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 STRTOSZ_DEFSUFFIX_B:
 280         return 1;
 281     case STRTOSZ_DEFSUFFIX_KB:
 282         return unit;
 283     case STRTOSZ_DEFSUFFIX_MB:
 284         return unit * unit;
 285     case STRTOSZ_DEFSUFFIX_GB:
 286         return unit * unit * unit;
 287     case STRTOSZ_DEFSUFFIX_TB:
 288         return unit * unit * unit * unit;
 289     case STRTOSZ_DEFSUFFIX_PB:
 290         return unit * unit * unit * unit * unit;
 291     case 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 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 strtosz_suffix(const char *nptr, char **end, const char default_suffix)
 347 {
 348     return strtosz_suffix_unit(nptr, end, default_suffix, 1024);
 349 }
 350
 351 int64_t strtosz(const char *nptr, char **end)
 352 {
 353     return strtosz_suffix(nptr, end, STRTOSZ_DEFSUFFIX_MB);
 354 }
 355
 356 /**
 357  * Helper function for qemu_strto*l() functions.
 358  */
 359 static int check_strtox_error(const char *p, char *endptr, const char **next,
 360                               int err)
 361 {
 362     /* If no conversion was performed, prefer BSD behavior over glibc
 363      * behavior.
 364      */
 365     if (err == 0 && endptr == p) {
 366         err = EINVAL;
 367     }
 368     if (!next && *endptr) {
 369         return -EINVAL;
 370     }
 371     if (next) {
 372         *next = endptr;
 373     }
 374     return -err;
 375 }
 376
 377 /**
 378  * QEMU wrappers for strtol(), strtoll(), strtoul(), strotull() C functions.
 379  *
 380  * Convert ASCII string @nptr to a long integer value
 381  * from the given @base. Parameters @nptr, @endptr, @base
 382  * follows same semantics as strtol() C function.
 383  *
 384  * Unlike from strtol() function, if @endptr is not NULL, this
 385  * function will return -EINVAL whenever it cannot fully convert
 386  * the string in @nptr with given @base to a long. This function returns
 387  * the result of the conversion only through the @result parameter.
 388  *
 389  * If NULL is passed in @endptr, then the whole string in @ntpr
 390  * is a number otherwise it returns -EINVAL.
 391  *
 392  * RETURN VALUE
 393  * Unlike from strtol() function, this wrapper returns either
 394  * -EINVAL or the errno set by strtol() function (e.g -ERANGE).
 395  * If the conversion overflows, -ERANGE is returned, and @result
 396  * is set to the max value of the desired type
 397  * (e.g. LONG_MAX, LLONG_MAX, ULONG_MAX, ULLONG_MAX). If the case
 398  * of underflow, -ERANGE is returned, and @result is set to the min
 399  * value of the desired type. For strtol(), strtoll(), @result is set to
 400  * LONG_MIN, LLONG_MIN, respectively, and for strtoul(), strtoull() it
 401  * is set to 0.
 402  */
 403 int qemu_strtol(const char *nptr, const char **endptr, int base,
 404                 long *result)
 405 {
 406     char *p;
 407     int err = 0;
 408     if (!nptr) {
 409         if (endptr) {
 410             *endptr = nptr;
 411         }
 412         err = -EINVAL;
 413     } else {
 414         errno = 0;
 415         *result = strtol(nptr, &p, base);
 416         err = check_strtox_error(nptr, p, endptr, errno);
 417     }
 418     return err;
 419 }
 420
 421 /**
 422  * Converts ASCII string to an unsigned long integer.
 423  *
 424  * If string contains a negative number, value will be converted to
 425  * the unsigned representation of the signed value, unless the original
 426  * (nonnegated) value would overflow, in this case, it will set @result
 427  * to ULONG_MAX, and return ERANGE.
 428  *
 429  * The same behavior holds, for qemu_strtoull() but sets @result to
 430  * ULLONG_MAX instead of ULONG_MAX.
 431  *
 432  * See qemu_strtol() documentation for more info.
 433  */
 434 int qemu_strtoul(const char *nptr, const char **endptr, int base,
 435                  unsigned long *result)
 436 {
 437     char *p;
 438     int err = 0;
 439     if (!nptr) {
 440         if (endptr) {
 441             *endptr = nptr;
 442         }
 443         err = -EINVAL;
 444     } else {
 445         errno = 0;
 446         *result = strtoul(nptr, &p, base);
 447         /* Windows returns 1 for negative out-of-range values.  */
 448         if (errno == ERANGE) {
 449             *result = -1;
 450         }
 451         err = check_strtox_error(nptr, p, endptr, errno);
 452     }
 453     return err;
 454 }
 455
 456 /**
 457  * Converts ASCII string to a long long integer.
 458  *
 459  * See qemu_strtol() documentation for more info.
 460  */
 461 int qemu_strtoll(const char *nptr, const char **endptr, int base,
 462                  int64_t *result)
 463 {
 464     char *p;
 465     int err = 0;
 466     if (!nptr) {
 467         if (endptr) {
 468             *endptr = nptr;
 469         }
 470         err = -EINVAL;
 471     } else {
 472         errno = 0;
 473         *result = strtoll(nptr, &p, base);
 474         err = check_strtox_error(nptr, p, endptr, errno);
 475     }
 476     return err;
 477 }
 478
 479 /**
 480  * Converts ASCII string to an unsigned long long integer.
 481  *
 482  * See qemu_strtol() documentation for more info.
 483  */
 484 int qemu_strtoull(const char *nptr, const char **endptr, int base,
 485                   uint64_t *result)
 486 {
 487     char *p;
 488     int err = 0;
 489     if (!nptr) {
 490         if (endptr) {
 491             *endptr = nptr;
 492         }
 493         err = -EINVAL;
 494     } else {
 495         errno = 0;
 496         *result = strtoull(nptr, &p, base);
 497         /* Windows returns 1 for negative out-of-range values.  */
 498         if (errno == ERANGE) {
 499             *result = -1;
 500         }
 501         err = check_strtox_error(nptr, p, endptr, errno);
 502     }
 503     return err;
 504 }
 505
 506 /**
 507  * parse_uint:
 508  *
 509  * @s: String to parse
 510  * @value: Destination for parsed integer value
 511  * @endptr: Destination for pointer to first character not consumed
 512  * @base: integer base, between 2 and 36 inclusive, or 0
 513  *
 514  * Parse unsigned integer
 515  *
 516  * Parsed syntax is like strtoull()'s: arbitrary whitespace, a single optional
 517  * '+' or '-', an optional "0x" if @base is 0 or 16, one or more digits.
 518  *
 519  * If @s is null, or @base is invalid, or @s doesn't start with an
 520  * integer in the syntax above, set *@value to 0, *@endptr to @s, and
 521  * return -EINVAL.
 522  *
 523  * Set *@endptr to point right beyond the parsed integer (even if the integer
 524  * overflows or is negative, all digits will be parsed and *@endptr will
 525  * point right beyond them).
 526  *
 527  * If the integer is negative, set *@value to 0, and return -ERANGE.
 528  *
 529  * If the integer overflows unsigned long long, set *@value to
 530  * ULLONG_MAX, and return -ERANGE.
 531  *
 532  * Else, set *@value to the parsed integer, and return 0.
 533  */
 534 int parse_uint(const char *s, unsigned long long *value, char **endptr,
 535                int base)
 536 {
 537     int r = 0;
 538     char *endp = (char *)s;
 539     unsigned long long val = 0;
 540
 541     if (!s) {
 542         r = -EINVAL;
 543         goto out;
 544     }
 545
 546     errno = 0;
 547     val = strtoull(s, &endp, base);
 548     if (errno) {
 549         r = -errno;
 550         goto out;
 551     }
 552
 553     if (endp == s) {
 554         r = -EINVAL;
 555         goto out;
 556     }
 557
 558     /* make sure we reject negative numbers: */
 559     while (isspace((unsigned char)*s)) {
 560         s++;
 561     }
 562     if (*s == '-') {
 563         val = 0;
 564         r = -ERANGE;
 565         goto out;
 566     }
 567
 568 out:
 569     *value = val;
 570     *endptr = endp;
 571     return r;
 572 }
 573
 574 /**
 575  * parse_uint_full:
 576  *
 577  * @s: String to parse
 578  * @value: Destination for parsed integer value
 579  * @base: integer base, between 2 and 36 inclusive, or 0
 580  *
 581  * Parse unsigned integer from entire string
 582  *
 583  * Have the same behavior of parse_uint(), but with an additional check
 584  * for additional data after the parsed number. If extra characters are present
 585  * after the parsed number, the function will return -EINVAL, and *@v will
 586  * be set to 0.
 587  */
 588 int parse_uint_full(const char *s, unsigned long long *value, int base)
 589 {
 590     char *endp;
 591     int r;
 592
 593     r = parse_uint(s, value, &endp, base);
 594     if (r < 0) {
 595         return r;
 596     }
 597     if (*endp) {
 598         *value = 0;
 599         return -EINVAL;
 600     }
 601
 602     return 0;
 603 }
 604
 605 int qemu_parse_fd(const char *param)
 606 {
 607     long fd;
 608     char *endptr;
 609
 610     errno = 0;
 611     fd = strtol(param, &endptr, 10);
 612     if (param == endptr /* no conversion performed */                    ||
 613         errno != 0      /* not representable as long; possibly others */ ||
 614         *endptr != '\0' /* final string not empty */                     ||
 615         fd < 0          /* invalid as file descriptor */                 ||
 616         fd > INT_MAX    /* not representable as int */) {
 617         return -1;
 618     }
 619     return fd;
 620 }
 621
 622 /*
 623  * Implementation of  ULEB128 (http://en.wikipedia.org/wiki/LEB128)
 624  * Input is limited to 14-bit numbers
 625  */
 626 int uleb128_encode_small(uint8_t *out, uint32_t n)
 627 {
 628     g_assert(n <= 0x3fff);
 629     if (n < 0x80) {
 630         *out++ = n;
 631         return 1;
 632     } else {
 633         *out++ = (n & 0x7f) | 0x80;
 634         *out++ = n >> 7;
 635         return 2;
 636     }
 637 }
 638
 639 int uleb128_decode_small(const uint8_t *in, uint32_t *n)
 640 {
 641     if (!(*in & 0x80)) {
 642         *n = *in++;
 643         return 1;
 644     } else {
 645         *n = *in++ & 0x7f;
 646         /* we exceed 14 bit number */
 647         if (*in & 0x80) {
 648             return -1;
 649         }
 650         *n |= *in++ << 7;
 651         return 2;
 652     }
 653 }
 654
 655 /*
 656  * helper to parse debug environment variables
 657  */
 658 int parse_debug_env(const char *name, int max, int initial)
 659 {
 660     char *debug_env = getenv(name);
 661     char *inv = NULL;
 662     long debug;
 663
 664     if (!debug_env) {
 665         return initial;
 666     }
 667     errno = 0;
 668     debug = strtol(debug_env, &inv, 10);
 669     if (inv == debug_env) {
 670         return initial;
 671     }
 672     if (debug < 0 || debug > max || errno != 0) {
 673         fprintf(stderr, "warning: %s not in [0, %d]", name, max);
 674         return initial;
 675     }
 676     return debug;
 677 }
 678
 679 /*
 680  * Helper to print ethernet mac address
 681  */
 682 const char *qemu_ether_ntoa(const MACAddr *mac)
 683 {
 684     static char ret[18];
 685
 686     snprintf(ret, sizeof(ret), "%02x:%02x:%02x:%02x:%02x:%02x",
 687              mac->a[0], mac->a[1], mac->a[2], mac->a[3], mac->a[4], mac->a[5]);
 688
 689     return ret;
 690 }