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 #include "qemu/error-report.h"
  34
  35 void strpadcpy(char *buf, int buf_size, const char *str, char pad)
  36 {
  37     int len = qemu_strnlen(str, buf_size);
  38     memcpy(buf, str, len);
  39     memset(buf + len, pad, buf_size - len);
  40 }
  41
  42 void pstrcpy(char *buf, int buf_size, const char *str)
  43 {
  44     int c;
  45     char *q = buf;
  46
  47     if (buf_size <= 0)
  48         return;
  49
  50     for(;;) {
  51         c = *str++;
  52         if (c == 0 || q >= buf + buf_size - 1)
  53             break;
  54         *q++ = c;
  55     }
  56     *q = '\0';
  57 }
  58
  59 /* strcat and truncate. */
  60 char *pstrcat(char *buf, int buf_size, const char *s)
  61 {
  62     int len;
  63     len = strlen(buf);
  64     if (len < buf_size)
  65         pstrcpy(buf + len, buf_size - len, s);
  66     return buf;
  67 }
  68
  69 int strstart(const char *str, const char *val, const char **ptr)
  70 {
  71     const char *p, *q;
  72     p = str;
  73     q = val;
  74     while (*q != '\0') {
  75         if (*p != *q)
  76             return 0;
  77         p++;
  78         q++;
  79     }
  80     if (ptr)
  81         *ptr = p;
  82     return 1;
  83 }
  84
  85 int stristart(const char *str, const char *val, const char **ptr)
  86 {
  87     const char *p, *q;
  88     p = str;
  89     q = val;
  90     while (*q != '\0') {
  91         if (qemu_toupper(*p) != qemu_toupper(*q))
  92             return 0;
  93         p++;
  94         q++;
  95     }
  96     if (ptr)
  97         *ptr = p;
  98     return 1;
  99 }
 100
 101 /* XXX: use host strnlen if available ? */
 102 int qemu_strnlen(const char *s, int max_len)
 103 {
 104     int i;
 105
 106     for(i = 0; i < max_len; i++) {
 107         if (s[i] == '\0') {
 108             break;
 109         }
 110     }
 111     return i;
 112 }
 113
 114 char *qemu_strsep(char **input, const char *delim)
 115 {
 116     char *result = *input;
 117     if (result != NULL) {
 118         char *p;
 119
 120         for (p = result; *p != '\0'; p++) {
 121             if (strchr(delim, *p)) {
 122                 break;
 123             }
 124         }
 125         if (*p == '\0') {
 126             *input = NULL;
 127         } else {
 128             *p = '\0';
 129             *input = p + 1;
 130         }
 131     }
 132     return result;
 133 }
 134
 135 time_t mktimegm(struct tm *tm)
 136 {
 137     time_t t;
 138     int y = tm->tm_year + 1900, m = tm->tm_mon + 1, d = tm->tm_mday;
 139     if (m < 3) {
 140         m += 12;
 141         y--;
 142     }
 143     t = 86400ULL * (d + (153 * m - 457) / 5 + 365 * y + y / 4 - y / 100 +
 144                  y / 400 - 719469);
 145     t += 3600 * tm->tm_hour + 60 * tm->tm_min + tm->tm_sec;
 146     return t;
 147 }
 148
 149 /*
 150  * Make sure data goes on disk, but if possible do not bother to
 151  * write out the inode just for timestamp updates.
 152  *
 153  * Unfortunately even in 2009 many operating systems do not support
 154  * fdatasync and have to fall back to fsync.
 155  */
 156 int qemu_fdatasync(int fd)
 157 {
 158 #ifdef CONFIG_FDATASYNC
 159     return fdatasync(fd);
 160 #else
 161     return fsync(fd);
 162 #endif
 163 }
 164
 165 #ifndef _WIN32
 166 /* Sets a specific flag */
 167 int fcntl_setfl(int fd, int flag)
 168 {
 169     int flags;
 170
 171     flags = fcntl(fd, F_GETFL);
 172     if (flags == -1)
 173         return -errno;
 174
 175     if (fcntl(fd, F_SETFL, flags | flag) == -1)
 176         return -errno;
 177
 178     return 0;
 179 }
 180 #endif
 181
 182 static int64_t suffix_mul(char suffix, int64_t unit)
 183 {
 184     switch (qemu_toupper(suffix)) {
 185     case 'B':
 186         return 1;
 187     case 'K':
 188         return unit;
 189     case 'M':
 190         return unit * unit;
 191     case 'G':
 192         return unit * unit * unit;
 193     case 'T':
 194         return unit * unit * unit * unit;
 195     case 'P':
 196         return unit * unit * unit * unit * unit;
 197     case 'E':
 198         return unit * unit * unit * unit * unit * unit;
 199     }
 200     return -1;
 201 }
 202
 203 /*
 204  * Convert string to bytes, allowing either B/b for bytes, K/k for KB,
 205  * M/m for MB, G/g for GB or T/t for TB. End pointer will be returned
 206  * in *end, if not NULL. Return -ERANGE on overflow, Return -EINVAL on
 207  * other error.
 208  */
 209 static int do_strtosz(const char *nptr, char **end,
 210                       const char default_suffix, int64_t unit,
 211                       uint64_t *result)
 212 {
 213     int retval;
 214     char *endptr;
 215     unsigned char c;
 216     int mul_required = 0;
 217     double val, mul, integral, fraction;
 218
 219     errno = 0;
 220     val = strtod(nptr, &endptr);
 221     if (isnan(val) || endptr == nptr || errno != 0) {
 222         retval = -EINVAL;
 223         goto out;
 224     }
 225     fraction = modf(val, &integral);
 226     if (fraction != 0) {
 227         mul_required = 1;
 228     }
 229     c = *endptr;
 230     mul = suffix_mul(c, unit);
 231     if (mul >= 0) {
 232         endptr++;
 233     } else {
 234         mul = suffix_mul(default_suffix, unit);
 235         assert(mul >= 0);
 236     }
 237     if (mul == 1 && mul_required) {
 238         retval = -EINVAL;
 239         goto out;
 240     }
 241     /*
 242      * Values >= 0xfffffffffffffc00 overflow uint64_t after their trip
 243      * through double (53 bits of precision).
 244      */
 245     if ((val * mul >= 0xfffffffffffffc00) || val < 0) {
 246         retval = -ERANGE;
 247         goto out;
 248     }
 249     *result = val * mul;
 250     retval = 0;
 251
 252 out:
 253     if (end) {
 254         *end = endptr;
 255     } else if (*endptr) {
 256         retval = -EINVAL;
 257     }
 258
 259     return retval;
 260 }
 261
 262 int qemu_strtosz(const char *nptr, char **end, uint64_t *result)
 263 {
 264     return do_strtosz(nptr, end, 'B', 1024, result);
 265 }
 266
 267 int qemu_strtosz_MiB(const char *nptr, char **end, uint64_t *result)
 268 {
 269     return do_strtosz(nptr, end, 'M', 1024, result);
 270 }
 271
 272 int qemu_strtosz_metric(const char *nptr, char **end, uint64_t *result)
 273 {
 274     return do_strtosz(nptr, end, 'B', 1000, result);
 275 }
 276
 277 /**
 278  * Helper function for error checking after strtol() and the like
 279  */
 280 static int check_strtox_error(const char *nptr, char *ep,
 281                               const char **endptr, int libc_errno)
 282 {
 283     if (endptr) {
 284         *endptr = ep;
 285     }
 286
 287     /* Turn "no conversion" into an error */
 288     if (libc_errno == 0 && ep == nptr) {
 289         return -EINVAL;
 290     }
 291
 292     /* Fail when we're expected to consume the string, but didn't */
 293     if (!endptr && *ep) {
 294         return -EINVAL;
 295     }
 296
 297     return -libc_errno;
 298 }
 299
 300 /**
 301  * Convert string @nptr to an integer, and store it in @result.
 302  *
 303  * This is a wrapper around strtol() that is harder to misuse.
 304  * Semantics of @nptr, @endptr, @base match strtol() with differences
 305  * noted below.
 306  *
 307  * @nptr may be null, and no conversion is performed then.
 308  *
 309  * If no conversion is performed, store @nptr in *@endptr and return
 310  * -EINVAL.
 311  *
 312  * If @endptr is null, and the string isn't fully converted, return
 313  * -EINVAL.  This is the case when the pointer that would be stored in
 314  * a non-null @endptr points to a character other than '\0'.
 315  *
 316  * If the conversion overflows @result, store INT_MAX in @result,
 317  * and return -ERANGE.
 318  *
 319  * If the conversion underflows @result, store INT_MIN in @result,
 320  * and return -ERANGE.
 321  *
 322  * Else store the converted value in @result, and return zero.
 323  */
 324 int qemu_strtoi(const char *nptr, const char **endptr, int base,
 325                 int *result)
 326 {
 327     char *ep;
 328     long long lresult;
 329
 330     if (!nptr) {
 331         if (endptr) {
 332             *endptr = nptr;
 333         }
 334         return -EINVAL;
 335     }
 336
 337     errno = 0;
 338     lresult = strtoll(nptr, &ep, base);
 339     if (lresult < INT_MIN) {
 340         *result = INT_MIN;
 341         errno = ERANGE;
 342     } else if (lresult > INT_MAX) {
 343         *result = INT_MAX;
 344         errno = ERANGE;
 345     } else {
 346         *result = lresult;
 347     }
 348     return check_strtox_error(nptr, ep, endptr, errno);
 349 }
 350
 351 /**
 352  * Convert string @nptr to an unsigned integer, and store it in @result.
 353  *
 354  * This is a wrapper around strtoul() that is harder to misuse.
 355  * Semantics of @nptr, @endptr, @base match strtoul() with differences
 356  * noted below.
 357  *
 358  * @nptr may be null, and no conversion is performed then.
 359  *
 360  * If no conversion is performed, store @nptr in *@endptr and return
 361  * -EINVAL.
 362  *
 363  * If @endptr is null, and the string isn't fully converted, return
 364  * -EINVAL.  This is the case when the pointer that would be stored in
 365  * a non-null @endptr points to a character other than '\0'.
 366  *
 367  * If the conversion overflows @result, store UINT_MAX in @result,
 368  * and return -ERANGE.
 369  *
 370  * Else store the converted value in @result, and return zero.
 371  *
 372  * Note that a number with a leading minus sign gets converted without
 373  * the minus sign, checked for overflow (see above), then negated (in
 374  * @result's type).  This is exactly how strtoul() works.
 375  */
 376 int qemu_strtoui(const char *nptr, const char **endptr, int base,
 377                  unsigned int *result)
 378 {
 379     char *ep;
 380     long long lresult;
 381
 382     if (!nptr) {
 383         if (endptr) {
 384             *endptr = nptr;
 385         }
 386         return -EINVAL;
 387     }
 388
 389     errno = 0;
 390     lresult = strtoull(nptr, &ep, base);
 391
 392     /* Windows returns 1 for negative out-of-range values.  */
 393     if (errno == ERANGE) {
 394         *result = -1;
 395     } else {
 396         if (lresult > UINT_MAX) {
 397             *result = UINT_MAX;
 398             errno = ERANGE;
 399         } else if (lresult < INT_MIN) {
 400             *result = UINT_MAX;
 401             errno = ERANGE;
 402         } else {
 403             *result = lresult;
 404         }
 405     }
 406     return check_strtox_error(nptr, ep, endptr, errno);
 407 }
 408
 409 /**
 410  * Convert string @nptr to a long integer, and store it in @result.
 411  *
 412  * This is a wrapper around strtol() that is harder to misuse.
 413  * Semantics of @nptr, @endptr, @base match strtol() with differences
 414  * noted below.
 415  *
 416  * @nptr may be null, and no conversion is performed then.
 417  *
 418  * If no conversion is performed, store @nptr in *@endptr and return
 419  * -EINVAL.
 420  *
 421  * If @endptr is null, and the string isn't fully converted, return
 422  * -EINVAL.  This is the case when the pointer that would be stored in
 423  * a non-null @endptr points to a character other than '\0'.
 424  *
 425  * If the conversion overflows @result, store LONG_MAX in @result,
 426  * and return -ERANGE.
 427  *
 428  * If the conversion underflows @result, store LONG_MIN in @result,
 429  * and return -ERANGE.
 430  *
 431  * Else store the converted value in @result, and return zero.
 432  */
 433 int qemu_strtol(const char *nptr, const char **endptr, int base,
 434                 long *result)
 435 {
 436     char *ep;
 437
 438     if (!nptr) {
 439         if (endptr) {
 440             *endptr = nptr;
 441         }
 442         return -EINVAL;
 443     }
 444
 445     errno = 0;
 446     *result = strtol(nptr, &ep, base);
 447     return check_strtox_error(nptr, ep, endptr, errno);
 448 }
 449
 450 /**
 451  * Convert string @nptr to an unsigned long, and store it in @result.
 452  *
 453  * This is a wrapper around strtoul() that is harder to misuse.
 454  * Semantics of @nptr, @endptr, @base match strtoul() with differences
 455  * noted below.
 456  *
 457  * @nptr may be null, and no conversion is performed then.
 458  *
 459  * If no conversion is performed, store @nptr in *@endptr and return
 460  * -EINVAL.
 461  *
 462  * If @endptr is null, and the string isn't fully converted, return
 463  * -EINVAL.  This is the case when the pointer that would be stored in
 464  * a non-null @endptr points to a character other than '\0'.
 465  *
 466  * If the conversion overflows @result, store ULONG_MAX in @result,
 467  * and return -ERANGE.
 468  *
 469  * Else store the converted value in @result, and return zero.
 470  *
 471  * Note that a number with a leading minus sign gets converted without
 472  * the minus sign, checked for overflow (see above), then negated (in
 473  * @result's type).  This is exactly how strtoul() works.
 474  */
 475 int qemu_strtoul(const char *nptr, const char **endptr, int base,
 476                  unsigned long *result)
 477 {
 478     char *ep;
 479
 480     if (!nptr) {
 481         if (endptr) {
 482             *endptr = nptr;
 483         }
 484         return -EINVAL;
 485     }
 486
 487     errno = 0;
 488     *result = strtoul(nptr, &ep, base);
 489     /* Windows returns 1 for negative out-of-range values.  */
 490     if (errno == ERANGE) {
 491         *result = -1;
 492     }
 493     return check_strtox_error(nptr, ep, endptr, errno);
 494 }
 495
 496 /**
 497  * Convert string @nptr to an int64_t.
 498  *
 499  * Works like qemu_strtol(), except it stores INT64_MAX on overflow,
 500  * and INT_MIN on underflow.
 501  */
 502 int qemu_strtoi64(const char *nptr, const char **endptr, int base,
 503                  int64_t *result)
 504 {
 505     char *ep;
 506
 507     if (!nptr) {
 508         if (endptr) {
 509             *endptr = nptr;
 510         }
 511         return -EINVAL;
 512     }
 513
 514     errno = 0;
 515     /* FIXME This assumes int64_t is long long */
 516     *result = strtoll(nptr, &ep, base);
 517     return check_strtox_error(nptr, ep, endptr, errno);
 518 }
 519
 520 /**
 521  * Convert string @nptr to an uint64_t.
 522  *
 523  * Works like qemu_strtoul(), except it stores UINT64_MAX on overflow.
 524  */
 525 int qemu_strtou64(const char *nptr, const char **endptr, int base,
 526                   uint64_t *result)
 527 {
 528     char *ep;
 529
 530     if (!nptr) {
 531         if (endptr) {
 532             *endptr = nptr;
 533         }
 534         return -EINVAL;
 535     }
 536
 537     errno = 0;
 538     /* FIXME This assumes uint64_t is unsigned long long */
 539     *result = strtoull(nptr, &ep, base);
 540     /* Windows returns 1 for negative out-of-range values.  */
 541     if (errno == ERANGE) {
 542         *result = -1;
 543     }
 544     return check_strtox_error(nptr, ep, endptr, errno);
 545 }
 546
 547 /**
 548  * Searches for the first occurrence of 'c' in 's', and returns a pointer
 549  * to the trailing null byte if none was found.
 550  */
 551 #ifndef HAVE_STRCHRNUL
 552 const char *qemu_strchrnul(const char *s, int c)
 553 {
 554     const char *e = strchr(s, c);
 555     if (!e) {
 556         e = s + strlen(s);
 557     }
 558     return e;
 559 }
 560 #endif
 561
 562 /**
 563  * parse_uint:
 564  *
 565  * @s: String to parse
 566  * @value: Destination for parsed integer value
 567  * @endptr: Destination for pointer to first character not consumed
 568  * @base: integer base, between 2 and 36 inclusive, or 0
 569  *
 570  * Parse unsigned integer
 571  *
 572  * Parsed syntax is like strtoull()'s: arbitrary whitespace, a single optional
 573  * '+' or '-', an optional "0x" if @base is 0 or 16, one or more digits.
 574  *
 575  * If @s is null, or @base is invalid, or @s doesn't start with an
 576  * integer in the syntax above, set *@value to 0, *@endptr to @s, and
 577  * return -EINVAL.
 578  *
 579  * Set *@endptr to point right beyond the parsed integer (even if the integer
 580  * overflows or is negative, all digits will be parsed and *@endptr will
 581  * point right beyond them).
 582  *
 583  * If the integer is negative, set *@value to 0, and return -ERANGE.
 584  *
 585  * If the integer overflows unsigned long long, set *@value to
 586  * ULLONG_MAX, and return -ERANGE.
 587  *
 588  * Else, set *@value to the parsed integer, and return 0.
 589  */
 590 int parse_uint(const char *s, unsigned long long *value, char **endptr,
 591                int base)
 592 {
 593     int r = 0;
 594     char *endp = (char *)s;
 595     unsigned long long val = 0;
 596
 597     if (!s) {
 598         r = -EINVAL;
 599         goto out;
 600     }
 601
 602     errno = 0;
 603     val = strtoull(s, &endp, base);
 604     if (errno) {
 605         r = -errno;
 606         goto out;
 607     }
 608
 609     if (endp == s) {
 610         r = -EINVAL;
 611         goto out;
 612     }
 613
 614     /* make sure we reject negative numbers: */
 615     while (isspace((unsigned char)*s)) {
 616         s++;
 617     }
 618     if (*s == '-') {
 619         val = 0;
 620         r = -ERANGE;
 621         goto out;
 622     }
 623
 624 out:
 625     *value = val;
 626     *endptr = endp;
 627     return r;
 628 }
 629
 630 /**
 631  * parse_uint_full:
 632  *
 633  * @s: String to parse
 634  * @value: Destination for parsed integer value
 635  * @base: integer base, between 2 and 36 inclusive, or 0
 636  *
 637  * Parse unsigned integer from entire string
 638  *
 639  * Have the same behavior of parse_uint(), but with an additional check
 640  * for additional data after the parsed number. If extra characters are present
 641  * after the parsed number, the function will return -EINVAL, and *@v will
 642  * be set to 0.
 643  */
 644 int parse_uint_full(const char *s, unsigned long long *value, int base)
 645 {
 646     char *endp;
 647     int r;
 648
 649     r = parse_uint(s, value, &endp, base);
 650     if (r < 0) {
 651         return r;
 652     }
 653     if (*endp) {
 654         *value = 0;
 655         return -EINVAL;
 656     }
 657
 658     return 0;
 659 }
 660
 661 int qemu_parse_fd(const char *param)
 662 {
 663     long fd;
 664     char *endptr;
 665
 666     errno = 0;
 667     fd = strtol(param, &endptr, 10);
 668     if (param == endptr /* no conversion performed */                    ||
 669         errno != 0      /* not representable as long; possibly others */ ||
 670         *endptr != '\0' /* final string not empty */                     ||
 671         fd < 0          /* invalid as file descriptor */                 ||
 672         fd > INT_MAX    /* not representable as int */) {
 673         return -1;
 674     }
 675     return fd;
 676 }
 677
 678 /*
 679  * Implementation of  ULEB128 (http://en.wikipedia.org/wiki/LEB128)
 680  * Input is limited to 14-bit numbers
 681  */
 682 int uleb128_encode_small(uint8_t *out, uint32_t n)
 683 {
 684     g_assert(n <= 0x3fff);
 685     if (n < 0x80) {
 686         *out++ = n;
 687         return 1;
 688     } else {
 689         *out++ = (n & 0x7f) | 0x80;
 690         *out++ = n >> 7;
 691         return 2;
 692     }
 693 }
 694
 695 int uleb128_decode_small(const uint8_t *in, uint32_t *n)
 696 {
 697     if (!(*in & 0x80)) {
 698         *n = *in++;
 699         return 1;
 700     } else {
 701         *n = *in++ & 0x7f;
 702         /* we exceed 14 bit number */
 703         if (*in & 0x80) {
 704             return -1;
 705         }
 706         *n |= *in++ << 7;
 707         return 2;
 708     }
 709 }
 710
 711 /*
 712  * helper to parse debug environment variables
 713  */
 714 int parse_debug_env(const char *name, int max, int initial)
 715 {
 716     char *debug_env = getenv(name);
 717     char *inv = NULL;
 718     long debug;
 719
 720     if (!debug_env) {
 721         return initial;
 722     }
 723     errno = 0;
 724     debug = strtol(debug_env, &inv, 10);
 725     if (inv == debug_env) {
 726         return initial;
 727     }
 728     if (debug < 0 || debug > max || errno != 0) {
 729         warn_report("%s not in [0, %d]", name, max);
 730         return initial;
 731     }
 732     return debug;
 733 }
 734
 735 /*
 736  * Helper to print ethernet mac address
 737  */
 738 const char *qemu_ether_ntoa(const MACAddr *mac)
 739 {
 740     static char ret[18];
 741
 742     snprintf(ret, sizeof(ret), "%02x:%02x:%02x:%02x:%02x:%02x",
 743              mac->a[0], mac->a[1], mac->a[2], mac->a[3], mac->a[4], mac->a[5]);
 744
 745     return ret;
 746 }
 747
 748 /*
 749  * Return human readable string for size @val.
 750  * @val can be anything that uint64_t allows (no more than "16 EiB").
 751  * Use IEC binary units like KiB, MiB, and so forth.
 752  * Caller is responsible for passing it to g_free().
 753  */
 754 char *size_to_str(uint64_t val)
 755 {
 756     static const char *suffixes[] = { "", "Ki", "Mi", "Gi", "Ti", "Pi", "Ei" };
 757     unsigned long div;
 758     int i;
 759
 760     /*
 761      * The exponent (returned in i) minus one gives us
 762      * floor(log2(val * 1024 / 1000).  The correction makes us
 763      * switch to the higher power when the integer part is >= 1000.
 764      * (see e41b509d68afb1f for more info)
 765      */
 766     frexp(val / (1000.0 / 1024.0), &i);
 767     i = (i - 1) / 10;
 768     div = 1ULL << (i * 10);
 769
 770     return g_strdup_printf("%0.3g %sB", (double)val / div, suffixes[i]);
 771 }