util/cutils.c

   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 }