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 QEMU_STRTOSZ_DEFSUFFIX_B:
 185         return 1;
 186     case QEMU_STRTOSZ_DEFSUFFIX_KB:
 187         return unit;
 188     case QEMU_STRTOSZ_DEFSUFFIX_MB:
 189         return unit * unit;
 190     case QEMU_STRTOSZ_DEFSUFFIX_GB:
 191         return unit * unit * unit;
 192     case QEMU_STRTOSZ_DEFSUFFIX_TB:
 193         return unit * unit * unit * unit;
 194     case QEMU_STRTOSZ_DEFSUFFIX_PB:
 195         return unit * unit * unit * unit * unit;
 196     case QEMU_STRTOSZ_DEFSUFFIX_EB:
 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 int64_t qemu_strtosz_suffix_unit(const char *nptr, char **end,
 209                             const char default_suffix, int64_t unit)
 210 {
 211     int64_t retval = -EINVAL;
 212     char *endptr;
 213     unsigned char c;
 214     int mul_required = 0;
 215     double val, mul, integral, fraction;
 216
 217     errno = 0;
 218     val = strtod(nptr, &endptr);
 219     if (isnan(val) || endptr == nptr || errno != 0) {
 220         goto fail;
 221     }
 222     fraction = modf(val, &integral);
 223     if (fraction != 0) {
 224         mul_required = 1;
 225     }
 226     c = *endptr;
 227     mul = suffix_mul(c, unit);
 228     if (mul >= 0) {
 229         endptr++;
 230     } else {
 231         mul = suffix_mul(default_suffix, unit);
 232         assert(mul >= 0);
 233     }
 234     if (mul == 1 && mul_required) {
 235         goto fail;
 236     }
 237     if ((val * mul >= INT64_MAX) || val < 0) {
 238         retval = -ERANGE;
 239         goto fail;
 240     }
 241     retval = val * mul;
 242
 243 fail:
 244     if (end) {
 245         *end = endptr;
 246     }
 247
 248     return retval;
 249 }
 250
 251 int64_t qemu_strtosz_suffix(const char *nptr, char **end,
 252                             const char default_suffix)
 253 {
 254     return qemu_strtosz_suffix_unit(nptr, end, default_suffix, 1024);
 255 }
 256
 257 int64_t qemu_strtosz(const char *nptr, char **end)
 258 {
 259     return qemu_strtosz_suffix(nptr, end, QEMU_STRTOSZ_DEFSUFFIX_MB);
 260 }
 261
 262 /**
 263  * Helper function for qemu_strto*l() functions.
 264  */
 265 static int check_strtox_error(const char *p, char *endptr, const char **next,
 266                               int err)
 267 {
 268     /* If no conversion was performed, prefer BSD behavior over glibc
 269      * behavior.
 270      */
 271     if (err == 0 && endptr == p) {
 272         err = EINVAL;
 273     }
 274     if (!next && *endptr) {
 275         return -EINVAL;
 276     }
 277     if (next) {
 278         *next = endptr;
 279     }
 280     return -err;
 281 }
 282
 283 /**
 284  * QEMU wrappers for strtol(), strtoll(), strtoul(), strotull() C functions.
 285  *
 286  * Convert ASCII string @nptr to a long integer value
 287  * from the given @base. Parameters @nptr, @endptr, @base
 288  * follows same semantics as strtol() C function.
 289  *
 290  * Unlike from strtol() function, if @endptr is not NULL, this
 291  * function will return -EINVAL whenever it cannot fully convert
 292  * the string in @nptr with given @base to a long. This function returns
 293  * the result of the conversion only through the @result parameter.
 294  *
 295  * If NULL is passed in @endptr, then the whole string in @ntpr
 296  * is a number otherwise it returns -EINVAL.
 297  *
 298  * RETURN VALUE
 299  * Unlike from strtol() function, this wrapper returns either
 300  * -EINVAL or the errno set by strtol() function (e.g -ERANGE).
 301  * If the conversion overflows, -ERANGE is returned, and @result
 302  * is set to the max value of the desired type
 303  * (e.g. LONG_MAX, LLONG_MAX, ULONG_MAX, ULLONG_MAX). If the case
 304  * of underflow, -ERANGE is returned, and @result is set to the min
 305  * value of the desired type. For strtol(), strtoll(), @result is set to
 306  * LONG_MIN, LLONG_MIN, respectively, and for strtoul(), strtoull() it
 307  * is set to 0.
 308  */
 309 int qemu_strtol(const char *nptr, const char **endptr, int base,
 310                 long *result)
 311 {
 312     char *p;
 313     int err = 0;
 314     if (!nptr) {
 315         if (endptr) {
 316             *endptr = nptr;
 317         }
 318         err = -EINVAL;
 319     } else {
 320         errno = 0;
 321         *result = strtol(nptr, &p, base);
 322         err = check_strtox_error(nptr, p, endptr, errno);
 323     }
 324     return err;
 325 }
 326
 327 /**
 328  * Converts ASCII string to an unsigned long integer.
 329  *
 330  * If string contains a negative number, value will be converted to
 331  * the unsigned representation of the signed value, unless the original
 332  * (nonnegated) value would overflow, in this case, it will set @result
 333  * to ULONG_MAX, and return ERANGE.
 334  *
 335  * The same behavior holds, for qemu_strtoull() but sets @result to
 336  * ULLONG_MAX instead of ULONG_MAX.
 337  *
 338  * See qemu_strtol() documentation for more info.
 339  */
 340 int qemu_strtoul(const char *nptr, const char **endptr, int base,
 341                  unsigned long *result)
 342 {
 343     char *p;
 344     int err = 0;
 345     if (!nptr) {
 346         if (endptr) {
 347             *endptr = nptr;
 348         }
 349         err = -EINVAL;
 350     } else {
 351         errno = 0;
 352         *result = strtoul(nptr, &p, base);
 353         /* Windows returns 1 for negative out-of-range values.  */
 354         if (errno == ERANGE) {
 355             *result = -1;
 356         }
 357         err = check_strtox_error(nptr, p, endptr, errno);
 358     }
 359     return err;
 360 }
 361
 362 /**
 363  * Converts ASCII string to a long long integer.
 364  *
 365  * See qemu_strtol() documentation for more info.
 366  */
 367 int qemu_strtoll(const char *nptr, const char **endptr, int base,
 368                  int64_t *result)
 369 {
 370     char *p;
 371     int err = 0;
 372     if (!nptr) {
 373         if (endptr) {
 374             *endptr = nptr;
 375         }
 376         err = -EINVAL;
 377     } else {
 378         errno = 0;
 379         *result = strtoll(nptr, &p, base);
 380         err = check_strtox_error(nptr, p, endptr, errno);
 381     }
 382     return err;
 383 }
 384
 385 /**
 386  * Converts ASCII string to an unsigned long long integer.
 387  *
 388  * See qemu_strtol() documentation for more info.
 389  */
 390 int qemu_strtoull(const char *nptr, const char **endptr, int base,
 391                   uint64_t *result)
 392 {
 393     char *p;
 394     int err = 0;
 395     if (!nptr) {
 396         if (endptr) {
 397             *endptr = nptr;
 398         }
 399         err = -EINVAL;
 400     } else {
 401         errno = 0;
 402         *result = strtoull(nptr, &p, base);
 403         /* Windows returns 1 for negative out-of-range values.  */
 404         if (errno == ERANGE) {
 405             *result = -1;
 406         }
 407         err = check_strtox_error(nptr, p, endptr, errno);
 408     }
 409     return err;
 410 }
 411
 412 /**
 413  * parse_uint:
 414  *
 415  * @s: String to parse
 416  * @value: Destination for parsed integer value
 417  * @endptr: Destination for pointer to first character not consumed
 418  * @base: integer base, between 2 and 36 inclusive, or 0
 419  *
 420  * Parse unsigned integer
 421  *
 422  * Parsed syntax is like strtoull()'s: arbitrary whitespace, a single optional
 423  * '+' or '-', an optional "0x" if @base is 0 or 16, one or more digits.
 424  *
 425  * If @s is null, or @base is invalid, or @s doesn't start with an
 426  * integer in the syntax above, set *@value to 0, *@endptr to @s, and
 427  * return -EINVAL.
 428  *
 429  * Set *@endptr to point right beyond the parsed integer (even if the integer
 430  * overflows or is negative, all digits will be parsed and *@endptr will
 431  * point right beyond them).
 432  *
 433  * If the integer is negative, set *@value to 0, and return -ERANGE.
 434  *
 435  * If the integer overflows unsigned long long, set *@value to
 436  * ULLONG_MAX, and return -ERANGE.
 437  *
 438  * Else, set *@value to the parsed integer, and return 0.
 439  */
 440 int parse_uint(const char *s, unsigned long long *value, char **endptr,
 441                int base)
 442 {
 443     int r = 0;
 444     char *endp = (char *)s;
 445     unsigned long long val = 0;
 446
 447     if (!s) {
 448         r = -EINVAL;
 449         goto out;
 450     }
 451
 452     errno = 0;
 453     val = strtoull(s, &endp, base);
 454     if (errno) {
 455         r = -errno;
 456         goto out;
 457     }
 458
 459     if (endp == s) {
 460         r = -EINVAL;
 461         goto out;
 462     }
 463
 464     /* make sure we reject negative numbers: */
 465     while (isspace((unsigned char)*s)) {
 466         s++;
 467     }
 468     if (*s == '-') {
 469         val = 0;
 470         r = -ERANGE;
 471         goto out;
 472     }
 473
 474 out:
 475     *value = val;
 476     *endptr = endp;
 477     return r;
 478 }
 479
 480 /**
 481  * parse_uint_full:
 482  *
 483  * @s: String to parse
 484  * @value: Destination for parsed integer value
 485  * @base: integer base, between 2 and 36 inclusive, or 0
 486  *
 487  * Parse unsigned integer from entire string
 488  *
 489  * Have the same behavior of parse_uint(), but with an additional check
 490  * for additional data after the parsed number. If extra characters are present
 491  * after the parsed number, the function will return -EINVAL, and *@v will
 492  * be set to 0.
 493  */
 494 int parse_uint_full(const char *s, unsigned long long *value, int base)
 495 {
 496     char *endp;
 497     int r;
 498
 499     r = parse_uint(s, value, &endp, base);
 500     if (r < 0) {
 501         return r;
 502     }
 503     if (*endp) {
 504         *value = 0;
 505         return -EINVAL;
 506     }
 507
 508     return 0;
 509 }
 510
 511 int qemu_parse_fd(const char *param)
 512 {
 513     long fd;
 514     char *endptr;
 515
 516     errno = 0;
 517     fd = strtol(param, &endptr, 10);
 518     if (param == endptr /* no conversion performed */                    ||
 519         errno != 0      /* not representable as long; possibly others */ ||
 520         *endptr != '\0' /* final string not empty */                     ||
 521         fd < 0          /* invalid as file descriptor */                 ||
 522         fd > INT_MAX    /* not representable as int */) {
 523         return -1;
 524     }
 525     return fd;
 526 }
 527
 528 /*
 529  * Implementation of  ULEB128 (http://en.wikipedia.org/wiki/LEB128)
 530  * Input is limited to 14-bit numbers
 531  */
 532 int uleb128_encode_small(uint8_t *out, uint32_t n)
 533 {
 534     g_assert(n <= 0x3fff);
 535     if (n < 0x80) {
 536         *out++ = n;
 537         return 1;
 538     } else {
 539         *out++ = (n & 0x7f) | 0x80;
 540         *out++ = n >> 7;
 541         return 2;
 542     }
 543 }
 544
 545 int uleb128_decode_small(const uint8_t *in, uint32_t *n)
 546 {
 547     if (!(*in & 0x80)) {
 548         *n = *in++;
 549         return 1;
 550     } else {
 551         *n = *in++ & 0x7f;
 552         /* we exceed 14 bit number */
 553         if (*in & 0x80) {
 554             return -1;
 555         }
 556         *n |= *in++ << 7;
 557         return 2;
 558     }
 559 }
 560
 561 /*
 562  * helper to parse debug environment variables
 563  */
 564 int parse_debug_env(const char *name, int max, int initial)
 565 {
 566     char *debug_env = getenv(name);
 567     char *inv = NULL;
 568     long debug;
 569
 570     if (!debug_env) {
 571         return initial;
 572     }
 573     errno = 0;
 574     debug = strtol(debug_env, &inv, 10);
 575     if (inv == debug_env) {
 576         return initial;
 577     }
 578     if (debug < 0 || debug > max || errno != 0) {
 579         fprintf(stderr, "warning: %s not in [0, %d]", name, max);
 580         return initial;
 581     }
 582     return debug;
 583 }
 584
 585 /*
 586  * Helper to print ethernet mac address
 587  */
 588 const char *qemu_ether_ntoa(const MACAddr *mac)
 589 {
 590     static char ret[18];
 591
 592     snprintf(ret, sizeof(ret), "%02x:%02x:%02x:%02x:%02x:%02x",
 593              mac->a[0], mac->a[1], mac->a[2], mac->a[3], mac->a[4], mac->a[5]);
 594
 595     return ret;
 596 }