busybox/libbb/xfuncs.c

/* 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 Denys Vlasenko
 *
 * Licensed under GPL version 2, see file LICENSE in this tarball for details.
 */

/* We need to have separate xfuncs.c and xfuncs_printf.c because
 * with current linkers, even with section garbage collection,
 * if *.o module references any of XXXprintf functions, you pull in
 * entire printf machinery. Even if you do not use the function
 * which uses XXXprintf.
 *
 * xfuncs.c contains functions (not necessarily xfuncs)
 * which do not pull in printf, directly or indirectly.
 * xfunc_printf.c contains those which do.
 *
 * TODO: move xmalloc() and xatonum() here.
 */

#include "libbb.h"

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

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

int FAST_FUNC close_on_exec_on(int fd)
{
	return fcntl(fd, F_SETFD, FD_CLOEXEC);
}

char* FAST_FUNC strncpy_IFNAMSIZ(char *dst, const char *src)
{
#ifndef IFNAMSIZ
	enum { IFNAMSIZ = 16 };
#endif
	return strncpy(dst, src, IFNAMSIZ);
}


// 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* FAST_FUNC 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* FAST_FUNC 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.
// It so happens that sizeof(int) * 3 is enough for 32+ bits.
// (sizeof(int) * 3 + 2 is correct for any width, even 8-bit)

static char local_buf[sizeof(int) * 3];

// Convert unsigned integer to ascii using a static buffer (returned).
char* FAST_FUNC 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* FAST_FUNC 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* FAST_FUNC 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;
}

/* Return how long the file at fd is, if there's any way to determine it. */
#ifdef UNUSED
off_t FAST_FUNC 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;
}
#endif

char* FAST_FUNC xmalloc_ttyname(int fd)
{
	char *buf = xzalloc(128);
	int r = ttyname_r(fd, buf, 127);
	if (r) {
		free(buf);
		buf = NULL;
	}
	return buf;
}

/* 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 FAST_FUNC get_terminal_width_height(int fd, unsigned *width, unsigned *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;
}

int FAST_FUNC tcsetattr_stdin_TCSANOW(const struct termios *tp)
{
	return tcsetattr(STDIN_FILENO, TCSANOW, tp);
}

void FAST_FUNC generate_uuid(uint8_t *buf)
{
	/* http://www.ietf.org/rfc/rfc4122.txt
	 *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
	 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	 * |                          time_low                             |
	 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	 * |       time_mid                |         time_hi_and_version   |
	 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	 * |clk_seq_and_variant            |         node (0-1)            |
	 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	 * |                         node (2-5)                            |
	 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	 * IOW, uuid has this layout:
	 * uint32_t time_low (big endian)
	 * uint16_t time_mid (big endian)
	 * uint16_t time_hi_and_version (big endian)
	 *  version is a 4-bit field:
	 *   1 Time-based
	 *   2 DCE Security, with embedded POSIX UIDs
	 *   3 Name-based (MD5)
	 *   4 Randomly generated
	 *   5 Name-based (SHA-1)
	 * uint16_t clk_seq_and_variant (big endian)
	 *  variant is a 3-bit field:
	 *   0xx Reserved, NCS backward compatibility
	 *   10x The variant specified in rfc4122
	 *   110 Reserved, Microsoft backward compatibility
	 *   111 Reserved for future definition
	 * uint8_t node[6]
	 *
	 * For version 4, these bits are set/cleared:
	 * time_hi_and_version & 0x0fff | 0x4000
	 * clk_seq_and_variant & 0x3fff | 0x8000
	 */
	pid_t pid;
	int i;

	i = open("/dev/urandom", O_RDONLY);
	if (i >= 0) {
		read(i, buf, 16);
		close(i);
	}
	/* Paranoia. /dev/urandom may be missing.
	 * rand() is guaranteed to generate at least [0, 2^15) range,
	 * but lowest bits in some libc are not so "random".  */
	srand(monotonic_us());
	pid = getpid();
	while (1) {
		for (i = 0; i < 16; i++)
			buf[i] ^= rand() >> 5;
		if (pid == 0)
			break;
		srand(pid);
		pid = 0;
	}

	/* version = 4 */
	buf[4 + 2    ] = (buf[4 + 2    ] & 0x0f) | 0x40;
	/* variant = 10x */
	buf[4 + 2 + 2] = (buf[4 + 2 + 2] & 0x3f) | 0x80;
}
1	/* vi: set sw=4 ts=4: */
2	/*
3	* Utility routines.
4	*
5	* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
6	* Copyright (C) 2006 Rob Landley
7	* Copyright (C) 2006 Denys Vlasenko
8	*
9	* Licensed under GPL version 2, see file LICENSE in this tarball for details.
10	*/
11
12	/* We need to have separate xfuncs.c and xfuncs_printf.c because
13	* with current linkers, even with section garbage collection,
14	* if *.o module references any of XXXprintf functions, you pull in
15	* entire printf machinery. Even if you do not use the function
16	* which uses XXXprintf.
17	*
18	* xfuncs.c contains functions (not necessarily xfuncs)
19	* which do not pull in printf, directly or indirectly.
20	* xfunc_printf.c contains those which do.
21	*
22	* TODO: move xmalloc() and xatonum() here.
23	*/
24
25	#include "libbb.h"
26
27	/* Turn on nonblocking I/O on a fd */
28	int FAST_FUNC ndelay_on(int fd)
29	{
30	return fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) \| O_NONBLOCK);
31	}
32
33	int FAST_FUNC ndelay_off(int fd)
34	{
35	return fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) & ~O_NONBLOCK);
36	}
37
38	int FAST_FUNC close_on_exec_on(int fd)
39	{
40	return fcntl(fd, F_SETFD, FD_CLOEXEC);
41	}
42
43	char* FAST_FUNC strncpy_IFNAMSIZ(char dst, const char src)
44	{
45	#ifndef IFNAMSIZ
46	enum { IFNAMSIZ = 16 };
47	#endif
48	return strncpy(dst, src, IFNAMSIZ);
49	}
50
51
52	// Convert unsigned integer to ascii, writing into supplied buffer.
53	// A truncated result contains the first few digits of the result ala strncpy.
54	// Returns a pointer past last generated digit, does _not_ store NUL.
55	void BUG_sizeof_unsigned_not_4(void);
56	char* FAST_FUNC utoa_to_buf(unsigned n, char *buf, unsigned buflen)
57	{
58	unsigned i, out, res;
59	if (sizeof(unsigned) != 4)
60	BUG_sizeof_unsigned_not_4();
61	if (buflen) {
62	out = 0;
63	for (i = 1000000000; i; i /= 10) {
64	res = n / i;
65	if (res \|\| out \|\| i == 1) {
66	if (!--buflen) break;
67	out++;
68	n -= res*i;
69	*buf++ = '0' + res;
70	}
71	}
72	}
73	return buf;
74	}
75
76	/* Convert signed integer to ascii, like utoa_to_buf() */
77	char* FAST_FUNC itoa_to_buf(int n, char *buf, unsigned buflen)
78	{
79	if (buflen && n < 0) {
80	n = -n;
81	*buf++ = '-';
82	buflen--;
83	}
84	return utoa_to_buf((unsigned)n, buf, buflen);
85	}
86
87	// The following two functions use a static buffer, so calling either one a
88	// second time will overwrite previous results.
89	//
90	// The largest 32 bit integer is -2 billion plus null terminator, or 12 bytes.
91	// It so happens that sizeof(int) * 3 is enough for 32+ bits.
92	// (sizeof(int) * 3 + 2 is correct for any width, even 8-bit)
93
94	static char local_buf[sizeof(int) * 3];
95
96	// Convert unsigned integer to ascii using a static buffer (returned).
97	char* FAST_FUNC utoa(unsigned n)
98	{
99	*(utoa_to_buf(n, local_buf, sizeof(local_buf))) = '\0';
100
101	return local_buf;
102	}
103
104	/* Convert signed integer to ascii using a static buffer (returned). */
105	char* FAST_FUNC itoa(int n)
106	{
107	*(itoa_to_buf(n, local_buf, sizeof(local_buf))) = '\0';
108
109	return local_buf;
110	}
111
112	/* Emit a string of hex representation of bytes */
113	char* FAST_FUNC bin2hex(char p, const char cp, int count)
114	{
115	while (count) {
116	unsigned char c = *cp++;
117	/* put lowercase hex digits */
118	*p++ = 0x20 \| bb_hexdigits_upcase[c >> 4];
119	*p++ = 0x20 \| bb_hexdigits_upcase[c & 0xf];
120	count--;
121	}
122	return p;
123	}
124
125	/* Return how long the file at fd is, if there's any way to determine it. */
126	#ifdef UNUSED
127	off_t FAST_FUNC fdlength(int fd)
128	{
129	off_t bottom = 0, top = 0, pos;
130	long size;
131
132	// If the ioctl works for this, return it.
133
134	if (ioctl(fd, BLKGETSIZE, &size) >= 0) return size*512;
135
136	// FIXME: explain why lseek(SEEK_END) is not used here!
137
138	// If not, do a binary search for the last location we can read. (Some
139	// block devices don't do BLKGETSIZE right.)
140
141	do {
142	char temp;
143
144	pos = bottom + (top - bottom) / 2;
145
146	// If we can read from the current location, it's bigger.
147
148	if (lseek(fd, pos, SEEK_SET)>=0 && safe_read(fd, &temp, 1)==1) {
149	if (bottom == top) bottom = top = (top+1) * 2;
150	else bottom = pos;
151
152	// If we can't, it's smaller.
153
154	} else {
155	if (bottom == top) {
156	if (!top) return 0;
157	bottom = top/2;
158	}
159	else top = pos;
160	}
161	} while (bottom + 1 != top);
162
163	return pos + 1;
164	}
165	#endif
166
167	char* FAST_FUNC xmalloc_ttyname(int fd)
168	{
169	char *buf = xzalloc(128);
170	int r = ttyname_r(fd, buf, 127);
171	if (r) {
172	free(buf);
173	buf = NULL;
174	}
175	return buf;
176	}
177
178	/* It is perfectly ok to pass in a NULL for either width or for
179	* height, in which case that value will not be set. */
180	int FAST_FUNC get_terminal_width_height(int fd, unsigned width, unsigned height)
181	{
182	struct winsize win = { 0, 0, 0, 0 };
183	int ret = ioctl(fd, TIOCGWINSZ, &win);
184
185	if (height) {
186	if (!win.ws_row) {
187	char *s = getenv("LINES");
188	if (s) win.ws_row = atoi(s);
189	}
190	if (win.ws_row <= 1 \|\| win.ws_row >= 30000)
191	win.ws_row = 24;
192	*height = (int) win.ws_row;
193	}
194
195	if (width) {
196	if (!win.ws_col) {
197	char *s = getenv("COLUMNS");
198	if (s) win.ws_col = atoi(s);
199	}
200	if (win.ws_col <= 1 \|\| win.ws_col >= 30000)
201	win.ws_col = 80;
202	*width = (int) win.ws_col;
203	}
204
205	return ret;
206	}
207
208	int FAST_FUNC tcsetattr_stdin_TCSANOW(const struct termios *tp)
209	{
210	return tcsetattr(STDIN_FILENO, TCSANOW, tp);
211	}
212
213	void FAST_FUNC generate_uuid(uint8_t *buf)
214	{
215	/* http://www.ietf.org/rfc/rfc4122.txt
216	* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
217	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
218	* \| time_low \|
219	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
220	* \| time_mid \| time_hi_and_version \|
221	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
222	* \|clk_seq_and_variant \| node (0-1) \|
223	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
224	* \| node (2-5) \|
225	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
226	* IOW, uuid has this layout:
227	* uint32_t time_low (big endian)
228	* uint16_t time_mid (big endian)
229	* uint16_t time_hi_and_version (big endian)
230	* version is a 4-bit field:
231	* 1 Time-based
232	* 2 DCE Security, with embedded POSIX UIDs
233	* 3 Name-based (MD5)
234	* 4 Randomly generated
235	* 5 Name-based (SHA-1)
236	* uint16_t clk_seq_and_variant (big endian)
237	* variant is a 3-bit field:
238	* 0xx Reserved, NCS backward compatibility
239	* 10x The variant specified in rfc4122
240	* 110 Reserved, Microsoft backward compatibility
241	* 111 Reserved for future definition
242	* uint8_t node[6]
243	*
244	* For version 4, these bits are set/cleared:
245	* time_hi_and_version & 0x0fff \| 0x4000
246	* clk_seq_and_variant & 0x3fff \| 0x8000
247	*/
248	pid_t pid;
249	int i;
250
251	i = open("/dev/urandom", O_RDONLY);
252	if (i >= 0) {
253	read(i, buf, 16);
254	close(i);
255	}
256	/* Paranoia. /dev/urandom may be missing.
257	* rand() is guaranteed to generate at least [0, 2^15) range,
258	* but lowest bits in some libc are not so "random". */
259	srand(monotonic_us());
260	pid = getpid();
261	while (1) {
262	for (i = 0; i < 16; i++)
263	buf[i] ^= rand() >> 5;
264	if (pid == 0)
265	break;
266	srand(pid);
267	pid = 0;
268	}
269
270	/* version = 4 */
271	buf[4 + 2 ] = (buf[4 + 2 ] & 0x0f) \| 0x40;
272	/* variant = 10x */
273	buf[4 + 2 + 2] = (buf[4 + 2 + 2] & 0x3f) \| 0x80;
274	}