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 a long 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 LONG_MAX in @result,
 317  * and return -ERANGE.
 318  *
 319  * If the conversion underflows @result, store LONG_MIN in @result,
 320  * and return -ERANGE.
 321  *
 322  * Else store the converted value in @result, and return zero.
 323  */
 324 int qemu_strtol(const char *nptr, const char **endptr, int base,
 325                 long *result)
 326 {
 327     char *ep;
 328
 329     if (!nptr) {
 330         if (endptr) {
 331             *endptr = nptr;
 332         }
 333         return -EINVAL;
 334     }
 335
 336     errno = 0;
 337     *result = strtol(nptr, &ep, base);
 338     return check_strtox_error(nptr, ep, endptr, errno);
 339 }
 340
 341 /**
 342  * Convert string @nptr to an unsigned long, and store it in @result.
 343  *
 344  * This is a wrapper around strtoul() that is harder to misuse.
 345  * Semantics of @nptr, @endptr, @base match strtoul() 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 ULONG_MAX in @result,
 358  * and return -ERANGE.
 359  *
 360  * Else store the converted value in @result, and return zero.
 361  *
 362  * Note that a number with a leading minus sign gets converted without
 363  * the minus sign, checked for overflow (see above), then negated (in
 364  * @result's type).  This is exactly how strtoul() works.
 365  */
 366 int qemu_strtoul(const char *nptr, const char **endptr, int base,
 367                  unsigned long *result)
 368 {
 369     char *ep;
 370
 371     if (!nptr) {
 372         if (endptr) {
 373             *endptr = nptr;
 374         }
 375         return -EINVAL;
 376     }
 377
 378     errno = 0;
 379     *result = strtoul(nptr, &ep, base);
 380     /* Windows returns 1 for negative out-of-range values.  */
 381     if (errno == ERANGE) {
 382         *result = -1;
 383     }
 384     return check_strtox_error(nptr, ep, endptr, errno);
 385 }
 386
 387 /**
 388  * Convert string @nptr to an int64_t.
 389  *
 390  * Works like qemu_strtol(), except it stores INT64_MAX on overflow,
 391  * and INT_MIN on underflow.
 392  */
 393 int qemu_strtoi64(const char *nptr, const char **endptr, int base,
 394                  int64_t *result)
 395 {
 396     char *ep;
 397
 398     if (!nptr) {
 399         if (endptr) {
 400             *endptr = nptr;
 401         }
 402         return -EINVAL;
 403     }
 404
 405     errno = 0;
 406     /* FIXME This assumes int64_t is long long */
 407     *result = strtoll(nptr, &ep, base);
 408     return check_strtox_error(nptr, ep, endptr, errno);
 409 }
 410
 411 /**
 412  * Convert string @nptr to an uint64_t.
 413  *
 414  * Works like qemu_strtoul(), except it stores UINT64_MAX on overflow.
 415  */
 416 int qemu_strtou64(const char *nptr, const char **endptr, int base,
 417                   uint64_t *result)
 418 {
 419     char *ep;
 420
 421     if (!nptr) {
 422         if (endptr) {
 423             *endptr = nptr;
 424         }
 425         return -EINVAL;
 426     }
 427
 428     errno = 0;
 429     /* FIXME This assumes uint64_t is unsigned long long */
 430     *result = strtoull(nptr, &ep, base);
 431     /* Windows returns 1 for negative out-of-range values.  */
 432     if (errno == ERANGE) {
 433         *result = -1;
 434     }
 435     return check_strtox_error(nptr, ep, endptr, errno);
 436 }
 437
 438 /**
 439  * parse_uint:
 440  *
 441  * @s: String to parse
 442  * @value: Destination for parsed integer value
 443  * @endptr: Destination for pointer to first character not consumed
 444  * @base: integer base, between 2 and 36 inclusive, or 0
 445  *
 446  * Parse unsigned integer
 447  *
 448  * Parsed syntax is like strtoull()'s: arbitrary whitespace, a single optional
 449  * '+' or '-', an optional "0x" if @base is 0 or 16, one or more digits.
 450  *
 451  * If @s is null, or @base is invalid, or @s doesn't start with an
 452  * integer in the syntax above, set *@value to 0, *@endptr to @s, and
 453  * return -EINVAL.
 454  *
 455  * Set *@endptr to point right beyond the parsed integer (even if the integer
 456  * overflows or is negative, all digits will be parsed and *@endptr will
 457  * point right beyond them).
 458  *
 459  * If the integer is negative, set *@value to 0, and return -ERANGE.
 460  *
 461  * If the integer overflows unsigned long long, set *@value to
 462  * ULLONG_MAX, and return -ERANGE.
 463  *
 464  * Else, set *@value to the parsed integer, and return 0.
 465  */
 466 int parse_uint(const char *s, unsigned long long *value, char **endptr,
 467                int base)
 468 {
 469     int r = 0;
 470     char *endp = (char *)s;
 471     unsigned long long val = 0;
 472
 473     if (!s) {
 474         r = -EINVAL;
 475         goto out;
 476     }
 477
 478     errno = 0;
 479     val = strtoull(s, &endp, base);
 480     if (errno) {
 481         r = -errno;
 482         goto out;
 483     }
 484
 485     if (endp == s) {
 486         r = -EINVAL;
 487         goto out;
 488     }
 489
 490     /* make sure we reject negative numbers: */
 491     while (isspace((unsigned char)*s)) {
 492         s++;
 493     }
 494     if (*s == '-') {
 495         val = 0;
 496         r = -ERANGE;
 497         goto out;
 498     }
 499
 500 out:
 501     *value = val;
 502     *endptr = endp;
 503     return r;
 504 }
 505
 506 /**
 507  * parse_uint_full:
 508  *
 509  * @s: String to parse
 510  * @value: Destination for parsed integer value
 511  * @base: integer base, between 2 and 36 inclusive, or 0
 512  *
 513  * Parse unsigned integer from entire string
 514  *
 515  * Have the same behavior of parse_uint(), but with an additional check
 516  * for additional data after the parsed number. If extra characters are present
 517  * after the parsed number, the function will return -EINVAL, and *@v will
 518  * be set to 0.
 519  */
 520 int parse_uint_full(const char *s, unsigned long long *value, int base)
 521 {
 522     char *endp;
 523     int r;
 524
 525     r = parse_uint(s, value, &endp, base);
 526     if (r < 0) {
 527         return r;
 528     }
 529     if (*endp) {
 530         *value = 0;
 531         return -EINVAL;
 532     }
 533
 534     return 0;
 535 }
 536
 537 int qemu_parse_fd(const char *param)
 538 {
 539     long fd;
 540     char *endptr;
 541
 542     errno = 0;
 543     fd = strtol(param, &endptr, 10);
 544     if (param == endptr /* no conversion performed */                    ||
 545         errno != 0      /* not representable as long; possibly others */ ||
 546         *endptr != '\0' /* final string not empty */                     ||
 547         fd < 0          /* invalid as file descriptor */                 ||
 548         fd > INT_MAX    /* not representable as int */) {
 549         return -1;
 550     }
 551     return fd;
 552 }
 553
 554 /*
 555  * Implementation of  ULEB128 (http://en.wikipedia.org/wiki/LEB128)
 556  * Input is limited to 14-bit numbers
 557  */
 558 int uleb128_encode_small(uint8_t *out, uint32_t n)
 559 {
 560     g_assert(n <= 0x3fff);
 561     if (n < 0x80) {
 562         *out++ = n;
 563         return 1;
 564     } else {
 565         *out++ = (n & 0x7f) | 0x80;
 566         *out++ = n >> 7;
 567         return 2;
 568     }
 569 }
 570
 571 int uleb128_decode_small(const uint8_t *in, uint32_t *n)
 572 {
 573     if (!(*in & 0x80)) {
 574         *n = *in++;
 575         return 1;
 576     } else {
 577         *n = *in++ & 0x7f;
 578         /* we exceed 14 bit number */
 579         if (*in & 0x80) {
 580             return -1;
 581         }
 582         *n |= *in++ << 7;
 583         return 2;
 584     }
 585 }
 586
 587 /*
 588  * helper to parse debug environment variables
 589  */
 590 int parse_debug_env(const char *name, int max, int initial)
 591 {
 592     char *debug_env = getenv(name);
 593     char *inv = NULL;
 594     long debug;
 595
 596     if (!debug_env) {
 597         return initial;
 598     }
 599     errno = 0;
 600     debug = strtol(debug_env, &inv, 10);
 601     if (inv == debug_env) {
 602         return initial;
 603     }
 604     if (debug < 0 || debug > max || errno != 0) {
 605         warn_report("%s not in [0, %d]", name, max);
 606         return initial;
 607     }
 608     return debug;
 609 }
 610
 611 /*
 612  * Helper to print ethernet mac address
 613  */
 614 const char *qemu_ether_ntoa(const MACAddr *mac)
 615 {
 616     static char ret[18];
 617
 618     snprintf(ret, sizeof(ret), "%02x:%02x:%02x:%02x:%02x:%02x",
 619              mac->a[0], mac->a[1], mac->a[2], mac->a[3], mac->a[4], mac->a[5]);
 620
 621     return ret;
 622 }
 623
 624 /*
 625  * Return human readable string for size @val.
 626  * @val can be anything that uint64_t allows (no more than "16 EiB").
 627  * Use IEC binary units like KiB, MiB, and so forth.
 628  * Caller is responsible for passing it to g_free().
 629  */
 630 char *size_to_str(uint64_t val)
 631 {
 632     static const char *suffixes[] = { "", "Ki", "Mi", "Gi", "Ti", "Pi", "Ei" };
 633     unsigned long div;
 634     int i;
 635
 636     /*
 637      * The exponent (returned in i) minus one gives us
 638      * floor(log2(val * 1024 / 1000).  The correction makes us
 639      * switch to the higher power when the integer part is >= 1000.
 640      * (see e41b509d68afb1f for more info)
 641      */
 642     frexp(val / (1000.0 / 1024.0), &i);
 643     i = (i - 1) / 10;
 644     div = 1ULL << (i * 10);
 645
 646     return g_strdup_printf("%0.3g %sB", (double)val / div, suffixes[i]);
 647 }