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 */
28int FAST_FUNC ndelay_on(int fd)
29{
30	return fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_NONBLOCK);
31}
32
33int FAST_FUNC ndelay_off(int fd)
34{
35	return fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) & ~O_NONBLOCK);
36}
37
38int FAST_FUNC close_on_exec_on(int fd)
39{
40	return fcntl(fd, F_SETFD, FD_CLOEXEC);
41}
42
43char* 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 */
56void BUG_sizeof(void);
57char* FAST_FUNC utoa_to_buf(unsigned n, char *buf, unsigned buflen)
58{
59	unsigned i, out, res;
60
61	if (buflen) {
62		out = 0;
63		if (sizeof(n) == 4)
64		// 2^32-1 = 4294967295
65			i = 1000000000;
66#if UINT_MAX > 4294967295 /* prevents warning about "const too large" */
67		else
68		if (sizeof(n) == 8)
69		// 2^64-1 = 18446744073709551615
70			i = 10000000000000000000;
71#endif
72		else
73			BUG_sizeof();
74		for (; i; i /= 10) {
75			res = n / i;
76			n = n % i;
77			if (res || out || i == 1) {
78				if (--buflen == 0)
79					break;
80				out++;
81				*buf++ = '0' + res;
82			}
83		}
84	}
85	return buf;
86}
87
88/* Convert signed integer to ascii, like utoa_to_buf() */
89char* FAST_FUNC itoa_to_buf(int n, char *buf, unsigned buflen)
90{
91	if (!buflen)
92		return buf;
93	if (n < 0) {
94		n = -n;
95		*buf++ = '-';
96		buflen--;
97	}
98	return utoa_to_buf((unsigned)n, buf, buflen);
99}
100
101// The following two functions use a static buffer, so calling either one a
102// second time will overwrite previous results.
103//
104// The largest 32 bit integer is -2 billion plus NUL, or 1+10+1=12 bytes.
105// It so happens that sizeof(int) * 3 is enough for 32+ bit ints.
106// (sizeof(int) * 3 + 2 is correct for any width, even 8-bit)
107
108static char local_buf[sizeof(int) * 3];
109
110/* Convert unsigned integer to ascii using a static buffer (returned). */
111char* FAST_FUNC utoa(unsigned n)
112{
113	*(utoa_to_buf(n, local_buf, sizeof(local_buf) - 1)) = '\0';
114
115	return local_buf;
116}
117
118/* Convert signed integer to ascii using a static buffer (returned). */
119char* FAST_FUNC itoa(int n)
120{
121	*(itoa_to_buf(n, local_buf, sizeof(local_buf) - 1)) = '\0';
122
123	return local_buf;
124}
125
126/* Emit a string of hex representation of bytes */
127char* FAST_FUNC bin2hex(char *p, const char *cp, int count)
128{
129	while (count) {
130		unsigned char c = *cp++;
131		/* put lowercase hex digits */
132		*p++ = 0x20 | bb_hexdigits_upcase[c >> 4];
133		*p++ = 0x20 | bb_hexdigits_upcase[c & 0xf];
134		count--;
135	}
136	return p;
137}
138
139/* Convert "[x]x[:][x]x[:][x]x[:][x]x" hex string to binary, no more than COUNT bytes */
140char* FAST_FUNC hex2bin(char *dst, const char *str, int count)
141{
142	errno = EINVAL;
143	while (*str && count) {
144		uint8_t val;
145		uint8_t c = *str++;
146		if (isdigit(c))
147			val = c - '0';
148		else if ((c|0x20) >= 'a' && (c|0x20) <= 'f')
149			val = (c|0x20) - ('a' - 10);
150		else
151			return NULL;
152		val <<= 4;
153		c = *str;
154		if (isdigit(c))
155			val |= c - '0';
156		else if ((c|0x20) >= 'a' && (c|0x20) <= 'f')
157			val |= (c|0x20) - ('a' - 10);
158		else if (c == ':' || c == '\0')
159			val >>= 4;
160		else
161			return NULL;
162
163		*dst++ = val;
164		if (c != '\0')
165			str++;
166		if (*str == ':')
167			str++;
168		count--;
169	}
170	errno = (*str ? ERANGE : 0);
171	return dst;
172}
173
174/* Return how long the file at fd is, if there's any way to determine it. */
175#ifdef UNUSED
176off_t FAST_FUNC fdlength(int fd)
177{
178	off_t bottom = 0, top = 0, pos;
179	long size;
180
181	// If the ioctl works for this, return it.
182
183	if (ioctl(fd, BLKGETSIZE, &size) >= 0) return size*512;
184
185	// FIXME: explain why lseek(SEEK_END) is not used here!
186
187	// If not, do a binary search for the last location we can read.  (Some
188	// block devices don't do BLKGETSIZE right.)
189
190	do {
191		char temp;
192
193		pos = bottom + (top - bottom) / 2;
194
195		// If we can read from the current location, it's bigger.
196
197		if (lseek(fd, pos, SEEK_SET)>=0 && safe_read(fd, &temp, 1)==1) {
198			if (bottom == top) bottom = top = (top+1) * 2;
199			else bottom = pos;
200
201		// If we can't, it's smaller.
202
203		} else {
204			if (bottom == top) {
205				if (!top) return 0;
206				bottom = top/2;
207			}
208			else top = pos;
209		}
210	} while (bottom + 1 != top);
211
212	return pos + 1;
213}
214#endif
215
216int FAST_FUNC bb_putchar_stderr(char ch)
217{
218	return write(STDERR_FILENO, &ch, 1);
219}
220
221ssize_t FAST_FUNC full_write1_str(const char *str)
222{
223	return full_write(STDOUT_FILENO, str, strlen(str));
224}
225
226ssize_t FAST_FUNC full_write2_str(const char *str)
227{
228	return full_write(STDERR_FILENO, str, strlen(str));
229}
230
231static int wh_helper(int value, int def_val, const char *env_name, int *err)
232{
233	if (value == 0) {
234		char *s = getenv(env_name);
235		if (s) {
236			value = atoi(s);
237			/* If LINES/COLUMNS are set, pretent that there is
238			 * no error getting w/h, this prevents some ugly
239			 * cursor tricks by our callers */
240			*err = 0;
241		}
242	}
243	if (value <= 1 || value >= 30000)
244		value = def_val;
245	return value;
246}
247
248/* It is perfectly ok to pass in a NULL for either width or for
249 * height, in which case that value will not be set.  */
250int FAST_FUNC get_terminal_width_height(int fd, unsigned *width, unsigned *height)
251{
252	struct winsize win;
253	int err;
254
255	win.ws_row = 0;
256	win.ws_col = 0;
257	/* I've seen ioctl returning 0, but row/col is (still?) 0.
258	 * We treat that as an error too.  */
259	err = ioctl(fd, TIOCGWINSZ, &win) != 0 || win.ws_row == 0;
260	if (height)
261		*height = wh_helper(win.ws_row, 24, "LINES", &err);
262	if (width)
263		*width = wh_helper(win.ws_col, 80, "COLUMNS", &err);
264	return err;
265}
266
267int FAST_FUNC tcsetattr_stdin_TCSANOW(const struct termios *tp)
268{
269	return tcsetattr(STDIN_FILENO, TCSANOW, tp);
270}
271
272pid_t FAST_FUNC safe_waitpid(pid_t pid, int *wstat, int options)
273{
274	pid_t r;
275
276	do
277		r = waitpid(pid, wstat, options);
278	while ((r == -1) && (errno == EINTR));
279	return r;
280}
281
282pid_t FAST_FUNC wait_any_nohang(int *wstat)
283{
284	return safe_waitpid(-1, wstat, WNOHANG);
285}
286
287// Wait for the specified child PID to exit, returning child's error return.
288int FAST_FUNC wait4pid(pid_t pid)
289{
290	int status;
291
292	if (pid <= 0) {
293		/*errno = ECHILD; -- wrong. */
294		/* we expect errno to be already set from failed [v]fork/exec */
295		return -1;
296	}
297	if (safe_waitpid(pid, &status, 0) == -1)
298		return -1;
299	if (WIFEXITED(status))
300		return WEXITSTATUS(status);
301	if (WIFSIGNALED(status))
302		return WTERMSIG(status) + 0x180;
303	return 0;
304}
305
306char * FAST_FUNC unparse_uuid(const uint8_t *uu, char *out)
307{
308        char uuid_string[32];
309
310        bin2hex(uuid_string, (char *)uu, 16);
311	/* f.e. UUID=dfd9c173-be52-4d27-99a5-c34c6c2ff55f */
312        sprintf(out, "%.8s-%.4s-%.4s-%.4s-%.12s",
313                uuid_string,
314                uuid_string+8,
315                uuid_string+8+4,
316                uuid_string+8+4+4,
317                uuid_string+8+4+4+4
318        );
319        return out;
320}
321
322static unsigned char fromhex(char c)
323{
324        if (isdigit(c))
325                return (c - '0');
326        return ((c|0x20) - 'a' + 10);
327}
328
329/* Parse & verify UUID string */
330int FAST_FUNC parse_uuid(const char *s, uint8_t *uuid)
331{
332	int i;
333
334	if (strlen(s) != 36 || s[8] != '-' || s[13] != '-'
335	 || s[18] != '-' || s[23] != '-'
336	) {
337		return -1;
338	}
339	for (i = 0; i < 16; i++) {
340		if (*s == '-')
341			s++;
342		if (!isxdigit(s[0]) || !isxdigit(s[1]))
343			return -2;
344		uuid[i] = ((fromhex(s[0]) << 4) | fromhex(s[1]));
345		s += 2;
346	}
347
348	return 0;
349}
350
351