summaryrefslogtreecommitdiff
path: root/libbb/xfuncs.c
blob: fad111aa95ae1acb499ba135ef1fb96193c5dc09 (plain)
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
/* vi: set sw=4 ts=4: */
/*
 * Utility routines.
 *
 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
 * Copyright (C) 2006 Rob Landley
 * Copyright (C) 2006 Denis Vlasenko
 *
 * Licensed under GPL version 2, see file LICENSE in this tarball for details.
 */

#include "libbb.h"

/* All the functions starting with "x" call bb_error_msg_and_die() if they
 * fail, so callers never need to check for errors.  If it returned, it
 * succeeded. */

#ifndef DMALLOC
/* dmalloc provides variants of these that do abort() on failure.
 * Since dmalloc's prototypes overwrite the impls here as they are
 * included after these prototypes in libbb.h, all is well.
 */
// Warn if we can't allocate size bytes of memory.
void *malloc_or_warn(size_t size)
{
	void *ptr = malloc(size);
	if (ptr == NULL && size != 0)
		bb_error_msg(bb_msg_memory_exhausted);
	return ptr;
}

// Die if we can't allocate size bytes of memory.
void *xmalloc(size_t size)
{
	void *ptr = malloc(size);
	if (ptr == NULL && size != 0)
		bb_error_msg_and_die(bb_msg_memory_exhausted);
	return ptr;
}

// Die if we can't resize previously allocated memory.  (This returns a pointer
// to the new memory, which may or may not be the same as the old memory.
// It'll copy the contents to a new chunk and free the old one if necessary.)
void *xrealloc(void *ptr, size_t size)
{
	ptr = realloc(ptr, size);
	if (ptr == NULL && size != 0)
		bb_error_msg_and_die(bb_msg_memory_exhausted);
	return ptr;
}
#endif /* DMALLOC */

// Die if we can't allocate and zero size bytes of memory.
void *xzalloc(size_t size)
{
	void *ptr = xmalloc(size);
	memset(ptr, 0, size);
	return ptr;
}

// Die if we can't copy a string to freshly allocated memory.
char * xstrdup(const char *s)
{
	char *t;

	if (s == NULL)
		return NULL;

	t = strdup(s);

	if (t == NULL)
		bb_error_msg_and_die(bb_msg_memory_exhausted);

	return t;
}

// Die if we can't allocate n+1 bytes (space for the null terminator) and copy
// the (possibly truncated to length n) string into it.
char * xstrndup(const char *s, int n)
{
	int m;
	char *t;

	if (ENABLE_DEBUG && s == NULL)
		bb_error_msg_and_die("xstrndup bug");

	/* We can just xmalloc(n+1) and strncpy into it, */
	/* but think about xstrndup("abc", 10000) wastage! */
	m = n;
	t = (char*) s;
	while (m) {
		if (!*t) break;
		m--;
		t++;
	}
	n -= m;
	t = xmalloc(n + 1);
	t[n] = '\0';

	return memcpy(t, s, n);
}

// Die if we can't open a file and return a FILE * to it.
// Notice we haven't got xfread(), This is for use with fscanf() and friends.
FILE *xfopen(const char *path, const char *mode)
{
	FILE *fp = fopen(path, mode);
	if (fp == NULL)
		bb_perror_msg_and_die("can't open '%s'", path);
	return fp;
}

// Die if we can't open a file and return a fd.
int xopen3(const char *pathname, int flags, int mode)
{
	int ret;

	ret = open(pathname, flags, mode);
	if (ret < 0) {
		bb_perror_msg_and_die("can't open '%s'", pathname);
	}
	return ret;
}

// Die if we can't open an existing file and return a fd.
int xopen(const char *pathname, int flags)
{
	return xopen3(pathname, flags, 0666);
}

// Warn if we can't open a file and return a fd.
int open3_or_warn(const char *pathname, int flags, int mode)
{
	int ret;

	ret = open(pathname, flags, mode);
	if (ret < 0) {
		bb_perror_msg("can't open '%s'", pathname);
	}
	return ret;
}

// Warn if we can't open a file and return a fd.
int open_or_warn(const char *pathname, int flags)
{
	return open3_or_warn(pathname, flags, 0666);
}

void xpipe(int filedes[2])
{
	if (pipe(filedes))
		bb_perror_msg_and_die("can't create pipe");
}

void xunlink(const char *pathname)
{
	if (unlink(pathname))
		bb_perror_msg_and_die("can't remove file '%s'", pathname);
}

// Turn on nonblocking I/O on a fd
int ndelay_on(int fd)
{
	return fcntl(fd, F_SETFL, fcntl(fd,F_GETFL,0) | O_NONBLOCK);
}

int ndelay_off(int fd)
{
	return fcntl(fd, F_SETFL, fcntl(fd,F_GETFL,0) & ~O_NONBLOCK);
}

// "Renumber" opened fd
void xmove_fd(int from, int to)
{
	if (from == to)
		return;
	if (dup2(from, to) != to)
		bb_perror_msg_and_die("can't duplicate file descriptor");
	close(from);
}

// Die with an error message if we can't write the entire buffer.
void xwrite(int fd, const void *buf, size_t count)
{
	if (count) {
		ssize_t size = full_write(fd, buf, count);
		if (size != count)
			bb_error_msg_and_die("short write");
	}
}

// Die with an error message if we can't lseek to the right spot.
off_t xlseek(int fd, off_t offset, int whence)
{
	off_t off = lseek(fd, offset, whence);
	if (off == (off_t)-1) {
		if (whence == SEEK_SET)
			bb_perror_msg_and_die("lseek(%"OFF_FMT"u)", offset);
		bb_perror_msg_and_die("lseek");
	}
	return off;
}

// Die with supplied filename if this FILE * has ferror set.
void die_if_ferror(FILE *fp, const char *fn)
{
	if (ferror(fp)) {
		/* ferror doesn't set useful errno */
		bb_error_msg_and_die("%s: I/O error", fn);
	}
}

// Die with an error message if stdout has ferror set.
void die_if_ferror_stdout(void)
{
	die_if_ferror(stdout, bb_msg_standard_output);
}

// Die with an error message if we have trouble flushing stdout.
void xfflush_stdout(void)
{
	if (fflush(stdout)) {
		bb_perror_msg_and_die(bb_msg_standard_output);
	}
}

void sig_block(int sig)
{
	sigset_t ss;
	sigemptyset(&ss);
	sigaddset(&ss, sig);
	sigprocmask(SIG_BLOCK, &ss, NULL);
}

void sig_unblock(int sig)
{
	sigset_t ss;
	sigemptyset(&ss);
	sigaddset(&ss, sig);
	sigprocmask(SIG_UNBLOCK, &ss, NULL);
}

#if 0
void sig_blocknone(void)
{
	sigset_t ss;
	sigemptyset(&ss);
	sigprocmask(SIG_SETMASK, &ss, NULL);
}
#endif

void sig_catch(int sig, void (*f)(int))
{
	struct sigaction sa;
	sa.sa_handler = f;
	sa.sa_flags = 0;
	sigemptyset(&sa.sa_mask);
	sigaction(sig, &sa, NULL);
}

void sig_pause(void)
{
	sigset_t ss;
	sigemptyset(&ss);
	sigsuspend(&ss);
}


void xsetenv(const char *key, const char *value)
{
	if (setenv(key, value, 1))
		bb_error_msg_and_die(bb_msg_memory_exhausted);
}

// Converts unsigned long long value into compact 4-char
// representation. Examples: "1234", "1.2k", " 27M", "123T"
// Fifth char is always '\0'
void smart_ulltoa5(unsigned long long ul, char buf[5])
{
	const char *fmt;
	char c;
	unsigned v,idx = 0;
	ul *= 10;
	if (ul > 9999*10) { // do not scale if 9999 or less
		while (ul >= 10000) {
			ul /= 1024;
			idx++;
		}
	}
	v = ul; // ullong divisions are expensive, avoid them

	fmt = " 123456789";
	if (!idx) {		// 9999 or less: use 1234 format
		c = buf[0] = " 123456789"[v/10000];
		if (c != ' ') fmt = "0123456789";
		c = buf[1] = fmt[v/1000%10];
		if (c != ' ') fmt = "0123456789";
		buf[2] = fmt[v/100%10];
		buf[3] = "0123456789"[v/10%10];
	} else {
		if (v >= 10*10) {	// scaled value is >=10: use 123M format
			c = buf[0] = " 123456789"[v/1000];
			if (c != ' ') fmt = "0123456789";
			buf[1] = fmt[v/100%10];
			buf[2] = "0123456789"[v/10%10];
		} else {	// scaled value is <10: use 1.2M format
			buf[0] = "0123456789"[v/10];
			buf[1] = '.';
			buf[2] = "0123456789"[v%10];
		}
		// see http://en.wikipedia.org/wiki/Tera
		buf[3] = " kMGTPEZY"[idx];
	}
	buf[4] = '\0';
}

// Convert unsigned integer to ascii, writing into supplied buffer.
// A truncated result contains the first few digits of the result ala strncpy.
// Returns a pointer past last generated digit, does _not_ store NUL.
void BUG_sizeof_unsigned_not_4(void);
char *utoa_to_buf(unsigned n, char *buf, unsigned buflen)
{
	unsigned i, out, res;
	if (sizeof(unsigned) != 4)
		BUG_sizeof_unsigned_not_4();
	if (buflen) {
		out = 0;
		for (i = 1000000000; i; i /= 10) {
			res = n / i;
			if (res || out || i == 1) {
				if (!--buflen) break;
				out++;
				n -= res*i;
				*buf++ = '0' + res;
			}
		}
	}
	return buf;
}

// Convert signed integer to ascii, like utoa_to_buf()
char *itoa_to_buf(int n, char *buf, unsigned buflen)
{
	if (buflen && n<0) {
		n = -n;
		*buf++ = '-';
		buflen--;
	}
	return utoa_to_buf((unsigned)n, buf, buflen);
}

// The following two functions use a static buffer, so calling either one a
// second time will overwrite previous results.
//
// The largest 32 bit integer is -2 billion plus null terminator, or 12 bytes.
// Int should always be 32 bits on any remotely Unix-like system, see
// http://www.unix.org/whitepapers/64bit.html for the reasons why.

static char local_buf[12];

// Convert unsigned integer to ascii using a static buffer (returned).
char *utoa(unsigned n)
{
	*(utoa_to_buf(n, local_buf, sizeof(local_buf))) = '\0';

	return local_buf;
}

// Convert signed integer to ascii using a static buffer (returned).
char *itoa(int n)
{
	*(itoa_to_buf(n, local_buf, sizeof(local_buf))) = '\0';

	return local_buf;
}

// Emit a string of hex representation of bytes
char *bin2hex(char *p, const char *cp, int count)
{
	while (count) {
		unsigned char c = *cp++;
		/* put lowercase hex digits */
		*p++ = 0x20 | bb_hexdigits_upcase[c >> 4];
		*p++ = 0x20 | bb_hexdigits_upcase[c & 0xf];
		count--;
	}
	return p;
}

// Die with an error message if we can't set gid.  (Because resource limits may
// limit this user to a given number of processes, and if that fills up the
// setgid() will fail and we'll _still_be_root_, which is bad.)
void xsetgid(gid_t gid)
{
	if (setgid(gid)) bb_perror_msg_and_die("setgid");
}

// Die with an error message if we can't set uid.  (See xsetgid() for why.)
void xsetuid(uid_t uid)
{
	if (setuid(uid)) bb_perror_msg_and_die("setuid");
}

// Return how long the file at fd is, if there's any way to determine it.
off_t fdlength(int fd)
{
	off_t bottom = 0, top = 0, pos;
	long size;

	// If the ioctl works for this, return it.

	if (ioctl(fd, BLKGETSIZE, &size) >= 0) return size*512;

	// FIXME: explain why lseek(SEEK_END) is not used here!

	// If not, do a binary search for the last location we can read.  (Some
	// block devices don't do BLKGETSIZE right.)

	do {
		char temp;

		pos = bottom + (top - bottom) / 2;

		// If we can read from the current location, it's bigger.

		if (lseek(fd, pos, SEEK_SET)>=0 && safe_read(fd, &temp, 1)==1) {
			if (bottom == top) bottom = top = (top+1) * 2;
			else bottom = pos;

		// If we can't, it's smaller.

		} else {
			if (bottom == top) {
				if (!top) return 0;
				bottom = top/2;
			}
			else top = pos;
		}
	} while (bottom + 1 != top);

	return pos + 1;
}

// Die with an error message if we can't malloc() enough space and do an
// sprintf() into that space.
char *xasprintf(const char *format, ...)
{
	va_list p;
	int r;
	char *string_ptr;

#if 1
	// GNU extension
	va_start(p, format);
	r = vasprintf(&string_ptr, format, p);
	va_end(p);
#else
	// Bloat for systems that haven't got the GNU extension.
	va_start(p, format);
	r = vsnprintf(NULL, 0, format, p);
	va_end(p);
	string_ptr = xmalloc(r+1);
	va_start(p, format);
	r = vsnprintf(string_ptr, r+1, format, p);
	va_end(p);
#endif

	if (r < 0) bb_error_msg_and_die(bb_msg_memory_exhausted);
	return string_ptr;
}

#if 0 /* If we will ever meet a libc which hasn't [f]dprintf... */
int fdprintf(int fd, const char *format, ...)
{
	va_list p;
	int r;
	char *string_ptr;

#if 1
	// GNU extension
	va_start(p, format);
	r = vasprintf(&string_ptr, format, p);
	va_end(p);
#else
	// Bloat for systems that haven't got the GNU extension.
	va_start(p, format);
	r = vsnprintf(NULL, 0, format, p);
	va_end(p);
	string_ptr = xmalloc(r+1);
	va_start(p, format);
	r = vsnprintf(string_ptr, r+1, format, p);
	va_end(p);
#endif

	if (r >= 0) {
		full_write(fd, string_ptr, r);
		free(string_ptr);
	}
	return r;
}
#endif

// Die with an error message if we can't copy an entire FILE * to stdout, then
// close that file.
void xprint_and_close_file(FILE *file)
{
	fflush(stdout);
	// copyfd outputs error messages for us.
	if (bb_copyfd_eof(fileno(file), 1) == -1)
		xfunc_die();

	fclose(file);
}

// Die if we can't chdir to a new path.
void xchdir(const char *path)
{
	if (chdir(path))
		bb_perror_msg_and_die("chdir(%s)", path);
}

// Print a warning message if opendir() fails, but don't die.
DIR *warn_opendir(const char *path)
{
	DIR *dp;

	dp = opendir(path);
	if (!dp)
		bb_perror_msg("can't open '%s'", path);
	return dp;
}

// Die with an error message if opendir() fails.
DIR *xopendir(const char *path)
{
	DIR *dp;

	dp = opendir(path);
	if (!dp)
		bb_perror_msg_and_die("can't open '%s'", path);
	return dp;
}

// Die with an error message if we can't open a new socket.
int xsocket(int domain, int type, int protocol)
{
	int r = socket(domain, type, protocol);

	if (r < 0) {
		/* Hijack vaguely related config option */
#if ENABLE_VERBOSE_RESOLUTION_ERRORS
		const char *s = "INET";
		if (domain == AF_PACKET) s = "PACKET";
		if (domain == AF_NETLINK) s = "NETLINK";
USE_FEATURE_IPV6(if (domain == AF_INET6) s = "INET6";)
		bb_perror_msg_and_die("socket(AF_%s)", s);
#else
		bb_perror_msg_and_die("socket");
#endif
	}

	return r;
}

// Die with an error message if we can't bind a socket to an address.
void xbind(int sockfd, struct sockaddr *my_addr, socklen_t addrlen)
{
	if (bind(sockfd, my_addr, addrlen)) bb_perror_msg_and_die("bind");
}

// Die with an error message if we can't listen for connections on a socket.
void xlisten(int s, int backlog)
{
	if (listen(s, backlog)) bb_perror_msg_and_die("listen");
}

/* Die with an error message if sendto failed.
 * Return bytes sent otherwise  */
ssize_t xsendto(int s, const  void *buf, size_t len, const struct sockaddr *to,
				socklen_t tolen)
{
	ssize_t ret = sendto(s, buf, len, 0, to, tolen);
	if (ret < 0) {
		if (ENABLE_FEATURE_CLEAN_UP)
			close(s);
		bb_perror_msg_and_die("sendto");
	}
	return ret;
}

// xstat() - a stat() which dies on failure with meaningful error message
void xstat(const char *name, struct stat *stat_buf)
{
	if (stat(name, stat_buf))
		bb_perror_msg_and_die("can't stat '%s'", name);
}

// selinux_or_die() - die if SELinux is disabled.
void selinux_or_die(void)
{
#if ENABLE_SELINUX
	int rc = is_selinux_enabled();
	if (rc == 0) {
		bb_error_msg_and_die("SELinux is disabled");
	} else if (rc < 0) {
		bb_error_msg_and_die("is_selinux_enabled() failed");
	}
#else
	bb_error_msg_and_die("SELinux support is disabled");
#endif
}

/* It is perfectly ok to pass in a NULL for either width or for
 * height, in which case that value will not be set.  */
int get_terminal_width_height(const int fd, int *width, int *height)
{
	struct winsize win = { 0, 0, 0, 0 };
	int ret = ioctl(fd, TIOCGWINSZ, &win);

	if (height) {
		if (!win.ws_row) {
			char *s = getenv("LINES");
			if (s) win.ws_row = atoi(s);
		}
		if (win.ws_row <= 1 || win.ws_row >= 30000)
			win.ws_row = 24;
		*height = (int) win.ws_row;
	}

	if (width) {
		if (!win.ws_col) {
			char *s = getenv("COLUMNS");
			if (s) win.ws_col = atoi(s);
		}
		if (win.ws_col <= 1 || win.ws_col >= 30000)
			win.ws_col = 80;
		*width = (int) win.ws_col;
	}

	return ret;
}

void ioctl_or_perror_and_die(int fd, int request, void *argp, const char *fmt,...)
{
	va_list p;

	if (ioctl(fd, request, argp) < 0) {
		va_start(p, fmt);
		bb_vperror_msg(fmt, p);
		/* xfunc_die can actually longjmp, so be nice */
		va_end(p);
		xfunc_die();
	}
}

int ioctl_or_perror(int fd, int request, void *argp, const char *fmt,...)
{
	va_list p;
	int ret = ioctl(fd, request, argp);

	if (ret < 0) {
		va_start(p, fmt);
		bb_vperror_msg(fmt, p);
		va_end(p);
	}
	return ret;
}

#if ENABLE_IOCTL_HEX2STR_ERROR
int bb_ioctl_or_warn(int fd, int request, void *argp, const char *ioctl_name)
{
	int ret;
	
	ret = ioctl(fd, request, argp);
	if (ret < 0)
		bb_perror_msg("%s", ioctl_name);
	return ret;
}
void bb_xioctl(int fd, int request, void *argp, const char *ioctl_name)
{
	if (ioctl(fd, request, argp) < 0)
		bb_perror_msg_and_die("%s", ioctl_name);
}
#else
int bb_ioctl_or_warn(int fd, int request, void *argp)
{
	int ret;
	
	ret = ioctl(fd, request, argp);
	if (ret < 0)
		bb_perror_msg("ioctl %#x failed", request);
	return ret;
}
void bb_xioctl(int fd, int request, void *argp)
{
	if (ioctl(fd, request, argp) < 0)
		bb_perror_msg_and_die("ioctl %#x failed", request);
}
#endif