xref: /openbmc/qemu/util/cutils.c (revision 80adf54e)
1 /*
2  * Simple C functions to supplement the C library
3  *
4  * Copyright (c) 2006 Fabrice Bellard
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 #include "qemu/osdep.h"
25 #include "qemu-common.h"
26 #include "qemu/host-utils.h"
27 #include <math.h>
28 
29 #include "qemu/sockets.h"
30 #include "qemu/iov.h"
31 #include "net/net.h"
32 #include "qemu/cutils.h"
33 
34 void strpadcpy(char *buf, int buf_size, const char *str, char pad)
35 {
36     int len = qemu_strnlen(str, buf_size);
37     memcpy(buf, str, len);
38     memset(buf + len, pad, buf_size - len);
39 }
40 
41 void pstrcpy(char *buf, int buf_size, const char *str)
42 {
43     int c;
44     char *q = buf;
45 
46     if (buf_size <= 0)
47         return;
48 
49     for(;;) {
50         c = *str++;
51         if (c == 0 || q >= buf + buf_size - 1)
52             break;
53         *q++ = c;
54     }
55     *q = '\0';
56 }
57 
58 /* strcat and truncate. */
59 char *pstrcat(char *buf, int buf_size, const char *s)
60 {
61     int len;
62     len = strlen(buf);
63     if (len < buf_size)
64         pstrcpy(buf + len, buf_size - len, s);
65     return buf;
66 }
67 
68 int strstart(const char *str, const char *val, const char **ptr)
69 {
70     const char *p, *q;
71     p = str;
72     q = val;
73     while (*q != '\0') {
74         if (*p != *q)
75             return 0;
76         p++;
77         q++;
78     }
79     if (ptr)
80         *ptr = p;
81     return 1;
82 }
83 
84 int stristart(const char *str, const char *val, const char **ptr)
85 {
86     const char *p, *q;
87     p = str;
88     q = val;
89     while (*q != '\0') {
90         if (qemu_toupper(*p) != qemu_toupper(*q))
91             return 0;
92         p++;
93         q++;
94     }
95     if (ptr)
96         *ptr = p;
97     return 1;
98 }
99 
100 /* XXX: use host strnlen if available ? */
101 int qemu_strnlen(const char *s, int max_len)
102 {
103     int i;
104 
105     for(i = 0; i < max_len; i++) {
106         if (s[i] == '\0') {
107             break;
108         }
109     }
110     return i;
111 }
112 
113 char *qemu_strsep(char **input, const char *delim)
114 {
115     char *result = *input;
116     if (result != NULL) {
117         char *p;
118 
119         for (p = result; *p != '\0'; p++) {
120             if (strchr(delim, *p)) {
121                 break;
122             }
123         }
124         if (*p == '\0') {
125             *input = NULL;
126         } else {
127             *p = '\0';
128             *input = p + 1;
129         }
130     }
131     return result;
132 }
133 
134 time_t mktimegm(struct tm *tm)
135 {
136     time_t t;
137     int y = tm->tm_year + 1900, m = tm->tm_mon + 1, d = tm->tm_mday;
138     if (m < 3) {
139         m += 12;
140         y--;
141     }
142     t = 86400ULL * (d + (153 * m - 457) / 5 + 365 * y + y / 4 - y / 100 +
143                  y / 400 - 719469);
144     t += 3600 * tm->tm_hour + 60 * tm->tm_min + tm->tm_sec;
145     return t;
146 }
147 
148 /*
149  * Make sure data goes on disk, but if possible do not bother to
150  * write out the inode just for timestamp updates.
151  *
152  * Unfortunately even in 2009 many operating systems do not support
153  * fdatasync and have to fall back to fsync.
154  */
155 int qemu_fdatasync(int fd)
156 {
157 #ifdef CONFIG_FDATASYNC
158     return fdatasync(fd);
159 #else
160     return fsync(fd);
161 #endif
162 }
163 
164 #ifndef _WIN32
165 /* Sets a specific flag */
166 int fcntl_setfl(int fd, int flag)
167 {
168     int flags;
169 
170     flags = fcntl(fd, F_GETFL);
171     if (flags == -1)
172         return -errno;
173 
174     if (fcntl(fd, F_SETFL, flags | flag) == -1)
175         return -errno;
176 
177     return 0;
178 }
179 #endif
180 
181 static int64_t suffix_mul(char suffix, int64_t unit)
182 {
183     switch (qemu_toupper(suffix)) {
184     case 'B':
185         return 1;
186     case 'K':
187         return unit;
188     case 'M':
189         return unit * unit;
190     case 'G':
191         return unit * unit * unit;
192     case 'T':
193         return unit * unit * unit * unit;
194     case 'P':
195         return unit * unit * unit * unit * unit;
196     case 'E':
197         return unit * unit * unit * unit * unit * unit;
198     }
199     return -1;
200 }
201 
202 /*
203  * Convert string to bytes, allowing either B/b for bytes, K/k for KB,
204  * M/m for MB, G/g for GB or T/t for TB. End pointer will be returned
205  * in *end, if not NULL. Return -ERANGE on overflow, Return -EINVAL on
206  * other error.
207  */
208 static int do_strtosz(const char *nptr, char **end,
209                       const char default_suffix, int64_t unit,
210                       uint64_t *result)
211 {
212     int retval;
213     char *endptr;
214     unsigned char c;
215     int mul_required = 0;
216     double val, mul, integral, fraction;
217 
218     errno = 0;
219     val = strtod(nptr, &endptr);
220     if (isnan(val) || endptr == nptr || errno != 0) {
221         retval = -EINVAL;
222         goto out;
223     }
224     fraction = modf(val, &integral);
225     if (fraction != 0) {
226         mul_required = 1;
227     }
228     c = *endptr;
229     mul = suffix_mul(c, unit);
230     if (mul >= 0) {
231         endptr++;
232     } else {
233         mul = suffix_mul(default_suffix, unit);
234         assert(mul >= 0);
235     }
236     if (mul == 1 && mul_required) {
237         retval = -EINVAL;
238         goto out;
239     }
240     /*
241      * Values >= 0xfffffffffffffc00 overflow uint64_t after their trip
242      * through double (53 bits of precision).
243      */
244     if ((val * mul >= 0xfffffffffffffc00) || val < 0) {
245         retval = -ERANGE;
246         goto out;
247     }
248     *result = val * mul;
249     retval = 0;
250 
251 out:
252     if (end) {
253         *end = endptr;
254     } else if (*endptr) {
255         retval = -EINVAL;
256     }
257 
258     return retval;
259 }
260 
261 int qemu_strtosz(const char *nptr, char **end, uint64_t *result)
262 {
263     return do_strtosz(nptr, end, 'B', 1024, result);
264 }
265 
266 int qemu_strtosz_MiB(const char *nptr, char **end, uint64_t *result)
267 {
268     return do_strtosz(nptr, end, 'M', 1024, result);
269 }
270 
271 int qemu_strtosz_metric(const char *nptr, char **end, uint64_t *result)
272 {
273     return do_strtosz(nptr, end, 'B', 1000, result);
274 }
275 
276 /**
277  * Helper function for error checking after strtol() and the like
278  */
279 static int check_strtox_error(const char *nptr, char *ep,
280                               const char **endptr, int libc_errno)
281 {
282     if (endptr) {
283         *endptr = ep;
284     }
285 
286     /* Turn "no conversion" into an error */
287     if (libc_errno == 0 && ep == nptr) {
288         return -EINVAL;
289     }
290 
291     /* Fail when we're expected to consume the string, but didn't */
292     if (!endptr && *ep) {
293         return -EINVAL;
294     }
295 
296     return -libc_errno;
297 }
298 
299 /**
300  * Convert string @nptr to a long integer, and store it in @result.
301  *
302  * This is a wrapper around strtol() that is harder to misuse.
303  * Semantics of @nptr, @endptr, @base match strtol() with differences
304  * noted below.
305  *
306  * @nptr may be null, and no conversion is performed then.
307  *
308  * If no conversion is performed, store @nptr in *@endptr and return
309  * -EINVAL.
310  *
311  * If @endptr is null, and the string isn't fully converted, return
312  * -EINVAL.  This is the case when the pointer that would be stored in
313  * a non-null @endptr points to a character other than '\0'.
314  *
315  * If the conversion overflows @result, store LONG_MAX in @result,
316  * and return -ERANGE.
317  *
318  * If the conversion underflows @result, store LONG_MIN in @result,
319  * and return -ERANGE.
320  *
321  * Else store the converted value in @result, and return zero.
322  */
323 int qemu_strtol(const char *nptr, const char **endptr, int base,
324                 long *result)
325 {
326     char *ep;
327 
328     if (!nptr) {
329         if (endptr) {
330             *endptr = nptr;
331         }
332         return -EINVAL;
333     }
334 
335     errno = 0;
336     *result = strtol(nptr, &ep, base);
337     return check_strtox_error(nptr, ep, endptr, errno);
338 }
339 
340 /**
341  * Convert string @nptr to an unsigned long, and store it in @result.
342  *
343  * This is a wrapper around strtoul() that is harder to misuse.
344  * Semantics of @nptr, @endptr, @base match strtoul() with differences
345  * noted below.
346  *
347  * @nptr may be null, and no conversion is performed then.
348  *
349  * If no conversion is performed, store @nptr in *@endptr and return
350  * -EINVAL.
351  *
352  * If @endptr is null, and the string isn't fully converted, return
353  * -EINVAL.  This is the case when the pointer that would be stored in
354  * a non-null @endptr points to a character other than '\0'.
355  *
356  * If the conversion overflows @result, store ULONG_MAX in @result,
357  * and return -ERANGE.
358  *
359  * Else store the converted value in @result, and return zero.
360  *
361  * Note that a number with a leading minus sign gets converted without
362  * the minus sign, checked for overflow (see above), then negated (in
363  * @result's type).  This is exactly how strtoul() works.
364  */
365 int qemu_strtoul(const char *nptr, const char **endptr, int base,
366                  unsigned long *result)
367 {
368     char *ep;
369 
370     if (!nptr) {
371         if (endptr) {
372             *endptr = nptr;
373         }
374         return -EINVAL;
375     }
376 
377     errno = 0;
378     *result = strtoul(nptr, &ep, base);
379     /* Windows returns 1 for negative out-of-range values.  */
380     if (errno == ERANGE) {
381         *result = -1;
382     }
383     return check_strtox_error(nptr, ep, endptr, errno);
384 }
385 
386 /**
387  * Convert string @nptr to an int64_t.
388  *
389  * Works like qemu_strtol(), except it stores INT64_MAX on overflow,
390  * and INT_MIN on underflow.
391  */
392 int qemu_strtoi64(const char *nptr, const char **endptr, int base,
393                  int64_t *result)
394 {
395     char *ep;
396 
397     if (!nptr) {
398         if (endptr) {
399             *endptr = nptr;
400         }
401         return -EINVAL;
402     }
403 
404     errno = 0;
405     /* FIXME This assumes int64_t is long long */
406     *result = strtoll(nptr, &ep, base);
407     return check_strtox_error(nptr, ep, endptr, errno);
408 }
409 
410 /**
411  * Convert string @nptr to an uint64_t.
412  *
413  * Works like qemu_strtoul(), except it stores UINT64_MAX on overflow.
414  */
415 int qemu_strtou64(const char *nptr, const char **endptr, int base,
416                   uint64_t *result)
417 {
418     char *ep;
419 
420     if (!nptr) {
421         if (endptr) {
422             *endptr = nptr;
423         }
424         return -EINVAL;
425     }
426 
427     errno = 0;
428     /* FIXME This assumes uint64_t is unsigned long long */
429     *result = strtoull(nptr, &ep, base);
430     /* Windows returns 1 for negative out-of-range values.  */
431     if (errno == ERANGE) {
432         *result = -1;
433     }
434     return check_strtox_error(nptr, ep, endptr, errno);
435 }
436 
437 /**
438  * parse_uint:
439  *
440  * @s: String to parse
441  * @value: Destination for parsed integer value
442  * @endptr: Destination for pointer to first character not consumed
443  * @base: integer base, between 2 and 36 inclusive, or 0
444  *
445  * Parse unsigned integer
446  *
447  * Parsed syntax is like strtoull()'s: arbitrary whitespace, a single optional
448  * '+' or '-', an optional "0x" if @base is 0 or 16, one or more digits.
449  *
450  * If @s is null, or @base is invalid, or @s doesn't start with an
451  * integer in the syntax above, set *@value to 0, *@endptr to @s, and
452  * return -EINVAL.
453  *
454  * Set *@endptr to point right beyond the parsed integer (even if the integer
455  * overflows or is negative, all digits will be parsed and *@endptr will
456  * point right beyond them).
457  *
458  * If the integer is negative, set *@value to 0, and return -ERANGE.
459  *
460  * If the integer overflows unsigned long long, set *@value to
461  * ULLONG_MAX, and return -ERANGE.
462  *
463  * Else, set *@value to the parsed integer, and return 0.
464  */
465 int parse_uint(const char *s, unsigned long long *value, char **endptr,
466                int base)
467 {
468     int r = 0;
469     char *endp = (char *)s;
470     unsigned long long val = 0;
471 
472     if (!s) {
473         r = -EINVAL;
474         goto out;
475     }
476 
477     errno = 0;
478     val = strtoull(s, &endp, base);
479     if (errno) {
480         r = -errno;
481         goto out;
482     }
483 
484     if (endp == s) {
485         r = -EINVAL;
486         goto out;
487     }
488 
489     /* make sure we reject negative numbers: */
490     while (isspace((unsigned char)*s)) {
491         s++;
492     }
493     if (*s == '-') {
494         val = 0;
495         r = -ERANGE;
496         goto out;
497     }
498 
499 out:
500     *value = val;
501     *endptr = endp;
502     return r;
503 }
504 
505 /**
506  * parse_uint_full:
507  *
508  * @s: String to parse
509  * @value: Destination for parsed integer value
510  * @base: integer base, between 2 and 36 inclusive, or 0
511  *
512  * Parse unsigned integer from entire string
513  *
514  * Have the same behavior of parse_uint(), but with an additional check
515  * for additional data after the parsed number. If extra characters are present
516  * after the parsed number, the function will return -EINVAL, and *@v will
517  * be set to 0.
518  */
519 int parse_uint_full(const char *s, unsigned long long *value, int base)
520 {
521     char *endp;
522     int r;
523 
524     r = parse_uint(s, value, &endp, base);
525     if (r < 0) {
526         return r;
527     }
528     if (*endp) {
529         *value = 0;
530         return -EINVAL;
531     }
532 
533     return 0;
534 }
535 
536 int qemu_parse_fd(const char *param)
537 {
538     long fd;
539     char *endptr;
540 
541     errno = 0;
542     fd = strtol(param, &endptr, 10);
543     if (param == endptr /* no conversion performed */                    ||
544         errno != 0      /* not representable as long; possibly others */ ||
545         *endptr != '\0' /* final string not empty */                     ||
546         fd < 0          /* invalid as file descriptor */                 ||
547         fd > INT_MAX    /* not representable as int */) {
548         return -1;
549     }
550     return fd;
551 }
552 
553 /*
554  * Implementation of  ULEB128 (http://en.wikipedia.org/wiki/LEB128)
555  * Input is limited to 14-bit numbers
556  */
557 int uleb128_encode_small(uint8_t *out, uint32_t n)
558 {
559     g_assert(n <= 0x3fff);
560     if (n < 0x80) {
561         *out++ = n;
562         return 1;
563     } else {
564         *out++ = (n & 0x7f) | 0x80;
565         *out++ = n >> 7;
566         return 2;
567     }
568 }
569 
570 int uleb128_decode_small(const uint8_t *in, uint32_t *n)
571 {
572     if (!(*in & 0x80)) {
573         *n = *in++;
574         return 1;
575     } else {
576         *n = *in++ & 0x7f;
577         /* we exceed 14 bit number */
578         if (*in & 0x80) {
579             return -1;
580         }
581         *n |= *in++ << 7;
582         return 2;
583     }
584 }
585 
586 /*
587  * helper to parse debug environment variables
588  */
589 int parse_debug_env(const char *name, int max, int initial)
590 {
591     char *debug_env = getenv(name);
592     char *inv = NULL;
593     long debug;
594 
595     if (!debug_env) {
596         return initial;
597     }
598     errno = 0;
599     debug = strtol(debug_env, &inv, 10);
600     if (inv == debug_env) {
601         return initial;
602     }
603     if (debug < 0 || debug > max || errno != 0) {
604         fprintf(stderr, "warning: %s not in [0, %d]", name, max);
605         return initial;
606     }
607     return debug;
608 }
609 
610 /*
611  * Helper to print ethernet mac address
612  */
613 const char *qemu_ether_ntoa(const MACAddr *mac)
614 {
615     static char ret[18];
616 
617     snprintf(ret, sizeof(ret), "%02x:%02x:%02x:%02x:%02x:%02x",
618              mac->a[0], mac->a[1], mac->a[2], mac->a[3], mac->a[4], mac->a[5]);
619 
620     return ret;
621 }
622 
623 /*
624  * Return human readable string for size @val.
625  * @val can be anything that uint64_t allows (no more than "16 EiB").
626  * Use IEC binary units like KiB, MiB, and so forth.
627  * Caller is responsible for passing it to g_free().
628  */
629 char *size_to_str(uint64_t val)
630 {
631     static const char *suffixes[] = { "", "Ki", "Mi", "Gi", "Ti", "Pi", "Ei" };
632     unsigned long div;
633     int i;
634 
635     /*
636      * The exponent (returned in i) minus one gives us
637      * floor(log2(val * 1024 / 1000).  The correction makes us
638      * switch to the higher power when the integer part is >= 1000.
639      * (see e41b509d68afb1f for more info)
640      */
641     frexp(val / (1000.0 / 1024.0), &i);
642     i = (i - 1) / 10;
643     div = 1ULL << (i * 10);
644 
645     return g_strdup_printf("%0.3g %sB", (double)val / div, suffixes[i]);
646 }
647