aboutsummaryrefslogtreecommitdiff
path: root/usr.sbin/config/main.cc
blob: f155b7c5387a1acbf92c5e0e203eb1d1da0f27d4 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1980, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1980, 1993\n\
	The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)main.c	8.1 (Berkeley) 6/6/93";
#endif
static const char rcsid[] =
  "$FreeBSD$";
#endif /* not lint */

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <sys/mman.h>
#include <sys/param.h>

#include <assert.h>
#include <ctype.h>
#include <dirent.h>
#include <err.h>
#include <iostream>
#include <sstream>
#include <stdio.h>
#include <string.h>
#include <sysexits.h>
#include <unistd.h>

#include "y.tab.h"
#include "config.h"
#include "configvers.h"

#ifndef TRUE
#define TRUE	(1)
#endif

#ifndef FALSE
#define FALSE	(0)
#endif

#define	CDIR	"../compile/"

char	*machinename;
char	*machinearch;

struct cfgfile_head	cfgfiles;
struct cputype_head	cputype;
struct opt_head		opt, mkopt, rmopts;
struct opt_list_head	otab;
struct envvar_head	envvars;
struct hint_head	hints;
struct includepath_head	includepath;

char *	PREFIX;
char 	destdir[MAXPATHLEN];
char 	srcdir[MAXPATHLEN];

int	debugging;
int	found_defaults;
int	incignore;

/*
 * Preserve old behaviour in INCLUDE_CONFIG_FILE handling (files are included
 * literally).
 */
int	filebased = 0;
int	versreq;

static void configfile(void);
static void get_srcdir(void);
static void usage(void);
static void cleanheaders(char *);
static void kernconfdump(const char *);
static void badversion(void);
static void checkversion(void);

struct hdr_list {
	const char *h_name;
	struct hdr_list *h_next;
} *htab;

static std::stringstream line_buf;

/*
 * Config builds a set of files for building a UNIX
 * system given a description of the desired system.
 */
int
main(int argc, char **argv)
{

	struct stat buf;
	int ch, len;
	char *p;
	char *kernfile;
	struct includepath* ipath;
	int printmachine;
	bool cust_dest = false;

	printmachine = 0;
	kernfile = NULL;
	SLIST_INIT(&includepath);
	SLIST_INIT(&cputype);
	SLIST_INIT(&mkopt);
	SLIST_INIT(&opt);
	SLIST_INIT(&rmopts);
	STAILQ_INIT(&cfgfiles);
	STAILQ_INIT(&dtab);
	STAILQ_INIT(&fntab);
	STAILQ_INIT(&ftab);
	STAILQ_INIT(&hints);
	STAILQ_INIT(&envvars);
	while ((ch = getopt(argc, argv, "Cd:gI:mps:Vx:")) != -1)
		switch (ch) {
		case 'C':
			filebased = 1;
			break;
		case 'd':
			if (*destdir == '\0')
				strlcpy(destdir, optarg, sizeof(destdir));
			else
				errx(EXIT_FAILURE, "directory already set");
			cust_dest = true;
			break;
		case 'g':
			debugging++;
			break;
		case 'I':
			ipath = (struct includepath *) \
			    	calloc(1, sizeof (struct includepath));
			if (ipath == NULL)
				err(EXIT_FAILURE, "calloc");
			ipath->path = optarg;
			SLIST_INSERT_HEAD(&includepath, ipath, path_next);
			break;
		case 'm':
			printmachine = 1;
			break;
		case 's':
			if (*srcdir == '\0')
				strlcpy(srcdir, optarg, sizeof(srcdir));
			else
				errx(EXIT_FAILURE, "src directory already set");
			break;
		case 'V':
			printf("%d\n", CONFIGVERS);
			exit(0);
		case 'x':
			kernfile = optarg;
			break;
		case '?':
		default:
			usage();
		}
	argc -= optind;
	argv += optind;

	if (kernfile != NULL) {
		kernconfdump(kernfile);
		exit(EXIT_SUCCESS);
	}

	if (argc != 1)
		usage();

	PREFIX = *argv;
	if (stat(PREFIX, &buf) != 0 || !S_ISREG(buf.st_mode))
		err(2, "%s", PREFIX);
	if (freopen("DEFAULTS", "r", stdin) != NULL) {
		found_defaults = 1;
		yyfile = "DEFAULTS";
	} else {
		if (freopen(PREFIX, "r", stdin) == NULL)
			err(2, "%s", PREFIX);
		yyfile = PREFIX;
	}
	if (*destdir != '\0') {
		len = strlen(destdir);
		while (len > 1 && destdir[len - 1] == '/')
			destdir[--len] = '\0';
		if (*srcdir == '\0')
			get_srcdir();
	} else {
		strlcpy(destdir, CDIR, sizeof(destdir));
		strlcat(destdir, PREFIX, sizeof(destdir));
	}

	if (yyparse())
		exit(3);

	/*
	 * Ensure that required elements (machine, cpu, ident) are present.
	 */
	if (machinename == NULL) {
		printf("Specify machine type, e.g. ``machine i386''\n");
		exit(1);
	}
	if (ident == NULL) {
		printf("no ident line specified\n");
		exit(1);
	}
	if (SLIST_EMPTY(&cputype)) {
		printf("cpu type must be specified\n");
		exit(1);
	}
	checkversion();

	if (printmachine) {
		printf("%s\t%s\n",machinename,machinearch);
		exit(0);
	}

	/*
	 * Make CDIR directory, if doing a default destination. Some version
	 * control systems delete empty directories and this seemlessly copes.
	 */
	if (!cust_dest && stat(CDIR, &buf))
		if (mkdir(CDIR, 0777))
			err(2, "%s", CDIR);
	/* Create the compile directory */
	p = path((char *)NULL);
	if (stat(p, &buf)) {
		if (mkdir(p, 0777))
			err(2, "%s", p);
	} else if (!S_ISDIR(buf.st_mode))
		errx(EXIT_FAILURE, "%s isn't a directory", p);

	configfile();			/* put config file into kernel*/
	options();			/* make options .h files */
	makefile();			/* build Makefile */
	makeenv();			/* build env.c */
	makehints();			/* build hints.c */
	headers();			/* make a lot of .h files */
	cleanheaders(p);
	printf("Kernel build directory is %s\n", p);
	printf("Don't forget to do ``make cleandepend && make depend''\n");
	exit(0);
}

/*
 * get_srcdir
 *	determine the root of the kernel source tree
 *	and save that in srcdir.
 */
static void
get_srcdir(void)
{
	struct stat lg, phy;
	char *p, *pwd;
	int i;

	if (realpath("../..", srcdir) == NULL)
		err(EXIT_FAILURE, "Unable to find root of source tree");
	if ((pwd = getenv("PWD")) != NULL && *pwd == '/' &&
	    (pwd = strdup(pwd)) != NULL) {
		/* Remove the last two path components. */
		for (i = 0; i < 2; i++) {
			if ((p = strrchr(pwd, '/')) == NULL) {
				free(pwd);
				return;
			}
			*p = '\0';
		}
		if (stat(pwd, &lg) != -1 && stat(srcdir, &phy) != -1 &&
		    lg.st_dev == phy.st_dev && lg.st_ino == phy.st_ino)
			strlcpy(srcdir, pwd, MAXPATHLEN);
		free(pwd);
	}
}

static void
usage(void)
{

	fprintf(stderr,
	    "usage: config [-CgmpV] [-d destdir] [-s srcdir] sysname\n");
	fprintf(stderr, "       config -x kernel\n");
	exit(EX_USAGE);
}

static void
init_line_buf(void)
{

	line_buf.str("");
}

static std::string
get_line_buf(void)
{

	line_buf.flush();
	if (!line_buf.good()) {
		errx(EXIT_FAILURE, "failed to generate line buffer, "
		    "partial line = %s", line_buf.str().c_str());
	}

	return line_buf.str();
}

/*
 * get_word
 *	returns EOF on end of file
 *	NULL on end of line
 *	pointer to the word otherwise
 */
configword
get_word(FILE *fp)
{
	int ch;
	int escaped_nl = 0;

	init_line_buf();
begin:
	while ((ch = getc(fp)) != EOF)
		if (ch != ' ' && ch != '\t')
			break;
	if (ch == EOF)
		return (configword().eof(true));
	if (ch == '\\'){
		escaped_nl = 1;
		goto begin;
	}
	if (ch == '\n') {
		if (escaped_nl){
			escaped_nl = 0;
			goto begin;
		}
		else
			return (configword().eol(true));
	}
	line_buf << (char)ch;
	/* Negation operator is a word by itself. */
	if (ch == '!') {
		return (configword(get_line_buf()));
	}
	while ((ch = getc(fp)) != EOF) {
		if (isspace(ch))
			break;
		line_buf << (char)ch;
	}
	if (ch == EOF)
		return (configword().eof(true));
	(void) ungetc(ch, fp);
	return (configword(get_line_buf()));
}

/*
 * get_quoted_word
 *	like get_word but will accept something in double or single quotes
 *	(to allow embedded spaces).
 */
configword
get_quoted_word(FILE *fp)
{
	int ch;
	int escaped_nl = 0;

	init_line_buf();
begin:
	while ((ch = getc(fp)) != EOF)
		if (ch != ' ' && ch != '\t')
			break;
	if (ch == EOF)
		return (configword().eof(true));
	if (ch == '\\'){
		escaped_nl = 1;
		goto begin;
	}
	if (ch == '\n') {
		if (escaped_nl){
			escaped_nl = 0;
			goto begin;
		}
		else
			return (configword().eol(true));
	}
	if (ch == '"' || ch == '\'') {
		int quote = ch;

		escaped_nl = 0;
		while ((ch = getc(fp)) != EOF) {
			if (ch == quote && !escaped_nl)
				break;
			if (ch == '\n' && !escaped_nl) {
				printf("config: missing quote reading `%s'\n",
					get_line_buf().c_str());
				exit(2);
			}
			if (ch == '\\' && !escaped_nl) {
				escaped_nl = 1;
				continue;
			}
			if (ch != quote && escaped_nl)
				line_buf << "\\";
			line_buf << (char)ch;
			escaped_nl = 0;
		}
	} else {
		line_buf << (char)ch;
		while ((ch = getc(fp)) != EOF) {
			if (isspace(ch))
				break;
			line_buf << (char)ch;
		}
		if (ch != EOF)
			(void) ungetc(ch, fp);
	}
	if (ch == EOF)
		return (configword().eof(true));
	return (configword(get_line_buf()));
}

/*
 * prepend the path to a filename
 */
char *
path(const char *file)
{
	char *cp = NULL;

	if (file)
		asprintf(&cp, "%s/%s", destdir, file);
	else
		cp = strdup(destdir);
	if (cp == NULL)
		err(EXIT_FAILURE, "malloc");
	return (cp);
}

/*
 * Generate configuration file based on actual settings. With this mode, user
 * will be able to obtain and build conifguration file with one command.
 */
static void
configfile_dynamic(std::ostringstream &cfg)
{
	struct cputype *cput;
	struct device *d;
	struct opt *ol;
	char *lend;
	unsigned int i;

	asprintf(&lend, "\\n\\\n");
	assert(lend != NULL);
	cfg << "options\t" << OPT_AUTOGEN << lend;
	cfg << "ident\t" << ident << lend;
	cfg << "machine\t" << machinename << lend;
	SLIST_FOREACH(cput, &cputype, cpu_next)
		cfg << "cpu\t" << cput->cpu_name << lend;
	SLIST_FOREACH(ol, &mkopt, op_next)
		cfg << "makeoptions\t" << ol->op_name << '=' <<
		    ol->op_value << lend;
	SLIST_FOREACH(ol, &opt, op_next) {
		if (strncmp(ol->op_name, "DEV_", 4) == 0)
			continue;
		cfg << "options\t" << ol->op_name;
		if (ol->op_value != NULL) {
			cfg << '=';
			for (i = 0; i < strlen(ol->op_value); i++) {
				if (ol->op_value[i] == '"')
					cfg << '\\' << ol->op_value[i];
				else
					cfg << ol->op_value[i];
			}
		}

		cfg << lend;
	}
	/*
	 * Mark this file as containing everything we need.
	 */
	STAILQ_FOREACH(d, &dtab, d_next)
		cfg << "device\t" << d->d_name << lend;
	free(lend);
}

/*
 * Generate file from the configuration files.
 */
static void
configfile_filebased(std::ostringstream &cfg)
{
	FILE *cff;
	struct cfgfile *cf;
	int i;

	/*
	 * Try to read all configuration files. Since those will be present as
	 * C string in the macro, we have to slash their ends then the line
	 * wraps.
	 */
	STAILQ_FOREACH(cf, &cfgfiles, cfg_next) {
		cff = fopen(cf->cfg_path, "r");
		if (cff == NULL) {
			warn("Couldn't open file %s", cf->cfg_path);
			continue;
		}
		while ((i = getc(cff)) != EOF) {
			if (i == '\n')
				cfg << "\\n\\\n";
			else if (i == '"' || i == '\'')
				cfg << '\\' << i;
			else
				cfg << i;
		}
		fclose(cff);
	}
}

static void
configfile(void)
{
	FILE *fo;
	std::ostringstream cfg;
	char *p;

	/* Add main configuration file to the list of files to be included */
	cfgfile_add(PREFIX);
	p = path("config.c.new");
	fo = fopen(p, "w");
	if (!fo)
		err(2, "%s", p);
	free(p);

	if (filebased) {
		/* Is needed, can be used for backward compatibility. */
		configfile_filebased(cfg);
	} else {
		configfile_dynamic(cfg);
	}

	cfg.flush();
	/* 
	 * We print first part of the template, replace our tag with
	 * configuration files content and later continue writing our
	 * template.
	 */
	p = strstr(kernconfstr, KERNCONFTAG);
	if (p == NULL)
		errx(EXIT_FAILURE, "Something went terribly wrong!");
	*p = '\0';
	fprintf(fo, "%s", kernconfstr);
	fprintf(fo, "%s", cfg.str().c_str());
	p += strlen(KERNCONFTAG);
	fprintf(fo, "%s", p);
	fclose(fo);
	moveifchanged(path("config.c.new"), path("config.c"));
	cfgfile_removeall();
}

/*
 * moveifchanged --
 *	compare two files; rename if changed.
 */
void
moveifchanged(const char *from_name, const char *to_name)
{
	char *p, *q;
	int changed;
	size_t tsize;
	struct stat from_sb, to_sb;
	int from_fd, to_fd;

	changed = 0;

	if ((from_fd = open(from_name, O_RDONLY)) < 0)
		err(EX_OSERR, "moveifchanged open(%s)", from_name);

	if ((to_fd = open(to_name, O_RDONLY)) < 0)
		changed++;

	if (!changed && fstat(from_fd, &from_sb) < 0)
		err(EX_OSERR, "moveifchanged fstat(%s)", from_name);

	if (!changed && fstat(to_fd, &to_sb) < 0)
		err(EX_OSERR, "moveifchanged fstat(%s)", to_name);

	if (!changed && from_sb.st_size != to_sb.st_size)
		changed++;

	tsize = (size_t)from_sb.st_size;

	if (!changed) {
		p = (char *)mmap(NULL, tsize, PROT_READ, MAP_SHARED, from_fd,
		    (off_t)0);
		if (p == MAP_FAILED)
			err(EX_OSERR, "mmap %s", from_name);
		q = (char *)mmap(NULL, tsize, PROT_READ, MAP_SHARED, to_fd,
		    (off_t)0);
		if (q == MAP_FAILED)
			err(EX_OSERR, "mmap %s", to_name);

		changed = memcmp(p, q, tsize);
		munmap(p, tsize);
		munmap(q, tsize);
	}
	if (changed) {
		if (rename(from_name, to_name) < 0)
			err(EX_OSERR, "rename(%s, %s)", from_name, to_name);
	} else {
		if (unlink(from_name) < 0)
			err(EX_OSERR, "unlink(%s)", from_name);
	}
}

static void
cleanheaders(char *p)
{
	DIR *dirp;
	struct dirent *dp;
	struct file_list *fl;
	struct hdr_list *hl;
	size_t len;

	remember("y.tab.h");
	remember("setdefs.h");
	STAILQ_FOREACH(fl, &ftab, f_next)
		remember(fl->f_fn);

	/*
	 * Scan the build directory and clean out stuff that looks like
	 * it might have been a leftover NFOO header, etc.
	 */
	if ((dirp = opendir(p)) == NULL)
		err(EX_OSERR, "opendir %s", p);
	while ((dp = readdir(dirp)) != NULL) {
		len = strlen(dp->d_name);
		/* Skip non-headers */
		if (len < 2 || dp->d_name[len - 2] != '.' ||
		    dp->d_name[len - 1] != 'h')
			continue;
		/* Skip special stuff, eg: bus_if.h, but check opt_*.h */
		if (strchr(dp->d_name, '_') &&
		    strncmp(dp->d_name, "opt_", 4) != 0)
			continue;
		/* Check if it is a target file */
		for (hl = htab; hl != NULL; hl = hl->h_next) {
			if (eq(dp->d_name, hl->h_name)) {
				break;
			}
		}
		if (hl)
			continue;
		printf("Removing stale header: %s\n", dp->d_name);
		p = path(dp->d_name);
		if (unlink(p) == -1)
			warn("unlink %s", dp->d_name);
		free(p);
	}
	(void)closedir(dirp);
}

void
remember(const char *file)
{
	const char *s;
	struct hdr_list *hl;

	if ((s = strrchr(file, '/')) != NULL)
		s = ns(s + 1);
	else
		s = ns(file);

	if (strchr(s, '_') && strncmp(s, "opt_", 4) != 0) {
		free(__DECONST(char *, s));
		return;
	}
	for (hl = htab; hl != NULL; hl = hl->h_next) {
		if (eq(s, hl->h_name)) {
			free(__DECONST(char *, s));
			return;
		}
	}
	hl = (struct hdr_list *)calloc(1, sizeof(*hl));
	if (hl == NULL)
		err(EXIT_FAILURE, "calloc");
	hl->h_name = s;
	hl->h_next = htab;
	htab = hl;
}

/*
 * This one is quick hack. Will be probably moved to elf(3) interface.
 * It takes kernel configuration file name, passes it as an argument to
 * elfdump -a, which output is parsed by some UNIX tools...
 */
static void
kernconfdump(const char *file)
{
	struct stat st;
	FILE *fp, *pp;
	int error, osz, r;
	unsigned int i, off, size, t1, t2, align;
	char *cmd, *o;

	r = open(file, O_RDONLY);
	if (r == -1)
		err(EXIT_FAILURE, "Couldn't open file '%s'", file);
	error = fstat(r, &st);
	if (error == -1)
		err(EXIT_FAILURE, "fstat() failed");
	if (S_ISDIR(st.st_mode))
		errx(EXIT_FAILURE, "'%s' is a directory", file);
	fp = fdopen(r, "r");
	if (fp == NULL)
		err(EXIT_FAILURE, "fdopen() failed");
	osz = 1024;
	o = (char *)calloc(1, osz);
	if (o == NULL)
		err(EXIT_FAILURE, "Couldn't allocate memory");
	/* ELF note section header. */
	asprintf(&cmd, "/usr/bin/elfdump -c %s | grep -A 8 kern_conf"
	    "| tail -5 | cut -d ' ' -f 2 | paste - - - - -", file);
	if (cmd == NULL)
		errx(EXIT_FAILURE, "asprintf() failed");
	pp = popen(cmd, "r");
	if (pp == NULL)
		errx(EXIT_FAILURE, "popen() failed");
	free(cmd);
	(void)fread(o, osz, 1, pp);
	pclose(pp);
	r = sscanf(o, "%d%d%d%d%d", &off, &size, &t1, &t2, &align);
	free(o);
	if (r != 5)
		errx(EXIT_FAILURE, "File %s doesn't contain configuration "
		    "file. Either unsupported, or not compiled with "
		    "INCLUDE_CONFIG_FILE", file);
	r = fseek(fp, off, SEEK_CUR);
	if (r != 0)
		err(EXIT_FAILURE, "fseek() failed");
	for (i = 0; i < size; i++) {
		r = fgetc(fp);
		if (r == EOF)
			break;
		if (r == '\0') {
			assert(i == size - 1 &&
			    ("\\0 found in the middle of a file"));
			break;
		}
		fputc(r, stdout);
	}
	fclose(fp);
}

static void
badversion(void)
{
	fprintf(stderr, "ERROR: version of config(8) does not match kernel!\n");
	fprintf(stderr, "config version = %d, ", CONFIGVERS);
	fprintf(stderr, "version required = %d\n\n", versreq);
	fprintf(stderr, "Make sure that /usr/src/usr.sbin/config is in sync\n");
	fprintf(stderr, "with your /usr/src/sys and install a new config binary\n");
	fprintf(stderr, "before trying this again.\n\n");
	fprintf(stderr, "If running the new config fails check your config\n");
	fprintf(stderr, "file against the GENERIC or LINT config files for\n");
	fprintf(stderr, "changes in config syntax, or option/device naming\n");
	fprintf(stderr, "conventions\n\n");
	exit(1);
}

static void
checkversion(void)
{
	FILE *ifp;
	char line[BUFSIZ];

	ifp = open_makefile_template();
	while (fgets(line, BUFSIZ, ifp) != 0) {
		if (*line != '%')
			continue;
		if (strncmp(line, "%VERSREQ=", 9) != 0)
			continue;
		versreq = atoi(line + 9);
		if (MAJOR_VERS(versreq) == MAJOR_VERS(CONFIGVERS) &&
		    versreq <= CONFIGVERS)
			continue;
		badversion();
	}
	fclose(ifp);
}