/usr/src/lib/libpcap/gencode.c

Bug Summary

File:	src/lib/libpcap/gencode.c
Warning:	line 1871, column 23 Although the value stored to 'fix5' is used in the enclosing expression, the value is never actually read from 'fix5'

Annotated Source Code

Press '?' to see keyboard shortcuts

Show analyzer invocation

clang -cc1 -cc1 -triple amd64-unknown-openbsd7.4 -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name gencode.c -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 1 -pic-is-pie -mframe-pointer=all -relaxed-aliasing -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -target-feature +retpoline-indirect-calls -target-feature +retpoline-indirect-branches -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/lib/libpcap/obj -resource-dir /usr/local/llvm16/lib/clang/16 -I . -I /usr/src/lib/libpcap -D yylval=pcap_yylval -D HAVE_SYS_IOCCOM_H -D HAVE_SYS_SOCKIO_H -D HAVE_ETHER_HOSTTON -D HAVE_STRERROR -D HAVE_SOCKADDR_SA_LEN -D LBL_ALIGN -D HAVE_IFADDRS_H -D INET6 -D HAVE_BSD_IEEE80211 -internal-isystem /usr/local/llvm16/lib/clang/16/include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir=/usr/src/lib/libpcap/obj -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -fcf-protection=branch -fno-jump-tables -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/scan/2024-01-11-140451-98009-1 -x c /usr/src/lib/libpcap/gencode.c

1	/* $OpenBSD: gencode.c,v 1.64 2022/12/27 17:10:07 jmc Exp $ */
2
3	/*
4	* Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998
5	* The Regents of the University of California. All rights reserved.
6	*
7	* Redistribution and use in source and binary forms, with or without
8	* modification, are permitted provided that: (1) source code distributions
9	* retain the above copyright notice and this paragraph in its entirety, (2)
10	* distributions including binary code include the above copyright notice and
11	* this paragraph in its entirety in the documentation or other materials
12	* provided with the distribution, and (3) all advertising materials mentioning
13	* features or use of this software display the following acknowledgement:
14	* ``This product includes software developed by the University of California,
15	* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
16	* the University nor the names of its contributors may be used to endorse
17	* or promote products derived from this software without specific prior
18	* written permission.
19	* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
20	* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
21	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
22	*/
23
24	#include <sys/types.h>
25	#include <sys/socket.h>
26	#include <sys/time.h>
27
28	#include <net/if.h>
29
30	#include <netinet/in.h>
31	#include <netinet/if_ether.h>
32
33	#include <net/if_pflog.h>
34	#include <net/pfvar.h>
35
36	#include <netmpls/mpls.h>
37
38	#include <net80211/ieee80211.h>
39	#include <net80211/ieee80211_radiotap.h>
40
41	#include <stdlib.h>
42	#include <stddef.h>
43	#include <setjmp.h>
44	#include <stdarg.h>
45	#include <string.h>
46
47	#include "pcap-int.h"
48
49	#include "ethertype.h"
50	#include "llc.h"
51	#include "gencode.h"
52	#include "ppp.h"
53	#include <pcap-namedb.h>
54	#ifdef INET61
55	#include <netdb.h>
56	#endif /INET6/
57
58	#ifdef HAVE_OS_PROTO_H
59	#include "os-proto.h"
60	#endif
61
62	#define JMP(c)((c)\|0x05\|0x00) ((c)\|BPF_JMP0x05\|BPF_K0x00)
63
64	/* Locals */
65	static jmp_buf top_ctx;
66	static pcap_t *bpf_pcap;
67
68	/* Hack for updating VLAN offsets. */
69	static u_int orig_linktype = -1, orig_nl = -1, orig_nl_nosnap = -1;
70	static u_int mpls_stack = 0;
71
72	/* XXX */
73	#ifdef PCAP_FDDIPAD
74	int pcap_fddipad = PCAP_FDDIPAD;
75	#else
76	int pcap_fddipad;
77	#endif
78
79	__dead__attribute__((__noreturn__)) void
80	bpf_error(const char *fmt, ...)
81	{
82	va_list ap;
83
84	va_start(ap, fmt)__builtin_va_start((ap), fmt);
85	if (bpf_pcap != NULL((void *)0))
86	(void)vsnprintf(pcap_geterr(bpf_pcap), PCAP_ERRBUF_SIZE256,
87	fmt, ap);
88	va_end(ap)__builtin_va_end((ap));
89	longjmp(top_ctx, 1);
90	/* NOTREACHED */
91	}
92
93	static void init_linktype(int);
94
95	static int alloc_reg(void);
96	static void free_reg(int);
97
98	static struct block *root;
99
100	/* initialization code used for variable link header */
101	static struct slist init_code = NULL((void )0);
102
103	/* Flags and registers for variable link type handling */
104	static int variable_nl;
105	static int nl_reg, iphl_reg;
106
107	/*
108	* Track memory allocations, for bulk freeing at the end
109	*/
110	#define NMEMBAG16 16
111	#define MEMBAG0SIZE(4096 / sizeof (void )) (4096 / sizeof (void ))
112	struct membag {
113	u_int total;
114	u_int slot;
115	void *ptrs; / allocated array[total] to each malloc */
116	};
117
118	static struct membag membag[NMEMBAG16];
119	static int cur_membag;
120
121	static void *newchunk(size_t);
122	static void freechunks(void);
123	static __inline struct block *new_block(int);
124	static __inline struct slist *new_stmt(int);
125	static struct block *gen_retblk(int);
126	static __inline void syntax(void);
127
128	static void backpatch(struct block , struct block );
129	static void merge(struct block , struct block );
130	static struct block *gen_cmp(u_int, u_int, bpf_int32);
131	static struct block *gen_cmp_gt(u_int, u_int, bpf_int32);
132	static struct block *gen_cmp_nl(u_int, u_int, bpf_int32);
133	static struct block *gen_mcmp(u_int, u_int, bpf_int32, bpf_u_int32);
134	static struct block *gen_mcmp_nl(u_int, u_int, bpf_int32, bpf_u_int32);
135	static struct block gen_bcmp(u_int, u_int, const u_char );
136	static struct block *gen_uncond(int);
137	static __inline struct block *gen_true(void);
138	static __inline struct block *gen_false(void);
139	static struct block *gen_linktype(int);
140	static struct block *gen_hostop(bpf_u_int32, bpf_u_int32, int, int, u_int, u_int);
141	#ifdef INET61
142	static struct block gen_hostop6(struct in6_addr , struct in6_addr *, int, int, u_int, u_int);
143	#endif
144	static struct block gen_ehostop(const u_char , int);
145	static struct block gen_fhostop(const u_char , int);
146	static struct block *gen_dnhostop(bpf_u_int32, int, u_int);
147	static struct block gen_p80211_hostop(const u_char , int);
148	static struct block gen_p80211_addr(int, u_int, const u_char );
149	static struct block *gen_host(bpf_u_int32, bpf_u_int32, int, int);
150	#ifdef INET61
151	static struct block gen_host6(struct in6_addr , struct in6_addr *, int, int);
152	#endif
153	#ifndef INET61
154	static struct block gen_gateway(const u_char , bpf_u_int32 **, int, int);
155	#endif
156	static struct block *gen_ipfrag(void);
157	static struct block *gen_portatom(int, bpf_int32);
158	#ifdef INET61
159	static struct block *gen_portatom6(int, bpf_int32);
160	#endif
161	struct block *gen_portop(int, int, int);
162	static struct block *gen_port(int, int, int);
163	#ifdef INET61
164	struct block *gen_portop6(int, int, int);
165	static struct block *gen_port6(int, int, int);
166	#endif
167	static int lookup_proto(const char *, int);
168	static struct block *gen_protochain(int, int, int);
169	static struct block *gen_proto(int, int, int);
170	static struct slist xfer_to_x(struct arth );
171	static struct slist xfer_to_a(struct arth );
172	static struct block *gen_len(int, int);
173
174	static void *
175	newchunk(size_t n)
176	{
177	struct membag *m;
178	int k, size;
179	void *p;
180
181	m = &membag[cur_membag];
182	if (m->total != 0 && m->total - m->slot == 0) {
183	if (++cur_membag == NMEMBAG16)
184	bpf_error("out of memory");
185	m = &membag[cur_membag];
186	}
187	if (m->total - m->slot == 0) {
188	m->ptrs = calloc(sizeof (char ), MEMBAG0SIZE(4096 / sizeof (void )) << cur_membag);
189	if (m->ptrs == NULL((void *)0))
190	bpf_error("out of memory");
191	m->total = MEMBAG0SIZE(4096 / sizeof (void *)) << cur_membag;
192	m->slot = 0;
193	}
194
195	p = calloc(1, n);
196	if (p == NULL((void *)0))
197	bpf_error("out of memory");
198	m->ptrs[m->slot++] = p;
199	return (p);
200	}
201
202	static void
203	freechunks(void)
204	{
205	int i, j;
206
207	for (i = 0; i <= cur_membag; i++) {
208	if (membag[i].ptrs == NULL((void *)0))
209	continue;
210	for (j = 0; j < membag[i].slot; j++)
211	free(membag[i].ptrs[j]);
212	free(membag[i].ptrs);
213	membag[i].ptrs = NULL((void *)0);
214	membag[i].slot = membag[i].total = 0;
215	}
216	cur_membag = 0;
217	}
218
219	/*
220	* A strdup whose allocations are freed after code generation is over.
221	*/
222	char *
223	sdup(s)
224	const char *s;
225	{
226	int n = strlen(s) + 1;
227	char *cp = newchunk(n);
228
229	strlcpy(cp, s, n);
230	return (cp);
231	}
232
233	static __inline struct block *
234	new_block(code)
235	int code;
236	{
237	struct block *p;
238
239	p = (struct block )newchunk(sizeof(p));
240	p->s.code = code;
241	p->head = p;
242
243	return p;
244	}
245
246	static __inline struct slist *
247	new_stmt(code)
248	int code;
249	{
250	struct slist *p;
251
252	p = (struct slist )newchunk(sizeof(p));
253	p->s.code = code;
254
255	return p;
256	}
257
258	static struct block *
259	gen_retblk(v)
260	int v;
261	{
262	struct block *b = new_block(BPF_RET0x06\|BPF_K0x00);
263
264	b->s.k = v;
265	return b;
266	}
267
268	static __inline void
269	syntax()
270	{
271	bpf_error("syntax error in filter expression");
272	}
273
274	static bpf_u_int32 netmask;
275	static int snaplen;
276	int no_optimize;
277
278	int
279	pcap_compile(pcap_t p, struct bpf_program program,
280	const char *buf, int optimize, bpf_u_int32 mask)
281	{
282	extern int n_errors;
283	int len;
284
285	no_optimize = 0;
286	n_errors = 0;
287	root = NULL((void *)0);
288	bpf_pcap = p;
289	if (setjmp(top_ctx)) {
290	freechunks();
291	return (-1);
292	}
293
294	netmask = mask;
295	snaplen = pcap_snapshot(p);
296
297	lex_init(buf ? buf : "");
298	init_linktype(pcap_datalink(p));
299	(void)pcap_parse();
300
301	if (n_errors)
302	syntax();
303
304	if (root == NULL((void *)0))
305	root = gen_retblk(snaplen);
306
307	if (optimize && !no_optimize) {
308	bpf_optimize(&root);
309	if (root == NULL((void *)0) \|\|
310	(root->s.code == (BPF_RET0x06\|BPF_K0x00) && root->s.k == 0))
311	bpf_error("expression rejects all packets");
312	}
313	program->bf_insns = icode_to_fcode(root, &len);
314	program->bf_len = len;
315
316	freechunks();
317	return (0);
318	}
319
320	/*
321	* entry point for using the compiler with no pcap open
322	* pass in all the stuff that is needed explicitly instead.
323	*/
324	int
325	pcap_compile_nopcap(int snaplen_arg, int linktype_arg,
326	struct bpf_program *program,
327	const char *buf, int optimize, bpf_u_int32 mask)
328	{
329	extern int n_errors;
330	int len;
331
332	n_errors = 0;
333	root = NULL((void *)0);
334	bpf_pcap = NULL((void *)0);
335	if (setjmp(top_ctx)) {
336	freechunks();
337	return (-1);
338	}
339
340	netmask = mask;
341
342	/* XXX needed? I don't grok the use of globals here. */
343	snaplen = snaplen_arg;
344
345	lex_init(buf ? buf : "");
346	init_linktype(linktype_arg);
347	(void)pcap_parse();
348
349	if (n_errors)
350	syntax();
351
352	if (root == NULL((void *)0))
353	root = gen_retblk(snaplen_arg);
354
355	if (optimize) {
356	bpf_optimize(&root);
357	if (root == NULL((void *)0) \|\|
358	(root->s.code == (BPF_RET0x06\|BPF_K0x00) && root->s.k == 0))
359	bpf_error("expression rejects all packets");
360	}
361	program->bf_insns = icode_to_fcode(root, &len);
362	program->bf_len = len;
363
364	freechunks();
365	return (0);
366	}
367
368	/*
369	* Clean up a "struct bpf_program" by freeing all the memory allocated
370	* in it.
371	*/
372	void
373	pcap_freecode(struct bpf_program *program)
374	{
375	program->bf_len = 0;
376	if (program->bf_insns != NULL((void *)0)) {
377	free((char *)program->bf_insns);
378	program->bf_insns = NULL((void *)0);
379	}
380	}
381
382	/*
383	* Backpatch the blocks in 'list' to 'target'. The 'sense' field indicates
384	* which of the jt and jf fields has been resolved and which is a pointer
385	* back to another unresolved block (or nil). At least one of the fields
386	* in each block is already resolved.
387	*/
388	static void
389	backpatch(list, target)
390	struct block list, target;
391	{
392	struct block *next;
393
394	while (list) {
395	if (!list->sense) {
396	next = JT(list)((list)->et.succ);
397	JT(list)((list)->et.succ) = target;
398	} else {
399	next = JF(list)((list)->ef.succ);
400	JF(list)((list)->ef.succ) = target;
401	}
402	list = next;
403	}
404	}
405
406	/*
407	* Merge the lists in b0 and b1, using the 'sense' field to indicate
408	* which of jt and jf is the link.
409	*/
410	static void
411	merge(b0, b1)
412	struct block b0, b1;
413	{
414	struct block **p = &b0;
415
416	/* Find end of list. */
417	while (*p)
418	p = !((p)->sense) ? &JT(p)((p)->et.succ) : &JF(p)((*p)->ef.succ);
419
420	/* Concatenate the lists. */
421	*p = b1;
422	}
423
424	void
425	finish_parse(p)
426	struct block *p;
427	{
428	backpatch(p, gen_retblk(snaplen));
429	p->sense = !p->sense;
430	backpatch(p, gen_retblk(0));
431	root = p->head;
432
433	/* prepend initialization code to root */
434	if (init_code != NULL((void )0) && root != NULL((void )0)) {
435	sappend(init_code, root->stmts);
436	root->stmts = init_code;
437	init_code = NULL((void *)0);
438	}
439
440	if (iphl_reg != -1) {
441	free_reg(iphl_reg);
442	iphl_reg = -1;
443	}
444	if (nl_reg != -1) {
445	free_reg(nl_reg);
446	nl_reg = -1;
447	}
448	}
449
450	void
451	gen_and(b0, b1)
452	struct block b0, b1;
453	{
454	backpatch(b0, b1->head);
455	b0->sense = !b0->sense;
456	b1->sense = !b1->sense;
457	merge(b1, b0);
458	b1->sense = !b1->sense;
459	b1->head = b0->head;
460	}
461
462	void
463	gen_or(b0, b1)
464	struct block b0, b1;
465	{
466	b0->sense = !b0->sense;
467	backpatch(b0, b1->head);
468	b0->sense = !b0->sense;
469	merge(b1, b0);
470	b1->head = b0->head;
471	}
472
473	void
474	gen_not(b)
475	struct block *b;
476	{
477	b->sense = !b->sense;
478	}
479
480	static struct block *
481	gen_cmp(offset, size, v)
482	u_int offset, size;
483	bpf_int32 v;
484	{
485	struct slist *s;
486	struct block *b;
487
488	s = new_stmt(BPF_LD0x00\|BPF_ABS0x20\|size);
489	s->s.k = offset;
490
491	b = new_block(JMP(BPF_JEQ)((0x10)\|0x05\|0x00));
492	b->stmts = s;
493	b->s.k = v;
494
495	return b;
496	}
497
498	static struct block *
499	gen_cmp_gt(offset, size, v)
500	u_int offset, size;
501	bpf_int32 v;
502	{
503	struct slist *s;
504	struct block *b;
505
506	s = new_stmt(BPF_LD0x00\|BPF_ABS0x20\|size);
507	s->s.k = offset;
508
509	b = new_block(JMP(BPF_JGT)((0x20)\|0x05\|0x00));
510	b->stmts = s;
511	b->s.k = v;
512
513	return b;
514	}
515
516	static struct block *
517	gen_mcmp(offset, size, v, mask)
518	u_int offset, size;
519	bpf_int32 v;
520	bpf_u_int32 mask;
521	{
522	struct block *b = gen_cmp(offset, size, v);
523	struct slist *s;
524
525	if (mask != 0xffffffff) {
526	s = new_stmt(BPF_ALU0x04\|BPF_AND0x50\|BPF_K0x00);
527	s->s.k = mask;
528	sappend(b->stmts, s);
529	}
530	return b;
531	}
532
533	/* Like gen_mcmp with 'dynamic off_nl' added to the offset */
534	static struct block *
535	gen_mcmp_nl(offset, size, v, mask)
536	u_int offset, size;
537	bpf_int32 v;
538	bpf_u_int32 mask;
539	{
540	struct block *b = gen_cmp_nl(offset, size, v);
541	struct slist *s;
542
543	if (mask != 0xffffffff) {
544	s = new_stmt(BPF_ALU0x04\|BPF_AND0x50\|BPF_K0x00);
545	s->s.k = mask;
546	sappend(b->stmts, s);
547	}
548	return b;
549	}
550
551	static struct block *
552	gen_bcmp(offset, size, v)
553	u_int offset, size;
554	const u_char *v;
555	{
556	struct block b, tmp;
557
558	b = NULL((void *)0);
559	while (size >= 4) {
560	const u_char *p = &v[size - 4];
561	bpf_int32 w = ((bpf_int32)p[0] << 24) \|
562	((bpf_int32)p[1] << 16) \| ((bpf_int32)p[2] << 8) \| p[3];
563
564	tmp = gen_cmp(offset + size - 4, BPF_W0x00, w);
565	if (b != NULL((void *)0))
566	gen_and(b, tmp);
567	b = tmp;
568	size -= 4;
569	}
570	while (size >= 2) {
571	const u_char *p = &v[size - 2];
572	bpf_int32 w = ((bpf_int32)p[0] << 8) \| p[1];
573
574	tmp = gen_cmp(offset + size - 2, BPF_H0x08, w);
575	if (b != NULL((void *)0))
576	gen_and(b, tmp);
577	b = tmp;
578	size -= 2;
579	}
580	if (size > 0) {
581	tmp = gen_cmp(offset, BPF_B0x10, (bpf_int32)v[0]);
582	if (b != NULL((void *)0))
583	gen_and(b, tmp);
584	b = tmp;
585	}
586	return b;
587	}
588
589	/*
590	* Various code constructs need to know the layout of the data link
591	* layer. These variables give the necessary offsets. off_linktype
592	* is set to -1 for no encapsulation, in which case, IP is assumed.
593	*/
594	static u_int off_linktype;
595	static u_int off_nl;
596	static u_int off_nl_nosnap;
597
598	static int linktype;
599
600	/* Generate code to load the dynamic 'off_nl' to the X register */
601	static struct slist *
602	nl2X_stmt(void)
603	{
604	struct slist s, tmp;
605
606	if (nl_reg == -1) {
607	switch (linktype) {
608	case DLT_PFLOG117:
609	/* The pflog header contains PFLOG_REAL_HDRLEN
610	which does NOT include the padding. Round
611	up to the nearest dword boundary */
612	s = new_stmt(BPF_LD0x00\|BPF_B0x10\|BPF_ABS0x20);
613	s->s.k = 0;
614
615	tmp = new_stmt(BPF_ALU0x04\|BPF_ADD0x00\|BPF_K0x00);
616	tmp->s.k = 3;
617	sappend(s, tmp);
618
619	tmp = new_stmt(BPF_ALU0x04\|BPF_AND0x50\|BPF_K0x00);
620	tmp->s.k = 0xfc;
621	sappend(s, tmp);
622
623	nl_reg = alloc_reg();
624	tmp = new_stmt(BPF_ST0x02);
625	tmp->s.k = nl_reg;
626	sappend(s, tmp);
627
628	break;
629	default:
630	bpf_error("Unknown header size for link type 0x%x",
631	linktype);
632	}
633
634	if (init_code == NULL((void *)0))
635	init_code = s;
636	else
637	sappend(init_code, s);
638	}
639
640	s = new_stmt(BPF_LDX0x01\|BPF_MEM0x60);
641	s->s.k = nl_reg;
642
643	return s;
644	}
645
646	/* Like gen_cmp but adds the dynamic 'off_nl' to the offset */
647	static struct block *
648	gen_cmp_nl(offset, size, v)
649	u_int offset, size;
650	bpf_int32 v;
651	{
652	struct slist s, tmp;
653	struct block *b;
654
655	if (variable_nl) {
656	s = nl2X_stmt();
657	tmp = new_stmt(BPF_LD0x00\|BPF_IND0x40\|size);
658	tmp->s.k = offset;
659	sappend(s, tmp);
660	} else {
661	s = new_stmt(BPF_LD0x00\|BPF_ABS0x20\|size);
662	s->s.k = offset + off_nl;
663	}
664	b = new_block(JMP(BPF_JEQ)((0x10)\|0x05\|0x00));
665	b->stmts = s;
666	b->s.k = v;
667
668	return b;
669	}
670
671	static void
672	init_linktype(type)
673	int type;
674	{
675	linktype = type;
676	init_code = NULL((void *)0);
677	nl_reg = iphl_reg = -1;
678
679	switch (type) {
680
681	case DLT_EN10MB1:
682	off_linktype = 12;
683	off_nl = 14;
684	return;
685
686	case DLT_SLIP8:
687	/*
688	* SLIP doesn't have a link level type. The 16 byte
689	* header is hacked into our SLIP driver.
690	*/
691	off_linktype = -1;
692	off_nl = 16;
693	return;
694
695	case DLT_SLIP_BSDOS15:
696	/* XXX this may be the same as the DLT_PPP_BSDOS case */
697	off_linktype = -1;
698	/* XXX end */
699	off_nl = 24;
700	return;
701
702	case DLT_NULL0:
703	off_linktype = 0;
704	off_nl = 4;
705	return;
706
707	case DLT_PPP9:
708	off_linktype = 2;
709	off_nl = 4;
710	return;
711
712	case DLT_PPP_SERIAL50:
713	off_linktype = -1;
714	off_nl = 2;
715	return;
716
717	case DLT_PPP_ETHER51:
718	/*
719	* This does not include the Ethernet header, and
720	* only covers session state.
721	*/
722	off_linktype = 6;
723	off_nl = 8;
724	return;
725
726	case DLT_PPP_BSDOS16:
727	off_linktype = 5;
728	off_nl = 24;
729	return;
730
731	case DLT_FDDI10:
732	/*
733	* FDDI doesn't really have a link-level type field.
734	* We assume that SSAP = SNAP is being used and pick
735	* out the encapsulated Ethernet type.
736	*/
737	off_linktype = 19;
738	#ifdef PCAP_FDDIPAD
739	off_linktype += pcap_fddipad;
740	#endif
741	off_nl = 21;
742	#ifdef PCAP_FDDIPAD
743	off_nl += pcap_fddipad;
744	#endif
745	return;
746
747	case DLT_IEEE8026:
748	off_linktype = 20;
749	off_nl = 22;
750	return;
751
752	case DLT_IEEE802_11105:
753	off_linktype = 30; /* XXX variable */
754	off_nl = 32;
755	return;
756
757	case DLT_IEEE802_11_RADIO127: /* XXX variable */
758	off_linktype = 30 + IEEE80211_RADIOTAP_HDRLEN64;
759	off_nl = 32 + IEEE80211_RADIOTAP_HDRLEN64;
760	return;
761
762	case DLT_ATM_RFC148311:
763	/*
764	* assume routed, non-ISO PDUs
765	* (i.e., LLC = 0xAA-AA-03, OUT = 0x00-00-00)
766	*/
767	off_linktype = 6;
768	off_nl = 8;
769	return;
770
771	case DLT_LOOP12:
772	off_linktype = 0;
773	off_nl = 4;
774	return;
775
776	case DLT_ENC13:
777	off_linktype = -1;
778	off_nl = 12;
779	return;
780
781	case DLT_PFLOG117:
782	off_linktype = 0;
783	variable_nl = 1;
784	off_nl = 0;
785	return;
786
787	case DLT_PFSYNC18:
788	off_linktype = -1;
789	off_nl = 4;
790	return;
791
792	case DLT_OPENFLOW267:
793	off_linktype = -1;
794	off_nl = 12;
795	return;
796
797	case DLT_USBPCAP249:
798	/* FALLTHROUGH */
799	case DLT_RAW14:
800	off_linktype = -1;
801	off_nl = 0;
802	return;
803	}
804	bpf_error("unknown data link type 0x%x", linktype);
805	/* NOTREACHED */
806	}
807
808	static struct block *
809	gen_uncond(rsense)
810	int rsense;
811	{
812	struct block *b;
813	struct slist *s;
814
815	s = new_stmt(BPF_LD0x00\|BPF_IMM0x00);
816	s->s.k = !rsense;
817	b = new_block(JMP(BPF_JEQ)((0x10)\|0x05\|0x00));
818	b->stmts = s;
819
820	return b;
821	}
822
823	static __inline struct block *
824	gen_true()
825	{
826	return gen_uncond(1);
827	}
828
829	static __inline struct block *
830	gen_false()
831	{
832	return gen_uncond(0);
833	}
834
835	static struct block *
836	gen_linktype(proto)
837	int proto;
838	{
839	struct block b0, b1;
840
841	/* If we're not using encapsulation and checking for IP, we're done */
842	if ((off_linktype == -1 \|\| mpls_stack > 0) && proto == ETHERTYPE_IP0x0800)
843	return gen_true();
844	#ifdef INET61
845	/* this isn't the right thing to do, but sometimes necessary */
846	if ((off_linktype == -1 \|\| mpls_stack > 0) && proto == ETHERTYPE_IPV60x86DD)
847	return gen_true();
848	#endif
849
850	switch (linktype) {
851
852	case DLT_EN10MB1:
853	if (proto <= ETHERMTU(1518 - ((6 * 2) + 2) - 4)) {
854	/* This is an LLC SAP value */
855	b0 = gen_cmp_gt(off_linktype, BPF_H0x08, ETHERMTU(1518 - ((6 * 2) + 2) - 4));
856	gen_not(b0);
857	b1 = gen_cmp(off_linktype + 2, BPF_B0x10, (bpf_int32)proto);
858	gen_and(b0, b1);
859	return b1;
860	} else {
861	/* This is an Ethernet type */
862	return gen_cmp(off_linktype, BPF_H0x08, (bpf_int32)proto);
863	}
864	break;
865
866	case DLT_SLIP8:
867	return gen_false();
868
869	case DLT_PPP9:
870	case DLT_PPP_ETHER51:
871	if (proto == ETHERTYPE_IP0x0800)
872	proto = PPP_IP0x0021; /* XXX was 0x21 */
873	#ifdef INET61
874	else if (proto == ETHERTYPE_IPV60x86DD)
875	proto = PPP_IPV60x0057;
876	#endif
877	break;
878
879	case DLT_PPP_BSDOS16:
880	switch (proto) {
881
882	case ETHERTYPE_IP0x0800:
883	b0 = gen_cmp(off_linktype, BPF_H0x08, PPP_IP0x0021);
884	b1 = gen_cmp(off_linktype, BPF_H0x08, PPP_VJC0x002d);
885	gen_or(b0, b1);
886	b0 = gen_cmp(off_linktype, BPF_H0x08, PPP_VJNC0x002f);
887	gen_or(b1, b0);
888	return b0;
889
890	#ifdef INET61
891	case ETHERTYPE_IPV60x86DD:
892	proto = PPP_IPV60x0057;
893	/* more to go? */
894	break;
895	#endif /* INET6 */
896
897	case ETHERTYPE_DN0x6003:
898	proto = PPP_DECNET0x0027;
899	break;
900
901	case ETHERTYPE_ATALK0x809B:
902	proto = PPP_APPLE0x0029;
903	break;
904
905	case ETHERTYPE_NS0x0600:
906	proto = PPP_NS0x0025;
907	break;
908	}
909	break;
910
911	case DLT_LOOP12:
912	case DLT_ENC13:
913	case DLT_NULL0:
914	{
915	int v;
916
917	if (proto == ETHERTYPE_IP0x0800)
918	v = AF_INET2;
919	#ifdef INET61
920	else if (proto == ETHERTYPE_IPV60x86DD)
921	v = AF_INET624;
922	#endif /* INET6 */
923	else
924	return gen_false();
925
926	/*
927	* For DLT_NULL, the link-layer header is a 32-bit word
928	* containing an AF_ value in host byte order, and for
929	* DLT_ENC, the link-layer header begins with a 32-bit
930	* word containing an AF_ value in host byte order.
931	*
932	* For DLT_LOOP, the link-layer header is a 32-bit
933	* word containing an AF_ value in network byte order.
934	*/
935	if (linktype != DLT_LOOP12)
936	v = htonl(v)(__uint32_t)(__builtin_constant_p(v) ? (__uint32_t)(((__uint32_t )(v) & 0xff) << 24 \| ((__uint32_t)(v) & 0xff00) << 8 \| ((__uint32_t)(v) & 0xff0000) >> 8 \| ( (__uint32_t)(v) & 0xff000000) >> 24) : __swap32md(v ));
937
938	return (gen_cmp(0, BPF_W0x00, (bpf_int32)v));
939	break;
940	}
941	case DLT_PFLOG117:
942	if (proto == ETHERTYPE_IP0x0800)
943	return (gen_cmp(offsetof(struct pfloghdr, af)__builtin_offsetof(struct pfloghdr, af), BPF_B0x10,
944	(bpf_int32)AF_INET2));
945	#ifdef INET61
946	else if (proto == ETHERTYPE_IPV60x86DD)
947	return (gen_cmp(offsetof(struct pfloghdr, af)__builtin_offsetof(struct pfloghdr, af), BPF_B0x10,
948	(bpf_int32)AF_INET624));
949	#endif /* INET6 */
950	else
951	return gen_false();
952	break;
953
954	}
955	return gen_cmp(off_linktype, BPF_H0x08, (bpf_int32)proto);
956	}
957
958	static struct block *
959	gen_hostop(addr, mask, dir, proto, src_off, dst_off)
960	bpf_u_int32 addr;
961	bpf_u_int32 mask;
962	int dir, proto;
963	u_int src_off, dst_off;
964	{
965	struct block b0, b1;
966	u_int offset;
967
968	switch (dir) {
969
970	case Q_SRC1:
971	offset = src_off;
972	break;
973
974	case Q_DST2:
975	offset = dst_off;
976	break;
977
978	case Q_AND4:
979	b0 = gen_hostop(addr, mask, Q_SRC1, proto, src_off, dst_off);
980	b1 = gen_hostop(addr, mask, Q_DST2, proto, src_off, dst_off);
981	gen_and(b0, b1);
982	return b1;
983
984	case Q_OR3:
985	case Q_DEFAULT0:
986	b0 = gen_hostop(addr, mask, Q_SRC1, proto, src_off, dst_off);
987	b1 = gen_hostop(addr, mask, Q_DST2, proto, src_off, dst_off);
988	gen_or(b0, b1);
989	return b1;
990
991	default:
992	bpf_error("direction not supported on linktype 0x%x",
993	linktype);
994	}
995	b0 = gen_linktype(proto);
996	b1 = gen_mcmp_nl(offset, BPF_W0x00, (bpf_int32)addr, mask);
997	gen_and(b0, b1);
998	return b1;
999	}
1000
1001	#ifdef INET61
1002	static struct block *
1003	gen_hostop6(addr, mask, dir, proto, src_off, dst_off)
1004	struct in6_addr *addr;
1005	struct in6_addr *mask;
1006	int dir, proto;
1007	u_int src_off, dst_off;
1008	{
1009	struct block b0, b1;
1010	u_int offset;
1011	u_int32_t a, m;
1012
1013	switch (dir) {
1014
1015	case Q_SRC1:
1016	offset = src_off;
1017	break;
1018
1019	case Q_DST2:
1020	offset = dst_off;
1021	break;
1022
1023	case Q_AND4:
1024	b0 = gen_hostop6(addr, mask, Q_SRC1, proto, src_off, dst_off);
1025	b1 = gen_hostop6(addr, mask, Q_DST2, proto, src_off, dst_off);
1026	gen_and(b0, b1);
1027	return b1;
1028
1029	case Q_OR3:
1030	case Q_DEFAULT0:
1031	b0 = gen_hostop6(addr, mask, Q_SRC1, proto, src_off, dst_off);
1032	b1 = gen_hostop6(addr, mask, Q_DST2, proto, src_off, dst_off);
1033	gen_or(b0, b1);
1034	return b1;
1035
1036	default:
1037	bpf_error("direction not supported on linktype 0x%x",
1038	linktype);
1039	}
1040	/* this order is important */
1041	a = (u_int32_t *)addr;
1042	m = (u_int32_t *)mask;
1043	b1 = gen_mcmp_nl(offset + 12, BPF_W0x00, ntohl(a[3])(__uint32_t)(__builtin_constant_p(a[3]) ? (__uint32_t)(((__uint32_t )(a[3]) & 0xff) << 24 \| ((__uint32_t)(a[3]) & 0xff00 ) << 8 \| ((__uint32_t)(a[3]) & 0xff0000) >> 8 \| ((__uint32_t)(a[3]) & 0xff000000) >> 24) : __swap32md (a[3])), ntohl(m[3])(__uint32_t)(__builtin_constant_p(m[3]) ? (__uint32_t)(((__uint32_t )(m[3]) & 0xff) << 24 \| ((__uint32_t)(m[3]) & 0xff00 ) << 8 \| ((__uint32_t)(m[3]) & 0xff0000) >> 8 \| ((__uint32_t)(m[3]) & 0xff000000) >> 24) : __swap32md (m[3])));
1044	b0 = gen_mcmp_nl(offset + 8, BPF_W0x00, ntohl(a[2])(__uint32_t)(__builtin_constant_p(a[2]) ? (__uint32_t)(((__uint32_t )(a[2]) & 0xff) << 24 \| ((__uint32_t)(a[2]) & 0xff00 ) << 8 \| ((__uint32_t)(a[2]) & 0xff0000) >> 8 \| ((__uint32_t)(a[2]) & 0xff000000) >> 24) : __swap32md (a[2])), ntohl(m[2])(__uint32_t)(__builtin_constant_p(m[2]) ? (__uint32_t)(((__uint32_t )(m[2]) & 0xff) << 24 \| ((__uint32_t)(m[2]) & 0xff00 ) << 8 \| ((__uint32_t)(m[2]) & 0xff0000) >> 8 \| ((__uint32_t)(m[2]) & 0xff000000) >> 24) : __swap32md (m[2])));
1045	gen_and(b0, b1);
1046	b0 = gen_mcmp_nl(offset + 4, BPF_W0x00, ntohl(a[1])(__uint32_t)(__builtin_constant_p(a[1]) ? (__uint32_t)(((__uint32_t )(a[1]) & 0xff) << 24 \| ((__uint32_t)(a[1]) & 0xff00 ) << 8 \| ((__uint32_t)(a[1]) & 0xff0000) >> 8 \| ((__uint32_t)(a[1]) & 0xff000000) >> 24) : __swap32md (a[1])), ntohl(m[1])(__uint32_t)(__builtin_constant_p(m[1]) ? (__uint32_t)(((__uint32_t )(m[1]) & 0xff) << 24 \| ((__uint32_t)(m[1]) & 0xff00 ) << 8 \| ((__uint32_t)(m[1]) & 0xff0000) >> 8 \| ((__uint32_t)(m[1]) & 0xff000000) >> 24) : __swap32md (m[1])));
1047	gen_and(b0, b1);
1048	b0 = gen_mcmp_nl(offset + 0, BPF_W0x00, ntohl(a[0])(__uint32_t)(__builtin_constant_p(a[0]) ? (__uint32_t)(((__uint32_t )(a[0]) & 0xff) << 24 \| ((__uint32_t)(a[0]) & 0xff00 ) << 8 \| ((__uint32_t)(a[0]) & 0xff0000) >> 8 \| ((__uint32_t)(a[0]) & 0xff000000) >> 24) : __swap32md (a[0])), ntohl(m[0])(__uint32_t)(__builtin_constant_p(m[0]) ? (__uint32_t)(((__uint32_t )(m[0]) & 0xff) << 24 \| ((__uint32_t)(m[0]) & 0xff00 ) << 8 \| ((__uint32_t)(m[0]) & 0xff0000) >> 8 \| ((__uint32_t)(m[0]) & 0xff000000) >> 24) : __swap32md (m[0])));
1049	gen_and(b0, b1);
1050	b0 = gen_linktype(proto);
1051	gen_and(b0, b1);
1052	return b1;
1053	}
1054	#endif /INET6/
1055
1056	static struct block *
1057	gen_ehostop(eaddr, dir)
1058	const u_char *eaddr;
1059	int dir;
1060	{
1061	struct block b0, b1;
1062
1063	switch (dir) {
1064	case Q_SRC1:
1065	return gen_bcmp(6, 6, eaddr);
1066
1067	case Q_DST2:
1068	return gen_bcmp(0, 6, eaddr);
1069
1070	case Q_AND4:
1071	b0 = gen_ehostop(eaddr, Q_SRC1);
1072	b1 = gen_ehostop(eaddr, Q_DST2);
1073	gen_and(b0, b1);
1074	return b1;
1075
1076	case Q_DEFAULT0:
1077	case Q_OR3:
1078	b0 = gen_ehostop(eaddr, Q_SRC1);
1079	b1 = gen_ehostop(eaddr, Q_DST2);
1080	gen_or(b0, b1);
1081	return b1;
1082	default:
1083	bpf_error("direction not supported on linktype 0x%x",
1084	linktype);
1085	}
1086	/* NOTREACHED */
1087	}
1088
1089	/*
1090	* Like gen_ehostop, but for DLT_FDDI
1091	*/
1092	static struct block *
1093	gen_fhostop(eaddr, dir)
1094	const u_char *eaddr;
1095	int dir;
1096	{
1097	struct block b0, b1;
1098
1099	switch (dir) {
1100	case Q_SRC1:
1101	#ifdef PCAP_FDDIPAD
1102	return gen_bcmp(6 + 1 + pcap_fddipad, 6, eaddr);
1103	#else
1104	return gen_bcmp(6 + 1, 6, eaddr);
1105	#endif
1106
1107	case Q_DST2:
1108	#ifdef PCAP_FDDIPAD
1109	return gen_bcmp(0 + 1 + pcap_fddipad, 6, eaddr);
1110	#else
1111	return gen_bcmp(0 + 1, 6, eaddr);
1112	#endif
1113
1114	case Q_AND4:
1115	b0 = gen_fhostop(eaddr, Q_SRC1);
1116	b1 = gen_fhostop(eaddr, Q_DST2);
1117	gen_and(b0, b1);
1118	return b1;
1119
1120	case Q_DEFAULT0:
1121	case Q_OR3:
1122	b0 = gen_fhostop(eaddr, Q_SRC1);
1123	b1 = gen_fhostop(eaddr, Q_DST2);
1124	gen_or(b0, b1);
1125	return b1;
1126	default:
1127	bpf_error("direction not supported on linktype 0x%x",
1128	linktype);
1129	}
1130	/* NOTREACHED */
1131	}
1132
1133	/*
1134	* This is quite tricky because there may be pad bytes in front of the
1135	* DECNET header, and then there are two possible data packet formats that
1136	* carry both src and dst addresses, plus 5 packet types in a format that
1137	* carries only the src node, plus 2 types that use a different format and
1138	* also carry just the src node.
1139	*
1140	* Yuck.
1141	*
1142	* Instead of doing those all right, we just look for data packets with
1143	* 0 or 1 bytes of padding. If you want to look at other packets, that
1144	* will require a lot more hacking.
1145	*
1146	* To add support for filtering on DECNET "areas" (network numbers)
1147	* one would want to add a "mask" argument to this routine. That would
1148	* make the filter even more inefficient, although one could be clever
1149	* and not generate masking instructions if the mask is 0xFFFF.
1150	*/
1151	static struct block *
1152	gen_dnhostop(addr, dir, base_off)
1153	bpf_u_int32 addr;
1154	int dir;
1155	u_int base_off;
1156	{
1157	struct block b0, b1, b2, tmp;
1158	u_int offset_lh; /* offset if long header is received */
1159	u_int offset_sh; /* offset if short header is received */
1160
1161	switch (dir) {
1162
1163	case Q_DST2:
1164	offset_sh = 1; /* follows flags */
1165	offset_lh = 7; /* flgs,darea,dsubarea,HIORD */
1166	break;
1167
1168	case Q_SRC1:
1169	offset_sh = 3; /* follows flags, dstnode */
1170	offset_lh = 15; /* flgs,darea,dsubarea,did,sarea,ssub,HIORD */
1171	break;
1172
1173	case Q_AND4:
1174	/* Inefficient because we do our Calvinball dance twice */
1175	b0 = gen_dnhostop(addr, Q_SRC1, base_off);
1176	b1 = gen_dnhostop(addr, Q_DST2, base_off);
1177	gen_and(b0, b1);
1178	return b1;
1179
1180	case Q_OR3:
1181	case Q_DEFAULT0:
1182	/* Inefficient because we do our Calvinball dance twice */
1183	b0 = gen_dnhostop(addr, Q_SRC1, base_off);
1184	b1 = gen_dnhostop(addr, Q_DST2, base_off);
1185	gen_or(b0, b1);
1186	return b1;
1187
1188	default:
1189	bpf_error("direction not supported on linktype 0x%x",
1190	linktype);
1191	}
1192	b0 = gen_linktype(ETHERTYPE_DN0x6003);
1193	/* Check for pad = 1, long header case */
1194	tmp = gen_mcmp_nl(base_off + 2, BPF_H0x08,
1195	(bpf_int32)ntohs(0x0681)(__uint16_t)(__builtin_constant_p(0x0681) ? (__uint16_t)(((__uint16_t )(0x0681) & 0xffU) << 8 \| ((__uint16_t)(0x0681) & 0xff00U) >> 8) : __swap16md(0x0681)), (bpf_int32)ntohs(0x07FF)(__uint16_t)(__builtin_constant_p(0x07FF) ? (__uint16_t)(((__uint16_t )(0x07FF) & 0xffU) << 8 \| ((__uint16_t)(0x07FF) & 0xff00U) >> 8) : __swap16md(0x07FF)));
1196	b1 = gen_cmp_nl(base_off + 2 + 1 + offset_lh,
1197	BPF_H0x08, (bpf_int32)ntohs(addr)(__uint16_t)(__builtin_constant_p(addr) ? (__uint16_t)(((__uint16_t )(addr) & 0xffU) << 8 \| ((__uint16_t)(addr) & 0xff00U ) >> 8) : __swap16md(addr)));
1198	gen_and(tmp, b1);
1199	/* Check for pad = 0, long header case */
1200	tmp = gen_mcmp_nl(base_off + 2, BPF_B0x10, (bpf_int32)0x06, (bpf_int32)0x7);
1201	b2 = gen_cmp_nl(base_off + 2 + offset_lh, BPF_H0x08, (bpf_int32)ntohs(addr)(__uint16_t)(__builtin_constant_p(addr) ? (__uint16_t)(((__uint16_t )(addr) & 0xffU) << 8 \| ((__uint16_t)(addr) & 0xff00U ) >> 8) : __swap16md(addr)));
1202	gen_and(tmp, b2);
1203	gen_or(b2, b1);
1204	/* Check for pad = 1, short header case */
1205	tmp = gen_mcmp_nl(base_off + 2, BPF_H0x08,
1206	(bpf_int32)ntohs(0x0281)(__uint16_t)(__builtin_constant_p(0x0281) ? (__uint16_t)(((__uint16_t )(0x0281) & 0xffU) << 8 \| ((__uint16_t)(0x0281) & 0xff00U) >> 8) : __swap16md(0x0281)), (bpf_int32)ntohs(0x07FF)(__uint16_t)(__builtin_constant_p(0x07FF) ? (__uint16_t)(((__uint16_t )(0x07FF) & 0xffU) << 8 \| ((__uint16_t)(0x07FF) & 0xff00U) >> 8) : __swap16md(0x07FF)));
1207	b2 = gen_cmp_nl(base_off + 2 + 1 + offset_sh,
1208	BPF_H0x08, (bpf_int32)ntohs(addr)(__uint16_t)(__builtin_constant_p(addr) ? (__uint16_t)(((__uint16_t )(addr) & 0xffU) << 8 \| ((__uint16_t)(addr) & 0xff00U ) >> 8) : __swap16md(addr)));
1209	gen_and(tmp, b2);
1210	gen_or(b2, b1);
1211	/* Check for pad = 0, short header case */
1212	tmp = gen_mcmp_nl(base_off + 2, BPF_B0x10, (bpf_int32)0x02, (bpf_int32)0x7);
1213	b2 = gen_cmp_nl(base_off + 2 + offset_sh, BPF_H0x08, (bpf_int32)ntohs(addr)(__uint16_t)(__builtin_constant_p(addr) ? (__uint16_t)(((__uint16_t )(addr) & 0xffU) << 8 \| ((__uint16_t)(addr) & 0xff00U ) >> 8) : __swap16md(addr)));
1214	gen_and(tmp, b2);
1215	gen_or(b2, b1);
1216
1217	/* Combine with test for linktype */
1218	gen_and(b0, b1);
1219	return b1;
1220	}
1221
1222	static struct block *
1223	gen_host(addr, mask, proto, dir)
1224	bpf_u_int32 addr;
1225	bpf_u_int32 mask;
1226	int proto;
1227	int dir;
1228	{
1229	struct block b0, b1;
1230
1231	switch (proto) {
1232
1233	case Q_DEFAULT0:
1234	b0 = gen_host(addr, mask, Q_IP2, dir);
1235	b1 = gen_host(addr, mask, Q_ARP3, dir);
1236	gen_or(b0, b1);
1237	b0 = gen_host(addr, mask, Q_RARP4, dir);
1238	gen_or(b1, b0);
1239	return b0;
1240
1241	case Q_IP2:
1242	return gen_hostop(addr, mask, dir, ETHERTYPE_IP0x0800,
1243	12, 16);
1244
1245	case Q_RARP4:
1246	return gen_hostop(addr, mask, dir, ETHERTYPE_REVARP0x8035,
1247	14, 24);
1248
1249	case Q_ARP3:
1250	return gen_hostop(addr, mask, dir, ETHERTYPE_ARP0x0806,
1251	14, 24);
1252
1253	case Q_TCP5:
1254	bpf_error("'tcp' modifier applied to host");
1255
1256	case Q_UDP6:
1257	bpf_error("'udp' modifier applied to host");
1258
1259	case Q_ICMP7:
1260	bpf_error("'icmp' modifier applied to host");
1261
1262	case Q_IGMP8:
1263	bpf_error("'igmp' modifier applied to host");
1264
1265	case Q_IGRP9:
1266	bpf_error("'igrp' modifier applied to host");
1267
1268	case Q_PIM20:
1269	bpf_error("'pim' modifier applied to host");
1270
1271	case Q_STP21:
1272	bpf_error("'stp' modifier applied to host");
1273
1274	case Q_ATALK10:
1275	bpf_error("ATALK host filtering not implemented");
1276
1277	case Q_DECNET11:
1278	return gen_dnhostop(addr, dir, 0);
1279
1280	case Q_SCA13:
1281	bpf_error("SCA host filtering not implemented");
1282
1283	case Q_LAT12:
1284	bpf_error("LAT host filtering not implemented");
1285
1286	case Q_MOPDL15:
1287	bpf_error("MOPDL host filtering not implemented");
1288
1289	case Q_MOPRC14:
1290	bpf_error("MOPRC host filtering not implemented");
1291
1292	#ifdef INET61
1293	case Q_IPV616:
1294	bpf_error("'ip6' modifier applied to ip host");
1295
1296	case Q_ICMPV617:
1297	bpf_error("'icmp6' modifier applied to host");
1298	#endif /* INET6 */
1299
1300	case Q_AH18:
1301	bpf_error("'ah' modifier applied to host");
1302
1303	case Q_ESP19:
1304	bpf_error("'esp' modifier applied to host");
1305
1306	default:
1307	bpf_error("direction not supported on linktype 0x%x",
1308	linktype);
1309	}
1310	/* NOTREACHED */
1311	}
1312
1313	#ifdef INET61
1314	static struct block *
1315	gen_host6(addr, mask, proto, dir)
1316	struct in6_addr *addr;
1317	struct in6_addr *mask;
1318	int proto;
1319	int dir;
1320	{
1321	switch (proto) {
1322
1323	case Q_DEFAULT0:
1324	return gen_host6(addr, mask, Q_IPV616, dir);
1325
1326	case Q_IP2:
1327	bpf_error("'ip' modifier applied to ip6 host");
1328
1329	case Q_RARP4:
1330	bpf_error("'rarp' modifier applied to ip6 host");
1331
1332	case Q_ARP3:
1333	bpf_error("'arp' modifier applied to ip6 host");
1334
1335	case Q_TCP5:
1336	bpf_error("'tcp' modifier applied to host");
1337
1338	case Q_UDP6:
1339	bpf_error("'udp' modifier applied to host");
1340
1341	case Q_ICMP7:
1342	bpf_error("'icmp' modifier applied to host");
1343
1344	case Q_IGMP8:
1345	bpf_error("'igmp' modifier applied to host");
1346
1347	case Q_IGRP9:
1348	bpf_error("'igrp' modifier applied to host");
1349
1350	case Q_PIM20:
1351	bpf_error("'pim' modifier applied to host");
1352
1353	case Q_STP21:
1354	bpf_error("'stp' modifier applied to host");
1355
1356	case Q_ATALK10:
1357	bpf_error("ATALK host filtering not implemented");
1358
1359	case Q_DECNET11:
1360	bpf_error("'decnet' modifier applied to ip6 host");
1361
1362	case Q_SCA13:
1363	bpf_error("SCA host filtering not implemented");
1364
1365	case Q_LAT12:
1366	bpf_error("LAT host filtering not implemented");
1367
1368	case Q_MOPDL15:
1369	bpf_error("MOPDL host filtering not implemented");
1370
1371	case Q_MOPRC14:
1372	bpf_error("MOPRC host filtering not implemented");
1373
1374	case Q_IPV616:
1375	return gen_hostop6(addr, mask, dir, ETHERTYPE_IPV60x86DD,
1376	8, 24);
1377
1378	case Q_ICMPV617:
1379	bpf_error("'icmp6' modifier applied to host");
1380
1381	case Q_AH18:
1382	bpf_error("'ah' modifier applied to host");
1383
1384	case Q_ESP19:
1385	bpf_error("'esp' modifier applied to host");
1386
1387	default:
1388	abort();
1389	}
1390	/* NOTREACHED */
1391	}
1392	#endif /INET6/
1393
1394	#ifndef INET61
1395	static struct block *
1396	gen_gateway(eaddr, alist, proto, dir)
1397	const u_char *eaddr;
1398	bpf_u_int32 **alist;
1399	int proto;
1400	int dir;
1401	{
1402	struct block b0, b1, *tmp;
1403
1404	if (dir != 0)
1405	bpf_error("direction applied to 'gateway'");
1406
1407	switch (proto) {
1408	case Q_DEFAULT0:
1409	case Q_IP2:
1410	case Q_ARP3:
1411	case Q_RARP4:
1412	if (linktype == DLT_EN10MB1)
1413	b0 = gen_ehostop(eaddr, Q_OR3);
1414	else if (linktype == DLT_FDDI10)
1415	b0 = gen_fhostop(eaddr, Q_OR3);
1416	else
1417	bpf_error(
1418	"'gateway' supported only on ethernet or FDDI");
1419
1420	b1 = gen_host(**alist++, 0xffffffff, proto, Q_OR3);
1421	while (*alist) {
1422	tmp = gen_host(**alist++, 0xffffffff, proto, Q_OR3);
1423	gen_or(b1, tmp);
1424	b1 = tmp;
1425	}
1426	gen_not(b1);
1427	gen_and(b0, b1);
1428	return b1;
1429	}
1430	bpf_error("illegal modifier of 'gateway'");
1431	/* NOTREACHED */
1432	}
1433	#endif /INET6/
1434
1435	struct block *
1436	gen_proto_abbrev(proto)
1437	int proto;
1438	{
1439	struct block b0 = NULL((void )0), *b1;
1440
1441	switch (proto) {
1442
1443	case Q_TCP5:
1444	b1 = gen_proto(IPPROTO_TCP6, Q_IP2, Q_DEFAULT0);
1445	#ifdef INET61
1446	b0 = gen_proto(IPPROTO_TCP6, Q_IPV616, Q_DEFAULT0);
1447	gen_or(b0, b1);
1448	#endif
1449	break;
1450
1451	case Q_UDP6:
1452	b1 = gen_proto(IPPROTO_UDP17, Q_IP2, Q_DEFAULT0);
1453	#ifdef INET61
1454	b0 = gen_proto(IPPROTO_UDP17, Q_IPV616, Q_DEFAULT0);
1455	gen_or(b0, b1);
1456	#endif
1457	break;
1458
1459	case Q_ICMP7:
1460	b1 = gen_proto(IPPROTO_ICMP1, Q_IP2, Q_DEFAULT0);
1461	break;
1462
1463	#ifndef IPPROTO_IGMP2
1464	#define IPPROTO_IGMP2 2
1465	#endif
1466
1467	case Q_IGMP8:
1468	b1 = gen_proto(IPPROTO_IGMP2, Q_IP2, Q_DEFAULT0);
1469	break;
1470
1471	#ifndef IPPROTO_IGRP9
1472	#define IPPROTO_IGRP9 9
1473	#endif
1474	case Q_IGRP9:
1475	b1 = gen_proto(IPPROTO_IGRP9, Q_IP2, Q_DEFAULT0);
1476	break;
1477
1478	#ifndef IPPROTO_PIM103
1479	#define IPPROTO_PIM103 103
1480	#endif
1481
1482	case Q_PIM20:
1483	b1 = gen_proto(IPPROTO_PIM103, Q_IP2, Q_DEFAULT0);
1484	#ifdef INET61
1485	b0 = gen_proto(IPPROTO_PIM103, Q_IPV616, Q_DEFAULT0);
1486	gen_or(b0, b1);
1487	#endif
1488	break;
1489
1490	case Q_IP2:
1491	b1 = gen_linktype(ETHERTYPE_IP0x0800);
1492	break;
1493
1494	case Q_ARP3:
1495	b1 = gen_linktype(ETHERTYPE_ARP0x0806);
1496	break;
1497
1498	case Q_RARP4:
1499	b1 = gen_linktype(ETHERTYPE_REVARP0x8035);
1500	break;
1501
1502	case Q_LINK1:
1503	bpf_error("link layer applied in wrong context");
1504
1505	case Q_ATALK10:
1506	b1 = gen_linktype(ETHERTYPE_ATALK0x809B);
1507	break;
1508
1509	case Q_DECNET11:
1510	b1 = gen_linktype(ETHERTYPE_DN0x6003);
1511	break;
1512
1513	case Q_SCA13:
1514	b1 = gen_linktype(ETHERTYPE_SCA0x6007);
1515	break;
1516
1517	case Q_LAT12:
1518	b1 = gen_linktype(ETHERTYPE_LAT0x6004);
1519	break;
1520
1521	case Q_MOPDL15:
1522	b1 = gen_linktype(ETHERTYPE_MOPDL0x6001);
1523	break;
1524
1525	case Q_MOPRC14:
1526	b1 = gen_linktype(ETHERTYPE_MOPRC0x6002);
1527	break;
1528
1529	case Q_STP21:
1530	b1 = gen_linktype(LLCSAP_8021D0x42);
1531	break;
1532
1533	#ifdef INET61
1534	case Q_IPV616:
1535	b1 = gen_linktype(ETHERTYPE_IPV60x86DD);
1536	break;
1537
1538	#ifndef IPPROTO_ICMPV658
1539	#define IPPROTO_ICMPV658 58
1540	#endif
1541	case Q_ICMPV617:
1542	b1 = gen_proto(IPPROTO_ICMPV658, Q_IPV616, Q_DEFAULT0);
1543	break;
1544	#endif /* INET6 */
1545
1546	#ifndef IPPROTO_AH51
1547	#define IPPROTO_AH51 51
1548	#endif
1549	case Q_AH18:
1550	b1 = gen_proto(IPPROTO_AH51, Q_IP2, Q_DEFAULT0);
1551	#ifdef INET61
1552	b0 = gen_proto(IPPROTO_AH51, Q_IPV616, Q_DEFAULT0);
1553	gen_or(b0, b1);
1554	#endif
1555	break;
1556
1557	#ifndef IPPROTO_ESP50
1558	#define IPPROTO_ESP50 50
1559	#endif
1560	case Q_ESP19:
1561	b1 = gen_proto(IPPROTO_ESP50, Q_IP2, Q_DEFAULT0);
1562	#ifdef INET61
1563	b0 = gen_proto(IPPROTO_ESP50, Q_IPV616, Q_DEFAULT0);
1564	gen_or(b0, b1);
1565	#endif
1566	break;
1567
1568	default:
1569	abort();
1570	}
1571	return b1;
1572	}
1573
1574	static struct block *
1575	gen_ipfrag()
1576	{
1577	struct slist s, tmp;
1578	struct block *b;
1579
1580	/* not ip frag */
1581	if (variable_nl) {
1582	s = nl2X_stmt();
1583	tmp = new_stmt(BPF_LD0x00\|BPF_H0x08\|BPF_IND0x40);
1584	tmp->s.k = 6;
1585	sappend(s, tmp);
1586	} else {
1587	s = new_stmt(BPF_LD0x00\|BPF_H0x08\|BPF_ABS0x20);
1588	s->s.k = off_nl + 6;
1589	}
1590	b = new_block(JMP(BPF_JSET)((0x40)\|0x05\|0x00));
1591	b->s.k = 0x1fff;
1592	b->stmts = s;
1593	gen_not(b);
1594
1595	return b;
1596	}
1597
1598	/* For dynamic off_nl, the BPF_LDX\|BPF_MSH instruction does not work
1599	This function generates code to set X to the start of the IP payload
1600	X = off_nl + IP header_len.
1601	*/
1602	static struct slist *
1603	iphl_to_x(void)
1604	{
1605	struct slist s, tmp;
1606
1607	/* XXX clobbers A if variable_nl*/
1608	if (variable_nl) {
1609	if (iphl_reg == -1) {
1610	/* X <- off_nl */
1611	s = nl2X_stmt();
1612
1613	/* A = p[X+0] */
1614	tmp = new_stmt(BPF_LD0x00\|BPF_B0x10\|BPF_IND0x40);
1615	tmp->s.k = 0;
1616	sappend(s, tmp);
1617
1618	/* A = A & 0x0f */
1619	tmp = new_stmt(BPF_ALU0x04\|BPF_AND0x50\|BPF_K0x00);
1620	tmp->s.k = 0x0f;
1621	sappend(s, tmp);
1622
1623	/* A = A << 2 */
1624	tmp = new_stmt(BPF_ALU0x04\|BPF_LSH0x60\|BPF_K0x00);
1625	tmp->s.k = 2;
1626	sappend(s, tmp);
1627
1628	/* A = A + X (add off_nl again to compensate) */
1629	sappend(s, new_stmt(BPF_ALU0x04\|BPF_ADD0x00\|BPF_X0x08));
1630
1631	/* MEM[iphl_reg] = A */
1632	iphl_reg = alloc_reg();
1633	tmp = new_stmt(BPF_ST0x02);
1634	tmp->s.k = iphl_reg;
1635	sappend(s, tmp);
1636
1637	sappend(init_code, s);
1638	}
1639	s = new_stmt(BPF_LDX0x01\|BPF_MEM0x60);
1640	s->s.k = iphl_reg;
1641
1642	} else {
1643	s = new_stmt(BPF_LDX0x01\|BPF_MSH0xa0\|BPF_B0x10);
1644	s->s.k = off_nl;
1645	}
1646
1647	return s;
1648	}
1649
1650	static struct block *
1651	gen_portatom(off, v)
1652	int off;
1653	bpf_int32 v;
1654	{
1655	struct slist s, tmp;
1656	struct block *b;
1657
1658	s = iphl_to_x();
1659
1660	tmp = new_stmt(BPF_LD0x00\|BPF_IND0x40\|BPF_H0x08);
1661	tmp->s.k = off_nl + off; /* off_nl == 0 if variable_nl */
1662	sappend(s, tmp);
1663
1664	b = new_block(JMP(BPF_JEQ)((0x10)\|0x05\|0x00));
1665	b->stmts = s;
1666	b->s.k = v;
1667
1668	return b;
1669	}
1670
1671	#ifdef INET61
1672	static struct block *
1673	gen_portatom6(off, v)
1674	int off;
1675	bpf_int32 v;
1676	{
1677	return gen_cmp_nl(40 + off, BPF_H0x08, v);
1678	}
1679	#endif/INET6/
1680
1681	struct block *
1682	gen_portop(port, proto, dir)
1683	int port, proto, dir;
1684	{
1685	struct block b0, b1, *tmp;
1686
1687	/* ip proto 'proto' */
1688	tmp = gen_cmp_nl(9, BPF_B0x10, (bpf_int32)proto);
1689	b0 = gen_ipfrag();
1690	gen_and(tmp, b0);
1691
1692	switch (dir) {
1693	case Q_SRC1:
1694	b1 = gen_portatom(0, (bpf_int32)port);
1695	break;
1696
1697	case Q_DST2:
1698	b1 = gen_portatom(2, (bpf_int32)port);
1699	break;
1700
1701	case Q_OR3:
1702	case Q_DEFAULT0:
1703	tmp = gen_portatom(0, (bpf_int32)port);
1704	b1 = gen_portatom(2, (bpf_int32)port);
1705	gen_or(tmp, b1);
1706	break;
1707
1708	case Q_AND4:
1709	tmp = gen_portatom(0, (bpf_int32)port);
1710	b1 = gen_portatom(2, (bpf_int32)port);
1711	gen_and(tmp, b1);
1712	break;
1713
1714	default:
1715	abort();
1716	}
1717	gen_and(b0, b1);
1718
1719	return b1;
1720	}
1721
1722	static struct block *
1723	gen_port(port, ip_proto, dir)
1724	int port;
1725	int ip_proto;
1726	int dir;
1727	{
1728	struct block b0, b1, *tmp;
1729
1730	/* ether proto ip */
1731	b0 = gen_linktype(ETHERTYPE_IP0x0800);
1732
1733	switch (ip_proto) {
1734	case IPPROTO_UDP17:
1735	case IPPROTO_TCP6:
1736	b1 = gen_portop(port, ip_proto, dir);
1737	break;
1738
1739	case PROTO_UNDEF-1:
1740	tmp = gen_portop(port, IPPROTO_TCP6, dir);
1741	b1 = gen_portop(port, IPPROTO_UDP17, dir);
1742	gen_or(tmp, b1);
1743	break;
1744
1745	default:
1746	abort();
1747	}
1748	gen_and(b0, b1);
1749	return b1;
1750	}
1751
1752	#ifdef INET61
1753	struct block *
1754	gen_portop6(port, proto, dir)
1755	int port, proto, dir;
1756	{
1757	struct block b0, b1, *tmp;
1758
1759	/* ip proto 'proto' */
1760	b0 = gen_cmp_nl(6, BPF_B0x10, (bpf_int32)proto);
1761
1762	switch (dir) {
1763	case Q_SRC1:
1764	b1 = gen_portatom6(0, (bpf_int32)port);
1765	break;
1766
1767	case Q_DST2:
1768	b1 = gen_portatom6(2, (bpf_int32)port);
1769	break;
1770
1771	case Q_OR3:
1772	case Q_DEFAULT0:
1773	tmp = gen_portatom6(0, (bpf_int32)port);
1774	b1 = gen_portatom6(2, (bpf_int32)port);
1775	gen_or(tmp, b1);
1776	break;
1777
1778	case Q_AND4:
1779	tmp = gen_portatom6(0, (bpf_int32)port);
1780	b1 = gen_portatom6(2, (bpf_int32)port);
1781	gen_and(tmp, b1);
1782	break;
1783
1784	default:
1785	abort();
1786	}
1787	gen_and(b0, b1);
1788
1789	return b1;
1790	}
1791
1792	static struct block *
1793	gen_port6(port, ip_proto, dir)
1794	int port;
1795	int ip_proto;
1796	int dir;
1797	{
1798	struct block b0, b1, *tmp;
1799
1800	/* ether proto ip */
1801	b0 = gen_linktype(ETHERTYPE_IPV60x86DD);
1802
1803	switch (ip_proto) {
1804	case IPPROTO_UDP17:
1805	case IPPROTO_TCP6:
1806	b1 = gen_portop6(port, ip_proto, dir);
1807	break;
1808
1809	case PROTO_UNDEF-1:
1810	tmp = gen_portop6(port, IPPROTO_TCP6, dir);
1811	b1 = gen_portop6(port, IPPROTO_UDP17, dir);
1812	gen_or(tmp, b1);
1813	break;
1814
1815	default:
1816	abort();
1817	}
1818	gen_and(b0, b1);
1819	return b1;
1820	}
1821	#endif /* INET6 */
1822
1823	static int
1824	lookup_proto(name, proto)
1825	const char *name;
1826	int proto;
1827	{
1828	int v;
1829
1830	switch (proto) {
1831
1832	case Q_DEFAULT0:
1833	case Q_IP2:
1834	v = pcap_nametoproto(name);
1835	if (v == PROTO_UNDEF-1)
1836	bpf_error("unknown ip proto '%s'", name);
1837	break;
1838
1839	case Q_LINK1:
1840	/* XXX should look up h/w protocol type based on linktype */
1841	v = pcap_nametoeproto(name);
1842	if (v == PROTO_UNDEF-1) {
1843	v = pcap_nametollc(name);
1844	if (v == PROTO_UNDEF-1)
1845	bpf_error("unknown ether proto '%s'", name);
1846	}
1847	break;
1848
1849	default:
1850	v = PROTO_UNDEF-1;
1851	break;
1852	}
1853	return v;
1854	}
1855
1856	static struct block *
1857	gen_protochain(v, proto, dir)
1858	int v;
1859	int proto;
1860	int dir;
1861	{
1862	struct block b0, b;
1863	struct slist *s[100];
1864	int fix2, fix3, fix4, fix5;
1865	int ahcheck, again, end;
1866	int i, max;
1867	int reg1 = alloc_reg();
1868	int reg2 = alloc_reg();
1869
1870	memset(s, 0, sizeof(s));
1871	fix2 = fix3 = fix4 = fix5 = 0;
	Although the value stored to 'fix5' is used in the enclosing expression, the value is never actually read from 'fix5'
1872
1873	if (variable_nl) {
1874	bpf_error("'gen_protochain' not supported for variable DLTs");
1875	/NOTREACHED/
1876	}
1877
1878	switch (proto) {
1879	case Q_IP2:
1880	case Q_IPV616:
1881	break;
1882	case Q_DEFAULT0:
1883	b0 = gen_protochain(v, Q_IP2, dir);
1884	b = gen_protochain(v, Q_IPV616, dir);
1885	gen_or(b0, b);
1886	return b;
1887	default:
1888	bpf_error("bad protocol applied for 'protochain'");
1889	/NOTREACHED/
1890	}
1891
1892	no_optimize = 1; /this code is not compatible with optimzer yet /
1893
1894	/*
1895	* s[0] is a dummy entry to protect other BPF insn from damaged
1896	* by s[fix] = foo with uninitialized variable "fix". It is somewhat
1897	* hard to find interdependency made by jump table fixup.
1898	*/
1899	i = 0;
1900	s[i] = new_stmt(0); /dummy/
1901	i++;
1902
1903	switch (proto) {
1904	case Q_IP2:
1905	b0 = gen_linktype(ETHERTYPE_IP0x0800);
1906
1907	/* A = ip->ip_p */
1908	s[i] = new_stmt(BPF_LD0x00\|BPF_ABS0x20\|BPF_B0x10);
1909	s[i]->s.k = off_nl + 9;
1910	i++;
1911	/* X = ip->ip_hl << 2 */
1912	s[i] = new_stmt(BPF_LDX0x01\|BPF_MSH0xa0\|BPF_B0x10);
1913	s[i]->s.k = off_nl;
1914	i++;
1915	break;
1916	case Q_IPV616:
1917	b0 = gen_linktype(ETHERTYPE_IPV60x86DD);
1918
1919	/* A = ip6->ip_nxt */
1920	s[i] = new_stmt(BPF_LD0x00\|BPF_ABS0x20\|BPF_B0x10);
1921	s[i]->s.k = off_nl + 6;
1922	i++;
1923	/* X = sizeof(struct ip6_hdr) */
1924	s[i] = new_stmt(BPF_LDX0x01\|BPF_IMM0x00);
1925	s[i]->s.k = 40;
1926	i++;
1927	break;
1928	default:
1929	bpf_error("unsupported proto to gen_protochain");
1930	/NOTREACHED/
1931	}
1932
1933	/* again: if (A == v) goto end; else fall through; */
1934	again = i;
1935	s[i] = new_stmt(BPF_JMP0x05\|BPF_JEQ0x10\|BPF_K0x00);
1936	s[i]->s.k = v;
1937	s[i]->s.jt = NULL((void )0); /later*/
1938	s[i]->s.jf = NULL((void )0); /update in next stmt*/
1939	fix5 = i;
1940	i++;
1941
1942	/* if (A == IPPROTO_NONE) goto end */
1943	s[i] = new_stmt(BPF_JMP0x05\|BPF_JEQ0x10\|BPF_K0x00);
1944	s[i]->s.jt = NULL((void )0); /later*/
1945	s[i]->s.jf = NULL((void )0); /update in next stmt*/
1946	s[i]->s.k = IPPROTO_NONE59;
1947	s[fix5]->s.jf = s[i];
1948	fix2 = i;
1949	i++;
1950
1951	if (proto == Q_IPV616) {
1952	int v6start, v6end, v6advance, j;
1953
1954	v6start = i;
1955	/* if (A == IPPROTO_HOPOPTS) goto v6advance */
1956	s[i] = new_stmt(BPF_JMP0x05\|BPF_JEQ0x10\|BPF_K0x00);
1957	s[i]->s.jt = NULL((void )0); /later*/
1958	s[i]->s.jf = NULL((void )0); /update in next stmt*/
1959	s[i]->s.k = IPPROTO_HOPOPTS0;
1960	s[fix2]->s.jf = s[i];
1961	i++;
1962	/* if (A == IPPROTO_DSTOPTS) goto v6advance */
1963	s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP0x05\|BPF_JEQ0x10\|BPF_K0x00);
1964	s[i]->s.jt = NULL((void )0); /later*/
1965	s[i]->s.jf = NULL((void )0); /update in next stmt*/
1966	s[i]->s.k = IPPROTO_DSTOPTS60;
1967	i++;
1968	/* if (A == IPPROTO_ROUTING) goto v6advance */
1969	s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP0x05\|BPF_JEQ0x10\|BPF_K0x00);
1970	s[i]->s.jt = NULL((void )0); /later*/
1971	s[i]->s.jf = NULL((void )0); /update in next stmt*/
1972	s[i]->s.k = IPPROTO_ROUTING43;
1973	i++;
1974	/* if (A == IPPROTO_FRAGMENT) goto v6advance; else goto ahcheck; */
1975	s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP0x05\|BPF_JEQ0x10\|BPF_K0x00);
1976	s[i]->s.jt = NULL((void )0); /later*/
1977	s[i]->s.jf = NULL((void )0); /later*/
1978	s[i]->s.k = IPPROTO_FRAGMENT44;
1979	fix3 = i;
1980	v6end = i;
1981	i++;
1982
1983	/* v6advance: */
1984	v6advance = i;
1985
1986	/*
1987	* in short,
1988	* A = P[X + 1];
1989	* X = X + (P[X] + 1) * 8;
1990	*/
1991	/* A = X */
1992	s[i] = new_stmt(BPF_MISC0x07\|BPF_TXA0x80);
1993	i++;
1994	/* MEM[reg1] = A */
1995	s[i] = new_stmt(BPF_ST0x02);
1996	s[i]->s.k = reg1;
1997	i++;
1998	/* A += 1 */
1999	s[i] = new_stmt(BPF_ALU0x04\|BPF_ADD0x00\|BPF_K0x00);
2000	s[i]->s.k = 1;
2001	i++;
2002	/* X = A */
2003	s[i] = new_stmt(BPF_MISC0x07\|BPF_TAX0x00);
2004	i++;
2005	/* A = P[X + packet head]; */
2006	s[i] = new_stmt(BPF_LD0x00\|BPF_IND0x40\|BPF_B0x10);
2007	s[i]->s.k = off_nl;
2008	i++;
2009	/* MEM[reg2] = A */
2010	s[i] = new_stmt(BPF_ST0x02);
2011	s[i]->s.k = reg2;
2012	i++;
2013	/* X = MEM[reg1] */
2014	s[i] = new_stmt(BPF_LDX0x01\|BPF_MEM0x60);
2015	s[i]->s.k = reg1;
2016	i++;
2017	/* A = P[X + packet head] */
2018	s[i] = new_stmt(BPF_LD0x00\|BPF_IND0x40\|BPF_B0x10);
2019	s[i]->s.k = off_nl;
2020	i++;
2021	/* A += 1 */
2022	s[i] = new_stmt(BPF_ALU0x04\|BPF_ADD0x00\|BPF_K0x00);
2023	s[i]->s.k = 1;
2024	i++;
2025	/* A = 8 /
2026	s[i] = new_stmt(BPF_ALU0x04\|BPF_MUL0x20\|BPF_K0x00);
2027	s[i]->s.k = 8;
2028	i++;
2029	/* X = A; */
2030	s[i] = new_stmt(BPF_MISC0x07\|BPF_TAX0x00);
2031	i++;
2032	/* A = MEM[reg2] */
2033	s[i] = new_stmt(BPF_LD0x00\|BPF_MEM0x60);
2034	s[i]->s.k = reg2;
2035	i++;
2036
2037	/* goto again; (must use BPF_JA for backward jump) */
2038	s[i] = new_stmt(BPF_JMP0x05\|BPF_JA0x00);
2039	s[i]->s.k = again - i - 1;
2040	s[i - 1]->s.jf = s[i];
2041	i++;
2042
2043	/* fixup */
2044	for (j = v6start; j <= v6end; j++)
2045	s[j]->s.jt = s[v6advance];
2046	} else {
2047	/* nop */
2048	s[i] = new_stmt(BPF_ALU0x04\|BPF_ADD0x00\|BPF_K0x00);
2049	s[i]->s.k = 0;
2050	s[fix2]->s.jf = s[i];
2051	i++;
2052	}
2053
2054	/* ahcheck: */
2055	ahcheck = i;
2056	/* if (A == IPPROTO_AH) then fall through; else goto end; */
2057	s[i] = new_stmt(BPF_JMP0x05\|BPF_JEQ0x10\|BPF_K0x00);
2058	s[i]->s.jt = NULL((void )0); /later*/
2059	s[i]->s.jf = NULL((void )0); /later*/
2060	s[i]->s.k = IPPROTO_AH51;
2061	if (fix3)
2062	s[fix3]->s.jf = s[ahcheck];
2063	fix4 = i;
2064	i++;
2065
2066	/*
2067	* in short,
2068	* A = P[X + 1];
2069	* X = X + (P[X] + 2) * 4;
2070	*/
2071	/* A = X */
2072	s[i - 1]->s.jt = s[i] = new_stmt(BPF_MISC0x07\|BPF_TXA0x80);
2073	i++;
2074	/* MEM[reg1] = A */
2075	s[i] = new_stmt(BPF_ST0x02);
2076	s[i]->s.k = reg1;
2077	i++;
2078	/* A += 1 */
2079	s[i] = new_stmt(BPF_ALU0x04\|BPF_ADD0x00\|BPF_K0x00);
2080	s[i]->s.k = 1;
2081	i++;
2082	/* X = A */
2083	s[i] = new_stmt(BPF_MISC0x07\|BPF_TAX0x00);
2084	i++;
2085	/* A = P[X + packet head]; */
2086	s[i] = new_stmt(BPF_LD0x00\|BPF_IND0x40\|BPF_B0x10);
2087	s[i]->s.k = off_nl;
2088	i++;
2089	/* MEM[reg2] = A */
2090	s[i] = new_stmt(BPF_ST0x02);
2091	s[i]->s.k = reg2;
2092	i++;
2093	/* X = MEM[reg1] */
2094	s[i] = new_stmt(BPF_LDX0x01\|BPF_MEM0x60);
2095	s[i]->s.k = reg1;
2096	i++;
2097	/* A = P[X + packet head] */
2098	s[i] = new_stmt(BPF_LD0x00\|BPF_IND0x40\|BPF_B0x10);
2099	s[i]->s.k = off_nl;
2100	i++;
2101	/* A += 2 */
2102	s[i] = new_stmt(BPF_ALU0x04\|BPF_ADD0x00\|BPF_K0x00);
2103	s[i]->s.k = 2;
2104	i++;
2105	/* A = 4 /
2106	s[i] = new_stmt(BPF_ALU0x04\|BPF_MUL0x20\|BPF_K0x00);
2107	s[i]->s.k = 4;
2108	i++;
2109	/* X = A; */
2110	s[i] = new_stmt(BPF_MISC0x07\|BPF_TAX0x00);
2111	i++;
2112	/* A = MEM[reg2] */
2113	s[i] = new_stmt(BPF_LD0x00\|BPF_MEM0x60);
2114	s[i]->s.k = reg2;
2115	i++;
2116
2117	/* goto again; (must use BPF_JA for backward jump) */
2118	s[i] = new_stmt(BPF_JMP0x05\|BPF_JA0x00);
2119	s[i]->s.k = again - i - 1;
2120	i++;
2121
2122	/* end: nop */
2123	end = i;
2124	s[i] = new_stmt(BPF_ALU0x04\|BPF_ADD0x00\|BPF_K0x00);
2125	s[i]->s.k = 0;
2126	s[fix2]->s.jt = s[end];
2127	s[fix4]->s.jf = s[end];
2128	s[fix5]->s.jt = s[end];
2129	i++;
2130
2131	/*
2132	* make slist chain
2133	*/
2134	max = i;
2135	for (i = 0; i < max - 1; i++)
2136	s[i]->next = s[i + 1];
2137	s[max - 1]->next = NULL((void *)0);
2138
2139	/*
2140	* emit final check
2141	*/
2142	b = new_block(JMP(BPF_JEQ)((0x10)\|0x05\|0x00));
2143	b->stmts = s[1]; /remember, s[0] is dummy/
2144	b->s.k = v;
2145
2146	free_reg(reg1);
2147	free_reg(reg2);
2148
2149	gen_and(b0, b);
2150	return b;
2151	}
2152
2153	static struct block *
2154	gen_proto(v, proto, dir)
2155	int v;
2156	int proto;
2157	int dir;
2158	{
2159	struct block b0, b1;
2160
2161	if (dir != Q_DEFAULT0)
2162	bpf_error("direction applied to 'proto'");
2163
2164	switch (proto) {
2165	case Q_DEFAULT0:
2166	#ifdef INET61
2167	b0 = gen_proto(v, Q_IP2, dir);
2168	b1 = gen_proto(v, Q_IPV616, dir);
2169	gen_or(b0, b1);
2170	return b1;
2171	#else
2172	/FALLTHROUGH/
2173	#endif
2174	case Q_IP2:
2175	b0 = gen_linktype(ETHERTYPE_IP0x0800);
2176	#ifndef CHASE_CHAIN
2177	b1 = gen_cmp_nl(9, BPF_B0x10, (bpf_int32)v);
2178	#else
2179	b1 = gen_protochain(v, Q_IP2);
2180	#endif
2181	gen_and(b0, b1);
2182	return b1;
2183
2184	case Q_ARP3:
2185	bpf_error("arp does not encapsulate another protocol");
2186	/* NOTREACHED */
2187
2188	case Q_RARP4:
2189	bpf_error("rarp does not encapsulate another protocol");
2190	/* NOTREACHED */
2191
2192	case Q_ATALK10:
2193	bpf_error("atalk encapsulation is not specifiable");
2194	/* NOTREACHED */
2195
2196	case Q_DECNET11:
2197	bpf_error("decnet encapsulation is not specifiable");
2198	/* NOTREACHED */
2199
2200	case Q_SCA13:
2201	bpf_error("sca does not encapsulate another protocol");
2202	/* NOTREACHED */
2203
2204	case Q_LAT12:
2205	bpf_error("lat does not encapsulate another protocol");
2206	/* NOTREACHED */
2207
2208	case Q_MOPRC14:
2209	bpf_error("moprc does not encapsulate another protocol");
2210	/* NOTREACHED */
2211
2212	case Q_MOPDL15:
2213	bpf_error("mopdl does not encapsulate another protocol");
2214	/* NOTREACHED */
2215
2216	case Q_LINK1:
2217	return gen_linktype(v);
2218
2219	case Q_UDP6:
2220	bpf_error("'udp proto' is bogus");
2221	/* NOTREACHED */
2222
2223	case Q_TCP5:
2224	bpf_error("'tcp proto' is bogus");
2225	/* NOTREACHED */
2226
2227	case Q_ICMP7:
2228	bpf_error("'icmp proto' is bogus");
2229	/* NOTREACHED */
2230
2231	case Q_IGMP8:
2232	bpf_error("'igmp proto' is bogus");
2233	/* NOTREACHED */
2234
2235	case Q_IGRP9:
2236	bpf_error("'igrp proto' is bogus");
2237	/* NOTREACHED */
2238
2239	case Q_PIM20:
2240	bpf_error("'pim proto' is bogus");
2241	/* NOTREACHED */
2242
2243	case Q_STP21:
2244	bpf_error("'stp proto' is bogus");
2245	/* NOTREACHED */
2246
2247	#ifdef INET61
2248	case Q_IPV616:
2249	b0 = gen_linktype(ETHERTYPE_IPV60x86DD);
2250	#ifndef CHASE_CHAIN
2251	b1 = gen_cmp_nl(6, BPF_B0x10, (bpf_int32)v);
2252	#else
2253	b1 = gen_protochain(v, Q_IPV616);
2254	#endif
2255	gen_and(b0, b1);
2256	return b1;
2257
2258	case Q_ICMPV617:
2259	bpf_error("'icmp6 proto' is bogus");
2260	#endif /* INET6 */
2261
2262	case Q_AH18:
2263	bpf_error("'ah proto' is bogus");
2264
2265	case Q_ESP19:
2266	bpf_error("'esp proto' is bogus");
2267
2268	default:
2269	abort();
2270	/* NOTREACHED */
2271	}
2272	/* NOTREACHED */
2273	}
2274
2275	struct block *
2276	gen_scode(name, q)
2277	const char *name;
2278	struct qual q;
2279	{
2280	int proto = q.proto;
2281	int dir = q.dir;
2282	int tproto;
2283	u_char *eaddr;
2284	bpf_u_int32 mask, addr;
2285	#ifndef INET61
2286	bpf_u_int32 **alist;
2287	#else
2288	int tproto6;
2289	struct sockaddr_in *sin;
2290	struct sockaddr_in6 *sin6;
2291	struct addrinfo res, res0;
2292	struct in6_addr mask128;
2293	#endif /INET6/
2294	struct block b, tmp;
2295	int port, real_proto;
2296
2297	switch (q.addr) {
2298
2299	case Q_NET2:
2300	addr = pcap_nametonetaddr(name);
2301	if (addr == 0)
2302	bpf_error("unknown network '%s'", name);
2303	/* Left justify network addr and calculate its network mask */
2304	mask = 0xffffffff;
2305	while (addr && (addr & 0xff000000) == 0) {
2306	addr <<= 8;
2307	mask <<= 8;
2308	}
2309	return gen_host(addr, mask, proto, dir);
2310
2311	case Q_DEFAULT0:
2312	case Q_HOST1:
2313	if (proto == Q_LINK1) {
2314	switch (linktype) {
2315
2316	case DLT_EN10MB1:
2317	eaddr = pcap_ether_hostton(name);
2318	if (eaddr == NULL((void *)0))
2319	bpf_error(
2320	"unknown ether host '%s'", name);
2321	return gen_ehostop(eaddr, dir);
2322
2323	case DLT_FDDI10:
2324	eaddr = pcap_ether_hostton(name);
2325	if (eaddr == NULL((void *)0))
2326	bpf_error(
2327	"unknown FDDI host '%s'", name);
2328	return gen_fhostop(eaddr, dir);
2329
2330	case DLT_IEEE802_11105:
2331	case DLT_IEEE802_11_RADIO127:
2332	eaddr = pcap_ether_hostton(name);
2333	if (eaddr == NULL((void *)0))
2334	bpf_error(
2335	"unknown 802.11 host '%s'", name);
2336
2337	return gen_p80211_hostop(eaddr, dir);
2338
2339	default:
2340	bpf_error(
2341	"only ethernet/FDDI supports link-level host name");
2342	break;
2343	}
2344	} else if (proto == Q_DECNET11) {
2345	unsigned short dn_addr = __pcap_nametodnaddr(name);
2346	/*
2347	* I don't think DECNET hosts can be multihomed, so
2348	* there is no need to build up a list of addresses
2349	*/
2350	return (gen_host(dn_addr, 0, proto, dir));
2351	} else {
2352	#ifndef INET61
2353	alist = pcap_nametoaddr(name);
2354	if (alist == NULL((void )0) \|\| alist == NULL((void *)0))
2355	bpf_error("unknown host '%s'", name);
2356	tproto = proto;
2357	if (off_linktype == -1 && tproto == Q_DEFAULT0)
2358	tproto = Q_IP2;
2359	b = gen_host(**alist++, 0xffffffff, tproto, dir);
2360	while (*alist) {
2361	tmp = gen_host(**alist++, 0xffffffff,
2362	tproto, dir);
2363	gen_or(b, tmp);
2364	b = tmp;
2365	}
2366	return b;
2367	#else
2368	memset(&mask128, 0xff, sizeof(mask128));
2369	res0 = res = pcap_nametoaddrinfo(name);
2370	if (res == NULL((void *)0))
2371	bpf_error("unknown host '%s'", name);
2372	b = tmp = NULL((void *)0);
2373	tproto = tproto6 = proto;
2374	if (off_linktype == -1 && tproto == Q_DEFAULT0) {
2375	tproto = Q_IP2;
2376	tproto6 = Q_IPV616;
2377	}
2378	for (res = res0; res; res = res->ai_next) {
2379	switch (res->ai_family) {
2380	case AF_INET2:
2381	if (tproto == Q_IPV616)
2382	continue;
2383
2384	sin = (struct sockaddr_in *)
2385	res->ai_addr;
2386	tmp = gen_host(ntohl(sin->sin_addr.s_addr)(__uint32_t)(__builtin_constant_p(sin->sin_addr.s_addr) ? ( __uint32_t)(((__uint32_t)(sin->sin_addr.s_addr) & 0xff ) << 24 \| ((__uint32_t)(sin->sin_addr.s_addr) & 0xff00 ) << 8 \| ((__uint32_t)(sin->sin_addr.s_addr) & 0xff0000 ) >> 8 \| ((__uint32_t)(sin->sin_addr.s_addr) & 0xff000000 ) >> 24) : __swap32md(sin->sin_addr.s_addr)),
2387	0xffffffff, tproto, dir);
2388	break;
2389	case AF_INET624:
2390	if (tproto6 == Q_IP2)
2391	continue;
2392
2393	sin6 = (struct sockaddr_in6 *)
2394	res->ai_addr;
2395	tmp = gen_host6(&sin6->sin6_addr,
2396	&mask128, tproto6, dir);
2397	break;
2398	}
2399	if (b)
2400	gen_or(b, tmp);
2401	b = tmp;
2402	}
2403	freeaddrinfo(res0);
2404	if (b == NULL((void *)0)) {
2405	bpf_error("unknown host '%s'%s", name,
2406	(proto == Q_DEFAULT0)
2407	? ""
2408	: " for specified address family");
2409	}
2410	return b;
2411	#endif /INET6/
2412	}
2413
2414	case Q_PORT3:
2415	if (proto != Q_DEFAULT0 && proto != Q_UDP6 && proto != Q_TCP5)
2416	bpf_error("illegal qualifier of 'port'");
2417	if (pcap_nametoport(name, &port, &real_proto) == 0)
2418	bpf_error("unknown port '%s'", name);
2419	if (proto == Q_UDP6) {
2420	if (real_proto == IPPROTO_TCP6)
2421	bpf_error("port '%s' is tcp", name);
2422	else
2423	/* override PROTO_UNDEF */
2424	real_proto = IPPROTO_UDP17;
2425	}
2426	if (proto == Q_TCP5) {
2427	if (real_proto == IPPROTO_UDP17)
2428	bpf_error("port '%s' is udp", name);
2429	else
2430	/* override PROTO_UNDEF */
2431	real_proto = IPPROTO_TCP6;
2432	}
2433	#ifndef INET61
2434	return gen_port(port, real_proto, dir);
2435	#else
2436	{
2437	struct block *b;
2438	b = gen_port(port, real_proto, dir);
2439	gen_or(gen_port6(port, real_proto, dir), b);
2440	return b;
2441	}
2442	#endif /* INET6 */
2443
2444	case Q_GATEWAY4:
2445	#ifndef INET61
2446	eaddr = pcap_ether_hostton(name);
2447	if (eaddr == NULL((void *)0))
2448	bpf_error("unknown ether host: %s", name);
2449
2450	alist = pcap_nametoaddr(name);
2451	if (alist == NULL((void )0) \|\| alist == NULL((void *)0))
2452	bpf_error("unknown host '%s'", name);
2453	return gen_gateway(eaddr, alist, proto, dir);
2454	#else
2455	bpf_error("'gateway' not supported in this configuration");
2456	#endif /INET6/
2457
2458	case Q_PROTO5:
2459	real_proto = lookup_proto(name, proto);
2460	if (real_proto >= 0)
2461	return gen_proto(real_proto, proto, dir);
2462	else
2463	bpf_error("unknown protocol: %s", name);
2464
2465	case Q_PROTOCHAIN6:
2466	real_proto = lookup_proto(name, proto);
2467	if (real_proto >= 0)
2468	return gen_protochain(real_proto, proto, dir);
2469	else
2470	bpf_error("unknown protocol: %s", name);
2471
2472
2473	case Q_UNDEF255:
2474	syntax();
2475	/* NOTREACHED */
2476	}
2477	abort();
2478	/* NOTREACHED */
2479	}
2480
2481	struct block *
2482	gen_mcode(s1, s2, masklen, q)
2483	const char s1, s2;
2484	int masklen;
2485	struct qual q;
2486	{
2487	int nlen, mlen;
2488	bpf_u_int32 n, m;
2489
2490	nlen = __pcap_atoin(s1, &n);
2491	/* Promote short ipaddr */
2492	n <<= 32 - nlen;
2493
2494	if (s2 != NULL((void *)0)) {
2495	mlen = __pcap_atoin(s2, &m);
2496	/* Promote short ipaddr */
2497	m <<= 32 - mlen;
2498	if ((n & ~m) != 0)
2499	bpf_error("non-network bits set in \"%s mask %s\"",
2500	s1, s2);
2501	} else {
2502	/* Convert mask len to mask */
2503	if (masklen > 32)
2504	bpf_error("mask length must be <= 32");
2505	m = 0xffffffff << (32 - masklen);
2506	if ((n & ~m) != 0)
2507	bpf_error("non-network bits set in \"%s/%d\"",
2508	s1, masklen);
2509	}
2510
2511	switch (q.addr) {
2512
2513	case Q_NET2:
2514	return gen_host(n, m, q.proto, q.dir);
2515
2516	default:
2517	bpf_error("Mask syntax for networks only");
2518	/* NOTREACHED */
2519	}
2520	}
2521
2522	struct block *
2523	gen_ncode(s, v, q)
2524	const char *s;
2525	bpf_u_int32 v;
2526	struct qual q;
2527	{
2528	bpf_u_int32 mask;
2529	int proto = q.proto;
2530	int dir = q.dir;
2531	int vlen;
2532
2533	if (s == NULL((void *)0))
2534	vlen = 32;
2535	else if (q.proto == Q_DECNET11)
2536	vlen = __pcap_atodn(s, &v);
2537	else
2538	vlen = __pcap_atoin(s, &v);
2539
2540	switch (q.addr) {
2541
2542	case Q_DEFAULT0:
2543	case Q_HOST1:
2544	case Q_NET2:
2545	if (proto == Q_DECNET11)
2546	return gen_host(v, 0, proto, dir);
2547	else if (proto == Q_LINK1) {
2548	bpf_error("illegal link layer address");
2549	} else {
2550	mask = 0xffffffff;
2551	if (s == NULL((void *)0) && q.addr == Q_NET2) {
2552	/* Promote short net number */
2553	while (v && (v & 0xff000000) == 0) {
2554	v <<= 8;
2555	mask <<= 8;
2556	}
2557	} else {
2558	/* Promote short ipaddr */
2559	v <<= 32 - vlen;
2560	mask <<= 32 - vlen;
2561	}
2562	return gen_host(v, mask, proto, dir);
2563	}
2564
2565	case Q_PORT3:
2566	if (proto == Q_UDP6)
2567	proto = IPPROTO_UDP17;
2568	else if (proto == Q_TCP5)
2569	proto = IPPROTO_TCP6;
2570	else if (proto == Q_DEFAULT0)
2571	proto = PROTO_UNDEF-1;
2572	else
2573	bpf_error("illegal qualifier of 'port'");
2574
2575	#ifndef INET61
2576	return gen_port((int)v, proto, dir);
2577	#else
2578	{
2579	struct block *b;
2580	b = gen_port((int)v, proto, dir);
2581	gen_or(gen_port6((int)v, proto, dir), b);
2582	return b;
2583	}
2584	#endif /* INET6 */
2585
2586	case Q_GATEWAY4:
2587	bpf_error("'gateway' requires a name");
2588	/* NOTREACHED */
2589
2590	case Q_PROTO5:
2591	return gen_proto((int)v, proto, dir);
2592
2593	case Q_PROTOCHAIN6:
2594	return gen_protochain((int)v, proto, dir);
2595
2596	case Q_UNDEF255:
2597	syntax();
2598	/* NOTREACHED */
2599
2600	default:
2601	abort();
2602	/* NOTREACHED */
2603	}
2604	/* NOTREACHED */
2605	}
2606
2607	#ifdef INET61
2608	struct block *
2609	gen_mcode6(s1, s2, masklen, q)
2610	const char s1, s2;
2611	int masklen;
2612	struct qual q;
2613	{
2614	struct addrinfo *res;
2615	struct in6_addr *addr;
2616	struct in6_addr mask;
2617	struct block *b;
2618	u_int32_t a, m;
2619
2620	if (s2)
2621	bpf_error("no mask %s supported", s2);
2622
2623	res = pcap_nametoaddrinfo(s1);
2624	if (!res)
2625	bpf_error("invalid ip6 address %s", s1);
2626	if (res->ai_next)
2627	bpf_error("%s resolved to multiple address", s1);
2628	addr = &((struct sockaddr_in6 *)res->ai_addr)->sin6_addr;
2629
2630	if (sizeof(mask) * 8 < masklen)
2631	bpf_error("mask length must be <= %u", (unsigned int)(sizeof(mask) * 8));
2632	memset(&mask, 0, sizeof(mask));
2633	memset(&mask, 0xff, masklen / 8);
2634	if (masklen % 8) {
2635	mask.s6_addr__u6_addr.__u6_addr8[masklen / 8] =
2636	(0xff << (8 - masklen % 8)) & 0xff;
2637	}
2638
2639	a = (u_int32_t *)addr;
2640	m = (u_int32_t *)&mask;
2641	if ((a[0] & ~m[0]) \|\| (a[1] & ~m[1])
2642	\|\| (a[2] & ~m[2]) \|\| (a[3] & ~m[3])) {
2643	bpf_error("non-network bits set in \"%s/%d\"", s1, masklen);
2644	}
2645
2646	switch (q.addr) {
2647
2648	case Q_DEFAULT0:
2649	case Q_HOST1:
2650	if (masklen != 128)
2651	bpf_error("Mask syntax for networks only");
2652	/* FALLTHROUGH */
2653
2654	case Q_NET2:
2655	b = gen_host6(addr, &mask, q.proto, q.dir);
2656	freeaddrinfo(res);
2657	return b;
2658
2659	default:
2660	bpf_error("invalid qualifier against IPv6 address");
2661	/* NOTREACHED */
2662	}
2663	}
2664	#endif /INET6/
2665
2666	struct block *
2667	gen_ecode(eaddr, q)
2668	const u_char *eaddr;
2669	struct qual q;
2670	{
2671	if ((q.addr == Q_HOST1 \|\| q.addr == Q_DEFAULT0) && q.proto == Q_LINK1) {
2672	if (linktype == DLT_EN10MB1)
2673	return gen_ehostop(eaddr, (int)q.dir);
2674	if (linktype == DLT_FDDI10)
2675	return gen_fhostop(eaddr, (int)q.dir);
2676	if (linktype == DLT_IEEE802_11105 \|\|
2677	linktype == DLT_IEEE802_11_RADIO127)
2678	return gen_p80211_hostop(eaddr, (int)q.dir);
2679	}
2680	bpf_error("ethernet address used in non-ether expression");
2681	/* NOTREACHED */
2682	}
2683
2684	void
2685	sappend(s0, s1)
2686	struct slist s0, s1;
2687	{
2688	/*
2689	* This is definitely not the best way to do this, but the
2690	* lists will rarely get long.
2691	*/
2692	while (s0->next)
2693	s0 = s0->next;
2694	s0->next = s1;
2695	}
2696
2697	static struct slist *
2698	xfer_to_x(a)
2699	struct arth *a;
2700	{
2701	struct slist *s;
2702
2703	s = new_stmt(BPF_LDX0x01\|BPF_MEM0x60);
2704	s->s.k = a->regno;
2705	return s;
2706	}
2707
2708	static struct slist *
2709	xfer_to_a(a)
2710	struct arth *a;
2711	{
2712	struct slist *s;
2713
2714	s = new_stmt(BPF_LD0x00\|BPF_MEM0x60);
2715	s->s.k = a->regno;
2716	return s;
2717	}
2718
2719	struct arth *
2720	gen_load(proto, index, size)
2721	int proto;
2722	struct arth *index;
2723	int size;
2724	{
2725	struct slist s, tmp;
2726	struct block *b;
2727	int regno = alloc_reg();
2728
2729	free_reg(index->regno);
2730	switch (size) {
2731
2732	default:
2733	bpf_error("data size must be 1, 2, or 4");
2734
2735	case 1:
2736	size = BPF_B0x10;
2737	break;
2738
2739	case 2:
2740	size = BPF_H0x08;
2741	break;
2742
2743	case 4:
2744	size = BPF_W0x00;
2745	break;
2746	}
2747	switch (proto) {
2748	default:
2749	bpf_error("unsupported index operation");
2750
2751	case Q_LINK1:
2752	s = xfer_to_x(index);
2753	tmp = new_stmt(BPF_LD0x00\|BPF_IND0x40\|size);
2754	sappend(s, tmp);
2755	sappend(index->s, s);
2756	break;
2757
2758	case Q_IP2:
2759	case Q_ARP3:
2760	case Q_RARP4:
2761	case Q_ATALK10:
2762	case Q_DECNET11:
2763	case Q_SCA13:
2764	case Q_LAT12:
2765	case Q_MOPRC14:
2766	case Q_MOPDL15:
2767	#ifdef INET61
2768	case Q_IPV616:
2769	#endif
2770	/* XXX Note that we assume a fixed link header here. */
2771	if (variable_nl) {
2772	s = nl2X_stmt();
2773	sappend(s, xfer_to_a(index));
2774	sappend(s, new_stmt(BPF_ALU0x04\|BPF_ADD0x00\|BPF_X0x08));
2775	sappend(s, new_stmt(BPF_MISC0x07\|BPF_TAX0x00));
2776	} else {
2777	s = xfer_to_x(index);
2778	}
2779	tmp = new_stmt(BPF_LD0x00\|BPF_IND0x40\|size);
2780	tmp->s.k = off_nl; /* off_nl == 0 for variable_nl */
2781	sappend(s, tmp);
2782	sappend(index->s, s);
2783
2784	b = gen_proto_abbrev(proto);
2785	if (index->b)
2786	gen_and(index->b, b);
2787	index->b = b;
2788	break;
2789
2790	case Q_TCP5:
2791	case Q_UDP6:
2792	case Q_ICMP7:
2793	case Q_IGMP8:
2794	case Q_IGRP9:
2795	case Q_PIM20:
2796	s = iphl_to_x();
2797	sappend(s, xfer_to_a(index));
2798	sappend(s, new_stmt(BPF_ALU0x04\|BPF_ADD0x00\|BPF_X0x08));
2799	sappend(s, new_stmt(BPF_MISC0x07\|BPF_TAX0x00));
2800	sappend(s, tmp = new_stmt(BPF_LD0x00\|BPF_IND0x40\|size));
2801	tmp->s.k = off_nl; /* off_nl is 0 if variable_nl */
2802	sappend(index->s, s);
2803
2804	gen_and(gen_proto_abbrev(proto), b = gen_ipfrag());
2805	if (index->b)
2806	gen_and(index->b, b);
2807	#ifdef INET61
2808	gen_and(gen_proto_abbrev(Q_IP2), b);
2809	#endif
2810	index->b = b;
2811	break;
2812	#ifdef INET61
2813	case Q_ICMPV617:
2814	bpf_error("IPv6 upper-layer protocol is not supported by proto[x]");
2815	/NOTREACHED/
2816	#endif
2817	}
2818	index->regno = regno;
2819	s = new_stmt(BPF_ST0x02);
2820	s->s.k = regno;
2821	sappend(index->s, s);
2822
2823	return index;
2824	}
2825
2826	struct block *
2827	gen_relation(code, a0, a1, reversed)
2828	int code;
2829	struct arth a0, a1;
2830	int reversed;
2831	{
2832	struct slist s0, s1, *s2;
2833	struct block b, tmp;
2834
2835	s0 = xfer_to_x(a1);
2836	s1 = xfer_to_a(a0);
2837	s2 = new_stmt(BPF_ALU0x04\|BPF_SUB0x10\|BPF_X0x08);
2838	b = new_block(JMP(code)((code)\|0x05\|0x00));
2839	if (code == BPF_JGT0x20 \|\| code == BPF_JGE0x30) {
2840	reversed = !reversed;
2841	b->s.k = 0x80000000;
2842	}
2843	if (reversed)
2844	gen_not(b);
2845
2846	sappend(s1, s2);
2847	sappend(s0, s1);
2848	sappend(a1->s, s0);
2849	sappend(a0->s, a1->s);
2850
2851	b->stmts = a0->s;
2852
2853	free_reg(a0->regno);
2854	free_reg(a1->regno);
2855
2856	/* 'and' together protocol checks */
2857	if (a0->b) {
2858	if (a1->b) {
2859	gen_and(a0->b, tmp = a1->b);
2860	}
2861	else
2862	tmp = a0->b;
2863	} else
2864	tmp = a1->b;
2865
2866	if (tmp)
2867	gen_and(tmp, b);
2868
2869	return b;
2870	}
2871
2872	struct arth *
2873	gen_loadlen()
2874	{
2875	int regno = alloc_reg();
2876	struct arth a = (struct arth )newchunk(sizeof(*a));
2877	struct slist *s;
2878
2879	s = new_stmt(BPF_LD0x00\|BPF_LEN0x80);
2880	s->next = new_stmt(BPF_ST0x02);
2881	s->next->s.k = regno;
2882	a->s = s;
2883	a->regno = regno;
2884
2885	return a;
2886	}
2887
2888	struct arth *
2889	gen_loadrnd()
2890	{
2891	int regno = alloc_reg();
2892	struct arth a = (struct arth )newchunk(sizeof(*a));
2893	struct slist *s;
2894
2895	s = new_stmt(BPF_LD0x00\|BPF_RND0xc0);
2896	s->next = new_stmt(BPF_ST0x02);
2897	s->next->s.k = regno;
2898	a->s = s;
2899	a->regno = regno;
2900
2901	return a;
2902	}
2903
2904	struct arth *
2905	gen_loadi(val)
2906	int val;
2907	{
2908	struct arth *a;
2909	struct slist *s;
2910	int reg;
2911
2912	a = (struct arth )newchunk(sizeof(a));
2913
2914	reg = alloc_reg();
2915
2916	s = new_stmt(BPF_LD0x00\|BPF_IMM0x00);
2917	s->s.k = val;
2918	s->next = new_stmt(BPF_ST0x02);
2919	s->next->s.k = reg;
2920	a->s = s;
2921	a->regno = reg;
2922
2923	return a;
2924	}
2925
2926	struct arth *
2927	gen_neg(a)
2928	struct arth *a;
2929	{
2930	struct slist *s;
2931
2932	s = xfer_to_a(a);
2933	sappend(a->s, s);
2934	s = new_stmt(BPF_ALU0x04\|BPF_NEG0x80);
2935	s->s.k = 0;
2936	sappend(a->s, s);
2937	s = new_stmt(BPF_ST0x02);
2938	s->s.k = a->regno;
2939	sappend(a->s, s);
2940
2941	return a;
2942	}
2943
2944	struct arth *
2945	gen_arth(code, a0, a1)
2946	int code;
2947	struct arth a0, a1;
2948	{
2949	struct slist s0, s1, *s2;
2950
2951	s0 = xfer_to_x(a1);
2952	s1 = xfer_to_a(a0);
2953	s2 = new_stmt(BPF_ALU0x04\|BPF_X0x08\|code);
2954
2955	sappend(s1, s2);
2956	sappend(s0, s1);
2957	sappend(a1->s, s0);
2958	sappend(a0->s, a1->s);
2959
2960	free_reg(a1->regno);
2961
2962	s0 = new_stmt(BPF_ST0x02);
2963	a0->regno = s0->s.k = alloc_reg();
2964	sappend(a0->s, s0);
2965
2966	return a0;
2967	}
2968
2969	/*
2970	* Here we handle simple allocation of the scratch registers.
2971	* If too many registers are alloc'd, the allocator punts.
2972	*/
2973	static int regused[BPF_MEMWORDS16];
2974	static int curreg;
2975
2976	/*
2977	* Return the next free register.
2978	*/
2979	static int
2980	alloc_reg()
2981	{
2982	int n = BPF_MEMWORDS16;
2983
2984	while (--n >= 0) {
2985	if (regused[curreg])
2986	curreg = (curreg + 1) % BPF_MEMWORDS16;
2987	else {
2988	regused[curreg] = 1;
2989	return curreg;
2990	}
2991	}
2992	bpf_error("too many registers needed to evaluate expression");
2993	/* NOTREACHED */
2994	}
2995
2996	/*
2997	* Return a register to the table so it can
2998	* be used later.
2999	*/
3000	static void
3001	free_reg(n)
3002	int n;
3003	{
3004	regused[n] = 0;
3005	}
3006
3007	static struct block *
3008	gen_len(jmp, n)
3009	int jmp, n;
3010	{
3011	struct slist *s;
3012	struct block *b;
3013
3014	s = new_stmt(BPF_LD0x00\|BPF_LEN0x80);
3015	b = new_block(JMP(jmp)((jmp)\|0x05\|0x00));
3016	b->stmts = s;
3017	b->s.k = n;
3018
3019	return b;
3020	}
3021
3022	struct block *
3023	gen_greater(n)
3024	int n;
3025	{
3026	return gen_len(BPF_JGE0x30, n);
3027	}
3028
3029	struct block *
3030	gen_less(n)
3031	int n;
3032	{
3033	struct block *b;
3034
3035	b = gen_len(BPF_JGT0x20, n);
3036	gen_not(b);
3037
3038	return b;
3039	}
3040
3041	struct block *
3042	gen_byteop(op, idx, val)
3043	int op, idx, val;
3044	{
3045	struct block *b;
3046	struct slist *s;
3047
3048	switch (op) {
3049	default:
3050	abort();
3051
3052	case '=':
3053	return gen_cmp((u_int)idx, BPF_B0x10, (bpf_int32)val);
3054
3055	case '<':
3056	b = gen_cmp((u_int)idx, BPF_B0x10, (bpf_int32)val);
3057	b->s.code = JMP(BPF_JGE)((0x30)\|0x05\|0x00);
3058	gen_not(b);
3059	return b;
3060
3061	case '>':
3062	b = gen_cmp((u_int)idx, BPF_B0x10, (bpf_int32)val);
3063	b->s.code = JMP(BPF_JGT)((0x20)\|0x05\|0x00);
3064	return b;
3065
3066	case '\|':
3067	s = new_stmt(BPF_ALU0x04\|BPF_OR0x40\|BPF_K0x00);
3068	break;
3069
3070	case '&':
3071	s = new_stmt(BPF_ALU0x04\|BPF_AND0x50\|BPF_K0x00);
3072	break;
3073	}
3074	s->s.k = val;
3075	b = new_block(JMP(BPF_JEQ)((0x10)\|0x05\|0x00));
3076	b->stmts = s;
3077	gen_not(b);
3078
3079	return b;
3080	}
3081
3082	struct block *
3083	gen_broadcast(proto)
3084	int proto;
3085	{
3086	bpf_u_int32 hostmask;
3087	struct block b0, b1, *b2;
3088	static u_char ebroadcast[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
3089
3090	switch (proto) {
3091
3092	case Q_DEFAULT0:
3093	case Q_LINK1:
3094	if (linktype == DLT_EN10MB1)
3095	return gen_ehostop(ebroadcast, Q_DST2);
3096	if (linktype == DLT_FDDI10)
3097	return gen_fhostop(ebroadcast, Q_DST2);
3098	if (linktype == DLT_IEEE802_11105 \|\|
3099	linktype == DLT_IEEE802_11_RADIO127)
3100	return gen_p80211_hostop(ebroadcast, Q_DST2);
3101	bpf_error("not a broadcast link");
3102	break;
3103
3104	case Q_IP2:
3105	/*
3106	* We treat a netmask of PCAP_NETMASK_UNKNOWN (0xffffffff)
3107	* as an indication that we don't know the netmask, and fail
3108	* in that case.
3109	*/
3110	if (netmask == PCAP_NETMASK_UNKNOWN0xffffffff)
3111	bpf_error("netmask not known, so 'ip broadcast' not supported");
3112	b0 = gen_linktype(ETHERTYPE_IP0x0800);
3113	hostmask = ~netmask;
3114	b1 = gen_mcmp_nl(16, BPF_W0x00, (bpf_int32)0, hostmask);
3115	b2 = gen_mcmp_nl(16, BPF_W0x00,
3116	(bpf_int32)(~0 & hostmask), hostmask);
3117	gen_or(b1, b2);
3118	gen_and(b0, b2);
3119	return b2;
3120	}
3121	bpf_error("only ether/ip broadcast filters supported");
3122	}
3123
3124	struct block *
3125	gen_multicast(proto)
3126	int proto;
3127	{
3128	struct block b0, b1;
3129	struct slist *s;
3130
3131	switch (proto) {
3132
3133	case Q_DEFAULT0:
3134	case Q_LINK1:
3135	if (linktype == DLT_EN10MB1) {
3136	/* ether[0] & 1 != 0 */
3137	s = new_stmt(BPF_LD0x00\|BPF_B0x10\|BPF_ABS0x20);
3138	s->s.k = 0;
3139	b0 = new_block(JMP(BPF_JSET)((0x40)\|0x05\|0x00));
3140	b0->s.k = 1;
3141	b0->stmts = s;
3142	return b0;
3143	}
3144
3145	if (linktype == DLT_FDDI10) {
3146	/* XXX TEST THIS: MIGHT NOT PORT PROPERLY XXX */
3147	/* fddi[1] & 1 != 0 */
3148	s = new_stmt(BPF_LD0x00\|BPF_B0x10\|BPF_ABS0x20);
3149	s->s.k = 1;
3150	b0 = new_block(JMP(BPF_JSET)((0x40)\|0x05\|0x00));
3151	b0->s.k = 1;
3152	b0->stmts = s;
3153	return b0;
3154	}
3155	/* Link not known to support multicasts */
3156	break;
3157
3158	case Q_IP2:
3159	b0 = gen_linktype(ETHERTYPE_IP0x0800);
3160	b1 = gen_cmp_nl(16, BPF_B0x10, (bpf_int32)224);
3161	b1->s.code = JMP(BPF_JGE)((0x30)\|0x05\|0x00);
3162	gen_and(b0, b1);
3163	return b1;
3164
3165	#ifdef INET61
3166	case Q_IPV616:
3167	b0 = gen_linktype(ETHERTYPE_IPV60x86DD);
3168	b1 = gen_cmp_nl(24, BPF_B0x10, (bpf_int32)255);
3169	gen_and(b0, b1);
3170	return b1;
3171	#endif /* INET6 */
3172	}
3173	bpf_error("only IP multicast filters supported on ethernet/FDDI");
3174	}
3175
3176	/*
3177	* generate command for inbound/outbound. It's here so we can
3178	* make it link-type specific. 'dir' = 0 implies "inbound",
3179	* = 1 implies "outbound".
3180	*/
3181	struct block *
3182	gen_inbound(dir)
3183	int dir;
3184	{
3185	struct block *b0;
3186
3187	/*
3188	* Only SLIP and old-style PPP data link types support
3189	* inbound/outbound qualifiers.
3190	*/
3191	switch (linktype) {
3192	case DLT_SLIP8:
3193	case DLT_PPP9:
3194	b0 = gen_relation(BPF_JEQ0x10,
3195	gen_load(Q_LINK1, gen_loadi(0), 1),
3196	gen_loadi(0),
3197	dir);
3198	break;
3199
3200	case DLT_PFLOG117:
3201	b0 = gen_cmp(offsetof(struct pfloghdr, dir)__builtin_offsetof(struct pfloghdr, dir), BPF_B0x10,
3202	(bpf_int32)((dir == 0) ? PF_IN : PF_OUT));
3203	break;
3204
3205	default:
3206	bpf_error("inbound/outbound not supported on linktype 0x%x",
3207	linktype);
3208	/* NOTREACHED */
3209	}
3210
3211	return (b0);
3212	}
3213
3214
3215	/* PF firewall log matched interface */
3216	struct block *
3217	gen_pf_ifname(char *ifname)
3218	{
3219	struct block *b0;
3220	u_int len, off;
3221
3222	if (linktype == DLT_PFLOG117) {
3223	len = sizeof(((struct pfloghdr *)0)->ifname);
3224	off = offsetof(struct pfloghdr, ifname)__builtin_offsetof(struct pfloghdr, ifname);
3225	} else {
3226	bpf_error("ifname not supported on linktype 0x%x", linktype);
3227	/* NOTREACHED */
3228	}
3229	if (strlen(ifname) >= len) {
3230	bpf_error("ifname interface names can only be %d characters",
3231	len - 1);
3232	/* NOTREACHED */
3233	}
3234	b0 = gen_bcmp(off, strlen(ifname) + 1, ifname);
3235	return (b0);
3236	}
3237
3238
3239	/* PF firewall log ruleset name */
3240	struct block *
3241	gen_pf_ruleset(char *ruleset)
3242	{
3243	struct block *b0;
3244
3245	if (linktype != DLT_PFLOG117) {
3246	bpf_error("ruleset not supported on linktype 0x%x", linktype);
3247	/* NOTREACHED */
3248	}
3249	if (strlen(ruleset) >= sizeof(((struct pfloghdr *)0)->ruleset)) {
3250	bpf_error("ruleset names can only be %zu characters",
3251	sizeof(((struct pfloghdr *)0)->ruleset) - 1);
3252	/* NOTREACHED */
3253	}
3254	b0 = gen_bcmp(offsetof(struct pfloghdr, ruleset)__builtin_offsetof(struct pfloghdr, ruleset),
3255	strlen(ruleset), ruleset);
3256	return (b0);
3257	}
3258
3259
3260	/* PF firewall log rule number */
3261	struct block *
3262	gen_pf_rnr(int rnr)
3263	{
3264	struct block *b0;
3265
3266	if (linktype == DLT_PFLOG117) {
3267	b0 = gen_cmp(offsetof(struct pfloghdr, rulenr)__builtin_offsetof(struct pfloghdr, rulenr), BPF_W0x00,
3268	(bpf_int32)rnr);
3269	} else {
3270	bpf_error("rnr not supported on linktype 0x%x", linktype);
3271	/* NOTREACHED */
3272	}
3273
3274	return (b0);
3275	}
3276
3277
3278	/* PF firewall log sub-rule number */
3279	struct block *
3280	gen_pf_srnr(int srnr)
3281	{
3282	struct block *b0;
3283
3284	if (linktype != DLT_PFLOG117) {
3285	bpf_error("srnr not supported on linktype 0x%x", linktype);
3286	/* NOTREACHED */
3287	}
3288
3289	b0 = gen_cmp(offsetof(struct pfloghdr, subrulenr)__builtin_offsetof(struct pfloghdr, subrulenr), BPF_W0x00,
3290	(bpf_int32)srnr);
3291	return (b0);
3292	}
3293
3294	/* PF firewall log reason code */
3295	struct block *
3296	gen_pf_reason(int reason)
3297	{
3298	struct block *b0;
3299
3300	if (linktype == DLT_PFLOG117) {
3301	b0 = gen_cmp(offsetof(struct pfloghdr, reason)__builtin_offsetof(struct pfloghdr, reason), BPF_B0x10,
3302	(bpf_int32)reason);
3303	} else {
3304	bpf_error("reason not supported on linktype 0x%x", linktype);
3305	/* NOTREACHED */
3306	}
3307
3308	return (b0);
3309	}
3310
3311	/* PF firewall log action */
3312	struct block *
3313	gen_pf_action(int action)
3314	{
3315	struct block *b0;
3316
3317	if (linktype == DLT_PFLOG117) {
3318	b0 = gen_cmp(offsetof(struct pfloghdr, action)__builtin_offsetof(struct pfloghdr, action), BPF_B0x10,
3319	(bpf_int32)action);
3320	} else {
3321	bpf_error("action not supported on linktype 0x%x", linktype);
3322	/* NOTREACHED */
3323	}
3324
3325	return (b0);
3326	}
3327
3328	/* IEEE 802.11 wireless header */
3329	struct block *
3330	gen_p80211_type(int type, int mask)
3331	{
3332	struct block *b0;
3333	u_int offset;
3334
3335	if (!(linktype == DLT_IEEE802_11105 \|\|
3336	linktype == DLT_IEEE802_11_RADIO127)) {
3337	bpf_error("type not supported on linktype 0x%x",
3338	linktype);
3339	/* NOTREACHED */
3340	}
3341	offset = (u_int)offsetof(struct ieee80211_frame, i_fc[0])__builtin_offsetof(struct ieee80211_frame, i_fc[0]);
3342	if (linktype == DLT_IEEE802_11_RADIO127)
3343	offset += IEEE80211_RADIOTAP_HDRLEN64;
3344
3345	b0 = gen_mcmp(offset, BPF_B0x10, (bpf_int32)type, (bpf_u_int32)mask);
3346
3347	return (b0);
3348	}
3349
3350	static struct block *
3351	gen_ahostop(eaddr, dir)
3352	const u_char *eaddr;
3353	int dir;
3354	{
3355	struct block b0, b1;
3356
3357	switch (dir) {
3358	/* src comes first, different from Ethernet */
3359	case Q_SRC1:
3360	return gen_bcmp(0, 1, eaddr);
3361
3362	case Q_DST2:
3363	return gen_bcmp(1, 1, eaddr);
3364
3365	case Q_AND4:
3366	b0 = gen_ahostop(eaddr, Q_SRC1);
3367	b1 = gen_ahostop(eaddr, Q_DST2);
3368	gen_and(b0, b1);
3369	return b1;
3370
3371	case Q_DEFAULT0:
3372	case Q_OR3:
3373	b0 = gen_ahostop(eaddr, Q_SRC1);
3374	b1 = gen_ahostop(eaddr, Q_DST2);
3375	gen_or(b0, b1);
3376	return b1;
3377	}
3378	abort();
3379	/* NOTREACHED */
3380	}
3381
3382	struct block *
3383	gen_acode(eaddr, q)
3384	const u_char *eaddr;
3385	struct qual q;
3386	{
3387	if ((q.addr == Q_HOST1 \|\| q.addr == Q_DEFAULT0) && q.proto == Q_LINK1) {
3388	if (linktype == DLT_ARCNET7)
3389	return gen_ahostop(eaddr, (int)q.dir);
3390	}
3391	bpf_error("ARCnet address used in non-arc expression");
3392	/* NOTREACHED */
3393	}
3394
3395	struct block *
3396	gen_mpls(label)
3397	int label;
3398	{
3399	struct block *b0;
3400
3401	if (label > MPLS_LABEL_MAX((1 << 20) - 1))
3402	bpf_error("invalid MPLS label : %d", label);
3403
3404	if (mpls_stack > 0) /* Bottom-Of-Label-Stack bit ? */
3405	b0 = gen_mcmp(off_nl-2, BPF_B0x10, (bpf_int32)0, 0x1);
3406	else
3407	b0 = gen_linktype(ETHERTYPE_MPLS0x8847);
3408
3409	if (label >= 0) {
3410	struct block *b1;
3411
3412	b1 = gen_mcmp(off_nl, BPF_W0x00, (bpf_int32)(label << 12),
3413	MPLS_LABEL_MASK((u_int32_t)(0xfffff000U)));
3414	gen_and(b0, b1);
3415	b0 = b1;
3416	}
3417	off_nl += 4;
3418	off_linktype += 4;
3419	mpls_stack++;
3420	return (b0);
3421	}
3422
3423	/*
3424	* support IEEE 802.1Q VLAN trunk over ethernet
3425	*/
3426	struct block *
3427	gen_vlan(vlan_num)
3428	int vlan_num;
3429	{
3430	struct block *b0;
3431
3432	if (variable_nl) {
3433	bpf_error("'vlan' not supported for variable DLTs");
3434	/NOTREACHED/
3435	}
3436
3437	if (vlan_num > 4095) {
3438	bpf_error("invalid VLAN number : %d", vlan_num);
3439	/NOTREACHED/
3440	}
3441
3442	/*
3443	* Change the offsets to point to the type and data fields within
3444	* the VLAN packet. This is somewhat of a kludge.
3445	*/
3446	if (orig_nl == (u_int)-1) {
3447	orig_linktype = off_linktype; /* save original values */
3448	orig_nl = off_nl;
3449	orig_nl_nosnap = off_nl_nosnap;
3450
3451	switch (linktype) {
3452
3453	case DLT_EN10MB1:
3454	off_linktype = 16;
3455	off_nl_nosnap = 18;
3456	off_nl = 18;
3457	break;
3458
3459	default:
3460	bpf_error("no VLAN support for data link type %d",
3461	linktype);
3462	/NOTREACHED/
3463	}
3464	}
3465
3466	/* check for VLAN */
3467	b0 = gen_cmp(orig_linktype, BPF_H0x08, (bpf_int32)ETHERTYPE_8021Q0x8100);
3468
3469	/* If a specific VLAN is requested, check VLAN id */
3470	if (vlan_num >= 0) {
3471	struct block *b1;
3472
3473	b1 = gen_mcmp(orig_nl, BPF_H0x08, (bpf_int32)vlan_num, 0x0FFF);
3474	gen_and(b0, b1);
3475	b0 = b1;
3476	}
3477
3478	return (b0);
3479	}
3480
3481	struct block *
3482	gen_sample(int rate)
3483	{
3484	struct block *b0;
3485	long long threshold = 0x100000000LL; /* 0xffffffff + 1 */
3486
3487	if (rate < 2) {
3488	bpf_error("sample %d is too low", rate);
3489	/NOTREACHED/
3490	}
3491	if (rate > (1 << 20)) {
3492	bpf_error("sample %d is too high", rate);
3493	/NOTREACHED/
3494	}
3495
3496	threshold /= rate;
3497	b0 = gen_relation(BPF_JGT0x20, gen_loadrnd(), gen_loadi(threshold), 1);
3498
3499	return (b0);
3500	}
3501
3502	struct block *
3503	gen_p80211_fcdir(int fcdir)
3504	{
3505	struct block *b0;
3506	u_int offset;
3507
3508	if (!(linktype == DLT_IEEE802_11105 \|\|
3509	linktype == DLT_IEEE802_11_RADIO127)) {
3510	bpf_error("frame direction not supported on linktype 0x%x",
3511	linktype);
3512	/* NOTREACHED */
3513	}
3514	offset = (u_int)offsetof(struct ieee80211_frame, i_fc[1])__builtin_offsetof(struct ieee80211_frame, i_fc[1]);
3515	if (linktype == DLT_IEEE802_11_RADIO127)
3516	offset += IEEE80211_RADIOTAP_HDRLEN64;
3517
3518	b0 = gen_mcmp(offset, BPF_B0x10, (bpf_int32)fcdir,
3519	(bpf_u_int32)IEEE80211_FC1_DIR_MASK0x03);
3520
3521	return (b0);
3522	}
3523
3524	static struct block *
3525	gen_p80211_hostop(const u_char *lladdr, int dir)
3526	{
3527	struct block b0, b1, b2, b3, *b4;
3528	u_int offset = 0;
3529
3530	if (linktype == DLT_IEEE802_11_RADIO127)
3531	offset = IEEE80211_RADIOTAP_HDRLEN64;
3532
3533	switch (dir) {
3534	case Q_SRC1:
3535	b0 = gen_p80211_addr(IEEE80211_FC1_DIR_NODS0x00, offset +
3536	(u_int)offsetof(struct ieee80211_frame, i_addr2)__builtin_offsetof(struct ieee80211_frame, i_addr2),
3537	lladdr);
3538	b1 = gen_p80211_addr(IEEE80211_FC1_DIR_TODS0x01, offset +
3539	(u_int)offsetof(struct ieee80211_frame, i_addr2)__builtin_offsetof(struct ieee80211_frame, i_addr2),
3540	lladdr);
3541	b2 = gen_p80211_addr(IEEE80211_FC1_DIR_FROMDS0x02, offset +
3542	(u_int)offsetof(struct ieee80211_frame, i_addr3)__builtin_offsetof(struct ieee80211_frame, i_addr3),
3543	lladdr);
3544	b3 = gen_p80211_addr(IEEE80211_FC1_DIR_DSTODS0x03, offset +
3545	(u_int)offsetof(struct ieee80211_frame_addr4, i_addr4)__builtin_offsetof(struct ieee80211_frame_addr4, i_addr4),
3546	lladdr);
3547	b4 = gen_p80211_addr(IEEE80211_FC1_DIR_DSTODS0x03, offset +
3548	(u_int)offsetof(struct ieee80211_frame_addr4, i_addr2)__builtin_offsetof(struct ieee80211_frame_addr4, i_addr2),
3549	lladdr);
3550
3551	gen_or(b0, b1);
3552	gen_or(b1, b2);
3553	gen_or(b2, b3);
3554	gen_or(b3, b4);
3555	return (b4);
3556
3557	case Q_DST2:
3558	b0 = gen_p80211_addr(IEEE80211_FC1_DIR_NODS0x00, offset +
3559	(u_int)offsetof(struct ieee80211_frame, i_addr1)__builtin_offsetof(struct ieee80211_frame, i_addr1),
3560	lladdr);
3561	b1 = gen_p80211_addr(IEEE80211_FC1_DIR_TODS0x01, offset +
3562	(u_int)offsetof(struct ieee80211_frame, i_addr3)__builtin_offsetof(struct ieee80211_frame, i_addr3),
3563	lladdr);
3564	b2 = gen_p80211_addr(IEEE80211_FC1_DIR_FROMDS0x02, offset +
3565	(u_int)offsetof(struct ieee80211_frame, i_addr1)__builtin_offsetof(struct ieee80211_frame, i_addr1),
3566	lladdr);
3567	b3 = gen_p80211_addr(IEEE80211_FC1_DIR_DSTODS0x03, offset +
3568	(u_int)offsetof(struct ieee80211_frame_addr4, i_addr3)__builtin_offsetof(struct ieee80211_frame_addr4, i_addr3),
3569	lladdr);
3570	b4 = gen_p80211_addr(IEEE80211_FC1_DIR_DSTODS0x03, offset +
3571	(u_int)offsetof(struct ieee80211_frame_addr4, i_addr1)__builtin_offsetof(struct ieee80211_frame_addr4, i_addr1),
3572	lladdr);
3573
3574	gen_or(b0, b1);
3575	gen_or(b1, b2);
3576	gen_or(b2, b3);
3577	gen_or(b3, b4);
3578	return (b4);
3579
3580	case Q_ADDR15:
3581	return (gen_bcmp(offset +
3582	(u_int)offsetof(struct ieee80211_frame,__builtin_offsetof(struct ieee80211_frame, i_addr1)
3583	i_addr1)__builtin_offsetof(struct ieee80211_frame, i_addr1), IEEE80211_ADDR_LEN6, lladdr));
3584
3585	case Q_ADDR26:
3586	return (gen_bcmp(offset +
3587	(u_int)offsetof(struct ieee80211_frame,__builtin_offsetof(struct ieee80211_frame, i_addr2)
3588	i_addr2)__builtin_offsetof(struct ieee80211_frame, i_addr2), IEEE80211_ADDR_LEN6, lladdr));
3589
3590	case Q_ADDR37:
3591	return (gen_bcmp(offset +
3592	(u_int)offsetof(struct ieee80211_frame,__builtin_offsetof(struct ieee80211_frame, i_addr3)
3593	i_addr3)__builtin_offsetof(struct ieee80211_frame, i_addr3), IEEE80211_ADDR_LEN6, lladdr));
3594
3595	case Q_ADDR48:
3596	return (gen_p80211_addr(IEEE80211_FC1_DIR_DSTODS0x03, offset +
3597	(u_int)offsetof(struct ieee80211_frame_addr4, i_addr4)__builtin_offsetof(struct ieee80211_frame_addr4, i_addr4),
3598	lladdr));
3599
3600	case Q_AND4:
3601	b0 = gen_p80211_hostop(lladdr, Q_SRC1);
3602	b1 = gen_p80211_hostop(lladdr, Q_DST2);
3603	gen_and(b0, b1);
3604	return (b1);
3605
3606	case Q_DEFAULT0:
3607	case Q_OR3:
3608	b0 = gen_p80211_hostop(lladdr, Q_ADDR15);
3609	b1 = gen_p80211_hostop(lladdr, Q_ADDR26);
3610	b2 = gen_p80211_hostop(lladdr, Q_ADDR37);
3611	b3 = gen_p80211_hostop(lladdr, Q_ADDR48);
3612	gen_or(b0, b1);
3613	gen_or(b1, b2);
3614	gen_or(b2, b3);
3615	return (b3);
3616
3617	default:
3618	bpf_error("direction not supported on linktype 0x%x",
3619	linktype);
3620	}
3621	/* NOTREACHED */
3622	}
3623
3624	static struct block *
3625	gen_p80211_addr(int fcdir, u_int offset, const u_char *lladdr)
3626	{
3627	struct block b0, b1;
3628
3629	b0 = gen_mcmp(offset, BPF_B0x10, (bpf_int32)fcdir, IEEE80211_FC1_DIR_MASK0x03);
3630	b1 = gen_bcmp(offset, IEEE80211_ADDR_LEN6, lladdr);
3631	gen_and(b0, b1);
3632
3633	return (b1);
3634	}