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
  25 #include "qemu/osdep.h"
  26 #include "qemu/host-utils.h"
  27 #include <math.h>
  28
  29 #include "qemu-common.h"
  30 #include "qemu/sockets.h"
  31 #include "qemu/iov.h"
  32 #include "net/net.h"
  33 #include "qemu/ctype.h"
  34 #include "qemu/cutils.h"
  35 #include "qemu/error-report.h"
  36
  37 void strpadcpy(char *buf, int buf_size, const char *str, char pad)
  38 {
  39     int len = qemu_strnlen(str, buf_size);
  40     memcpy(buf, str, len);
  41     memset(buf + len, pad, buf_size - len);
  42 }
  43
  44 void pstrcpy(char *buf, int buf_size, const char *str)
  45 {
  46     int c;
  47     char *q = buf;
  48
  49     if (buf_size <= 0)
  50         return;
  51
  52     for(;;) {
  53         c = *str++;
  54         if (c == 0 || q >= buf + buf_size - 1)
  55             break;
  56         *q++ = c;
  57     }
  58     *q = '\0';
  59 }
  60
  61 /* strcat and truncate. */
  62 char *pstrcat(char *buf, int buf_size, const char *s)
  63 {
  64     int len;
  65     len = strlen(buf);
  66     if (len < buf_size)
  67         pstrcpy(buf + len, buf_size - len, s);
  68     return buf;
  69 }
  70
  71 int strstart(const char *str, const char *val, const char **ptr)
  72 {
  73     const char *p, *q;
  74     p = str;
  75     q = val;
  76     while (*q != '\0') {
  77         if (*p != *q)
  78             return 0;
  79         p++;
  80         q++;
  81     }
  82     if (ptr)
  83         *ptr = p;
  84     return 1;
  85 }
  86
  87 int stristart(const char *str, const char *val, const char **ptr)
  88 {
  89     const char *p, *q;
  90     p = str;
  91     q = val;
  92     while (*q != '\0') {
  93         if (qemu_toupper(*p) != qemu_toupper(*q))
  94             return 0;
  95         p++;
  96         q++;
  97     }
  98     if (ptr)
  99         *ptr = p;
 100     return 1;
 101 }
 102
 103 /* XXX: use host strnlen if available ? */
 104 int qemu_strnlen(const char *s, int max_len)
 105 {
 106     int i;
 107
 108     for(i = 0; i < max_len; i++) {
 109         if (s[i] == '\0') {
 110             break;
 111         }
 112     }
 113     return i;
 114 }
 115
 116 char *qemu_strsep(char **input, const char *delim)
 117 {
 118     char *result = *input;
 119     if (result != NULL) {
 120         char *p;
 121
 122         for (p = result; *p != '\0'; p++) {
 123             if (strchr(delim, *p)) {
 124                 break;
 125             }
 126         }
 127         if (*p == '\0') {
 128             *input = NULL;
 129         } else {
 130             *p = '\0';
 131             *input = p + 1;
 132         }
 133     }
 134     return result;
 135 }
 136
 137 time_t mktimegm(struct tm *tm)
 138 {
 139     time_t t;
 140     int y = tm->tm_year + 1900, m = tm->tm_mon + 1, d = tm->tm_mday;
 141     if (m < 3) {
 142         m += 12;
 143         y--;
 144     }
 145     t = 86400ULL * (d + (153 * m - 457) / 5 + 365 * y + y / 4 - y / 100 +
 146                  y / 400 - 719469);
 147     t += 3600 * tm->tm_hour + 60 * tm->tm_min + tm->tm_sec;
 148     return t;
 149 }
 150
 151 /*
 152  * Make sure data goes on disk, but if possible do not bother to
 153  * write out the inode just for timestamp updates.
 154  *
 155  * Unfortunately even in 2009 many operating systems do not support
 156  * fdatasync and have to fall back to fsync.
 157  */
 158 int qemu_fdatasync(int fd)
 159 {
 160 #ifdef CONFIG_FDATASYNC
 161     return fdatasync(fd);
 162 #else
 163     return fsync(fd);
 164 #endif
 165 }
 166
 167 /**
 168  * Sync changes made to the memory mapped file back to the backing
 169  * storage. For POSIX compliant systems this will fallback
 170  * to regular msync call. Otherwise it will trigger whole file sync
 171  * (including the metadata case there is no support to skip that otherwise)
 172  *
 173  * @addr   - start of the memory area to be synced
 174  * @length - length of the are to be synced
 175  * @fd     - file descriptor for the file to be synced
 176  *           (mandatory only for POSIX non-compliant systems)
 177  */
 178 int qemu_msync(void *addr, size_t length, int fd)
 179 {
 180 #ifdef CONFIG_POSIX
 181     size_t align_mask = ~(qemu_real_host_page_size - 1);
 182
 183     /**
 184      * There are no strict reqs as per the length of mapping
 185      * to be synced. Still the length needs to follow the address
 186      * alignment changes. Additionally - round the size to the multiple
 187      * of PAGE_SIZE
 188      */
 189     length += ((uintptr_t)addr & (qemu_real_host_page_size - 1));
 190     length = (length + ~align_mask) & align_mask;
 191
 192     addr = (void *)((uintptr_t)addr & align_mask);
 193
 194     return msync(addr, length, MS_SYNC);
 195 #else /* CONFIG_POSIX */
 196     /**
 197      * Perform the sync based on the file descriptor
 198      * The sync range will most probably be wider than the one
 199      * requested - but it will still get the job done
 200      */
 201     return qemu_fdatasync(fd);
 202 #endif /* CONFIG_POSIX */
 203 }
 204
 205 #ifndef _WIN32
 206 /* Sets a specific flag */
 207 int fcntl_setfl(int fd, int flag)
 208 {
 209     int flags;
 210
 211     flags = fcntl(fd, F_GETFL);
 212     if (flags == -1)
 213         return -errno;
 214
 215     if (fcntl(fd, F_SETFL, flags | flag) == -1)
 216         return -errno;
 217
 218     return 0;
 219 }
 220 #endif
 221
 222 static int64_t suffix_mul(char suffix, int64_t unit)
 223 {
 224     switch (qemu_toupper(suffix)) {
 225     case 'B':
 226         return 1;
 227     case 'K':
 228         return unit;
 229     case 'M':
 230         return unit * unit;
 231     case 'G':
 232         return unit * unit * unit;
 233     case 'T':
 234         return unit * unit * unit * unit;
 235     case 'P':
 236         return unit * unit * unit * unit * unit;
 237     case 'E':
 238         return unit * unit * unit * unit * unit * unit;
 239     }
 240     return -1;
 241 }
 242
 243 /*
 244  * Convert string to bytes, allowing either B/b for bytes, K/k for KB,
 245  * M/m for MB, G/g for GB or T/t for TB. End pointer will be returned
 246  * in *end, if not NULL. Return -ERANGE on overflow, and -EINVAL on
 247  * other error.
 248  */
 249 static int do_strtosz(const char *nptr, const char **end,
 250                       const char default_suffix, int64_t unit,
 251                       uint64_t *result)
 252 {
 253     int retval;
 254     const char *endptr;
 255     unsigned char c;
 256     int mul_required = 0;
 257     double val, mul, integral, fraction;
 258
 259     retval = qemu_strtod_finite(nptr, &endptr, &val);
 260     if (retval) {
 261         goto out;
 262     }
 263     fraction = modf(val, &integral);
 264     if (fraction != 0) {
 265         mul_required = 1;
 266     }
 267     c = *endptr;
 268     mul = suffix_mul(c, unit);
 269     if (mul >= 0) {
 270         endptr++;
 271     } else {
 272         mul = suffix_mul(default_suffix, unit);
 273         assert(mul >= 0);
 274     }
 275     if (mul == 1 && mul_required) {
 276         retval = -EINVAL;
 277         goto out;
 278     }
 279     /*
 280      * Values near UINT64_MAX overflow to 2**64 when converting to double
 281      * precision.  Compare against the maximum representable double precision
 282      * value below 2**64, computed as "the next value after 2**64 (0x1p64) in
 283      * the direction of 0".
 284      */
 285     if ((val * mul > nextafter(0x1p64, 0)) || val < 0) {
 286         retval = -ERANGE;
 287         goto out;
 288     }
 289     *result = val * mul;
 290     retval = 0;
 291
 292 out:
 293     if (end) {
 294         *end = endptr;
 295     } else if (*endptr) {
 296         retval = -EINVAL;
 297     }
 298
 299     return retval;
 300 }
 301
 302 int qemu_strtosz(const char *nptr, const char **end, uint64_t *result)
 303 {
 304     return do_strtosz(nptr, end, 'B', 1024, result);
 305 }
 306
 307 int qemu_strtosz_MiB(const char *nptr, const char **end, uint64_t *result)
 308 {
 309     return do_strtosz(nptr, end, 'M', 1024, result);
 310 }
 311
 312 int qemu_strtosz_metric(const char *nptr, const char **end, uint64_t *result)
 313 {
 314     return do_strtosz(nptr, end, 'B', 1000, result);
 315 }
 316
 317 /**
 318  * Helper function for error checking after strtol() and the like
 319  */
 320 static int check_strtox_error(const char *nptr, char *ep,
 321                               const char **endptr, int libc_errno)
 322 {
 323     assert(ep >= nptr);
 324     if (endptr) {
 325         *endptr = ep;
 326     }
 327
 328     /* Turn "no conversion" into an error */
 329     if (libc_errno == 0 && ep == nptr) {
 330         return -EINVAL;
 331     }
 332
 333     /* Fail when we're expected to consume the string, but didn't */
 334     if (!endptr && *ep) {
 335         return -EINVAL;
 336     }
 337
 338     return -libc_errno;
 339 }
 340
 341 /**
 342  * Convert string @nptr to an integer, and store it in @result.
 343  *
 344  * This is a wrapper around strtol() that is harder to misuse.
 345  * Semantics of @nptr, @endptr, @base match strtol() with differences
 346  * noted below.
 347  *
 348  * @nptr may be null, and no conversion is performed then.
 349  *
 350  * If no conversion is performed, store @nptr in *@endptr and return
 351  * -EINVAL.
 352  *
 353  * If @endptr is null, and the string isn't fully converted, return
 354  * -EINVAL.  This is the case when the pointer that would be stored in
 355  * a non-null @endptr points to a character other than '\0'.
 356  *
 357  * If the conversion overflows @result, store INT_MAX in @result,
 358  * and return -ERANGE.
 359  *
 360  * If the conversion underflows @result, store INT_MIN in @result,
 361  * and return -ERANGE.
 362  *
 363  * Else store the converted value in @result, and return zero.
 364  */
 365 int qemu_strtoi(const char *nptr, const char **endptr, int base,
 366                 int *result)
 367 {
 368     char *ep;
 369     long long lresult;
 370
 371     assert((unsigned) base <= 36 && base != 1);
 372     if (!nptr) {
 373         if (endptr) {
 374             *endptr = nptr;
 375         }
 376         return -EINVAL;
 377     }
 378
 379     errno = 0;
 380     lresult = strtoll(nptr, &ep, base);
 381     if (lresult < INT_MIN) {
 382         *result = INT_MIN;
 383         errno = ERANGE;
 384     } else if (lresult > INT_MAX) {
 385         *result = INT_MAX;
 386         errno = ERANGE;
 387     } else {
 388         *result = lresult;
 389     }
 390     return check_strtox_error(nptr, ep, endptr, errno);
 391 }
 392
 393 /**
 394  * Convert string @nptr to an unsigned integer, and store it in @result.
 395  *
 396  * This is a wrapper around strtoul() that is harder to misuse.
 397  * Semantics of @nptr, @endptr, @base match strtoul() with differences
 398  * noted below.
 399  *
 400  * @nptr may be null, and no conversion is performed then.
 401  *
 402  * If no conversion is performed, store @nptr in *@endptr and return
 403  * -EINVAL.
 404  *
 405  * If @endptr is null, and the string isn't fully converted, return
 406  * -EINVAL.  This is the case when the pointer that would be stored in
 407  * a non-null @endptr points to a character other than '\0'.
 408  *
 409  * If the conversion overflows @result, store UINT_MAX in @result,
 410  * and return -ERANGE.
 411  *
 412  * Else store the converted value in @result, and return zero.
 413  *
 414  * Note that a number with a leading minus sign gets converted without
 415  * the minus sign, checked for overflow (see above), then negated (in
 416  * @result's type).  This is exactly how strtoul() works.
 417  */
 418 int qemu_strtoui(const char *nptr, const char **endptr, int base,
 419                  unsigned int *result)
 420 {
 421     char *ep;
 422     long long lresult;
 423
 424     assert((unsigned) base <= 36 && base != 1);
 425     if (!nptr) {
 426         if (endptr) {
 427             *endptr = nptr;
 428         }
 429         return -EINVAL;
 430     }
 431
 432     errno = 0;
 433     lresult = strtoull(nptr, &ep, base);
 434
 435     /* Windows returns 1 for negative out-of-range values.  */
 436     if (errno == ERANGE) {
 437         *result = -1;
 438     } else {
 439         if (lresult > UINT_MAX) {
 440             *result = UINT_MAX;
 441             errno = ERANGE;
 442         } else if (lresult < INT_MIN) {
 443             *result = UINT_MAX;
 444             errno = ERANGE;
 445         } else {
 446             *result = lresult;
 447         }
 448     }
 449     return check_strtox_error(nptr, ep, endptr, errno);
 450 }
 451
 452 /**
 453  * Convert string @nptr to a long integer, and store it in @result.
 454  *
 455  * This is a wrapper around strtol() that is harder to misuse.
 456  * Semantics of @nptr, @endptr, @base match strtol() with differences
 457  * noted below.
 458  *
 459  * @nptr may be null, and no conversion is performed then.
 460  *
 461  * If no conversion is performed, store @nptr in *@endptr and return
 462  * -EINVAL.
 463  *
 464  * If @endptr is null, and the string isn't fully converted, return
 465  * -EINVAL.  This is the case when the pointer that would be stored in
 466  * a non-null @endptr points to a character other than '\0'.
 467  *
 468  * If the conversion overflows @result, store LONG_MAX in @result,
 469  * and return -ERANGE.
 470  *
 471  * If the conversion underflows @result, store LONG_MIN in @result,
 472  * and return -ERANGE.
 473  *
 474  * Else store the converted value in @result, and return zero.
 475  */
 476 int qemu_strtol(const char *nptr, const char **endptr, int base,
 477                 long *result)
 478 {
 479     char *ep;
 480
 481     assert((unsigned) base <= 36 && base != 1);
 482     if (!nptr) {
 483         if (endptr) {
 484             *endptr = nptr;
 485         }
 486         return -EINVAL;
 487     }
 488
 489     errno = 0;
 490     *result = strtol(nptr, &ep, base);
 491     return check_strtox_error(nptr, ep, endptr, errno);
 492 }
 493
 494 /**
 495  * Convert string @nptr to an unsigned long, and store it in @result.
 496  *
 497  * This is a wrapper around strtoul() that is harder to misuse.
 498  * Semantics of @nptr, @endptr, @base match strtoul() with differences
 499  * noted below.
 500  *
 501  * @nptr may be null, and no conversion is performed then.
 502  *
 503  * If no conversion is performed, store @nptr in *@endptr and return
 504  * -EINVAL.
 505  *
 506  * If @endptr is null, and the string isn't fully converted, return
 507  * -EINVAL.  This is the case when the pointer that would be stored in
 508  * a non-null @endptr points to a character other than '\0'.
 509  *
 510  * If the conversion overflows @result, store ULONG_MAX in @result,
 511  * and return -ERANGE.
 512  *
 513  * Else store the converted value in @result, and return zero.
 514  *
 515  * Note that a number with a leading minus sign gets converted without
 516  * the minus sign, checked for overflow (see above), then negated (in
 517  * @result's type).  This is exactly how strtoul() works.
 518  */
 519 int qemu_strtoul(const char *nptr, const char **endptr, int base,
 520                  unsigned long *result)
 521 {
 522     char *ep;
 523
 524     assert((unsigned) base <= 36 && base != 1);
 525     if (!nptr) {
 526         if (endptr) {
 527             *endptr = nptr;
 528         }
 529         return -EINVAL;
 530     }
 531
 532     errno = 0;
 533     *result = strtoul(nptr, &ep, base);
 534     /* Windows returns 1 for negative out-of-range values.  */
 535     if (errno == ERANGE) {
 536         *result = -1;
 537     }
 538     return check_strtox_error(nptr, ep, endptr, errno);
 539 }
 540
 541 /**
 542  * Convert string @nptr to an int64_t.
 543  *
 544  * Works like qemu_strtol(), except it stores INT64_MAX on overflow,
 545  * and INT_MIN on underflow.
 546  */
 547 int qemu_strtoi64(const char *nptr, const char **endptr, int base,
 548                  int64_t *result)
 549 {
 550     char *ep;
 551
 552     assert((unsigned) base <= 36 && base != 1);
 553     if (!nptr) {
 554         if (endptr) {
 555             *endptr = nptr;
 556         }
 557         return -EINVAL;
 558     }
 559
 560     errno = 0;
 561     /* FIXME This assumes int64_t is long long */
 562     *result = strtoll(nptr, &ep, base);
 563     return check_strtox_error(nptr, ep, endptr, errno);
 564 }
 565
 566 /**
 567  * Convert string @nptr to an uint64_t.
 568  *
 569  * Works like qemu_strtoul(), except it stores UINT64_MAX on overflow.
 570  */
 571 int qemu_strtou64(const char *nptr, const char **endptr, int base,
 572                   uint64_t *result)
 573 {
 574     char *ep;
 575
 576     assert((unsigned) base <= 36 && base != 1);
 577     if (!nptr) {
 578         if (endptr) {
 579             *endptr = nptr;
 580         }
 581         return -EINVAL;
 582     }
 583
 584     errno = 0;
 585     /* FIXME This assumes uint64_t is unsigned long long */
 586     *result = strtoull(nptr, &ep, base);
 587     /* Windows returns 1 for negative out-of-range values.  */
 588     if (errno == ERANGE) {
 589         *result = -1;
 590     }
 591     return check_strtox_error(nptr, ep, endptr, errno);
 592 }
 593
 594 /**
 595  * Convert string @nptr to a double.
 596   *
 597  * This is a wrapper around strtod() that is harder to misuse.
 598  * Semantics of @nptr and @endptr match strtod() with differences
 599  * noted below.
 600  *
 601  * @nptr may be null, and no conversion is performed then.
 602  *
 603  * If no conversion is performed, store @nptr in *@endptr and return
 604  * -EINVAL.
 605  *
 606  * If @endptr is null, and the string isn't fully converted, return
 607  * -EINVAL. This is the case when the pointer that would be stored in
 608  * a non-null @endptr points to a character other than '\0'.
 609  *
 610  * If the conversion overflows, store +/-HUGE_VAL in @result, depending
 611  * on the sign, and return -ERANGE.
 612  *
 613  * If the conversion underflows, store +/-0.0 in @result, depending on the
 614  * sign, and return -ERANGE.
 615  *
 616  * Else store the converted value in @result, and return zero.
 617  */
 618 int qemu_strtod(const char *nptr, const char **endptr, double *result)
 619 {
 620     char *ep;
 621
 622     if (!nptr) {
 623         if (endptr) {
 624             *endptr = nptr;
 625         }
 626         return -EINVAL;
 627     }
 628
 629     errno = 0;
 630     *result = strtod(nptr, &ep);
 631     return check_strtox_error(nptr, ep, endptr, errno);
 632 }
 633
 634 /**
 635  * Convert string @nptr to a finite double.
 636  *
 637  * Works like qemu_strtod(), except that "NaN" and "inf" are rejected
 638  * with -EINVAL and no conversion is performed.
 639  */
 640 int qemu_strtod_finite(const char *nptr, const char **endptr, double *result)
 641 {
 642     double tmp;
 643     int ret;
 644
 645     ret = qemu_strtod(nptr, endptr, &tmp);
 646     if (!ret && !isfinite(tmp)) {
 647         if (endptr) {
 648             *endptr = nptr;
 649         }
 650         ret = -EINVAL;
 651     }
 652
 653     if (ret != -EINVAL) {
 654         *result = tmp;
 655     }
 656     return ret;
 657 }
 658
 659 /**
 660  * Searches for the first occurrence of 'c' in 's', and returns a pointer
 661  * to the trailing null byte if none was found.
 662  */
 663 #ifndef HAVE_STRCHRNUL
 664 const char *qemu_strchrnul(const char *s, int c)
 665 {
 666     const char *e = strchr(s, c);
 667     if (!e) {
 668         e = s + strlen(s);
 669     }
 670     return e;
 671 }
 672 #endif
 673
 674 /**
 675  * parse_uint:
 676  *
 677  * @s: String to parse
 678  * @value: Destination for parsed integer value
 679  * @endptr: Destination for pointer to first character not consumed
 680  * @base: integer base, between 2 and 36 inclusive, or 0
 681  *
 682  * Parse unsigned integer
 683  *
 684  * Parsed syntax is like strtoull()'s: arbitrary whitespace, a single optional
 685  * '+' or '-', an optional "0x" if @base is 0 or 16, one or more digits.
 686  *
 687  * If @s is null, or @base is invalid, or @s doesn't start with an
 688  * integer in the syntax above, set *@value to 0, *@endptr to @s, and
 689  * return -EINVAL.
 690  *
 691  * Set *@endptr to point right beyond the parsed integer (even if the integer
 692  * overflows or is negative, all digits will be parsed and *@endptr will
 693  * point right beyond them).
 694  *
 695  * If the integer is negative, set *@value to 0, and return -ERANGE.
 696  *
 697  * If the integer overflows unsigned long long, set *@value to
 698  * ULLONG_MAX, and return -ERANGE.
 699  *
 700  * Else, set *@value to the parsed integer, and return 0.
 701  */
 702 int parse_uint(const char *s, unsigned long long *value, char **endptr,
 703                int base)
 704 {
 705     int r = 0;
 706     char *endp = (char *)s;
 707     unsigned long long val = 0;
 708
 709     assert((unsigned) base <= 36 && base != 1);
 710     if (!s) {
 711         r = -EINVAL;
 712         goto out;
 713     }
 714
 715     errno = 0;
 716     val = strtoull(s, &endp, base);
 717     if (errno) {
 718         r = -errno;
 719         goto out;
 720     }
 721
 722     if (endp == s) {
 723         r = -EINVAL;
 724         goto out;
 725     }
 726
 727     /* make sure we reject negative numbers: */
 728     while (qemu_isspace(*s)) {
 729         s++;
 730     }
 731     if (*s == '-') {
 732         val = 0;
 733         r = -ERANGE;
 734         goto out;
 735     }
 736
 737 out:
 738     *value = val;
 739     *endptr = endp;
 740     return r;
 741 }
 742
 743 /**
 744  * parse_uint_full:
 745  *
 746  * @s: String to parse
 747  * @value: Destination for parsed integer value
 748  * @base: integer base, between 2 and 36 inclusive, or 0
 749  *
 750  * Parse unsigned integer from entire string
 751  *
 752  * Have the same behavior of parse_uint(), but with an additional check
 753  * for additional data after the parsed number. If extra characters are present
 754  * after the parsed number, the function will return -EINVAL, and *@v will
 755  * be set to 0.
 756  */
 757 int parse_uint_full(const char *s, unsigned long long *value, int base)
 758 {
 759     char *endp;
 760     int r;
 761
 762     r = parse_uint(s, value, &endp, base);
 763     if (r < 0) {
 764         return r;
 765     }
 766     if (*endp) {
 767         *value = 0;
 768         return -EINVAL;
 769     }
 770
 771     return 0;
 772 }
 773
 774 int qemu_parse_fd(const char *param)
 775 {
 776     long fd;
 777     char *endptr;
 778
 779     errno = 0;
 780     fd = strtol(param, &endptr, 10);
 781     if (param == endptr /* no conversion performed */                    ||
 782         errno != 0      /* not representable as long; possibly others */ ||
 783         *endptr != '\0' /* final string not empty */                     ||
 784         fd < 0          /* invalid as file descriptor */                 ||
 785         fd > INT_MAX    /* not representable as int */) {
 786         return -1;
 787     }
 788     return fd;
 789 }
 790
 791 /*
 792  * Implementation of  ULEB128 (http://en.wikipedia.org/wiki/LEB128)
 793  * Input is limited to 14-bit numbers
 794  */
 795 int uleb128_encode_small(uint8_t *out, uint32_t n)
 796 {
 797     g_assert(n <= 0x3fff);
 798     if (n < 0x80) {
 799         *out = n;
 800         return 1;
 801     } else {
 802         *out++ = (n & 0x7f) | 0x80;
 803         *out = n >> 7;
 804         return 2;
 805     }
 806 }
 807
 808 int uleb128_decode_small(const uint8_t *in, uint32_t *n)
 809 {
 810     if (!(*in & 0x80)) {
 811         *n = *in;
 812         return 1;
 813     } else {
 814         *n = *in++ & 0x7f;
 815         /* we exceed 14 bit number */
 816         if (*in & 0x80) {
 817             return -1;
 818         }
 819         *n |= *in << 7;
 820         return 2;
 821     }
 822 }
 823
 824 /*
 825  * helper to parse debug environment variables
 826  */
 827 int parse_debug_env(const char *name, int max, int initial)
 828 {
 829     char *debug_env = getenv(name);
 830     char *inv = NULL;
 831     long debug;
 832
 833     if (!debug_env) {
 834         return initial;
 835     }
 836     errno = 0;
 837     debug = strtol(debug_env, &inv, 10);
 838     if (inv == debug_env) {
 839         return initial;
 840     }
 841     if (debug < 0 || debug > max || errno != 0) {
 842         warn_report("%s not in [0, %d]", name, max);
 843         return initial;
 844     }
 845     return debug;
 846 }
 847
 848 /*
 849  * Helper to print ethernet mac address
 850  */
 851 const char *qemu_ether_ntoa(const MACAddr *mac)
 852 {
 853     static char ret[18];
 854
 855     snprintf(ret, sizeof(ret), "%02x:%02x:%02x:%02x:%02x:%02x",
 856              mac->a[0], mac->a[1], mac->a[2], mac->a[3], mac->a[4], mac->a[5]);
 857
 858     return ret;
 859 }
 860
 861 /*
 862  * Return human readable string for size @val.
 863  * @val can be anything that uint64_t allows (no more than "16 EiB").
 864  * Use IEC binary units like KiB, MiB, and so forth.
 865  * Caller is responsible for passing it to g_free().
 866  */
 867 char *size_to_str(uint64_t val)
 868 {
 869     static const char *suffixes[] = { "", "Ki", "Mi", "Gi", "Ti", "Pi", "Ei" };
 870     uint64_t div;
 871     int i;
 872
 873     /*
 874      * The exponent (returned in i) minus one gives us
 875      * floor(log2(val * 1024 / 1000).  The correction makes us
 876      * switch to the higher power when the integer part is >= 1000.
 877      * (see e41b509d68afb1f for more info)
 878      */
 879     frexp(val / (1000.0 / 1024.0), &i);
 880     i = (i - 1) / 10;
 881     div = 1ULL << (i * 10);
 882
 883     return g_strdup_printf("%0.3g %sB", (double)val / div, suffixes[i]);
 884 }
 885
 886 int qemu_pstrcmp0(const char **str1, const char **str2)
 887 {
 888     return g_strcmp0(*str1, *str2);
 889 }