proto != Q_TCP && proto != Q_SCTP)
5189 bpf_error("illegal qualifier of 'portrange'");
5190 if (pcap_nametoportrange(name, &port1, &port2, &real_proto) == 0)
5191 bpf_error("unknown port in range '%s'", name);
5192 if (proto == Q_UDP) {
5193 if (real_proto == IPPROTO_TCP)
5194 bpf_error("port in range '%s' is tcp", name);
5195 else if (real_proto == IPPROTO_SCTP)
5196 bpf_error("port in range '%s' is sctp", name);
5197 else
5198 /* override PROTO_UNDEF */
5199 real_proto = IPPROTO_UDP;
5200 }
5201 if (proto == Q_TCP) {
5202 if (real_proto == IPPROTO_UDP)
5203 bpf_error("port in range '%s' is udp", name);
5204 else if (real_proto == IPPROTO_SCTP)
5205 bpf_error("port in range '%s' is sctp", name);
5206 else
5207 /* override PROTO_UNDEF */
5208 real_proto = IPPROTO_TCP;
5209 }
5210 if (proto == Q_SCTP) {
5211 if (real_proto == IPPROTO_UDP)
5212 bpf_error("port in range '%s' is udp", name);
5213 else if (real_proto == IPPROTO_TCP)
5214 bpf_error("port in range '%s' is tcp", name);
5215 else
5216 /* override PROTO_UNDEF */
5217 real_proto = IPPROTO_SCTP;
5218 }
5219 #ifndef INET6
5220 return gen_portrange(port1, port2, real_proto, dir);
5221 #else
5222 b = gen_portrange(port1, port2, real_proto, dir);
5223 gen_or(gen_portrange6(port1, port2, real_proto, dir), b);
5224 return b;
5225 #endif /* INET6 */
5226
5227 case Q_GATEWAY:
5228 #ifndef INET6
5229 eaddr = pcap_ether_hostton(name);
5230 if (eaddr == NULL)
5231 bpf_error("unknown ether host: %s", name);
5232
5233 alist = pcap_nametoaddr(name);
5234 if (alist == NULL || *alist == NULL)
5235 bpf_error("unknown host '%s'", name);
5236 b = gen_gateway(eaddr, alist, proto, dir);
5237 free(eaddr);
5238 return b;
5239 #else
5240 bpf_error("'gateway' not supported in this configuration");
5241 #endif /*INET6*/
5242
5243 case Q_PROTO:
5244 real_proto = lookup_proto(name, proto);
5245 if (real_proto >= 0)
5246 return gen_proto(real_proto, proto, dir);
5247 else
5248 bpf_error("unknown protocol: %s", name);
5249
5250 case Q_PROTOCHAIN:
5251 real_proto = lookup_proto(name, proto);
5252 if (real_proto >= 0)
5253 return gen_protochain(real_proto, proto, dir);
5254 else
5255 bpf_error("unknown protocol: %s", name);
5256
5257
5258 case Q_UNDEF:
5259 syntax();
5260 /* NOTREACHED */
5261 }
5262 abort();
5263 /* NOTREACHED */
5264 }
5265
5266 struct block *
5267 gen_mcode(s1, s2, masklen, q)
5268 register const char *s1, *s2;
5269 register int masklen;
5270 struct qual q;
5271 {
5272 register int nlen, mlen;
5273 bpf_u_int32 n, m;
5274
5275 nlen = __pcap_atoin(s1, &n);
5276 /* Promote short ipaddr */
5277 n <<= 32 - nlen;
5278
5279 if (s2 != NULL) {
5280 mlen = __pcap_atoin(s2, &m);
5281 /* Promote short ipaddr */
5282 m <<= 32 - mlen;
5283 if ((n & ~m) != 0)
5284 bpf_error("non-network bits set in \"%s mask %s\"",
5285 s1, s2);
5286 } else {
5287 /* Convert mask len to mask */
5288 if (masklen > 32)
5289 bpf_error("mask length must be <= 32");
5290 if (masklen == 0) {
5291 /*
5292 * X << 32 is not guaranteed by C to be 0; it's
5293 * undefined.
5294 */
5295 m = 0;
5296 } else
5297 m = 0xffffffff << (32 - masklen);
5298 if ((n & ~m) != 0)
5299 bpf_error("non-network bits set in \"%s/%d\"",
5300 s1, masklen);
5301 }
5302
5303 switch (q.addr) {
5304
5305 case Q_NET:
5306 return gen_host(n, m, q.proto, q.dir, q.addr);
5307
5308 default:
5309 bpf_error("Mask syntax for networks only");
5310 /* NOTREACHED */
5311 }
5312 /* NOTREACHED */
5313 return NULL;
5314 }
5315
5316 struct block *
5317 gen_ncode(s, v, q)
5318 register const char *s;
5319 bpf_u_int32 v;
5320 struct qual q;
5321 {
5322 bpf_u_int32 mask;
5323 int proto = q.proto;
5324 int dir = q.dir;
5325 register int vlen;
5326
5327 if (s == NULL)
5328 vlen = 32;
5329 else if (q.proto == Q_DECNET)
5330 vlen = __pcap_atodn(s, &v);
5331 else
5332 vlen = __pcap_atoin(s, &v);
5333
5334 switch (q.addr) {
5335
5336 case Q_DEFAULT:
5337 case Q_HOST:
5338 case Q_NET:
5339 if (proto == Q_DECNET)
5340 return gen_host(v, 0, proto, dir, q.addr);
5341 else if (proto == Q_LINK) {
5342 bpf_error("illegal link layer address");
5343 } else {
5344 mask = 0xffffffff;
5345 if (s == NULL && q.addr == Q_NET) {
5346 /* Promote short net number */
5347 while (v && (v & 0xff000000) == 0) {
5348 v <<= 8;
5349 mask <<= 8;
5350 }
5351 } else {
5352 /* Promote short ipaddr */
5353 v <<= 32 - vlen;
5354 mask <<= 32 - vlen;
5355 }
5356 return gen_host(v, mask, proto, dir, q.addr);
5357 }
5358
5359 case Q_PORT:
5360 if (proto == Q_UDP)
5361 proto = IPPROTO_UDP;
5362 else if (proto == Q_TCP)
5363 proto = IPPROTO_TCP;
5364 else if (proto == Q_SCTP)
5365 proto = IPPROTO_SCTP;
5366 else if (proto == Q_DEFAULT)
5367 proto = PROTO_UNDEF;
5368 else
5369 bpf_error("illegal qualifier of 'port'");
5370
5371 #ifndef INET6
5372 return gen_port((int)v, proto, dir);
5373 #else
5374 {
5375 struct block *b;
5376 b = gen_port((int)v, proto, dir);
5377 gen_or(gen_port6((int)v, proto, dir), b);
5378 return b;
5379 }
5380 #endif /* INET6 */
5381
5382 case Q_PORTRANGE:
5383 if (proto == Q_UDP)
5384 proto = IPPROTO_UDP;
5385 else if (proto == Q_TCP)
5386 proto = IPPROTO_TCP;
5387 else if (proto == Q_SCTP)
5388 proto = IPPROTO_SCTP;
5389 else if (proto == Q_DEFAULT)
5390 proto = PROTO_UNDEF;
5391 else
5392 bpf_error("illegal qualifier of 'portrange'");
5393
5394 #ifndef INET6
5395 return gen_portrange((int)v, (int)v, proto, dir);
5396 #else
5397 {
5398 struct block *b;
5399 b = gen_portrange((int)v, (int)v, proto, dir);
5400 gen_or(gen_portrange6((int)v, (int)v, proto, dir), b);
5401 return b;
5402 }
5403 #endif /* INET6 */
5404
5405 case Q_GATEWAY:
5406 bpf_error("'gateway' requires a name");
5407 /* NOTREACHED */
5408
5409 case Q_PROTO:
5410 return gen_proto((int)v, proto, dir);
5411
5412 case Q_PROTOCHAIN:
5413 return gen_protochain((int)v, proto, dir);
5414
5415 case Q_UNDEF:
5416 syntax();
5417 /* NOTREACHED */
5418
5419 default:
5420 abort();
5421 /* NOTREACHED */
5422 }
5423 /* NOTREACHED */
5424 }
5425
5426 #ifdef INET6
5427 struct block *
5428 gen_mcode6(s1, s2, masklen, q)
5429 register const char *s1, *s2;
5430 register int masklen;
5431 struct qual q;
5432 {
5433 struct addrinfo *res;
5434 struct in6_addr *addr;
5435 struct in6_addr mask;
5436 struct block *b;
5437 u_int32_t *a, *m;
5438
5439 if (s2)
5440 bpf_error("no mask %s supported", s2);
5441
5442 res = pcap_nametoaddrinfo(s1);
5443 if (!res)
5444 bpf_error("invalid ip6 address %s", s1);
5445 if (res->ai_next)
5446 bpf_error("%s resolved to multiple address", s1);
5447 addr = &((struct sockaddr_in6 *)res->ai_addr)->sin6_addr;
5448
5449 if (sizeof(mask) * 8 < masklen)
5450 bpf_error("mask length must be <= %u", (unsigned int)(sizeof(mask) * 8));
5451 memset(&mask, 0, sizeof(mask));
5452 memset(&mask, 0xff, masklen / 8);
5453 if (masklen % 8) {
5454 mask.s6_addr[masklen / 8] =
5455 (0xff << (8 - masklen % 8)) & 0xff;
5456 }
5457
5458 a = (u_int32_t *)addr;
5459 m = (u_int32_t *)&mask;
5460 if ((a[0] & ~m[0]) || (a[1] & ~m[1])
5461 || (a[2] & ~m[2]) || (a[3] & ~m[3])) {
5462 bpf_error("non-network bits set in \"%s/%d\"", s1, masklen);
5463 }
5464
5465 switch (q.addr) {
5466
5467 case Q_DEFAULT:
5468 case Q_HOST:
5469 if (masklen != 128)
5470 bpf_error("Mask syntax for networks only");
5471 /* FALLTHROUGH */
5472
5473 case Q_NET:
5474 b = gen_host6(addr, &mask, q.proto, q.dir, q.addr);
5475 freeaddrinfo(res);
5476 return b;
5477
5478 default:
5479 bpf_error("invalid qualifier against IPv6 address");
5480 /* NOTREACHED */
5481 }
5482 return NULL;
5483 }
5484 #endif /*INET6*/
5485
5486 struct block *
5487 gen_ecode(eaddr, q)
5488 register const u_char *eaddr;
5489 struct qual q;
5490 {
5491 struct block *b, *tmp;
5492
5493 if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) && q.proto == Q_LINK) {
5494 switch (linktype) {
5495 case DLT_EN10MB:
5496 return gen_ehostop(eaddr, (int)q.dir);
5497 case DLT_FDDI:
5498 return gen_fhostop(eaddr, (int)q.dir);
5499 case DLT_IEEE802:
5500 return gen_thostop(eaddr, (int)q.dir);
5501 case DLT_IEEE802_11:
5502 case DLT_IEEE802_11_RADIO_AVS:
5503 case DLT_IEEE802_11_RADIO:
5504 case DLT_PRISM_HEADER:
5505 case DLT_PPI:
5506 return gen_wlanhostop(eaddr, (int)q.dir);
5507 case DLT_SUNATM:
5508 if (is_lane) {
5509 /*
5510 * Check that the packet doesn't begin with an
5511 * LE Control marker. (We've already generated
5512 * a test for LANE.)
5513 */
5514 tmp = gen_cmp(OR_LINK, SUNATM_PKT_BEGIN_POS, BPF_H,
5515 0xFF00);
5516 gen_not(tmp);
5517
5518 /*
5519 * Now check the MAC address.
5520 */
5521 b = gen_ehostop(eaddr, (int)q.dir);
5522 gen_and(tmp, b);
5523 return b;
5524 }
5525 break;
5526 case DLT_IP_OVER_FC:
5527 return gen_ipfchostop(eaddr, (int)q.dir);
5528 default:
5529 bpf_error("ethernet addresses supported only on ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel");
5530 break;
5531 }
5532 }
5533 bpf_error("ethernet address used in non-ether expression");
5534 /* NOTREACHED */
5535 return NULL;
5536 }
5537
5538 void
5539 sappend(s0, s1)
5540 struct slist *s0, *s1;
5541 {
5542 /*
5543 * This is definitely not the best way to do this, but the
5544 * lists will rarely get long.
5545 */
5546 while (s0->next)
5547 s0 = s0->next;
5548 s0->next = s1;
5549 }
5550
5551 static struct slist *
5552 xfer_to_x(a)
5553 struct arth *a;
5554 {
5555 struct slist *s;
5556
5557 s = new_stmt(BPF_LDX|BPF_MEM);
5558 s->s.k = a->regno;
5559 return s;
5560 }
5561
5562 static struct slist *
5563 xfer_to_a(a)
5564 struct arth *a;
5565 {
5566 struct slist *s;
5567
5568 s = new_stmt(BPF_LD|BPF_MEM);
5569 s->s.k = a->regno;
5570 return s;
5571 }
5572
5573 /*
5574 * Modify "index" to use the value stored into its register as an
5575 * offset relative to the beginning of the header for the protocol
5576 * "proto", and allocate a register and put an item "size" bytes long
5577 * (1, 2, or 4) at that offset into that register, making it the register
5578 * for "index".
5579 */
5580 struct arth *
5581 gen_load(proto, inst, size)
5582 int proto;
5583 struct arth *inst;
5584 int size;
5585 {
5586 struct slist *s, *tmp;
5587 struct block *b;
5588 int regno = alloc_reg();
5589
5590 free_reg(inst->regno);
5591 switch (size) {
5592
5593 default:
5594 bpf_error("data size must be 1, 2, or 4");
5595
5596 case 1:
5597 size = BPF_B;
5598 break;
5599
5600 case 2:
5601 size = BPF_H;
5602 break;
5603
5604 case 4:
5605 size = BPF_W;
5606 break;
5607 }
5608 switch (proto) {
5609 default:
5610 bpf_error("unsupported index operation");
5611
5612 case Q_RADIO:
5613 /*
5614 * The offset is relative to the beginning of the packet
5615 * data, if we have a radio header. (If we don't, this
5616 * is an error.)
5617 */
5618 if (linktype != DLT_IEEE802_11_RADIO_AVS &&
5619 linktype != DLT_IEEE802_11_RADIO &&
5620 linktype != DLT_PRISM_HEADER)
5621 bpf_error("radio information not present in capture");
5622
5623 /*
5624 * Load into the X register the offset computed into the
5625 * register specifed by "index".
5626 */
5627 s = xfer_to_x(inst);
5628
5629 /*
5630 * Load the item at that offset.
5631 */
5632 tmp = new_stmt(BPF_LD|BPF_IND|size);
5633 sappend(s, tmp);
5634 sappend(inst->s, s);
5635 break;
5636
5637 case Q_LINK:
5638 /*
5639 * The offset is relative to the beginning of
5640 * the link-layer header.
5641 *
5642 * XXX - what about ATM LANE? Should the index be
5643 * relative to the beginning of the AAL5 frame, so
5644 * that 0 refers to the beginning of the LE Control
5645 * field, or relative to the beginning of the LAN
5646 * frame, so that 0 refers, for Ethernet LANE, to
5647 * the beginning of the destination address?
5648 */
5649 s = gen_llprefixlen();
5650
5651 /*
5652 * If "s" is non-null, it has code to arrange that the
5653 * X register contains the length of the prefix preceding
5654 * the link-layer header. Add to it the offset computed
5655 * into the register specified by "index", and move that
5656 * into the X register. Otherwise, just load into the X
5657 * register the offset computed into the register specifed
5658 * by "index".
5659 */
5660 if (s != NULL) {
5661 sappend(s, xfer_to_a(inst));
5662 sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X));
5663 sappend(s, new_stmt(BPF_MISC|BPF_TAX));
5664 } else
5665 s = xfer_to_x(inst);
5666
5667 /*
5668 * Load the item at the sum of the offset we've put in the
5669 * X register and the offset of the start of the link
5670 * layer header (which is 0 if the radio header is
5671 * variable-length; that header length is what we put
5672 * into the X register and then added to the index).
5673 */
5674 tmp = new_stmt(BPF_LD|BPF_IND|size);
5675 tmp->s.k = off_ll;
5676 sappend(s, tmp);
5677 sappend(inst->s, s);
5678 break;
5679
5680 case Q_IP:
5681 case Q_ARP:
5682 case Q_RARP:
5683 case Q_ATALK:
5684 case Q_DECNET:
5685 case Q_SCA:
5686 case Q_LAT:
5687 case Q_MOPRC:
5688 case Q_MOPDL:
5689 #ifdef INET6
5690 case Q_IPV6:
5691 #endif
5692 /*
5693 * The offset is relative to the beginning of
5694 * the network-layer header.
5695 * XXX - are there any cases where we want
5696 * off_nl_nosnap?
5697 */
5698 s = gen_llprefixlen();
5699
5700 /*
5701 * If "s" is non-null, it has code to arrange that the
5702 * X register contains the length of the prefix preceding
5703 * the link-layer header. Add to it the offset computed
5704 * into the register specified by "index", and move that
5705 * into the X register. Otherwise, just load into the X
5706 * register the offset computed into the register specifed
5707 * by "index".
5708 */
5709 if (s != NULL) {
5710 sappend(s, xfer_to_a(inst));
5711 sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X));
5712 sappend(s, new_stmt(BPF_MISC|BPF_TAX));
5713 } else
5714 s = xfer_to_x(inst);
5715
5716 /*
5717 * Load the item at the sum of the offset we've put in the
5718 * X register, the offset of the start of the network
5719 * layer header, and the offset of the start of the link
5720 * layer header (which is 0 if the radio header is
5721 * variable-length; that header length is what we put
5722 * into the X register and then added to the index).
5723 */
5724 tmp = new_stmt(BPF_LD|BPF_IND|size);
5725 tmp->s.k = off_ll + off_nl;
5726 sappend(s, tmp);
5727 sappend(inst->s, s);
5728
5729 /*
5730 * Do the computation only if the packet contains
5731 * the protocol in question.
5732 */
5733 b = gen_proto_abbrev(proto);
5734 if (inst->b)
5735 gen_and(inst->b, b);
5736 inst->b = b;
5737 break;
5738
5739 case Q_SCTP:
5740 case Q_TCP:
5741 case Q_UDP:
5742 case Q_ICMP:
5743 case Q_IGMP:
5744 case Q_IGRP:
5745 case Q_PIM:
5746 case Q_VRRP:
5747 /*
5748 * The offset is relative to the beginning of
5749 * the transport-layer header.
5750 *
5751 * Load the X register with the length of the IPv4 header
5752 * (plus the offset of the link-layer header, if it's
5753 * a variable-length header), in bytes.
5754 *
5755 * XXX - are there any cases where we want
5756 * off_nl_nosnap?
5757 * XXX - we should, if we're built with
5758 * IPv6 support, generate code to load either
5759 * IPv4, IPv6, or both, as appropriate.
5760 */
5761 s = gen_loadx_iphdrlen();
5762
5763 /*
5764 * The X register now contains the sum of the length
5765 * of any variable-length header preceding the link-layer
5766 * header and the length of the network-layer header.
5767 * Load into the A register the offset relative to
5768 * the beginning of the transport layer header,
5769 * add the X register to that, move that to the
5770 * X register, and load with an offset from the
5771 * X register equal to the offset of the network
5772 * layer header relative to the beginning of
5773 * the link-layer header plus the length of any
5774 * fixed-length header preceding the link-layer
5775 * header.
5776 */
5777 sappend(s, xfer_to_a(inst));
5778 sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X));
5779 sappend(s, new_stmt(BPF_MISC|BPF_TAX));
5780 sappend(s, tmp = new_stmt(BPF_LD|BPF_IND|size));
5781 tmp->s.k = off_ll + off_nl;
5782 sappend(inst->s, s);
5783
5784 /*
5785 * Do the computation only if the packet contains
5786 * the protocol in question - which is true only
5787 * if this is an IP datagram and is the first or
5788 * only fragment of that datagram.
5789 */
5790 gen_and(gen_proto_abbrev(proto), b = gen_ipfrag());
5791 if (inst->b)
5792 gen_and(inst->b, b);
5793 #ifdef INET6
5794 gen_and(gen_proto_abbrev(Q_IP), b);
5795 #endif
5796 inst->b = b;
5797 break;
5798 #ifdef INET6
5799 case Q_ICMPV6:
5800 bpf_error("IPv6 upper-layer protocol is not supported by proto[x]");
5801 /*NOTREACHED*/
5802 #endif
5803 }
5804 inst->regno = regno;
5805 s = new_stmt(BPF_ST);
5806 s->s.k = regno;
5807 sappend(inst->s, s);
5808
5809 return inst;
5810 }
5811
5812 struct block *
5813 gen_relation(code, a0, a1, reversed)
5814 int code;
5815 struct arth *a0, *a1;
5816 int reversed;
5817 {
5818 struct slist *s0, *s1, *s2;
5819 struct block *b, *tmp;
5820
5821 s0 = xfer_to_x(a1);
5822 s1 = xfer_to_a(a0);
5823 if (code == BPF_JEQ) {
5824 s2 = new_stmt(BPF_ALU|BPF_SUB|BPF_X);
5825 b = new_block(JMP(code));
5826 sappend(s1, s2);
5827 }
5828 else
5829 b = new_block(BPF_JMP|code|BPF_X);
5830 if (reversed)
5831 gen_not(b);
5832
5833 sappend(s0, s1);
5834 sappend(a1->s, s0);
5835 sappend(a0->s, a1->s);
5836
5837 b->stmts = a0->s;
5838
5839 free_reg(a0->regno);
5840 free_reg(a1->regno);
5841
5842 /* 'and' together protocol checks */
5843 if (a0->b) {
5844 if (a1->b) {
5845 gen_and(a0->b, tmp = a1->b);
5846 }
5847 else
5848 tmp = a0->b;
5849 } else
5850 tmp = a1->b;
5851
5852 if (tmp)
5853 gen_and(tmp, b);
5854
5855 return b;
5856 }
5857
5858 struct arth *
5859 gen_loadlen()
5860 {
5861 int regno = alloc_reg();
5862 struct arth *a = (struct arth *)newchunk(sizeof(*a));
5863 struct slist *s;
5864
5865 s = new_stmt(BPF_LD|BPF_LEN);
5866 s->next = new_stmt(BPF_ST);
5867 s->next->s.k = regno;
5868 a->s = s;
5869 a->regno = regno;
5870
5871 return a;
5872 }
5873
5874 struct arth *
5875 gen_loadi(val)
5876 int val;
5877 {
5878 struct arth *a;
5879 struct slist *s;
5880 int reg;
5881
5882 a = (struct arth *)newchunk(sizeof(*a));
5883
5884 reg = alloc_reg();
5885
5886 s = new_stmt(BPF_LD|BPF_IMM);
5887 s->s.k = val;
5888 s->next = new_stmt(BPF_ST);
5889 s->next->s.k = reg;
5890 a->s = s;
5891 a->regno = reg;
5892
5893 return a;
5894 }
5895
5896 struct arth *
5897 gen_neg(a)
5898 struct arth *a;
5899 {
5900 struct slist *s;
5901
5902 s = xfer_to_a(a);
5903 sappend(a->s, s);
5904 s = new_stmt(BPF_ALU|BPF_NEG);
5905 s->s.k = 0;
5906 sappend(a->s, s);
5907 s = new_stmt(BPF_ST);
5908 s->s.k = a->regno;
5909 sappend(a->s, s);
5910
5911 return a;
5912 }
5913
5914 struct arth *
5915 gen_arth(code, a0, a1)
5916 int code;
5917 struct arth *a0, *a1;
5918 {
5919 struct slist *s0, *s1, *s2;
5920
5921 s0 = xfer_to_x(a1);
5922 s1 = xfer_to_a(a0);
5923 s2 = new_stmt(BPF_ALU|BPF_X|code);
5924
5925 sappend(s1, s2);
5926 sappend(s0, s1);
5927 sappend(a1->s, s0);
5928 sappend(a0->s, a1->s);
5929
5930 free_reg(a0->regno);
5931 free_reg(a1->regno);
5932
5933 s0 = new_stmt(BPF_ST);
5934 a0->regno = s0->s.k = alloc_reg();
5935 sappend(a0->s, s0);
5936
5937 return a0;
5938 }
5939
5940 /*
5941 * Here we handle simple allocation of the scratch registers.
5942 * If too many registers are alloc'd, the allocator punts.
5943 */
5944 static int regused[BPF_MEMWORDS];
5945 static int curreg;
5946
5947 /*
5948 * Return the next free register.
5949 */
5950 static int
5951 alloc_reg()
5952 {
5953 int n = BPF_MEMWORDS;
5954
5955 while (--n >= 0) {
5956 if (regused[curreg])
5957 curreg = (curreg + 1) % BPF_MEMWORDS;
5958 else {
5959 regused[curreg] = 1;
5960 return curreg;
5961 }
5962 }
5963 bpf_error("too many registers needed to evaluate expression");
5964 /* NOTREACHED */
5965 return 0;
5966 }
5967
5968 /*
5969 * Return a register to the table so it can
5970 * be used later.
5971 */
5972 static void
5973 free_reg(n)
5974 int n;
5975 {
5976 regused[n] = 0;
5977 }
5978
5979 static struct block *
5980 gen_len(jmp, n)
5981 int jmp, n;
5982 {
5983 struct slist *s;
5984 struct block *b;
5985
5986 s = new_stmt(BPF_LD|BPF_LEN);
5987 b = new_block(JMP(jmp));
5988 b->stmts = s;
5989 b->s.k = n;
5990
5991 return b;
5992 }
5993
5994 struct block *
5995 gen_greater(n)
5996 int n;
5997 {
5998 return gen_len(BPF_JGE, n);
5999 }
6000
6001 /*
6002 * Actually, this is less than or equal.
6003 */
6004 struct block *
6005 gen_less(n)
6006 int n;
6007 {
6008 struct block *b;
6009
6010 b = gen_len(BPF_JGT, n);
6011 gen_not(b);
6012
6013 return b;
6014 }
6015
6016 /*
6017 * This is for "byte {idx} {op} {val}"; "idx" is treated as relative to
6018 * the beginning of the link-layer header.
6019 * XXX - that means you can't test values in the radiotap header, but
6020 * as that header is difficult if not impossible to parse generally
6021 * without a loop, that might not be a severe problem. A new keyword
6022 * "radio" could be added for that, although what you'd really want
6023 * would be a way of testing particular radio header values, which
6024 * would generate code appropriate to the radio header in question.
6025 */
6026 struct block *
6027 gen_byteop(op, idx, val)
6028 int op, idx, val;
6029 {
6030 struct block *b;
6031 struct slist *s;
6032
6033 switch (op) {
6034 default:
6035 abort();
6036
6037 case '=':
6038 return gen_cmp(OR_LINK, (u_int)idx, BPF_B, (bpf_int32)val);
6039
6040 case '<':
6041 b = gen_cmp_lt(OR_LINK, (u_int)idx, BPF_B, (bpf_int32)val);
6042 return b;
6043
6044 case '>':
6045 b = gen_cmp_gt(OR_LINK, (u_int)idx, BPF_B, (bpf_int32)val);
6046 return b;
6047
6048 case '|':
6049 s = new_stmt(BPF_ALU|BPF_OR|BPF_K);
6050 break;
6051
6052 case '&':
6053 s = new_stmt(BPF_ALU|BPF_AND|BPF_K);
6054 break;
6055 }
6056 s->s.k = val;
6057 b = new_block(JMP(BPF_JEQ));
6058 b->stmts = s;
6059 gen_not(b);
6060
6061 return b;
6062 }
6063
6064 static u_char abroadcast[] = { 0x0 };
6065
6066 struct block *
6067 gen_broadcast(proto)
6068 int proto;
6069 {
6070 bpf_u_int32 hostmask;
6071 struct block *b0, *b1, *b2;
6072 static u_char ebroadcast[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
6073
6074 switch (proto) {
6075
6076 case Q_DEFAULT:
6077 case Q_LINK:
6078 switch (linktype) {
6079 case DLT_ARCNET:
6080 case DLT_ARCNET_LINUX:
6081 return gen_ahostop(abroadcast, Q_DST);
6082 case DLT_EN10MB:
6083 return gen_ehostop(ebroadcast, Q_DST);
6084 case DLT_FDDI:
6085 return gen_fhostop(ebroadcast, Q_DST);
6086 case DLT_IEEE802:
6087 return gen_thostop(ebroadcast, Q_DST);
6088 case DLT_IEEE802_11:
6089 case DLT_IEEE802_11_RADIO_AVS:
6090 case DLT_IEEE802_11_RADIO:
6091 case DLT_PPI:
6092 case DLT_PRISM_HEADER:
6093 return gen_wlanhostop(ebroadcast, Q_DST);
6094 case DLT_IP_OVER_FC:
6095 return gen_ipfchostop(ebroadcast, Q_DST);
6096 case DLT_SUNATM:
6097 if (is_lane) {
6098 /*
6099 * Check that the packet doesn't begin with an
6100 * LE Control marker. (We've already generated
6101 * a test for LANE.)
6102 */
6103 b1 = gen_cmp(OR_LINK, SUNATM_PKT_BEGIN_POS, BPF_H,
6104 0xFF00);
6105 gen_not(b1);
6106
6107 /*
6108 * Now check the MAC address.
6109 */
6110 b0 = gen_ehostop(ebroadcast, Q_DST);
6111 gen_and(b1, b0);
6112 return b0;
6113 }
6114 break;
6115 default:
6116 bpf_error("not a broadcast link");
6117 }
6118 break;
6119
6120 case Q_IP:
6121 b0 = gen_linktype(ETHERTYPE_IP);
6122 hostmask = ~netmask;
6123 b1 = gen_mcmp(OR_NET, 16, BPF_W, (bpf_int32)0, hostmask);
6124 b2 = gen_mcmp(OR_NET, 16, BPF_W,
6125 (bpf_int32)(~0 & hostmask), hostmask);
6126 gen_or(b1, b2);
6127 gen_and(b0, b2);
6128 return b2;
6129 }
6130 bpf_error("only link-layer/IP broadcast filters supported");
6131 /* NOTREACHED */
6132 return NULL;
6133 }
6134
6135 /*
6136 * Generate code to test the low-order bit of a MAC address (that's
6137 * the bottom bit of the *first* byte).
6138 */
6139 static struct block *
6140 gen_mac_multicast(offset)
6141 int offset;
6142 {
6143 register struct block *b0;
6144 register struct slist *s;
6145
6146 /* link[offset] & 1 != 0 */
6147 s = gen_load_a(OR_LINK, offset, BPF_B);
6148 b0 = new_block(JMP(BPF_JSET));
6149 b0->s.k = 1;
6150 b0->stmts = s;
6151 return b0;
6152 }
6153
6154 struct block *
6155 gen_multicast(proto)
6156 int proto;
6157 {
6158 register struct block *b0, *b1, *b2;
6159 register struct slist *s;
6160
6161 switch (proto) {
6162
6163 case Q_DEFAULT:
6164 case Q_LINK:
6165 switch (linktype) {
6166 case DLT_ARCNET:
6167 case DLT_ARCNET_LINUX:
6168 /* all ARCnet multicasts use the same address */
6169 return gen_ahostop(abroadcast, Q_DST);
6170 case DLT_EN10MB:
6171 /* ether[0] & 1 != 0 */
6172 return gen_mac_multicast(0);
6173 case DLT_FDDI:
6174 /*
6175 * XXX TEST THIS: MIGHT NOT PORT PROPERLY XXX
6176 *
6177 * XXX - was that referring to bit-order issues?
6178 */
6179 /* fddi[1] & 1 != 0 */
6180 return gen_mac_multicast(1);
6181 case DLT_IEEE802:
6182 /* tr[2] & 1 != 0 */
6183 return gen_mac_multicast(2);
6184 case DLT_IEEE802_11:
6185 case DLT_IEEE802_11_RADIO_AVS:
6186 case DLT_PPI:
6187 case DLT_IEEE802_11_RADIO:
6188 case DLT_PRISM_HEADER:
6189 /*
6190 * Oh, yuk.
6191 *
6192 * For control frames, there is no DA.
6193 *
6194 * For management frames, DA is at an
6195 * offset of 4 from the beginning of
6196 * the packet.
6197 *
6198 * For data frames, DA is at an offset
6199 * of 4 from the beginning of the packet
6200 * if To DS is clear and at an offset of
6201 * 16 from the beginning of the packet
6202 * if To DS is set.
6203 */
6204
6205 /*
6206 * Generate the tests to be done for data frames.
6207 *
6208 * First, check for To DS set, i.e. "link[1] & 0x01".
6209 */
6210 s = gen_load_a(OR_LINK, 1, BPF_B);
6211 b1 = new_block(JMP(BPF_JSET));
6212 b1->s.k = 0x01; /* To DS */
6213 b1->stmts = s;
6214
6215 /*
6216 * If To DS is set, the DA is at 16.
6217 */
6218 b0 = gen_mac_multicast(16);
6219 gen_and(b1, b0);
6220
6221 /*
6222 * Now, check for To DS not set, i.e. check
6223 * "!(link[1] & 0x01)".
6224 */
6225 s = gen_load_a(OR_LINK, 1, BPF_B);
6226 b2 = new_block(JMP(BPF_JSET));
6227 b2->s.k = 0x01; /* To DS */
6228 b2->stmts = s;
6229 gen_not(b2);
6230
6231 /*
6232 * If To DS is not set, the DA is at 4.
6233 */
6234 b1 = gen_mac_multicast(4);
6235 gen_and(b2, b1);
6236
6237 /*
6238 * Now OR together the last two checks. That gives
6239 * the complete set of checks for data frames.
6240 */
6241 gen_or(b1, b0);
6242
6243 /*
6244 * Now check for a data frame.
6245 * I.e, check "link[0] & 0x08".
6246 */
6247 s = gen_load_a(OR_LINK, 0, BPF_B);
6248 b1 = new_block(JMP(BPF_JSET));
6249 b1->s.k = 0x08;
6250 b1->stmts = s;
6251
6252 /*
6253 * AND that with the checks done for data frames.
6254 */
6255 gen_and(b1, b0);
6256
6257 /*
6258 * If the high-order bit of the type value is 0, this
6259 * is a management frame.
6260 * I.e, check "!(link[0] & 0x08)".
6261 */
6262 s = gen_load_a(OR_LINK, 0, BPF_B);
6263 b2 = new_block(JMP(BPF_JSET));
6264 b2->s.k = 0x08;
6265 b2->stmts = s;
6266 gen_not(b2);
6267
6268 /*
6269 * For management frames, the DA is at 4.
6270 */
6271 b1 = gen_mac_multicast(4);
6272 gen_and(b2, b1);
6273
6274 /*
6275 * OR that with the checks done for data frames.
6276 * That gives the checks done for management and
6277 * data frames.
6278 */
6279 gen_or(b1, b0);
6280
6281 /*
6282 * If the low-order bit of the type value is 1,
6283 * this is either a control frame or a frame
6284 * with a reserved type, and thus not a
6285 * frame with an SA.
6286 *
6287 * I.e., check "!(link[0] & 0x04)".
6288 */
6289 s = gen_load_a(OR_LINK, 0, BPF_B);
6290 b1 = new_block(JMP(BPF_JSET));
6291 b1->s.k = 0x04;
6292 b1->stmts = s;
6293 gen_not(b1);
6294
6295 /*
6296 * AND that with the checks for data and management
6297 * frames.
6298 */
6299 gen_and(b1, b0);
6300 return b0;
6301 case DLT_IP_OVER_FC:
6302 b0 = gen_mac_multicast(2);
6303 return b0;
6304 case DLT_SUNATM:
6305 if (is_lane) {
6306 /*
6307 * Check that the packet doesn't begin with an
6308 * LE Control marker. (We've already generated
6309 * a test for LANE.)
6310 */
6311 b1 = gen_cmp(OR_LINK, SUNATM_PKT_BEGIN_POS, BPF_H,
6312 0xFF00);
6313 gen_not(b1);
6314
6315 /* ether[off_mac] & 1 != 0 */
6316 b0 = gen_mac_multicast(off_mac);
6317 gen_and(b1, b0);
6318 return b0;
6319 }
6320 break;
6321 default:
6322 break;
6323 }
6324 /* Link not known to support multicasts */
6325 break;
6326
6327 case Q_IP:
6328 b0 = gen_linktype(ETHERTYPE_IP);
6329 b1 = gen_cmp_ge(OR_NET, 16, BPF_B, (bpf_int32)224);
6330 gen_and(b0, b1);
6331 return b1;
6332
6333 #ifdef INET6
6334 case Q_IPV6:
6335 b0 = gen_linktype(ETHERTYPE_IPV6);
6336 b1 = gen_cmp(OR_NET, 24, BPF_B, (bpf_int32)255);
6337 gen_and(b0, b1);
6338 return b1;
6339 #endif /* INET6 */
6340 }
6341 bpf_error("link-layer multicast filters supported only on ethernet/FDDI/token ring/ARCNET/802.11/ATM LANE/Fibre Channel");
6342 /* NOTREACHED */
6343 return NULL;
6344 }
6345
6346 /*
6347 * generate command for inbound/outbound. It's here so we can
6348 * make it link-type specific. 'dir' = 0 implies "inbound",
6349 * = 1 implies "outbound".
6350 */
6351 struct block *
6352 gen_inbound(dir)
6353 int dir;
6354 {
6355 register struct block *b0;
6356
6357 /*
6358 * Only some data link types support inbound/outbound qualifiers.
6359 */
6360 switch (linktype) {
6361 case DLT_SLIP:
6362 b0 = gen_relation(BPF_JEQ,
6363 gen_load(Q_LINK, gen_loadi(0), 1),
6364 gen_loadi(0),
6365 dir);
6366 break;
6367
6368 case DLT_LINUX_SLL:
6369 if (dir) {
6370 /*
6371 * Match packets sent by this machine.
6372 */
6373 b0 = gen_cmp(OR_LINK, 0, BPF_H, LINUX_SLL_OUTGOING);
6374 } else {
6375 /*
6376 * Match packets sent to this machine.
6377 * (No broadcast or multicast packets, or
6378 * packets sent to some other machine and
6379 * received promiscuously.)
6380 *
6381 * XXX - packets sent to other machines probably
6382 * shouldn't be matched, but what about broadcast
6383 * or multicast packets we received?
6384 */
6385 b0 = gen_cmp(OR_LINK, 0, BPF_H, LINUX_SLL_HOST);
6386 }
6387 break;
6388
6389 #ifdef HAVE_NET_PFVAR_H
6390 case DLT_PFLOG:
6391 b0 = gen_cmp(OR_LINK, offsetof(struct pfloghdr, dir), BPF_B,
6392 (bpf_int32)((dir == 0) ? PF_IN : PF_OUT));
6393 break;
6394 #endif
6395
6396 case DLT_PPP_PPPD:
6397 if (dir) {
6398 /* match outgoing packets */
6399 b0 = gen_cmp(OR_LINK, 0, BPF_B, PPP_PPPD_OUT);
6400 } else {
6401 /* match incoming packets */
6402 b0 = gen_cmp(OR_LINK, 0, BPF_B, PPP_PPPD_IN);
6403 }
6404 break;
6405
6406 case DLT_JUNIPER_MFR:
6407 case DLT_JUNIPER_MLFR:
6408 case DLT_JUNIPER_MLPPP:
6409 case DLT_JUNIPER_ATM1:
6410 case DLT_JUNIPER_ATM2:
6411 case DLT_JUNIPER_PPPOE:
6412 case DLT_JUNIPER_PPPOE_ATM:
6413 case DLT_JUNIPER_GGSN:
6414 case DLT_JUNIPER_ES:
6415 case DLT_JUNIPER_MONITOR:
6416 case DLT_JUNIPER_SERVICES:
6417 case DLT_JUNIPER_ETHER:
6418 case DLT_JUNIPER_PPP:
6419 case DLT_JUNIPER_FRELAY:
6420 case DLT_JUNIPER_CHDLC:
6421 case DLT_JUNIPER_VP:
6422 /* juniper flags (including direction) are stored
6423 * the byte after the 3-byte magic number */
6424 if (dir) {
6425 /* match outgoing packets */
6426 b0 = gen_mcmp(OR_LINK, 3, BPF_B, 0, 0x01);
6427 } else {
6428 /* match incoming packets */
6429 b0 = gen_mcmp(OR_LINK, 3, BPF_B, 1, 0x01);
6430 }
6431 break;
6432
6433 default:
6434 bpf_error("inbound/outbound not supported on linktype %d",
6435 linktype);
6436 b0 = NULL;
6437 /* NOTREACHED */
6438 }
6439 return (b0);
6440 }
6441
6442 #ifdef HAVE_NET_PFVAR_H
6443 /* PF firewall log matched interface */
6444 struct block *
6445 gen_pf_ifname(const char *ifname)
6446 {
6447 struct block *b0;
6448 u_int len, off;
6449
6450 if (linktype == DLT_PFLOG) {
6451 len = sizeof(((struct pfloghdr *)0)->ifname);
6452 off = offsetof(struct pfloghdr, ifname);
6453 } else {
6454 bpf_error("ifname not supported on linktype 0x%x", linktype);
6455 /* NOTREACHED */
6456 }
6457 if (strlen(ifname) >= len) {
6458 bpf_error("ifname interface names can only be %d characters",
6459 len-1);
6460 /* NOTREACHED */
6461 }
6462 b0 = gen_bcmp(OR_LINK, off, strlen(ifname), (const u_char *)ifname);
6463 return (b0);
6464 }
6465
6466 /* PF firewall log ruleset name */
6467 struct block *
6468 gen_pf_ruleset(char *ruleset)
6469 {
6470 struct block *b0;
6471
6472 if (linktype != DLT_PFLOG) {
6473 bpf_error("ruleset not supported on linktype 0x%x", linktype);
6474 /* NOTREACHED */
6475 }
6476 if (strlen(ruleset) >= sizeof(((struct pfloghdr *)0)->ruleset)) {
6477 bpf_error("ruleset names can only be %ld characters",
6478 (long)(sizeof(((struct pfloghdr *)0)->ruleset) - 1));
6479 /* NOTREACHED */
6480 }
6481 b0 = gen_bcmp(OR_LINK, offsetof(struct pfloghdr, ruleset),
6482 strlen(ruleset), (const u_char *)ruleset);
6483 return (b0);
6484 }
6485
6486 /* PF firewall log rule number */
6487 struct block *
6488 gen_pf_rnr(int rnr)
6489 {
6490 struct block *b0;
6491
6492 if (linktype == DLT_PFLOG) {
6493 b0 = gen_cmp(OR_LINK, offsetof(struct pfloghdr, rulenr), BPF_W,
6494 (bpf_int32)rnr);
6495 } else {
6496 bpf_error("rnr not supported on linktype 0x%x", linktype);
6497 /* NOTREACHED */
6498 }
6499
6500 return (b0);
6501 }
6502
6503 /* PF firewall log sub-rule number */
6504 struct block *
6505 gen_pf_srnr(int srnr)
6506 {
6507 struct block *b0;
6508
6509 if (linktype != DLT_PFLOG) {
6510 bpf_error("srnr not supported on linktype 0x%x", linktype);
6511 /* NOTREACHED */
6512 }
6513
6514 b0 = gen_cmp(OR_LINK, offsetof(struct pfloghdr, subrulenr), BPF_W,
6515 (bpf_int32)srnr);
6516 return (b0);
6517 }
6518
6519 /* PF firewall log reason code */
6520 struct block *
6521 gen_pf_reason(int reason)
6522 {
6523 struct block *b0;
6524
6525 if (linktype == DLT_PFLOG) {
6526 b0 = gen_cmp(OR_LINK, offsetof(struct pfloghdr, reason), BPF_B,
6527 (bpf_int32)reason);
6528 } else {
6529 bpf_error("reason not supported on linktype 0x%x", linktype);
6530 /* NOTREACHED */
6531 }
6532
6533 return (b0);
6534 }
6535
6536 /* PF firewall log action */
6537 struct block *
6538 gen_pf_action(int action)
6539 {
6540 struct block *b0;
6541
6542 if (linktype == DLT_PFLOG) {
6543 b0 = gen_cmp(OR_LINK, offsetof(struct pfloghdr, action), BPF_B,
6544 (bpf_int32)action);
6545 } else {
6546 bpf_error("action not supported on linktype 0x%x", linktype);
6547 /* NOTREACHED */
6548 }
6549
6550 return (b0);
6551 }
6552 #else /* !HAVE_NET_PFVAR_H */
6553 struct block *
6554 gen_pf_ifname(const char *ifname)
6555 {
6556 bpf_error("libpcap was compiled without pf support");
6557 /* NOTREACHED */
6558 return (NULL);
6559 }
6560
6561 struct block *
6562 gen_pf_ruleset(char *ruleset)
6563 {
6564 bpf_error("libpcap was compiled on a machine without pf support");
6565 /* NOTREACHED */
6566 return (NULL);
6567 }
6568
6569 struct block *
6570 gen_pf_rnr(int rnr)
6571 {
6572 bpf_error("libpcap was compiled on a machine without pf support");
6573 /* NOTREACHED */
6574 return (NULL);
6575 }
6576
6577 struct block *
6578 gen_pf_srnr(int srnr)
6579 {
6580 bpf_error("libpcap was compiled on a machine without pf support");
6581 /* NOTREACHED */
6582 return (NULL);
6583 }
6584
6585 struct block *
6586 gen_pf_reason(int reason)
6587 {
6588 bpf_error("libpcap was compiled on a machine without pf support");
6589 /* NOTREACHED */
6590 return (NULL);
6591 }
6592
6593 struct block *
6594 gen_pf_action(int action)
6595 {
6596 bpf_error("libpcap was compiled on a machine without pf support");
6597 /* NOTREACHED */
6598 return (NULL);
6599 }
6600 #endif /* HAVE_NET_PFVAR_H */
6601
6602 /* IEEE 802.11 wireless header */
6603 struct block *
6604 gen_p80211_type(int type, int mask)
6605 {
6606 struct block *b0;
6607
6608 if (linktype != DLT_IEEE802_11 && linktype != DLT_IEEE802_11_RADIO) {
6609 bpf_error("action not supported on linktype 0x%x\n", linktype);
6610 /* NOTREACHED */
6611 }
6612 b0 = gen_mcmp(OR_LINK, offsetof(struct ieee80211_frame, i_fc[0]),
6613 BPF_B, (bpf_int32)type, (bpf_int32)mask);
6614 return (b0);
6615 }
6616
6617 struct block *
6618 gen_acode(eaddr, q)
6619 register const u_char *eaddr;
6620 struct qual q;
6621 {
6622 if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) && q.proto == Q_LINK) {
6623 if (linktype == DLT_ARCNET || linktype == DLT_ARCNET_LINUX)
6624 return gen_ahostop(eaddr, (int)q.dir);
6625 }
6626 bpf_error("ARCnet address used in non-arc expression");
6627 /* NOTREACHED */
6628 return NULL;
6629 }
6630
6631 static struct block *
6632 gen_ahostop(eaddr, dir)
6633 register const u_char *eaddr;
6634 register int dir;
6635 {
6636 register struct block *b0, *b1;
6637
6638 switch (dir) {
6639 /* src comes first, different from Ethernet */
6640 case Q_SRC:
6641 return gen_bcmp(OR_LINK, 0, 1, eaddr);
6642
6643 case Q_DST:
6644 return gen_bcmp(OR_LINK, 1, 1, eaddr);
6645
6646 case Q_AND:
6647 b0 = gen_ahostop(eaddr, Q_SRC);
6648 b1 = gen_ahostop(eaddr, Q_DST);
6649 gen_and(b0, b1);
6650 return b1;
6651
6652 case Q_DEFAULT:
6653 case Q_OR:
6654 b0 = gen_ahostop(eaddr, Q_SRC);
6655 b1 = gen_ahostop(eaddr, Q_DST);
6656 gen_or(b0, b1);
6657 return b1;
6658 }
6659 abort();
6660 /* NOTREACHED */
6661 }
6662
6663 /*
6664 * support IEEE 802.1Q VLAN trunk over ethernet
6665 */
6666 struct block *
6667 gen_vlan(vlan_num)
6668 int vlan_num;
6669 {
6670 struct block *b0, *b1;
6671
6672 /* can't check for VLAN-encapsulated packets inside MPLS */
6673 if (label_stack_depth > 0)
6674 bpf_error("no VLAN match after MPLS");
6675
6676 /*
6677 * Change the offsets to point to the type and data fields within
6678 * the VLAN packet. Just increment the offsets, so that we
6679 * can support a hierarchy, e.g. "vlan 300 && vlan 200" to
6680 * capture VLAN 200 encapsulated within VLAN 100.
6681 *
6682 * XXX - this is a bit of a kludge. If we were to split the
6683 * compiler into a parser that parses an expression and
6684 * generates an expression tree, and a code generator that
6685 * takes an expression tree (which could come from our
6686 * parser or from some other parser) and generates BPF code,
6687 * we could perhaps make the offsets parameters of routines
6688 * and, in the handler for an "AND" node, pass to subnodes
6689 * other than the VLAN node the adjusted offsets.
6690 *
6691 * This would mean that "vlan" would, instead of changing the
6692 * behavior of *all* tests after it, change only the behavior
6693 * of tests ANDed with it. That would change the documented
6694 * semantics of "vlan", which might break some expressions.
6695 * However, it would mean that "(vlan and ip) or ip" would check
6696 * both for VLAN-encapsulated IP and IP-over-Ethernet, rather than
6697 * checking only for VLAN-encapsulated IP, so that could still
6698 * be considered worth doing; it wouldn't break expressions
6699 * that are of the form "vlan and ..." or "vlan N and ...",
6700 * which I suspect are the most common expressions involving
6701 * "vlan". "vlan or ..." doesn't necessarily do what the user
6702 * would really want, now, as all the "or ..." tests would
6703 * be done assuming a VLAN, even though the "or" could be viewed
6704 * as meaning "or, if this isn't a VLAN packet...".
6705 */
6706 orig_linktype = off_linktype; /* save original values */
6707 orig_nl = off_nl;
6708
6709 switch (linktype) {
6710
6711 case DLT_EN10MB:
6712 off_linktype += 4;
6713 off_nl_nosnap += 4;
6714 off_nl += 4;
6715 break;
6716
6717 default:
6718 bpf_error("no VLAN support for data link type %d",
6719 linktype);
6720 /*NOTREACHED*/
6721 }
6722
6723 /* check for VLAN */
6724 b0 = gen_cmp(OR_LINK, orig_linktype, BPF_H, (bpf_int32)ETHERTYPE_8021Q);
6725
6726 /* If a specific VLAN is requested, check VLAN id */
6727 if (vlan_num >= 0) {
6728 b1 = gen_mcmp(OR_LINK, orig_nl, BPF_H, (bpf_int32)vlan_num,
6729 0x0fff);
6730 gen_and(b0, b1);
6731 b0 = b1;
6732 }
6733
6734 return (b0);
6735 }
6736
6737 /*
6738 * support for MPLS
6739 */
6740 struct block *
6741 gen_mpls(label_num)
6742 int label_num;
6743 {
6744 struct block *b0,*b1;
6745
6746 /*
6747 * Change the offsets to point to the type and data fields within
6748 * the MPLS packet. Just increment the offsets, so that we
6749 * can support a hierarchy, e.g. "mpls 100000 && mpls 1024" to
6750 * capture packets with an outer label of 100000 and an inner
6751 * label of 1024.
6752 *
6753 * XXX - this is a bit of a kludge. See comments in gen_vlan().
6754 */
6755 orig_nl = off_nl;
6756
6757 if (label_stack_depth > 0) {
6758 /* just match the bottom-of-stack bit clear */
6759 b0 = gen_mcmp(OR_LINK, orig_nl-2, BPF_B, 0, 0x01);
6760 } else {
6761 /*
6762 * Indicate that we're checking MPLS-encapsulated headers,
6763 * to make sure higher level code generators don't try to
6764 * match against IP-related protocols such as Q_ARP, Q_RARP
6765 * etc.
6766 */
6767 switch (linktype) {
6768
6769 case DLT_C_HDLC: /* fall through */
6770 case DLT_EN10MB:
6771 b0 = gen_linktype(ETHERTYPE_MPLS);
6772 break;
6773
6774 case DLT_PPP:
6775 b0 = gen_linktype(PPP_MPLS_UCAST);
6776 break;
6777
6778 /* FIXME add other DLT_s ...
6779 * for Frame-Relay/and ATM this may get messy due to SNAP headers
6780 * leave it for now */
6781
6782 default:
6783 bpf_error("no MPLS support for data link type %d",
6784 linktype);
6785 b0 = NULL;
6786 /*NOTREACHED*/
6787 break;
6788 }
6789 }
6790
6791 /* If a specific MPLS label is requested, check it */
6792 if (label_num >= 0) {
6793 label_num = label_num << 12; /* label is shifted 12 bits on the wire */
6794 b1 = gen_mcmp(OR_LINK, orig_nl, BPF_W, (bpf_int32)label_num,
6795 0xfffff000); /* only compare the first 20 bits */
6796 gen_and(b0, b1);
6797 b0 = b1;
6798 }
6799
6800 off_nl_nosnap += 4;
6801 off_nl += 4;
6802 label_stack_depth++;
6803 return (b0);
6804 }
6805
6806 /*
6807 * Support PPPOE discovery and session.
6808 */
6809 struct block *
6810 gen_pppoed()
6811 {
6812 /* check for PPPoE discovery */
6813 return gen_linktype((bpf_int32)ETHERTYPE_PPPOED);
6814 }
6815
6816 struct block *
6817 gen_pppoes()
6818 {
6819 struct block *b0;
6820
6821 /*
6822 * Test against the PPPoE session link-layer type.
6823 */
6824 b0 = gen_linktype((bpf_int32)ETHERTYPE_PPPOES);
6825
6826 /*
6827 * Change the offsets to point to the type and data fields within
6828 * the PPP packet.
6829 *
6830 * XXX - this is a bit of a kludge. If we were to split the
6831 * compiler into a parser that parses an expression and
6832 * generates an expression tree, and a code generator that
6833 * takes an expression tree (which could come from our
6834 * parser or from some other parser) and generates BPF code,
6835 * we could perhaps make the offsets parameters of routines
6836 * and, in the handler for an "AND" node, pass to subnodes
6837 * other than the PPPoE node the adjusted offsets.
6838 *
6839 * This would mean that "pppoes" would, instead of changing the
6840 * behavior of *all* tests after it, change only the behavior
6841 * of tests ANDed with it. That would change the documented
6842 * semantics of "pppoes", which might break some expressions.
6843 * However, it would mean that "(pppoes and ip) or ip" would check
6844 * both for VLAN-encapsulated IP and IP-over-Ethernet, rather than
6845 * checking only for VLAN-encapsulated IP, so that could still
6846 * be considered worth doing; it wouldn't break expressions
6847 * that are of the form "pppoes and ..." which I suspect are the
6848 * most common expressions involving "pppoes". "pppoes or ..."
6849 * doesn't necessarily do what the user would really want, now,
6850 * as all the "or ..." tests would be done assuming PPPoE, even
6851 * though the "or" could be viewed as meaning "or, if this isn't
6852 * a PPPoE packet...".
6853 */
6854 orig_linktype = off_linktype; /* save original values */
6855 orig_nl = off_nl;
6856
6857 /*
6858 * The "network-layer" protocol is PPPoE, which has a 6-byte
6859 * PPPoE header, followed by PPP payload, so we set the
6860 * offsets to the network layer offset plus 6 bytes for
6861 * the PPPoE header plus the values appropriate for PPP when
6862 * encapsulated in Ethernet (which means there's no HDLC
6863 * encapsulation).
6864 */
6865 off_linktype = orig_nl + 6;
6866 off_nl = orig_nl + 6 + 2;
6867 off_nl_nosnap = orig_nl + 6 + 2;
6868
6869 /*
6870 * Set the link-layer type to PPP, as all subsequent tests will
6871 * be on the encapsulated PPP header.
6872 */
6873 linktype = DLT_PPP;
6874
6875 return b0;
6876 }
6877
6878 struct block *
6879 gen_atmfield_code(atmfield, jvalue, jtype, reverse)
6880 int atmfield;
6881 bpf_int32 jvalue;
6882 bpf_u_int32 jtype;
6883 int reverse;
6884 {
6885 struct block *b0;
6886
6887 switch (atmfield) {
6888
6889 case A_VPI:
6890 if (!is_atm)
6891 bpf_error("'vpi' supported only on raw ATM");
6892 if (off_vpi == (u_int)-1)
6893 abort();
6894 b0 = gen_ncmp(OR_LINK, off_vpi, BPF_B, 0xffffffff, jtype,
6895 reverse, jvalue);
6896 break;
6897
6898 case A_VCI:
6899 if (!is_atm)
6900 bpf_error("'vci' supported only on raw ATM");
6901 if (off_vci == (u_int)-1)
6902 abort();
6903 b0 = gen_ncmp(OR_LINK, off_vci, BPF_H, 0xffffffff, jtype,
6904 reverse, jvalue);
6905 break;
6906
6907 case A_PROTOTYPE:
6908 if (off_proto == (u_int)-1)
6909 abort(); /* XXX - this isn't on FreeBSD */
6910 b0 = gen_ncmp(OR_LINK, off_proto, BPF_B, 0x0f, jtype,
6911 reverse, jvalue);
6912 break;
6913
6914 case A_MSGTYPE:
6915 if (off_payload == (u_int)-1)
6916 abort();
6917 b0 = gen_ncmp(OR_LINK, off_payload + MSG_TYPE_POS, BPF_B,
6918 0xffffffff, jtype, reverse, jvalue);
6919 break;
6920
6921 case A_CALLREFTYPE:
6922 if (!is_atm)
6923 bpf_error("'callref' supported only on raw ATM");
6924 if (off_proto == (u_int)-1)
6925 abort();
6926 b0 = gen_ncmp(OR_LINK, off_proto, BPF_B, 0xffffffff,
6927 jtype, reverse, jvalue);
6928 break;
6929
6930 default:
6931 abort();
6932 }
6933 return b0;
6934 }
6935
6936 struct block *
6937 gen_atmtype_abbrev(type)
6938 int type;
6939 {
6940 struct block *b0, *b1;
6941
6942 switch (type) {
6943
6944 case A_METAC:
6945 /* Get all packets in Meta signalling Circuit */
6946 if (!is_atm)
6947 bpf_error("'metac' supported only on raw ATM");
6948 b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0);
6949 b1 = gen_atmfield_code(A_VCI, 1, BPF_JEQ, 0);
6950 gen_and(b0, b1);
6951 break;
6952
6953 case A_BCC:
6954 /* Get all packets in Broadcast Circuit*/
6955 if (!is_atm)
6956 bpf_error("'bcc' supported only on raw ATM");
6957 b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0);
6958 b1 = gen_atmfield_code(A_VCI, 2, BPF_JEQ, 0);
6959 gen_and(b0, b1);
6960 break;
6961
6962 case A_OAMF4SC:
6963 /* Get all cells in Segment OAM F4 circuit*/
6964 if (!is_atm)
6965 bpf_error("'oam4sc' supported only on raw ATM");
6966 b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0);
6967 b1 = gen_atmfield_code(A_VCI, 3, BPF_JEQ, 0);
6968 gen_and(b0, b1);
6969 break;
6970
6971 case A_OAMF4EC:
6972 /* Get all cells in End-to-End OAM F4 Circuit*/
6973 if (!is_atm)
6974 bpf_error("'oam4ec' supported only on raw ATM");
6975 b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0);
6976 b1 = gen_atmfield_code(A_VCI, 4, BPF_JEQ, 0);
6977 gen_and(b0, b1);
6978 break;
6979
6980 case A_SC:
6981 /* Get all packets in connection Signalling Circuit */
6982 if (!is_atm)
6983 bpf_error("'sc' supported only on raw ATM");
6984 b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0);
6985 b1 = gen_atmfield_code(A_VCI, 5, BPF_JEQ, 0);
6986 gen_and(b0, b1);
6987 break;
6988
6989 case A_ILMIC:
6990 /* Get all packets in ILMI Circuit */
6991 if (!is_atm)
6992 bpf_error("'ilmic' supported only on raw ATM");
6993 b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0);
6994 b1 = gen_atmfield_code(A_VCI, 16, BPF_JEQ, 0);
6995 gen_and(b0, b1);
6996 break;
6997
6998 case A_LANE:
6999 /* Get all LANE packets */
7000 if (!is_atm)
7001 bpf_error("'lane' supported only on raw ATM");
7002 b1 = gen_atmfield_code(A_PROTOTYPE, PT_LANE, BPF_JEQ, 0);
7003
7004 /*
7005 * Arrange that all subsequent tests assume LANE
7006 * rather than LLC-encapsulated packets, and set
7007 * the offsets appropriately for LANE-encapsulated
7008 * Ethernet.
7009 *
7010 * "off_mac" is the offset of the Ethernet header,
7011 * which is 2 bytes past the ATM pseudo-header
7012 * (skipping the pseudo-header and 2-byte LE Client
7013 * field). The other offsets are Ethernet offsets
7014 * relative to "off_mac".
7015 */
7016 is_lane = 1;
7017 off_mac = off_payload + 2; /* MAC header */
7018 off_linktype = off_mac + 12;
7019 off_nl = off_mac + 14; /* Ethernet II */
7020 off_nl_nosnap = off_mac + 17; /* 802.3+802.2 */
7021 break;
7022
7023 case A_LLC:
7024 /* Get all LLC-encapsulated packets */
7025 if (!is_atm)
7026 bpf_error("'llc' supported only on raw ATM");
7027 b1 = gen_atmfield_code(A_PROTOTYPE, PT_LLC, BPF_JEQ, 0);
7028 is_lane = 0;
7029 break;
7030
7031 default:
7032 abort();
7033 }
7034 return b1;
7035 }
7036
7037 /*
7038 * Filtering for MTP2 messages based on li value
7039 * FISU, length is null
7040 * LSSU, length is 1 or 2
7041 * MSU, length is 3 or more
7042 */
7043 struct block *
7044 gen_mtp2type_abbrev(type)
7045 int type;
7046 {
7047 struct block *b0, *b1;
7048
7049 switch (type) {
7050
7051 case M_FISU:
7052 if ( (linktype != DLT_MTP2) &&
7053 (linktype != DLT_MTP2_WITH_PHDR) )
7054 bpf_error("'fisu' supported only on MTP2");
7055 /* gen_ncmp(offrel, offset, size, mask, jtype, reverse, value) */
7056 b0 = gen_ncmp(OR_PACKET, off_li, BPF_B, 0x3f, BPF_JEQ, 0, 0);
7057 break;
7058
7059 case M_LSSU:
7060 if ( (linktype != DLT_MTP2) &&
7061 (linktype != DLT_MTP2_WITH_PHDR) )
7062 bpf_error("'lssu' supported only on MTP2");
7063 b0 = gen_ncmp(OR_PACKET, off_li, BPF_B, 0x3f, BPF_JGT, 1, 2);
7064 b1 = gen_ncmp(OR_PACKET, off_li, BPF_B, 0x3f, BPF_JGT, 0, 0);
7065 gen_and(b1, b0);
7066 break;
7067
7068 case M_MSU:
7069 if ( (linktype != DLT_MTP2) &&
7070 (linktype != DLT_MTP2_WITH_PHDR) )
7071 bpf_error("'msu' supported only on MTP2");
7072 b0 = gen_ncmp(OR_PACKET, off_li, BPF_B, 0x3f, BPF_JGT, 0, 2);
7073 break;
7074
7075 default:
7076 abort();
7077 }
7078 return b0;
7079 }
7080
7081 struct block *
7082 gen_mtp3field_code(mtp3field, jvalue, jtype, reverse)
7083 int mtp3field;
7084 bpf_u_int32 jvalue;
7085 bpf_u_int32 jtype;
7086 int reverse;
7087 {
7088 struct block *b0;
7089 bpf_u_int32 val1 , val2 , val3;
7090
7091 switch (mtp3field) {
7092
7093 case M_SIO:
7094 if (off_sio == (u_int)-1)
7095 bpf_error("'sio' supported only on SS7");
7096 /* sio coded on 1 byte so max value 255 */
7097 if(jvalue > 255)
7098 bpf_error("sio value %u too big; max value = 255",
7099 jvalue);
7100 b0 = gen_ncmp(OR_PACKET, off_sio, BPF_B, 0xffffffff,
7101 (u_int)jtype, reverse, (u_int)jvalue);
7102 break;
7103
7104 case M_OPC:
7105 if (off_opc == (u_int)-1)
7106 bpf_error("'opc' supported only on SS7");
7107 /* opc coded on 14 bits so max value 16383 */
7108 if (jvalue > 16383)
7109 bpf_error("opc value %u too big; max value = 16383",
7110 jvalue);
7111 /* the following instructions are made to convert jvalue
7112 * to the form used to write opc in an ss7 message*/
7113 val1 = jvalue & 0x00003c00;
7114 val1 = val1 >>10;
7115 val2 = jvalue & 0x000003fc;
7116 val2 = val2 <<6;
7117 val3 = jvalue & 0x00000003;
7118 val3 = val3 <<22;
7119 jvalue = val1 + val2 + val3;
7120 b0 = gen_ncmp(OR_PACKET, off_opc, BPF_W, 0x00c0ff0f,
7121 (u_int)jtype, reverse, (u_int)jvalue);
7122 break;
7123
7124 case M_DPC:
7125 if (off_dpc == (u_int)-1)
7126 bpf_error("'dpc' supported only on SS7");
7127 /* dpc coded on 14 bits so max value 16383 */
7128 if (jvalue > 16383)
7129 bpf_error("dpc value %u too big; max value = 16383",
7130 jvalue);
7131 /* the following instructions are made to convert jvalue
7132 * to the forme used to write dpc in an ss7 message*/
7133 val1 = jvalue & 0x000000ff;
7134 val1 = val1 << 24;
7135 val2 = jvalue & 0x00003f00;
7136 val2 = val2 << 8;
7137 jvalue = val1 + val2;
7138 b0 = gen_ncmp(OR_PACKET, off_dpc, BPF_W, 0xff3f0000,
7139 (u_int)jtype, reverse, (u_int)jvalue);
7140 break;
7141
7142 case M_SLS:
7143 if (off_sls == (u_int)-1)
7144 bpf_error("'sls' supported only on SS7");
7145 /* sls coded on 4 bits so max value 15 */
7146 if (jvalue > 15)
7147 bpf_error("sls value %u too big; max value = 15",
7148 jvalue);
7149 /* the following instruction is made to convert jvalue
7150 * to the forme used to write sls in an ss7 message*/
7151 jvalue = jvalue << 4;
7152 b0 = gen_ncmp(OR_PACKET, off_sls, BPF_B, 0xf0,
7153 (u_int)jtype,reverse, (u_int)jvalue);
7154 break;
7155
7156 default:
7157 abort();
7158 }
7159 return b0;
7160 }
7161
7162 static struct block *
7163 gen_msg_abbrev(type)
7164 int type;
7165 {
7166 struct block *b1;
7167
7168 /*
7169 * Q.2931 signalling protocol messages for handling virtual circuits
7170 * establishment and teardown
7171 */
7172 switch (type) {
7173
7174 case A_SETUP:
7175 b1 = gen_atmfield_code(A_MSGTYPE, SETUP, BPF_JEQ, 0);
7176 break;
7177
7178 case A_CALLPROCEED:
7179 b1 = gen_atmfield_code(A_MSGTYPE, CALL_PROCEED, BPF_JEQ, 0);
7180 break;
7181
7182 case A_CONNECT:
7183 b1 = gen_atmfield_code(A_MSGTYPE, CONNECT, BPF_JEQ, 0);
7184 break;
7185
7186 case A_CONNECTACK:
7187 b1 = gen_atmfield_code(A_MSGTYPE, CONNECT_ACK, BPF_JEQ, 0);
7188 break;
7189
7190 case A_RELEASE:
7191 b1 = gen_atmfield_code(A_MSGTYPE, RELEASE, BPF_JEQ, 0);
7192 break;
7193
7194 case A_RELEASE_DONE:
7195 b1 = gen_atmfield_code(A_MSGTYPE, RELEASE_DONE, BPF_JEQ, 0);
7196 break;
7197
7198 default:
7199 abort();
7200 }
7201 return b1;
7202 }
7203
7204 struct block *
7205 gen_atmmulti_abbrev(type)
7206 int type;
7207 {
7208 struct block *b0, *b1;
7209
7210 switch (type) {
7211
7212 case A_OAM:
7213 if (!is_atm)
7214 bpf_error("'oam' supported only on raw ATM");
7215 b1 = gen_atmmulti_abbrev(A_OAMF4);
7216 break;
7217
7218 case A_OAMF4:
7219 if (!is_atm)
7220 bpf_error("'oamf4' supported only on raw ATM");
7221 /* OAM F4 type */
7222 b0 = gen_atmfield_code(A_VCI, 3, BPF_JEQ, 0);
7223 b1 = gen_atmfield_code(A_VCI, 4, BPF_JEQ, 0);
7224 gen_or(b0, b1);
7225 b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0);
7226 gen_and(b0, b1);
7227 break;
7228
7229 case A_CONNECTMSG:
7230 /*
7231 * Get Q.2931 signalling messages for switched
7232 * virtual connection
7233 */
7234 if (!is_atm)
7235 bpf_error("'connectmsg' supported only on raw ATM");
7236 b0 = gen_msg_abbrev(A_SETUP);
7237 b1 = gen_msg_abbrev(A_CALLPROCEED);
7238 gen_or(b0, b1);
7239 b0 = gen_msg_abbrev(A_CONNECT);
7240 gen_or(b0, b1);
7241 b0 = gen_msg_abbrev(A_CONNECTACK);
7242 gen_or(b0, b1);
7243 b0 = gen_msg_abbrev(A_RELEASE);
7244 gen_or(b0, b1);
7245 b0 = gen_msg_abbrev(A_RELEASE_DONE);
7246 gen_or(b0, b1);
7247 b0 = gen_atmtype_abbrev(A_SC);
7248 gen_and(b0, b1);
7249 break;
7250
7251 case A_METACONNECT:
7252 if (!is_atm)
7253 bpf_error("'metaconnect' supported only on raw ATM");
7254 b0 = gen_msg_abbrev(A_SETUP);
7255 b1 = gen_msg_abbrev(A_CALLPROCEED);
7256 gen_or(b0, b1);
7257 b0 = gen_msg_abbrev(A_CONNECT);
7258 gen_or(b0, b1);
7259 b0 = gen_msg_abbrev(A_RELEASE);
7260 gen_or(b0, b1);
7261 b0 = gen_msg_abbrev(A_RELEASE_DONE);
7262 gen_or(b0, b1);
7263 b0 = gen_atmtype_abbrev(A_METAC);
7264 gen_and(b0, b1);
7265 break;
7266
7267 default:
7268 abort();
7269 }
7270 return b1;
7271 }
DragonFly BSD