about summary refs log tree commit diff
path: root/db2/common/db_appinit.c
blob: 05fc7cc0848983e9a1f77f27beb823f914307906 (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
/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1996, 1997
 *	Sleepycat Software.  All rights reserved.
 */

#include "config.h"

#ifndef lint
static const char sccsid[] = "@(#)db_appinit.c	10.37 (Sleepycat) 11/25/97";
#endif /* not lint */

#ifndef NO_SYSTEM_INCLUDES
#include <sys/param.h>
#include <sys/stat.h>

#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#endif

#include "db_int.h"
#include "shqueue.h"
#include "db_page.h"
#include "btree.h"
#include "hash.h"
#include "log.h"
#include "txn.h"
#include "clib_ext.h"
#include "common_ext.h"

static int __db_home __P((DB_ENV *, const char *, int));
static int __db_parse __P((DB_ENV *, char *));
static int __db_tmp_dir __P((DB_ENV *, int));
static int __db_tmp_open __P((DB_ENV *, char *, int *));

/*
 * db_version --
 *	Return verision information.
 */
char *
db_version(majverp, minverp, patchp)
	int *majverp, *minverp, *patchp;
{
	if (majverp != NULL)
		*majverp = DB_VERSION_MAJOR;
	if (minverp != NULL)
		*minverp = DB_VERSION_MINOR;
	if (patchp != NULL)
		*patchp = DB_VERSION_PATCH;
	return ((char *)DB_VERSION_STRING);
}

/*
 * db_appinit --
 *	Initialize the application environment.
 */
int
db_appinit(db_home, db_config, dbenv, flags)
	const char *db_home;
	char * const *db_config;
	DB_ENV *dbenv;
	int flags;
{
	FILE *fp;
	int ret;
	char *lp, **p, buf[MAXPATHLEN * 2];

	/* Validate arguments. */
	if (dbenv == NULL)
		return (EINVAL);
#ifdef HAVE_SPINLOCKS
#define	OKFLAGS								\
   (DB_CREATE | DB_NOMMAP | DB_THREAD | DB_INIT_LOCK | DB_INIT_LOG |	\
    DB_INIT_MPOOL | DB_INIT_TXN | DB_MPOOL_PRIVATE | DB_RECOVER |	\
    DB_RECOVER_FATAL | DB_TXN_NOSYNC | DB_USE_ENVIRON | DB_USE_ENVIRON_ROOT)
#else
#define	OKFLAGS								\
   (DB_CREATE | DB_NOMMAP | DB_INIT_LOCK | DB_INIT_LOG |		\
    DB_INIT_MPOOL | DB_INIT_TXN | DB_MPOOL_PRIVATE | DB_RECOVER |	\
    DB_RECOVER_FATAL | DB_TXN_NOSYNC | DB_USE_ENVIRON | DB_USE_ENVIRON_ROOT)
#endif
	if ((ret = __db_fchk(dbenv, "db_appinit", flags, OKFLAGS)) != 0)
		return (ret);

#define	RECOVERY_FLAGS (DB_CREATE | DB_INIT_TXN | DB_INIT_LOG)
	if (LF_ISSET(DB_RECOVER | DB_RECOVER_FATAL) &&
	    LF_ISSET(RECOVERY_FLAGS) != RECOVERY_FLAGS)
		return (__db_ferr(dbenv, "db_appinit", 1));

	/* Convert the db_appinit(3) flags. */
	if (LF_ISSET(DB_THREAD))
		F_SET(dbenv, DB_ENV_THREAD);

	fp = NULL;

	/* Set the database home. */
	if ((ret = __db_home(dbenv, db_home, flags)) != 0)
		goto err;

	/* Parse the config array. */
	for (p = (char **)db_config; p != NULL && *p != NULL; ++p)
		if ((ret = __db_parse(dbenv, *p)) != 0)
			goto err;

	/*
	 * Parse the config file.
	 *
	 * XXX
	 * Don't use sprintf(3)/snprintf(3) -- the former is dangerous, and
	 * the latter isn't standard, and we're manipulating strings handed
	 * us by the application.
	 */
	if (dbenv->db_home != NULL) {
#define	CONFIG_NAME	"/DB_CONFIG"
		if (strlen(dbenv->db_home) +
		    strlen(CONFIG_NAME) + 1 > sizeof(buf)) {
			ret = ENAMETOOLONG;
			goto err;
		}
		(void)strcpy(buf, dbenv->db_home);
		(void)strcat(buf, CONFIG_NAME);
		if ((fp = fopen(buf, "r")) != NULL) {
			while (fgets(buf, sizeof(buf), fp) != NULL) {
				if ((lp = strchr(buf, '\n')) != NULL)
					*lp = '\0';
				if ((ret = __db_parse(dbenv, buf)) != 0)
					goto err;
			}
			(void)fclose(fp);
			fp = NULL;
		}
	}

	/* Set up the tmp directory path. */
	if (dbenv->db_tmp_dir == NULL &&
	    (ret = __db_tmp_dir(dbenv, flags)) != 0)
		goto err;

	/* Indicate that the path names have been set. */
	F_SET(dbenv, DB_ENV_APPINIT);

	/*
	 * If we are doing recovery, remove all the regions.
	 */
	if (LF_ISSET(DB_RECOVER | DB_RECOVER_FATAL)) {
		/* Remove all the old shared memory regions.  */
		if ((ret = log_unlink(NULL, 1 /* force */, dbenv)) != 0)
			goto err;
		if ((ret = memp_unlink(NULL, 1 /* force */, dbenv)) != 0)
			goto err;
		if ((ret = lock_unlink(NULL, 1 /* force */, dbenv)) != 0)
			goto err;
		if ((ret = txn_unlink(NULL, 1 /* force */, dbenv)) != 0)
			goto err;
	}

	/* Transactions imply logging. */
	if (LF_ISSET(DB_INIT_TXN))
		LF_SET(DB_INIT_LOG);

	/* Default permissions are 0660. */
#undef	DB_DEFPERM
#define	DB_DEFPERM	(S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP)

	/* Initialize the subsystems. */
	if (LF_ISSET(DB_INIT_LOCK) && (ret = lock_open(NULL,
	    LF_ISSET(DB_CREATE | DB_THREAD),
	    DB_DEFPERM, dbenv, &dbenv->lk_info)) != 0)
		goto err;
	if (LF_ISSET(DB_INIT_LOG) && (ret = log_open(NULL,
	    LF_ISSET(DB_CREATE | DB_THREAD),
	    DB_DEFPERM, dbenv, &dbenv->lg_info)) != 0)
		goto err;
	if (LF_ISSET(DB_INIT_MPOOL) && (ret = memp_open(NULL,
	    LF_ISSET(DB_CREATE | DB_MPOOL_PRIVATE | DB_NOMMAP | DB_THREAD),
	    DB_DEFPERM, dbenv, &dbenv->mp_info)) != 0)
		goto err;
	if (LF_ISSET(DB_INIT_TXN) && (ret = txn_open(NULL,
	    LF_ISSET(DB_CREATE | DB_THREAD | DB_TXN_NOSYNC),
	    DB_DEFPERM, dbenv, &dbenv->tx_info)) != 0)
		goto err;

	/* Initialize recovery. */
	if (LF_ISSET(DB_INIT_TXN)) {
		if ((ret = __bam_init_recover(dbenv)) != 0)
			goto err;
		if ((ret = __db_init_recover(dbenv)) != 0)
			goto err;
		if ((ret = __ham_init_recover(dbenv)) != 0)
			goto err;
		if ((ret = __log_init_recover(dbenv)) != 0)
			goto err;
		if ((ret = __txn_init_recover(dbenv)) != 0)
			goto err;
	}

	/* Run recovery if necessary. */
	if (LF_ISSET(DB_RECOVER | DB_RECOVER_FATAL) && (ret =
	    __db_apprec(dbenv, LF_ISSET(DB_RECOVER | DB_RECOVER_FATAL))) != 0)
		goto err;

	return (ret);

err:	if (fp != NULL)
		(void)fclose(fp);

	(void)db_appexit(dbenv);
	return (ret);
}

/*
 * db_appexit --
 *	Close down the default application environment.
 */
int
db_appexit(dbenv)
	DB_ENV *dbenv;
{
	int ret, t_ret;
	char **p;

	ret = 0;

	/* Close subsystems. */
	if (dbenv->tx_info && (t_ret = txn_close(dbenv->tx_info)) != 0)
		if (ret == 0)
			ret = t_ret;
	if (dbenv->mp_info && (t_ret = memp_close(dbenv->mp_info)) != 0)
		if (ret == 0)
			ret = t_ret;
	if (dbenv->lg_info && (t_ret = log_close(dbenv->lg_info)) != 0)
		if (ret == 0)
			ret = t_ret;
	if (dbenv->lk_info && (t_ret = lock_close(dbenv->lk_info)) != 0)
		if (ret == 0)
			ret = t_ret;

	/* Free allocated memory. */
	if (dbenv->db_home != NULL)
		FREES(dbenv->db_home);
	if ((p = dbenv->db_data_dir) != NULL) {
		for (; *p != NULL; ++p)
			FREES(*p);
		FREE(dbenv->db_data_dir, dbenv->data_cnt * sizeof(char **));
	}
	if (dbenv->db_log_dir != NULL)
		FREES(dbenv->db_log_dir);
	if (dbenv->db_tmp_dir != NULL)
		FREES(dbenv->db_tmp_dir);

	return (ret);
}

#define	DB_ADDSTR(str) {						\
	if ((str) != NULL) {						\
		/* If leading slash, start over. */			\
		if (__db_abspath(str)) {				\
			p = start;					\
			slash = 0;					\
		}							\
		/* Append to the current string. */			\
		len = strlen(str);					\
		if (slash)						\
			*p++ = PATH_SEPARATOR[0];			\
		memcpy(p, str, len);					\
		p += len;						\
		slash = strchr(PATH_SEPARATOR, p[-1]) == NULL;		\
	}								\
}

/*
 * __db_appname --
 *	Given an optional DB environment, directory and file name and type
 *	of call, build a path based on the db_appinit(3) rules, and return
 *	it in allocated space.
 *
 * PUBLIC: int __db_appname __P((DB_ENV *,
 * PUBLIC:    APPNAME, const char *, const char *, int *, char **));
 */
int
__db_appname(dbenv, appname, dir, file, fdp, namep)
	DB_ENV *dbenv;
	APPNAME appname;
	const char *dir, *file;
	int *fdp;
	char **namep;
{
	DB_ENV etmp;
	size_t len;
	int ret, slash, tmp_create, tmp_free;
	const char *a, *b, *c;
	int data_entry;
	char *p, *start;

	a = b = c = NULL;
	data_entry = -1;
	tmp_create = tmp_free = 0;

	/*
	 * We don't return a name when creating temporary files, just an fd.
	 * Default to error now.
	 */
	if (fdp != NULL)
		*fdp = -1;
	if (namep != NULL)
		*namep = NULL;

	/*
	 * Absolute path names are never modified.  If the file is an absolute
	 * path, we're done.  If the directory is, simply append the file and
	 * return.
	 */
	if (file != NULL && __db_abspath(file))
		return ((*namep =
		    (char *)__db_strdup(file)) == NULL ? ENOMEM : 0);
	if (dir != NULL && __db_abspath(dir)) {
		a = dir;
		goto done;
	}

	/*
	 * DB_ENV  DIR	   APPNAME	   RESULT
	 * -------------------------------------------
	 * null	   null	   none		   <tmp>/file
	 * null	   set	   none		   DIR/file
	 * set	   null	   none		   DB_HOME/file
	 * set	   set	   none		   DB_HOME/DIR/file
	 *
	 * DB_ENV  FILE	   APPNAME	   RESULT
	 * -------------------------------------------
	 * null	   null	   DB_APP_DATA	   <tmp>/<create>
	 * null	   set	   DB_APP_DATA	   ./file
	 * set	   null	   DB_APP_DATA	   <tmp>/<create>
	 * set	   set	   DB_APP_DATA	   DB_HOME/DB_DATA_DIR/file
	 *
	 * DB_ENV  DIR	   APPNAME	   RESULT
	 * -------------------------------------------
	 * null	   null	   DB_APP_LOG	   <tmp>/file
	 * null	   set	   DB_APP_LOG	   DIR/file
	 * set	   null	   DB_APP_LOG	   DB_HOME/DB_LOG_DIR/file
	 * set	   set	   DB_APP_LOG	   DB_HOME/DB_LOG_DIR/DIR/file
	 *
	 * DB_ENV	   APPNAME	   RESULT
	 * -------------------------------------------
	 * null		   DB_APP_TMP	   <tmp>/<create>
	 * set		   DB_APP_TMP	   DB_HOME/DB_TMP_DIR/<create>
	 */
retry:	switch (appname) {
	case DB_APP_NONE:
		if (dbenv == NULL || !F_ISSET(dbenv, DB_ENV_APPINIT)) {
			if (dir == NULL)
				goto tmp;
			a = dir;
		} else {
			a = dbenv->db_home;
			b = dir;
		}
		break;
	case DB_APP_DATA:
		if (dir != NULL) {
			__db_err(dbenv,
			    "DB_APP_DATA: illegal directory specification");
			return (EINVAL);
		}

		if (file == NULL) {
			tmp_create = 1;
			goto tmp;
		}
		if (dbenv == NULL || !F_ISSET(dbenv, DB_ENV_APPINIT))
			a = PATH_DOT;
		else {
			a = dbenv->db_home;
			if (dbenv->db_data_dir != NULL &&
			    (b = dbenv->db_data_dir[++data_entry]) == NULL) {
				data_entry = -1;
				b = dbenv->db_data_dir[0];
			}
		}
		break;
	case DB_APP_LOG:
		if (dbenv == NULL || !F_ISSET(dbenv, DB_ENV_APPINIT)) {
			if (dir == NULL)
				goto tmp;
			a = dir;
		} else {
			a = dbenv->db_home;
			b = dbenv->db_log_dir;
			c = dir;
		}
		break;
	case DB_APP_TMP:
		if (dir != NULL || file != NULL) {
			__db_err(dbenv,
		    "DB_APP_TMP: illegal directory or file specification");
			return (EINVAL);
		}

		tmp_create = 1;
		if (dbenv == NULL || !F_ISSET(dbenv, DB_ENV_APPINIT))
			goto tmp;
		else {
			a = dbenv->db_home;
			b = dbenv->db_tmp_dir;
		}
		break;
	}

	/* Reference a file from the appropriate temporary directory. */
	if (0) {
tmp:		if (dbenv == NULL || !F_ISSET(dbenv, DB_ENV_APPINIT)) {
			memset(&etmp, 0, sizeof(etmp));
			if ((ret = __db_tmp_dir(&etmp, DB_USE_ENVIRON)) != 0)
				return (ret);
			tmp_free = 1;
			a = etmp.db_tmp_dir;
		} else
			a = dbenv->db_tmp_dir;
	}

done:	len =
	    (a == NULL ? 0 : strlen(a) + 1) +
	    (b == NULL ? 0 : strlen(b) + 1) +
	    (c == NULL ? 0 : strlen(c) + 1) +
	    (file == NULL ? 0 : strlen(file) + 1);

	if ((start = (char *)__db_malloc(len)) == NULL) {
		__db_err(dbenv, "%s", strerror(ENOMEM));
		if (tmp_free)
			FREES(etmp.db_tmp_dir);
		return (ENOMEM);
	}

	slash = 0;
	p = start;
	DB_ADDSTR(a);
	DB_ADDSTR(b);
	DB_ADDSTR(file);
	*p = '\0';

	/*
	 * If we're opening a data file, see if it exists.  If it does,
	 * return it, otherwise, try and find another one to open.
	 */
	if (data_entry != -1 && __db_exists(start, NULL) != 0) {
		FREES(start);
		a = b = c = NULL;
		goto retry;
	}

	/* Discard any space allocated to find the temp directory. */
	if (tmp_free)
		FREES(etmp.db_tmp_dir);

	/* Create the file if so requested. */
	if (tmp_create) {
		ret = __db_tmp_open(dbenv, start, fdp);
		FREES(start);
	} else {
		*namep = start;
		ret = 0;
	}
	return (ret);
}

/*
 * __db_home --
 *	Find the database home.
 */
static int
__db_home(dbenv, db_home, flags)
	DB_ENV *dbenv;
	const char *db_home;
	int flags;
{
	const char *p;

	p = db_home;

	/* Use the environment if it's permitted and initialized. */
#ifdef HAVE_GETUID
	if (LF_ISSET(DB_USE_ENVIRON) ||
	    (LF_ISSET(DB_USE_ENVIRON_ROOT) && getuid() == 0)) {
#else
	if (LF_ISSET(DB_USE_ENVIRON)) {
#endif
		if ((p = getenv("DB_HOME")) == NULL)
			p = db_home;
		else if (p[0] == '\0') {
			__db_err(dbenv,
			    "illegal DB_HOME environment variable");
			return (EINVAL);
		}
	}

	if (p == NULL)
		return (0);

	if ((dbenv->db_home = (char *)__db_strdup(p)) == NULL) {
		__db_err(dbenv, "%s", strerror(ENOMEM));
		return (ENOMEM);
	}
	return (0);
}

/*
 * __db_parse --
 *	Parse a single NAME VALUE pair.
 */
static int
__db_parse(dbenv, s)
	DB_ENV *dbenv;
	char *s;
{
	int ret;
	char *local_s, *name, *value, **p, *tp;

	ret = 0;

	/*
	 * We need to strdup the argument in case the caller passed us
	 * static data.
	 */
	if ((local_s = (char *)__db_strdup(s)) == NULL)
		return (ENOMEM);

	tp = local_s;
	while ((name = strsep(&tp, " \t")) != NULL && *name == '\0');
	if (name == NULL)
		goto illegal;
	while ((value = strsep(&tp, " \t")) != NULL && *value == '\0');
	if (value == NULL) {
illegal:	ret = EINVAL;
		__db_err(dbenv, "illegal name-value pair: %s", s);
		goto err;
	}

#define	DATA_INIT_CNT	20			/* Start with 20 data slots. */
	if (!strcmp(name, "DB_DATA_DIR")) {
		if (dbenv->db_data_dir == NULL) {
			if ((dbenv->db_data_dir =
			    (char **)__db_calloc(DATA_INIT_CNT,
			    sizeof(char **))) == NULL)
				goto nomem;
			dbenv->data_cnt = DATA_INIT_CNT;
		} else if (dbenv->data_next == dbenv->data_cnt - 1) {
			dbenv->data_cnt *= 2;
			if ((dbenv->db_data_dir =
			    (char **)__db_realloc(dbenv->db_data_dir,
			    dbenv->data_cnt * sizeof(char **))) == NULL)
				goto nomem;
		}
		p = &dbenv->db_data_dir[dbenv->data_next++];
	} else if (!strcmp(name, "DB_LOG_DIR")) {
		if (dbenv->db_log_dir != NULL)
			FREES(dbenv->db_log_dir);
		p = &dbenv->db_log_dir;
	} else if (!strcmp(name, "DB_TMP_DIR")) {
		if (dbenv->db_tmp_dir != NULL)
			FREES(dbenv->db_tmp_dir);
		p = &dbenv->db_tmp_dir;
	} else
		goto err;

	if ((*p = (char *)__db_strdup(value)) == NULL) {
nomem:		ret = ENOMEM;
		__db_err(dbenv, "%s", strerror(ENOMEM));
	}

err:	FREES(local_s);
	return (ret);
}

#ifdef macintosh
#include <TFileSpec.h>

static char *sTempFolder;
#endif

/*
 * tmp --
 *	Set the temporary directory path.
 */
static int
__db_tmp_dir(dbenv, flags)
	DB_ENV *dbenv;
	int flags;
{
	static const char * list[] = {	/* Ordered: see db_appinit(3). */
		"/var/tmp",
		"/usr/tmp",
		"/temp",		/* WIN32. */
		"/tmp",
		"C:/temp",		/* WIN32. */
		"C:/tmp",		/* WIN32. */
		NULL
	};
	const char **lp, *p;

	/* Use the environment if it's permitted and initialized. */
	p = NULL;
#ifdef HAVE_GETEUID
	if (LF_ISSET(DB_USE_ENVIRON) ||
	    (LF_ISSET(DB_USE_ENVIRON_ROOT) && getuid() == 0)) {
#else
	if (LF_ISSET(DB_USE_ENVIRON)) {
#endif
		if ((p = getenv("TMPDIR")) != NULL && p[0] == '\0') {
			__db_err(dbenv, "illegal TMPDIR environment variable");
			return (EINVAL);
		}
		/* WIN32 */
		if (p == NULL && (p = getenv("TEMP")) != NULL && p[0] == '\0') {
			__db_err(dbenv, "illegal TEMP environment variable");
			return (EINVAL);
		}
		/* WIN32 */
		if (p == NULL && (p = getenv("TMP")) != NULL && p[0] == '\0') {
			__db_err(dbenv, "illegal TMP environment variable");
			return (EINVAL);
		}
		/* Macintosh */
		if (p == NULL &&
		    (p = getenv("TempFolder")) != NULL && p[0] == '\0') {
			__db_err(dbenv,
			    "illegal TempFolder environment variable");
			return (EINVAL);
		}
	}

#ifdef macintosh
	/* Get the path to the temporary folder. */
	if (p == NULL) {
		FSSpec spec;

		if (!Special2FSSpec(kTemporaryFolderType,
		    kOnSystemDisk, 0, &spec)) {
			p = FSp2FullPath(&spec);
			sTempFolder = __db_malloc(strlen(p) + 1);
			strcpy(sTempFolder, p);
			p = sTempFolder;
		}
	}
#endif

	/* Step through the list looking for a possibility. */
	if (p == NULL)
		for (lp = list; *lp != NULL; ++lp)
			if (__db_exists(p = *lp, NULL) == 0)
				break;

	if (p == NULL)
		return (0);

	if ((dbenv->db_tmp_dir = (char *)__db_strdup(p)) == NULL) {
		__db_err(dbenv, "%s", strerror(ENOMEM));
		return (ENOMEM);
	}
	return (0);
}

/*
 * __db_tmp_open --
 *	Create a temporary file.
 */
static int
__db_tmp_open(dbenv, dir, fdp)
	DB_ENV *dbenv;
	char *dir;
	int *fdp;
{
#ifdef HAVE_SIGFILLSET
	sigset_t set, oset;
#endif
	u_long pid;
	size_t len;
	int isdir, ret;
	char *trv, buf[MAXPATHLEN];

	/*
	 * Check the target directory; if you have six X's and it doesn't
	 * exist, this runs for a *very* long time.
	 */
	if ((ret = __db_exists(dir, &isdir)) != 0) {
		__db_err(dbenv, "%s: %s", dir, strerror(ret));
		return (ret);
	}
	if (!isdir) {
		__db_err(dbenv, "%s: %s", dir, strerror(EINVAL));
		return (EINVAL);
	}

	/* Build the path. */
#define	DB_TRAIL	"/XXXXXX"
	if ((len = strlen(dir)) + sizeof(DB_TRAIL) > sizeof(buf)) {
		__db_err(dbenv,
		    "tmp_open: %s: %s", buf, strerror(ENAMETOOLONG));
		return (ENAMETOOLONG);
	}
	(void)strcpy(buf, dir);
	(void)strcpy(buf + len, DB_TRAIL);
	buf[len] = PATH_SEPARATOR[0];			/* WIN32 */

	/*
	 * Replace the X's with the process ID.  Pid should be a pid_t,
	 * but we use unsigned long for portability.
	 */
	for (pid = getpid(),
	    trv = buf + len + sizeof(DB_TRAIL) - 1; *--trv == 'X'; pid /= 10)
		switch (pid % 10) {
		case 0: *trv = '0'; break;
		case 1: *trv = '1'; break;
		case 2: *trv = '2'; break;
		case 3: *trv = '3'; break;
		case 4: *trv = '4'; break;
		case 5: *trv = '5'; break;
		case 6: *trv = '6'; break;
		case 7: *trv = '7'; break;
		case 8: *trv = '8'; break;
		case 9: *trv = '9'; break;
		}
	++trv;

	/*
	 * Try and open a file.  We block every signal we can get our hands
	 * on so that, if we're interrupted at the wrong time, the temporary
	 * file isn't left around -- of course, if we drop core in-between
	 * the calls we'll hang forever, but that's probably okay.  ;-}
	 */
#ifdef HAVE_SIGFILLSET
	(void)sigfillset(&set);
#endif
	for (;;) {
#ifdef HAVE_SIGFILLSET
		(void)sigprocmask(SIG_BLOCK, &set, &oset);
#endif
#define	DB_TEMPOPEN	DB_CREATE | DB_EXCL | DB_TEMPORARY
		if ((ret = __db_open(buf,
		    DB_TEMPOPEN, DB_TEMPOPEN, S_IRUSR | S_IWUSR, fdp)) == 0) {
#ifdef HAVE_SIGFILLSET
			(void)sigprocmask(SIG_SETMASK, &oset, NULL);
#endif
			return (0);
		}
#ifdef HAVE_SIGFILLSET
		(void)sigprocmask(SIG_SETMASK, &oset, NULL);
#endif
		/*
		 * XXX:
		 * If we don't get an EEXIST error, then there's something
		 * seriously wrong.  Unfortunately, if the implementation
		 * doesn't return EEXIST for O_CREAT and O_EXCL regardless
		 * of other possible errors, we've lost.
		 */
		if (ret != EEXIST) {
			__db_err(dbenv,
			    "tmp_open: %s: %s", buf, strerror(ret));
			return (ret);
		}

		/*
		 * Tricky little algorithm for backward compatibility.
		 * Assumes the ASCII ordering of lower-case characters.
		 */
		for (;;) {
			if (*trv == '\0')
				return (EINVAL);
			if (*trv == 'z')
				*trv++ = 'a';
			else {
				if (isdigit(*trv))
					*trv = 'a';
				else
					++*trv;
				break;
			}
		}
	}
	/* NOTREACHED */
}