summaryrefslogtreecommitdiffstats
path: root/freebsd/contrib/wpa/src/utils/os_unix.c
blob: b5879dc864c61510a681c79c5e22ae3abfa0e49d (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
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
#include <machine/rtems-bsd-user-space.h>

/*
 * OS specific functions for UNIX/POSIX systems
 * Copyright (c) 2005-2009, Jouni Malinen <j@w1.fi>
 *
 * This software may be distributed under the terms of the BSD license.
 * See README for more details.
 */

#include "includes.h"

#include <time.h>
#include <sys/wait.h>

#ifdef ANDROID
#include <sys/capability.h>
#include <sys/prctl.h>
#include <private/android_filesystem_config.h>
#endif /* ANDROID */

#ifdef __MACH__
#include <CoreServices/CoreServices.h>
#include <mach/mach.h>
#include <mach/mach_time.h>
#endif /* __MACH__ */

#ifdef __rtems__
#include <stdlib.h>
#endif /* __rtems__ */


#include "os.h"
#include "common.h"

#ifdef WPA_TRACE

#include "wpa_debug.h"
#include "trace.h"
#include "list.h"

static struct dl_list alloc_list = DL_LIST_HEAD_INIT(alloc_list);

#define ALLOC_MAGIC 0xa84ef1b2
#define FREED_MAGIC 0x67fd487a

struct os_alloc_trace {
	unsigned int magic;
	struct dl_list list;
	size_t len;
	WPA_TRACE_INFO
} __attribute__((aligned(16)));

#endif /* WPA_TRACE */


void os_sleep(os_time_t sec, os_time_t usec)
{
	if (sec)
		sleep(sec);
	if (usec)
		usleep(usec);
}


int os_get_time(struct os_time *t)
{
	int res;
	struct timeval tv;
	res = gettimeofday(&tv, NULL);
	t->sec = tv.tv_sec;
	t->usec = tv.tv_usec;
	return res;
}


int os_get_reltime(struct os_reltime *t)
{
#ifndef __MACH__
#if defined(CLOCK_BOOTTIME)
	static clockid_t clock_id = CLOCK_BOOTTIME;
#elif defined(CLOCK_MONOTONIC)
	static clockid_t clock_id = CLOCK_MONOTONIC;
#else
	static clockid_t clock_id = CLOCK_REALTIME;
#endif
	struct timespec ts;
	int res;

	while (1) {
		res = clock_gettime(clock_id, &ts);
		if (res == 0) {
			t->sec = ts.tv_sec;
			t->usec = ts.tv_nsec / 1000;
			return 0;
		}
		switch (clock_id) {
#ifdef CLOCK_BOOTTIME
		case CLOCK_BOOTTIME:
			clock_id = CLOCK_MONOTONIC;
			break;
#endif
#ifdef CLOCK_MONOTONIC
		case CLOCK_MONOTONIC:
			clock_id = CLOCK_REALTIME;
			break;
#endif
		case CLOCK_REALTIME:
			return -1;
		}
	}
#else /* __MACH__ */
	uint64_t abstime, nano;
	static mach_timebase_info_data_t info = { 0, 0 };

	if (!info.denom) {
		if (mach_timebase_info(&info) != KERN_SUCCESS)
			return -1;
	}

	abstime = mach_absolute_time();
	nano = (abstime * info.numer) / info.denom;

	t->sec = nano / NSEC_PER_SEC;
	t->usec = (nano - (((uint64_t) t->sec) * NSEC_PER_SEC)) / NSEC_PER_USEC;

	return 0;
#endif /* __MACH__ */
}


int os_mktime(int year, int month, int day, int hour, int min, int sec,
	      os_time_t *t)
{
	struct tm tm, *tm1;
	time_t t_local, t1, t2;
	os_time_t tz_offset;

	if (year < 1970 || month < 1 || month > 12 || day < 1 || day > 31 ||
	    hour < 0 || hour > 23 || min < 0 || min > 59 || sec < 0 ||
	    sec > 60)
		return -1;

	memset(&tm, 0, sizeof(tm));
	tm.tm_year = year - 1900;
	tm.tm_mon = month - 1;
	tm.tm_mday = day;
	tm.tm_hour = hour;
	tm.tm_min = min;
	tm.tm_sec = sec;

	t_local = mktime(&tm);

	/* figure out offset to UTC */
	tm1 = localtime(&t_local);
	if (tm1) {
		t1 = mktime(tm1);
		tm1 = gmtime(&t_local);
		if (tm1) {
			t2 = mktime(tm1);
			tz_offset = t2 - t1;
		} else
			tz_offset = 0;
	} else
		tz_offset = 0;

	*t = (os_time_t) t_local - tz_offset;
	return 0;
}


int os_gmtime(os_time_t t, struct os_tm *tm)
{
	struct tm *tm2;
	time_t t2 = t;

	tm2 = gmtime(&t2);
	if (tm2 == NULL)
		return -1;
	tm->sec = tm2->tm_sec;
	tm->min = tm2->tm_min;
	tm->hour = tm2->tm_hour;
	tm->day = tm2->tm_mday;
	tm->month = tm2->tm_mon + 1;
	tm->year = tm2->tm_year + 1900;
	return 0;
}


#ifdef __APPLE__
#include <fcntl.h>
static int os_daemon(int nochdir, int noclose)
{
	int devnull;

	if (chdir("/") < 0)
		return -1;

	devnull = open("/dev/null", O_RDWR);
	if (devnull < 0)
		return -1;

	if (dup2(devnull, STDIN_FILENO) < 0) {
		close(devnull);
		return -1;
	}

	if (dup2(devnull, STDOUT_FILENO) < 0) {
		close(devnull);
		return -1;
	}

	if (dup2(devnull, STDERR_FILENO) < 0) {
		close(devnull);
		return -1;
	}

	return 0;
}
#else /* __APPLE__ */
#define os_daemon daemon
#endif /* __APPLE__ */


#ifdef __FreeBSD__
#include <err.h>
#include <libutil.h>
#include <stdint.h>
#endif /* __FreeBSD__ */

int os_daemonize(const char *pid_file)
{
#if defined(__uClinux__) || defined(__sun__) || defined(__rtems__)
	return -1;
#else /* defined(__uClinux__) || defined(__sun__) */
#ifdef __FreeBSD__
	pid_t otherpid;
	struct pidfh *pfh;

	pfh = pidfile_open(pid_file, 0600, &otherpid);
	if (pfh == NULL) {
		if (errno == EEXIST) {
			errx(1, "Daemon already running, pid: %jd.",
			    (intmax_t)otherpid);
		}
		warn("Cannot open or create pidfile.");
	}
#endif /* __FreeBSD__ */

	if (os_daemon(0, 0)) {
		perror("daemon");
#ifdef __FreeBSD__
		pidfile_remove(pfh);
#endif /* __FreeBSD__ */
		return -1;
	}

#ifndef __FreeBSD__
	if (pid_file) {
		FILE *f = fopen(pid_file, "w");
		if (f) {
			fprintf(f, "%u\n", getpid());
			fclose(f);
		}
	}
#else /* __FreeBSD__ */
	pidfile_write(pfh);
#endif /* __FreeBSD__ */

	return -0;
#endif /* defined(__uClinux__) || defined(__sun__) */
}


void os_daemonize_terminate(const char *pid_file)
{
	if (pid_file)
		unlink(pid_file);
}


int os_get_random(unsigned char *buf, size_t len)
{
	FILE *f;
	size_t rc;

	if (TEST_FAIL())
		return -1;

#ifdef __rtems__
	arc4random_buf(buf, len);
	return 0;
#else /* __rtems__ */
	f = fopen("/dev/urandom", "rb");
	if (f == NULL) {
		printf("Could not open /dev/urandom.\n");
		return -1;
	}

	rc = fread(buf, 1, len, f);
	fclose(f);

	return rc != len ? -1 : 0;
#endif /* __rtems__ */
}


unsigned long os_random(void)
{
	return random();
}


char * os_rel2abs_path(const char *rel_path)
{
	char *buf = NULL, *cwd, *ret;
	size_t len = 128, cwd_len, rel_len, ret_len;
	int last_errno;

	if (!rel_path)
		return NULL;

	if (rel_path[0] == '/')
		return os_strdup(rel_path);

	for (;;) {
		buf = os_malloc(len);
		if (buf == NULL)
			return NULL;
		cwd = getcwd(buf, len);
		if (cwd == NULL) {
			last_errno = errno;
			os_free(buf);
			if (last_errno != ERANGE)
				return NULL;
			len *= 2;
			if (len > 2000)
				return NULL;
		} else {
			buf[len - 1] = '\0';
			break;
		}
	}

	cwd_len = os_strlen(cwd);
	rel_len = os_strlen(rel_path);
	ret_len = cwd_len + 1 + rel_len + 1;
	ret = os_malloc(ret_len);
	if (ret) {
		os_memcpy(ret, cwd, cwd_len);
		ret[cwd_len] = '/';
		os_memcpy(ret + cwd_len + 1, rel_path, rel_len);
		ret[ret_len - 1] = '\0';
	}
	os_free(buf);
	return ret;
}


int os_program_init(void)
{
#ifdef ANDROID
	/*
	 * We ignore errors here since errors are normal if we
	 * are already running as non-root.
	 */
#ifdef ANDROID_SETGROUPS_OVERRIDE
	gid_t groups[] = { ANDROID_SETGROUPS_OVERRIDE };
#else /* ANDROID_SETGROUPS_OVERRIDE */
	gid_t groups[] = { AID_INET, AID_WIFI, AID_KEYSTORE };
#endif /* ANDROID_SETGROUPS_OVERRIDE */
	struct __user_cap_header_struct header;
	struct __user_cap_data_struct cap;

	setgroups(ARRAY_SIZE(groups), groups);

	prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0);

	setgid(AID_WIFI);
	setuid(AID_WIFI);

	header.version = _LINUX_CAPABILITY_VERSION;
	header.pid = 0;
	cap.effective = cap.permitted =
		(1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW);
	cap.inheritable = 0;
	capset(&header, &cap);
#endif /* ANDROID */

	return 0;
}


void os_program_deinit(void)
{
#ifdef WPA_TRACE
	struct os_alloc_trace *a;
	unsigned long total = 0;
	dl_list_for_each(a, &alloc_list, struct os_alloc_trace, list) {
		total += a->len;
		if (a->magic != ALLOC_MAGIC) {
			wpa_printf(MSG_INFO, "MEMLEAK[%p]: invalid magic 0x%x "
				   "len %lu",
				   a, a->magic, (unsigned long) a->len);
			continue;
		}
		wpa_printf(MSG_INFO, "MEMLEAK[%p]: len %lu",
			   a, (unsigned long) a->len);
		wpa_trace_dump("memleak", a);
	}
	if (total)
		wpa_printf(MSG_INFO, "MEMLEAK: total %lu bytes",
			   (unsigned long) total);
	wpa_trace_deinit();
#endif /* WPA_TRACE */
}


int os_setenv(const char *name, const char *value, int overwrite)
{
	return setenv(name, value, overwrite);
}


int os_unsetenv(const char *name)
{
#if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__APPLE__) || \
    defined(__OpenBSD__)
	unsetenv(name);
	return 0;
#else
	return unsetenv(name);
#endif
}


char * os_readfile(const char *name, size_t *len)
{
	FILE *f;
	char *buf;
	long pos;

	f = fopen(name, "rb");
	if (f == NULL)
		return NULL;

	if (fseek(f, 0, SEEK_END) < 0 || (pos = ftell(f)) < 0) {
		fclose(f);
		return NULL;
	}
	*len = pos;
	if (fseek(f, 0, SEEK_SET) < 0) {
		fclose(f);
		return NULL;
	}

	buf = os_malloc(*len);
	if (buf == NULL) {
		fclose(f);
		return NULL;
	}

	if (fread(buf, 1, *len, f) != *len) {
		fclose(f);
		os_free(buf);
		return NULL;
	}

	fclose(f);

	return buf;
}


int os_file_exists(const char *fname)
{
	return access(fname, F_OK) == 0;
}


int os_fdatasync(FILE *stream)
{
	if (!fflush(stream)) {
#ifdef __linux__
		return fdatasync(fileno(stream));
#else /* !__linux__ */
#ifdef F_FULLFSYNC
		/* OS X does not implement fdatasync(). */
		return fcntl(fileno(stream), F_FULLFSYNC);
#else /* F_FULLFSYNC */
		return fsync(fileno(stream));
#endif /* F_FULLFSYNC */
#endif /* __linux__ */
	}

	return -1;
}


#ifndef WPA_TRACE
void * os_zalloc(size_t size)
{
	return calloc(1, size);
}
#endif /* WPA_TRACE */


size_t os_strlcpy(char *dest, const char *src, size_t siz)
{
	const char *s = src;
	size_t left = siz;

	if (left) {
		/* Copy string up to the maximum size of the dest buffer */
		while (--left != 0) {
			if ((*dest++ = *s++) == '\0')
				break;
		}
	}

	if (left == 0) {
		/* Not enough room for the string; force NUL-termination */
		if (siz != 0)
			*dest = '\0';
		while (*s++)
			; /* determine total src string length */
	}

	return s - src - 1;
}


int os_memcmp_const(const void *a, const void *b, size_t len)
{
	const u8 *aa = a;
	const u8 *bb = b;
	size_t i;
	u8 res;

	for (res = 0, i = 0; i < len; i++)
		res |= aa[i] ^ bb[i];

	return res;
}


#ifdef WPA_TRACE

#if defined(WPA_TRACE_BFD) && defined(CONFIG_TESTING_OPTIONS)
char wpa_trace_fail_func[256] = { 0 };
unsigned int wpa_trace_fail_after;

static int testing_fail_alloc(void)
{
	const char *func[WPA_TRACE_LEN];
	size_t i, res, len;
	char *pos, *next;
	int match;

	if (!wpa_trace_fail_after)
		return 0;

	res = wpa_trace_calling_func(func, WPA_TRACE_LEN);
	i = 0;
	if (i < res && os_strcmp(func[i], __func__) == 0)
		i++;
	if (i < res && os_strcmp(func[i], "os_malloc") == 0)
		i++;
	if (i < res && os_strcmp(func[i], "os_zalloc") == 0)
		i++;
	if (i < res && os_strcmp(func[i], "os_calloc") == 0)
		i++;
	if (i < res && os_strcmp(func[i], "os_realloc") == 0)
		i++;
	if (i < res && os_strcmp(func[i], "os_realloc_array") == 0)
		i++;
	if (i < res && os_strcmp(func[i], "os_strdup") == 0)
		i++;

	pos = wpa_trace_fail_func;

	match = 0;
	while (i < res) {
		int allow_skip = 1;
		int maybe = 0;

		if (*pos == '=') {
			allow_skip = 0;
			pos++;
		} else if (*pos == '?') {
			maybe = 1;
			pos++;
		}
		next = os_strchr(pos, ';');
		if (next)
			len = next - pos;
		else
			len = os_strlen(pos);
		if (os_memcmp(pos, func[i], len) != 0) {
			if (maybe && next) {
				pos = next + 1;
				continue;
			}
			if (allow_skip) {
				i++;
				continue;
			}
			return 0;
		}
		if (!next) {
			match = 1;
			break;
		}
		pos = next + 1;
		i++;
	}
	if (!match)
		return 0;

	wpa_trace_fail_after--;
	if (wpa_trace_fail_after == 0) {
		wpa_printf(MSG_INFO, "TESTING: fail allocation at %s",
			   wpa_trace_fail_func);
		for (i = 0; i < res; i++)
			wpa_printf(MSG_INFO, "backtrace[%d] = %s",
				   (int) i, func[i]);
		return 1;
	}

	return 0;
}


char wpa_trace_test_fail_func[256] = { 0 };
unsigned int wpa_trace_test_fail_after;

int testing_test_fail(void)
{
	const char *func[WPA_TRACE_LEN];
	size_t i, res, len;
	char *pos, *next;
	int match;

	if (!wpa_trace_test_fail_after)
		return 0;

	res = wpa_trace_calling_func(func, WPA_TRACE_LEN);
	i = 0;
	if (i < res && os_strcmp(func[i], __func__) == 0)
		i++;

	pos = wpa_trace_test_fail_func;

	match = 0;
	while (i < res) {
		int allow_skip = 1;
		int maybe = 0;

		if (*pos == '=') {
			allow_skip = 0;
			pos++;
		} else if (*pos == '?') {
			maybe = 1;
			pos++;
		}
		next = os_strchr(pos, ';');
		if (next)
			len = next - pos;
		else
			len = os_strlen(pos);
		if (os_memcmp(pos, func[i], len) != 0) {
			if (maybe && next) {
				pos = next + 1;
				continue;
			}
			if (allow_skip) {
				i++;
				continue;
			}
			return 0;
		}
		if (!next) {
			match = 1;
			break;
		}
		pos = next + 1;
		i++;
	}
	if (!match)
		return 0;

	wpa_trace_test_fail_after--;
	if (wpa_trace_test_fail_after == 0) {
		wpa_printf(MSG_INFO, "TESTING: fail at %s",
			   wpa_trace_test_fail_func);
		for (i = 0; i < res; i++)
			wpa_printf(MSG_INFO, "backtrace[%d] = %s",
				   (int) i, func[i]);
		return 1;
	}

	return 0;
}

#else

static inline int testing_fail_alloc(void)
{
	return 0;
}
#endif

void * os_malloc(size_t size)
{
	struct os_alloc_trace *a;

	if (testing_fail_alloc())
		return NULL;

	a = malloc(sizeof(*a) + size);
	if (a == NULL)
		return NULL;
	a->magic = ALLOC_MAGIC;
	dl_list_add(&alloc_list, &a->list);
	a->len = size;
	wpa_trace_record(a);
	return a + 1;
}


void * os_realloc(void *ptr, size_t size)
{
	struct os_alloc_trace *a;
	size_t copy_len;
	void *n;

	if (ptr == NULL)
		return os_malloc(size);

	a = (struct os_alloc_trace *) ptr - 1;
	if (a->magic != ALLOC_MAGIC) {
		wpa_printf(MSG_INFO, "REALLOC[%p]: invalid magic 0x%x%s",
			   a, a->magic,
			   a->magic == FREED_MAGIC ? " (already freed)" : "");
		wpa_trace_show("Invalid os_realloc() call");
		abort();
	}
	n = os_malloc(size);
	if (n == NULL)
		return NULL;
	copy_len = a->len;
	if (copy_len > size)
		copy_len = size;
	os_memcpy(n, a + 1, copy_len);
	os_free(ptr);
	return n;
}


void os_free(void *ptr)
{
	struct os_alloc_trace *a;

	if (ptr == NULL)
		return;
	a = (struct os_alloc_trace *) ptr - 1;
	if (a->magic != ALLOC_MAGIC) {
		wpa_printf(MSG_INFO, "FREE[%p]: invalid magic 0x%x%s",
			   a, a->magic,
			   a->magic == FREED_MAGIC ? " (already freed)" : "");
		wpa_trace_show("Invalid os_free() call");
		abort();
	}
	dl_list_del(&a->list);
	a->magic = FREED_MAGIC;

	wpa_trace_check_ref(ptr);
	free(a);
}


void * os_zalloc(size_t size)
{
	void *ptr = os_malloc(size);
	if (ptr)
		os_memset(ptr, 0, size);
	return ptr;
}


char * os_strdup(const char *s)
{
	size_t len;
	char *d;
	len = os_strlen(s);
	d = os_malloc(len + 1);
	if (d == NULL)
		return NULL;
	os_memcpy(d, s, len);
	d[len] = '\0';
	return d;
}

#endif /* WPA_TRACE */


int os_exec(const char *program, const char *arg, int wait_completion)
{
	pid_t pid;
	int pid_status;

	pid = fork();
	if (pid < 0) {
		perror("fork");
		return -1;
	}

	if (pid == 0) {
		/* run the external command in the child process */
		const int MAX_ARG = 30;
		char *_program, *_arg, *pos;
		char *argv[MAX_ARG + 1];
		int i;

		_program = os_strdup(program);
		_arg = os_strdup(arg);

		argv[0] = _program;

		i = 1;
		pos = _arg;
		while (i < MAX_ARG && pos && *pos) {
			while (*pos == ' ')
				pos++;
			if (*pos == '\0')
				break;
			argv[i++] = pos;
			pos = os_strchr(pos, ' ');
			if (pos)
				*pos++ = '\0';
		}
		argv[i] = NULL;

		execv(program, argv);
		perror("execv");
		os_free(_program);
		os_free(_arg);
		exit(0);
		return -1;
	}

	if (wait_completion) {
		/* wait for the child process to complete in the parent */
		waitpid(pid, &pid_status, 0);
	}

	return 0;
}