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 #define QEMU_STRTOSZ_DEFSUFFIX_EB 'E'
 182 #define QEMU_STRTOSZ_DEFSUFFIX_PB 'P'
 183 #define QEMU_STRTOSZ_DEFSUFFIX_TB 'T'
 184 #define QEMU_STRTOSZ_DEFSUFFIX_GB 'G'
 185 #define QEMU_STRTOSZ_DEFSUFFIX_MB 'M'
 186 #define QEMU_STRTOSZ_DEFSUFFIX_KB 'K'
 187 #define QEMU_STRTOSZ_DEFSUFFIX_B 'B'
 188
 189 static int64_t suffix_mul(char suffix, int64_t unit)
 190 {
 191     switch (qemu_toupper(suffix)) {
 192     case QEMU_STRTOSZ_DEFSUFFIX_B:
 193         return 1;
 194     case QEMU_STRTOSZ_DEFSUFFIX_KB:
 195         return unit;
 196     case QEMU_STRTOSZ_DEFSUFFIX_MB:
 197         return unit * unit;
 198     case QEMU_STRTOSZ_DEFSUFFIX_GB:
 199         return unit * unit * unit;
 200     case QEMU_STRTOSZ_DEFSUFFIX_TB:
 201         return unit * unit * unit * unit;
 202     case QEMU_STRTOSZ_DEFSUFFIX_PB:
 203         return unit * unit * unit * unit * unit;
 204     case QEMU_STRTOSZ_DEFSUFFIX_EB:
 205         return unit * unit * unit * unit * unit * unit;
 206     }
 207     return -1;
 208 }
 209
 210 /*
 211  * Convert string to bytes, allowing either B/b for bytes, K/k for KB,
 212  * M/m for MB, G/g for GB or T/t for TB. End pointer will be returned
 213  * in *end, if not NULL. Return -ERANGE on overflow, Return -EINVAL on
 214  * other error.
 215  */
 216 static int64_t do_strtosz(const char *nptr, char **end,
 217                           const char default_suffix, int64_t unit)
 218 {
 219     int64_t retval = -EINVAL;
 220     char *endptr;
 221     unsigned char c;
 222     int mul_required = 0;
 223     double val, mul, integral, fraction;
 224
 225     errno = 0;
 226     val = strtod(nptr, &endptr);
 227     if (isnan(val) || endptr == nptr || errno != 0) {
 228         goto fail;
 229     }
 230     fraction = modf(val, &integral);
 231     if (fraction != 0) {
 232         mul_required = 1;
 233     }
 234     c = *endptr;
 235     mul = suffix_mul(c, unit);
 236     if (mul >= 0) {
 237         endptr++;
 238     } else {
 239         mul = suffix_mul(default_suffix, unit);
 240         assert(mul >= 0);
 241     }
 242     if (mul == 1 && mul_required) {
 243         goto fail;
 244     }
 245     if ((val * mul >= INT64_MAX) || val < 0) {
 246         retval = -ERANGE;
 247         goto fail;
 248     }
 249     retval = val * mul;
 250
 251 fail:
 252     if (end) {
 253         *end = endptr;
 254     }
 255
 256     return retval;
 257 }
 258
 259 int64_t qemu_strtosz(const char *nptr, char **end)
 260 {
 261     return do_strtosz(nptr, end, QEMU_STRTOSZ_DEFSUFFIX_B, 1024);
 262 }
 263
 264 int64_t qemu_strtosz_MiB(const char *nptr, char **end)
 265 {
 266     return do_strtosz(nptr, end, QEMU_STRTOSZ_DEFSUFFIX_MB, 1024);
 267 }
 268
 269 int64_t qemu_strtosz_metric(const char *nptr, char **end)
 270 {
 271     return do_strtosz(nptr, end, QEMU_STRTOSZ_DEFSUFFIX_B, 1000);
 272 }
 273
 274 /**
 275  * Helper function for error checking after strtol() and the like
 276  */
 277 static int check_strtox_error(const char *nptr, char *ep,
 278                               const char **endptr, int libc_errno)
 279 {
 280     if (endptr) {
 281         *endptr = ep;
 282     }
 283
 284     /* Turn "no conversion" into an error */
 285     if (libc_errno == 0 && ep == nptr) {
 286         return -EINVAL;
 287     }
 288
 289     /* Fail when we're expected to consume the string, but didn't */
 290     if (!endptr && *ep) {
 291         return -EINVAL;
 292     }
 293
 294     return -libc_errno;
 295 }
 296
 297 /**
 298  * Convert string @nptr to a long integer, and store it in @result.
 299  *
 300  * This is a wrapper around strtol() that is harder to misuse.
 301  * Semantics of @nptr, @endptr, @base match strtol() with differences
 302  * noted below.
 303  *
 304  * @nptr may be null, and no conversion is performed then.
 305  *
 306  * If no conversion is performed, store @nptr in *@endptr and return
 307  * -EINVAL.
 308  *
 309  * If @endptr is null, and the string isn't fully converted, return
 310  * -EINVAL.  This is the case when the pointer that would be stored in
 311  * a non-null @endptr points to a character other than '\0'.
 312  *
 313  * If the conversion overflows @result, store LONG_MAX in @result,
 314  * and return -ERANGE.
 315  *
 316  * If the conversion underflows @result, store LONG_MIN in @result,
 317  * and return -ERANGE.
 318  *
 319  * Else store the converted value in @result, and return zero.
 320  */
 321 int qemu_strtol(const char *nptr, const char **endptr, int base,
 322                 long *result)
 323 {
 324     char *ep;
 325
 326     if (!nptr) {
 327         if (endptr) {
 328             *endptr = nptr;
 329         }
 330         return -EINVAL;
 331     }
 332
 333     errno = 0;
 334     *result = strtol(nptr, &ep, base);
 335     return check_strtox_error(nptr, ep, endptr, errno);
 336 }
 337
 338 /**
 339  * Convert string @nptr to an unsigned long, and store it in @result.
 340  *
 341  * This is a wrapper around strtoul() that is harder to misuse.
 342  * Semantics of @nptr, @endptr, @base match strtoul() with differences
 343  * noted below.
 344  *
 345  * @nptr may be null, and no conversion is performed then.
 346  *
 347  * If no conversion is performed, store @nptr in *@endptr and return
 348  * -EINVAL.
 349  *
 350  * If @endptr is null, and the string isn't fully converted, return
 351  * -EINVAL.  This is the case when the pointer that would be stored in
 352  * a non-null @endptr points to a character other than '\0'.
 353  *
 354  * If the conversion overflows @result, store ULONG_MAX in @result,
 355  * and return -ERANGE.
 356  *
 357  * Else store the converted value in @result, and return zero.
 358  *
 359  * Note that a number with a leading minus sign gets converted without
 360  * the minus sign, checked for overflow (see above), then negated (in
 361  * @result's type).  This is exactly how strtoul() works.
 362  */
 363 int qemu_strtoul(const char *nptr, const char **endptr, int base,
 364                  unsigned long *result)
 365 {
 366     char *ep;
 367
 368     if (!nptr) {
 369         if (endptr) {
 370             *endptr = nptr;
 371         }
 372         return -EINVAL;
 373     }
 374
 375     errno = 0;
 376     *result = strtoul(nptr, &ep, base);
 377     /* Windows returns 1 for negative out-of-range values.  */
 378     if (errno == ERANGE) {
 379         *result = -1;
 380     }
 381     return check_strtox_error(nptr, ep, endptr, errno);
 382 }
 383
 384 /**
 385  * Convert string @nptr to an int64_t.
 386  *
 387  * Works like qemu_strtol(), except it stores INT64_MAX on overflow,
 388  * and INT_MIN on underflow.
 389  */
 390 int qemu_strtoi64(const char *nptr, const char **endptr, int base,
 391                  int64_t *result)
 392 {
 393     char *ep;
 394
 395     if (!nptr) {
 396         if (endptr) {
 397             *endptr = nptr;
 398         }
 399         return -EINVAL;
 400     }
 401
 402     errno = 0;
 403     /* FIXME This assumes int64_t is long long */
 404     *result = strtoll(nptr, &ep, base);
 405     return check_strtox_error(nptr, ep, endptr, errno);
 406 }
 407
 408 /**
 409  * Convert string @nptr to an uint64_t.
 410  *
 411  * Works like qemu_strtoul(), except it stores UINT64_MAX on overflow.
 412  */
 413 int qemu_strtou64(const char *nptr, const char **endptr, int base,
 414                   uint64_t *result)
 415 {
 416     char *ep;
 417
 418     if (!nptr) {
 419         if (endptr) {
 420             *endptr = nptr;
 421         }
 422         return -EINVAL;
 423     }
 424
 425     errno = 0;
 426     /* FIXME This assumes uint64_t is unsigned long long */
 427     *result = strtoull(nptr, &ep, base);
 428     /* Windows returns 1 for negative out-of-range values.  */
 429     if (errno == ERANGE) {
 430         *result = -1;
 431     }
 432     return check_strtox_error(nptr, ep, endptr, errno);
 433 }
 434
 435 /**
 436  * parse_uint:
 437  *
 438  * @s: String to parse
 439  * @value: Destination for parsed integer value
 440  * @endptr: Destination for pointer to first character not consumed
 441  * @base: integer base, between 2 and 36 inclusive, or 0
 442  *
 443  * Parse unsigned integer
 444  *
 445  * Parsed syntax is like strtoull()'s: arbitrary whitespace, a single optional
 446  * '+' or '-', an optional "0x" if @base is 0 or 16, one or more digits.
 447  *
 448  * If @s is null, or @base is invalid, or @s doesn't start with an
 449  * integer in the syntax above, set *@value to 0, *@endptr to @s, and
 450  * return -EINVAL.
 451  *
 452  * Set *@endptr to point right beyond the parsed integer (even if the integer
 453  * overflows or is negative, all digits will be parsed and *@endptr will
 454  * point right beyond them).
 455  *
 456  * If the integer is negative, set *@value to 0, and return -ERANGE.
 457  *
 458  * If the integer overflows unsigned long long, set *@value to
 459  * ULLONG_MAX, and return -ERANGE.
 460  *
 461  * Else, set *@value to the parsed integer, and return 0.
 462  */
 463 int parse_uint(const char *s, unsigned long long *value, char **endptr,
 464                int base)
 465 {
 466     int r = 0;
 467     char *endp = (char *)s;
 468     unsigned long long val = 0;
 469
 470     if (!s) {
 471         r = -EINVAL;
 472         goto out;
 473     }
 474
 475     errno = 0;
 476     val = strtoull(s, &endp, base);
 477     if (errno) {
 478         r = -errno;
 479         goto out;
 480     }
 481
 482     if (endp == s) {
 483         r = -EINVAL;
 484         goto out;
 485     }
 486
 487     /* make sure we reject negative numbers: */
 488     while (isspace((unsigned char)*s)) {
 489         s++;
 490     }
 491     if (*s == '-') {
 492         val = 0;
 493         r = -ERANGE;
 494         goto out;
 495     }
 496
 497 out:
 498     *value = val;
 499     *endptr = endp;
 500     return r;
 501 }
 502
 503 /**
 504  * parse_uint_full:
 505  *
 506  * @s: String to parse
 507  * @value: Destination for parsed integer value
 508  * @base: integer base, between 2 and 36 inclusive, or 0
 509  *
 510  * Parse unsigned integer from entire string
 511  *
 512  * Have the same behavior of parse_uint(), but with an additional check
 513  * for additional data after the parsed number. If extra characters are present
 514  * after the parsed number, the function will return -EINVAL, and *@v will
 515  * be set to 0.
 516  */
 517 int parse_uint_full(const char *s, unsigned long long *value, int base)
 518 {
 519     char *endp;
 520     int r;
 521
 522     r = parse_uint(s, value, &endp, base);
 523     if (r < 0) {
 524         return r;
 525     }
 526     if (*endp) {
 527         *value = 0;
 528         return -EINVAL;
 529     }
 530
 531     return 0;
 532 }
 533
 534 int qemu_parse_fd(const char *param)
 535 {
 536     long fd;
 537     char *endptr;
 538
 539     errno = 0;
 540     fd = strtol(param, &endptr, 10);
 541     if (param == endptr /* no conversion performed */                    ||
 542         errno != 0      /* not representable as long; possibly others */ ||
 543         *endptr != '\0' /* final string not empty */                     ||
 544         fd < 0          /* invalid as file descriptor */                 ||
 545         fd > INT_MAX    /* not representable as int */) {
 546         return -1;
 547     }
 548     return fd;
 549 }
 550
 551 /*
 552  * Implementation of  ULEB128 (http://en.wikipedia.org/wiki/LEB128)
 553  * Input is limited to 14-bit numbers
 554  */
 555 int uleb128_encode_small(uint8_t *out, uint32_t n)
 556 {
 557     g_assert(n <= 0x3fff);
 558     if (n < 0x80) {
 559         *out++ = n;
 560         return 1;
 561     } else {
 562         *out++ = (n & 0x7f) | 0x80;
 563         *out++ = n >> 7;
 564         return 2;
 565     }
 566 }
 567
 568 int uleb128_decode_small(const uint8_t *in, uint32_t *n)
 569 {
 570     if (!(*in & 0x80)) {
 571         *n = *in++;
 572         return 1;
 573     } else {
 574         *n = *in++ & 0x7f;
 575         /* we exceed 14 bit number */
 576         if (*in & 0x80) {
 577             return -1;
 578         }
 579         *n |= *in++ << 7;
 580         return 2;
 581     }
 582 }
 583
 584 /*
 585  * helper to parse debug environment variables
 586  */
 587 int parse_debug_env(const char *name, int max, int initial)
 588 {
 589     char *debug_env = getenv(name);
 590     char *inv = NULL;
 591     long debug;
 592
 593     if (!debug_env) {
 594         return initial;
 595     }
 596     errno = 0;
 597     debug = strtol(debug_env, &inv, 10);
 598     if (inv == debug_env) {
 599         return initial;
 600     }
 601     if (debug < 0 || debug > max || errno != 0) {
 602         fprintf(stderr, "warning: %s not in [0, %d]", name, max);
 603         return initial;
 604     }
 605     return debug;
 606 }
 607
 608 /*
 609  * Helper to print ethernet mac address
 610  */
 611 const char *qemu_ether_ntoa(const MACAddr *mac)
 612 {
 613     static char ret[18];
 614
 615     snprintf(ret, sizeof(ret), "%02x:%02x:%02x:%02x:%02x:%02x",
 616              mac->a[0], mac->a[1], mac->a[2], mac->a[3], mac->a[4], mac->a[5]);
 617
 618     return ret;
 619 }