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-common.h"
  25 #include "qemu/host-utils.h"
  26 #include <math.h>
  27 #include <limits.h>
  28 #include <errno.h>
  29
  30 #include "qemu/sockets.h"
  31 #include "qemu/iov.h"
  32 #include "net/net.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 /*
 165  * Searches for an area with non-zero content in a buffer
 166  *
 167  * Attention! The len must be a multiple of
 168  * BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR * sizeof(VECTYPE)
 169  * and addr must be a multiple of sizeof(VECTYPE) due to
 170  * restriction of optimizations in this function.
 171  *
 172  * can_use_buffer_find_nonzero_offset() can be used to check
 173  * these requirements.
 174  *
 175  * The return value is the offset of the non-zero area rounded
 176  * down to a multiple of sizeof(VECTYPE) for the first
 177  * BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR chunks and down to
 178  * BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR * sizeof(VECTYPE)
 179  * afterwards.
 180  *
 181  * If the buffer is all zero the return value is equal to len.
 182  */
 183
 184 size_t buffer_find_nonzero_offset(const void *buf, size_t len)
 185 {
 186     const VECTYPE *p = buf;
 187     const VECTYPE zero = (VECTYPE){0};
 188     size_t i;
 189
 190     assert(can_use_buffer_find_nonzero_offset(buf, len));
 191
 192     if (!len) {
 193         return 0;
 194     }
 195
 196     for (i = 0; i < BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR; i++) {
 197         if (!ALL_EQ(p[i], zero)) {
 198             return i * sizeof(VECTYPE);
 199         }
 200     }
 201
 202     for (i = BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR;
 203          i < len / sizeof(VECTYPE);
 204          i += BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR) {
 205         VECTYPE tmp0 = VEC_OR(p[i + 0], p[i + 1]);
 206         VECTYPE tmp1 = VEC_OR(p[i + 2], p[i + 3]);
 207         VECTYPE tmp2 = VEC_OR(p[i + 4], p[i + 5]);
 208         VECTYPE tmp3 = VEC_OR(p[i + 6], p[i + 7]);
 209         VECTYPE tmp01 = VEC_OR(tmp0, tmp1);
 210         VECTYPE tmp23 = VEC_OR(tmp2, tmp3);
 211         if (!ALL_EQ(VEC_OR(tmp01, tmp23), zero)) {
 212             break;
 213         }
 214     }
 215
 216     return i * sizeof(VECTYPE);
 217 }
 218
 219 /*
 220  * Checks if a buffer is all zeroes
 221  *
 222  * Attention! The len must be a multiple of 4 * sizeof(long) due to
 223  * restriction of optimizations in this function.
 224  */
 225 bool buffer_is_zero(const void *buf, size_t len)
 226 {
 227     /*
 228      * Use long as the biggest available internal data type that fits into the
 229      * CPU register and unroll the loop to smooth out the effect of memory
 230      * latency.
 231      */
 232
 233     size_t i;
 234     long d0, d1, d2, d3;
 235     const long * const data = buf;
 236
 237     /* use vector optimized zero check if possible */
 238     if (can_use_buffer_find_nonzero_offset(buf, len)) {
 239         return buffer_find_nonzero_offset(buf, len) == len;
 240     }
 241
 242     assert(len % (4 * sizeof(long)) == 0);
 243     len /= sizeof(long);
 244
 245     for (i = 0; i < len; i += 4) {
 246         d0 = data[i + 0];
 247         d1 = data[i + 1];
 248         d2 = data[i + 2];
 249         d3 = data[i + 3];
 250
 251         if (d0 || d1 || d2 || d3) {
 252             return false;
 253         }
 254     }
 255
 256     return true;
 257 }
 258
 259 #ifndef _WIN32
 260 /* Sets a specific flag */
 261 int fcntl_setfl(int fd, int flag)
 262 {
 263     int flags;
 264
 265     flags = fcntl(fd, F_GETFL);
 266     if (flags == -1)
 267         return -errno;
 268
 269     if (fcntl(fd, F_SETFL, flags | flag) == -1)
 270         return -errno;
 271
 272     return 0;
 273 }
 274 #endif
 275
 276 static int64_t suffix_mul(char suffix, int64_t unit)
 277 {
 278     switch (qemu_toupper(suffix)) {
 279     case QEMU_STRTOSZ_DEFSUFFIX_B:
 280         return 1;
 281     case QEMU_STRTOSZ_DEFSUFFIX_KB:
 282         return unit;
 283     case QEMU_STRTOSZ_DEFSUFFIX_MB:
 284         return unit * unit;
 285     case QEMU_STRTOSZ_DEFSUFFIX_GB:
 286         return unit * unit * unit;
 287     case QEMU_STRTOSZ_DEFSUFFIX_TB:
 288         return unit * unit * unit * unit;
 289     case QEMU_STRTOSZ_DEFSUFFIX_PB:
 290         return unit * unit * unit * unit * unit;
 291     case QEMU_STRTOSZ_DEFSUFFIX_EB:
 292         return unit * unit * unit * unit * unit * unit;
 293     }
 294     return -1;
 295 }
 296
 297 /*
 298  * Convert string to bytes, allowing either B/b for bytes, K/k for KB,
 299  * M/m for MB, G/g for GB or T/t for TB. End pointer will be returned
 300  * in *end, if not NULL. Return -ERANGE on overflow, Return -EINVAL on
 301  * other error.
 302  */
 303 int64_t qemu_strtosz_suffix_unit(const char *nptr, char **end,
 304                             const char default_suffix, int64_t unit)
 305 {
 306     int64_t retval = -EINVAL;
 307     char *endptr;
 308     unsigned char c;
 309     int mul_required = 0;
 310     double val, mul, integral, fraction;
 311
 312     errno = 0;
 313     val = strtod(nptr, &endptr);
 314     if (isnan(val) || endptr == nptr || errno != 0) {
 315         goto fail;
 316     }
 317     fraction = modf(val, &integral);
 318     if (fraction != 0) {
 319         mul_required = 1;
 320     }
 321     c = *endptr;
 322     mul = suffix_mul(c, unit);
 323     if (mul >= 0) {
 324         endptr++;
 325     } else {
 326         mul = suffix_mul(default_suffix, unit);
 327         assert(mul >= 0);
 328     }
 329     if (mul == 1 && mul_required) {
 330         goto fail;
 331     }
 332     if ((val * mul >= INT64_MAX) || val < 0) {
 333         retval = -ERANGE;
 334         goto fail;
 335     }
 336     retval = val * mul;
 337
 338 fail:
 339     if (end) {
 340         *end = endptr;
 341     }
 342
 343     return retval;
 344 }
 345
 346 int64_t qemu_strtosz_suffix(const char *nptr, char **end,
 347                             const char default_suffix)
 348 {
 349     return qemu_strtosz_suffix_unit(nptr, end, default_suffix, 1024);
 350 }
 351
 352 int64_t qemu_strtosz(const char *nptr, char **end)
 353 {
 354     return qemu_strtosz_suffix(nptr, end, QEMU_STRTOSZ_DEFSUFFIX_MB);
 355 }
 356
 357 /**
 358  * Helper function for qemu_strto*l() functions.
 359  */
 360 static int check_strtox_error(const char *p, char *endptr, const char **next,
 361                               int err)
 362 {
 363     /* If no conversion was performed, prefer BSD behavior over glibc
 364      * behavior.
 365      */
 366     if (err == 0 && endptr == p) {
 367         err = EINVAL;
 368     }
 369     if (!next && *endptr) {
 370         return -EINVAL;
 371     }
 372     if (next) {
 373         *next = endptr;
 374     }
 375     return -err;
 376 }
 377
 378 /**
 379  * QEMU wrappers for strtol(), strtoll(), strtoul(), strotull() C functions.
 380  *
 381  * Convert ASCII string @nptr to a long integer value
 382  * from the given @base. Parameters @nptr, @endptr, @base
 383  * follows same semantics as strtol() C function.
 384  *
 385  * Unlike from strtol() function, if @endptr is not NULL, this
 386  * function will return -EINVAL whenever it cannot fully convert
 387  * the string in @nptr with given @base to a long. This function returns
 388  * the result of the conversion only through the @result parameter.
 389  *
 390  * If NULL is passed in @endptr, then the whole string in @ntpr
 391  * is a number otherwise it returns -EINVAL.
 392  *
 393  * RETURN VALUE
 394  * Unlike from strtol() function, this wrapper returns either
 395  * -EINVAL or the errno set by strtol() function (e.g -ERANGE).
 396  * If the conversion overflows, -ERANGE is returned, and @result
 397  * is set to the max value of the desired type
 398  * (e.g. LONG_MAX, LLONG_MAX, ULONG_MAX, ULLONG_MAX). If the case
 399  * of underflow, -ERANGE is returned, and @result is set to the min
 400  * value of the desired type. For strtol(), strtoll(), @result is set to
 401  * LONG_MIN, LLONG_MIN, respectively, and for strtoul(), strtoull() it
 402  * is set to 0.
 403  */
 404 int qemu_strtol(const char *nptr, const char **endptr, int base,
 405                 long *result)
 406 {
 407     char *p;
 408     int err = 0;
 409     if (!nptr) {
 410         if (endptr) {
 411             *endptr = nptr;
 412         }
 413         err = -EINVAL;
 414     } else {
 415         errno = 0;
 416         *result = strtol(nptr, &p, base);
 417         err = check_strtox_error(nptr, p, endptr, errno);
 418     }
 419     return err;
 420 }
 421
 422 /**
 423  * Converts ASCII string to an unsigned long integer.
 424  *
 425  * If string contains a negative number, value will be converted to
 426  * the unsigned representation of the signed value, unless the original
 427  * (nonnegated) value would overflow, in this case, it will set @result
 428  * to ULONG_MAX, and return ERANGE.
 429  *
 430  * The same behavior holds, for qemu_strtoull() but sets @result to
 431  * ULLONG_MAX instead of ULONG_MAX.
 432  *
 433  * See qemu_strtol() documentation for more info.
 434  */
 435 int qemu_strtoul(const char *nptr, const char **endptr, int base,
 436                  unsigned long *result)
 437 {
 438     char *p;
 439     int err = 0;
 440     if (!nptr) {
 441         if (endptr) {
 442             *endptr = nptr;
 443         }
 444         err = -EINVAL;
 445     } else {
 446         errno = 0;
 447         *result = strtoul(nptr, &p, base);
 448         /* Windows returns 1 for negative out-of-range values.  */
 449         if (errno == ERANGE) {
 450             *result = -1;
 451         }
 452         err = check_strtox_error(nptr, p, endptr, errno);
 453     }
 454     return err;
 455 }
 456
 457 /**
 458  * Converts ASCII string to a long long integer.
 459  *
 460  * See qemu_strtol() documentation for more info.
 461  */
 462 int qemu_strtoll(const char *nptr, const char **endptr, int base,
 463                  int64_t *result)
 464 {
 465     char *p;
 466     int err = 0;
 467     if (!nptr) {
 468         if (endptr) {
 469             *endptr = nptr;
 470         }
 471         err = -EINVAL;
 472     } else {
 473         errno = 0;
 474         *result = strtoll(nptr, &p, base);
 475         err = check_strtox_error(nptr, p, endptr, errno);
 476     }
 477     return err;
 478 }
 479
 480 /**
 481  * Converts ASCII string to an unsigned long long integer.
 482  *
 483  * See qemu_strtol() documentation for more info.
 484  */
 485 int qemu_strtoull(const char *nptr, const char **endptr, int base,
 486                   uint64_t *result)
 487 {
 488     char *p;
 489     int err = 0;
 490     if (!nptr) {
 491         if (endptr) {
 492             *endptr = nptr;
 493         }
 494         err = -EINVAL;
 495     } else {
 496         errno = 0;
 497         *result = strtoull(nptr, &p, base);
 498         /* Windows returns 1 for negative out-of-range values.  */
 499         if (errno == ERANGE) {
 500             *result = -1;
 501         }
 502         err = check_strtox_error(nptr, p, endptr, errno);
 503     }
 504     return err;
 505 }
 506
 507 /**
 508  * parse_uint:
 509  *
 510  * @s: String to parse
 511  * @value: Destination for parsed integer value
 512  * @endptr: Destination for pointer to first character not consumed
 513  * @base: integer base, between 2 and 36 inclusive, or 0
 514  *
 515  * Parse unsigned integer
 516  *
 517  * Parsed syntax is like strtoull()'s: arbitrary whitespace, a single optional
 518  * '+' or '-', an optional "0x" if @base is 0 or 16, one or more digits.
 519  *
 520  * If @s is null, or @base is invalid, or @s doesn't start with an
 521  * integer in the syntax above, set *@value to 0, *@endptr to @s, and
 522  * return -EINVAL.
 523  *
 524  * Set *@endptr to point right beyond the parsed integer (even if the integer
 525  * overflows or is negative, all digits will be parsed and *@endptr will
 526  * point right beyond them).
 527  *
 528  * If the integer is negative, set *@value to 0, and return -ERANGE.
 529  *
 530  * If the integer overflows unsigned long long, set *@value to
 531  * ULLONG_MAX, and return -ERANGE.
 532  *
 533  * Else, set *@value to the parsed integer, and return 0.
 534  */
 535 int parse_uint(const char *s, unsigned long long *value, char **endptr,
 536                int base)
 537 {
 538     int r = 0;
 539     char *endp = (char *)s;
 540     unsigned long long val = 0;
 541
 542     if (!s) {
 543         r = -EINVAL;
 544         goto out;
 545     }
 546
 547     errno = 0;
 548     val = strtoull(s, &endp, base);
 549     if (errno) {
 550         r = -errno;
 551         goto out;
 552     }
 553
 554     if (endp == s) {
 555         r = -EINVAL;
 556         goto out;
 557     }
 558
 559     /* make sure we reject negative numbers: */
 560     while (isspace((unsigned char)*s)) {
 561         s++;
 562     }
 563     if (*s == '-') {
 564         val = 0;
 565         r = -ERANGE;
 566         goto out;
 567     }
 568
 569 out:
 570     *value = val;
 571     *endptr = endp;
 572     return r;
 573 }
 574
 575 /**
 576  * parse_uint_full:
 577  *
 578  * @s: String to parse
 579  * @value: Destination for parsed integer value
 580  * @base: integer base, between 2 and 36 inclusive, or 0
 581  *
 582  * Parse unsigned integer from entire string
 583  *
 584  * Have the same behavior of parse_uint(), but with an additional check
 585  * for additional data after the parsed number. If extra characters are present
 586  * after the parsed number, the function will return -EINVAL, and *@v will
 587  * be set to 0.
 588  */
 589 int parse_uint_full(const char *s, unsigned long long *value, int base)
 590 {
 591     char *endp;
 592     int r;
 593
 594     r = parse_uint(s, value, &endp, base);
 595     if (r < 0) {
 596         return r;
 597     }
 598     if (*endp) {
 599         *value = 0;
 600         return -EINVAL;
 601     }
 602
 603     return 0;
 604 }
 605
 606 int qemu_parse_fd(const char *param)
 607 {
 608     long fd;
 609     char *endptr;
 610
 611     errno = 0;
 612     fd = strtol(param, &endptr, 10);
 613     if (param == endptr /* no conversion performed */                    ||
 614         errno != 0      /* not representable as long; possibly others */ ||
 615         *endptr != '\0' /* final string not empty */                     ||
 616         fd < 0          /* invalid as file descriptor */                 ||
 617         fd > INT_MAX    /* not representable as int */) {
 618         return -1;
 619     }
 620     return fd;
 621 }
 622
 623 /*
 624  * Implementation of  ULEB128 (http://en.wikipedia.org/wiki/LEB128)
 625  * Input is limited to 14-bit numbers
 626  */
 627 int uleb128_encode_small(uint8_t *out, uint32_t n)
 628 {
 629     g_assert(n <= 0x3fff);
 630     if (n < 0x80) {
 631         *out++ = n;
 632         return 1;
 633     } else {
 634         *out++ = (n & 0x7f) | 0x80;
 635         *out++ = n >> 7;
 636         return 2;
 637     }
 638 }
 639
 640 int uleb128_decode_small(const uint8_t *in, uint32_t *n)
 641 {
 642     if (!(*in & 0x80)) {
 643         *n = *in++;
 644         return 1;
 645     } else {
 646         *n = *in++ & 0x7f;
 647         /* we exceed 14 bit number */
 648         if (*in & 0x80) {
 649             return -1;
 650         }
 651         *n |= *in++ << 7;
 652         return 2;
 653     }
 654 }
 655
 656 /*
 657  * helper to parse debug environment variables
 658  */
 659 int parse_debug_env(const char *name, int max, int initial)
 660 {
 661     char *debug_env = getenv(name);
 662     char *inv = NULL;
 663     long debug;
 664
 665     if (!debug_env) {
 666         return initial;
 667     }
 668     errno = 0;
 669     debug = strtol(debug_env, &inv, 10);
 670     if (inv == debug_env) {
 671         return initial;
 672     }
 673     if (debug < 0 || debug > max || errno != 0) {
 674         fprintf(stderr, "warning: %s not in [0, %d]", name, max);
 675         return initial;
 676     }
 677     return debug;
 678 }
 679
 680 /*
 681  * Helper to print ethernet mac address
 682  */
 683 const char *qemu_ether_ntoa(const MACAddr *mac)
 684 {
 685     static char ret[18];
 686
 687     snprintf(ret, sizeof(ret), "%02x:%02x:%02x:%02x:%02x:%02x",
 688              mac->a[0], mac->a[1], mac->a[2], mac->a[3], mac->a[4], mac->a[5]);
 689
 690     return ret;
 691 }