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 #elif defined(_WIN64)
 160     /* TODO: Implement fsync for w64, too. */
 161     return NOERROR;
 162 #else
 163     return fsync(fd);
 164 #endif
 165 }
 166
 167 /*
 168  * Searches for an area with non-zero content in a buffer
 169  *
 170  * Attention! The len must be a multiple of
 171  * BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR * sizeof(VECTYPE)
 172  * and addr must be a multiple of sizeof(VECTYPE) due to
 173  * restriction of optimizations in this function.
 174  *
 175  * can_use_buffer_find_nonzero_offset() can be used to check
 176  * these requirements.
 177  *
 178  * The return value is the offset of the non-zero area rounded
 179  * down to a multiple of sizeof(VECTYPE) for the first
 180  * BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR chunks and down to
 181  * BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR * sizeof(VECTYPE)
 182  * afterwards.
 183  *
 184  * If the buffer is all zero the return value is equal to len.
 185  */
 186
 187 size_t buffer_find_nonzero_offset(const void *buf, size_t len)
 188 {
 189     const VECTYPE *p = buf;
 190     const VECTYPE zero = (VECTYPE){0};
 191     size_t i;
 192
 193     assert(can_use_buffer_find_nonzero_offset(buf, len));
 194
 195     if (!len) {
 196         return 0;
 197     }
 198
 199     for (i = 0; i < BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR; i++) {
 200         if (!ALL_EQ(p[i], zero)) {
 201             return i * sizeof(VECTYPE);
 202         }
 203     }
 204
 205     for (i = BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR;
 206          i < len / sizeof(VECTYPE);
 207          i += BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR) {
 208         VECTYPE tmp0 = VEC_OR(p[i + 0], p[i + 1]);
 209         VECTYPE tmp1 = VEC_OR(p[i + 2], p[i + 3]);
 210         VECTYPE tmp2 = VEC_OR(p[i + 4], p[i + 5]);
 211         VECTYPE tmp3 = VEC_OR(p[i + 6], p[i + 7]);
 212         VECTYPE tmp01 = VEC_OR(tmp0, tmp1);
 213         VECTYPE tmp23 = VEC_OR(tmp2, tmp3);
 214         if (!ALL_EQ(VEC_OR(tmp01, tmp23), zero)) {
 215             break;
 216         }
 217     }
 218
 219     return i * sizeof(VECTYPE);
 220 }
 221
 222 /*
 223  * Checks if a buffer is all zeroes
 224  *
 225  * Attention! The len must be a multiple of 4 * sizeof(long) due to
 226  * restriction of optimizations in this function.
 227  */
 228 bool buffer_is_zero(const void *buf, size_t len)
 229 {
 230     /*
 231      * Use long as the biggest available internal data type that fits into the
 232      * CPU register and unroll the loop to smooth out the effect of memory
 233      * latency.
 234      */
 235
 236     size_t i;
 237     long d0, d1, d2, d3;
 238     const long * const data = buf;
 239
 240     /* use vector optimized zero check if possible */
 241     if (can_use_buffer_find_nonzero_offset(buf, len)) {
 242         return buffer_find_nonzero_offset(buf, len) == len;
 243     }
 244
 245     assert(len % (4 * sizeof(long)) == 0);
 246     len /= sizeof(long);
 247
 248     for (i = 0; i < len; i += 4) {
 249         d0 = data[i + 0];
 250         d1 = data[i + 1];
 251         d2 = data[i + 2];
 252         d3 = data[i + 3];
 253
 254         if (d0 || d1 || d2 || d3) {
 255             return false;
 256         }
 257     }
 258
 259     return true;
 260 }
 261
 262 #ifndef _WIN32
 263 /* Sets a specific flag */
 264 int fcntl_setfl(int fd, int flag)
 265 {
 266     int flags;
 267
 268     flags = fcntl(fd, F_GETFL);
 269     if (flags == -1)
 270         return -errno;
 271
 272     if (fcntl(fd, F_SETFL, flags | flag) == -1)
 273         return -errno;
 274
 275     return 0;
 276 }
 277 #endif
 278
 279 static int64_t suffix_mul(char suffix, int64_t unit)
 280 {
 281     switch (qemu_toupper(suffix)) {
 282     case QEMU_STRTOSZ_DEFSUFFIX_B:
 283         return 1;
 284     case QEMU_STRTOSZ_DEFSUFFIX_KB:
 285         return unit;
 286     case QEMU_STRTOSZ_DEFSUFFIX_MB:
 287         return unit * unit;
 288     case QEMU_STRTOSZ_DEFSUFFIX_GB:
 289         return unit * unit * unit;
 290     case QEMU_STRTOSZ_DEFSUFFIX_TB:
 291         return unit * unit * unit * unit;
 292     case QEMU_STRTOSZ_DEFSUFFIX_PB:
 293         return unit * unit * unit * unit * unit;
 294     case QEMU_STRTOSZ_DEFSUFFIX_EB:
 295         return unit * unit * unit * unit * unit * unit;
 296     }
 297     return -1;
 298 }
 299
 300 /*
 301  * Convert string to bytes, allowing either B/b for bytes, K/k for KB,
 302  * M/m for MB, G/g for GB or T/t for TB. End pointer will be returned
 303  * in *end, if not NULL. Return -ERANGE on overflow, Return -EINVAL on
 304  * other error.
 305  */
 306 int64_t qemu_strtosz_suffix_unit(const char *nptr, char **end,
 307                             const char default_suffix, int64_t unit)
 308 {
 309     int64_t retval = -EINVAL;
 310     char *endptr;
 311     unsigned char c;
 312     int mul_required = 0;
 313     double val, mul, integral, fraction;
 314
 315     errno = 0;
 316     val = strtod(nptr, &endptr);
 317     if (isnan(val) || endptr == nptr || errno != 0) {
 318         goto fail;
 319     }
 320     fraction = modf(val, &integral);
 321     if (fraction != 0) {
 322         mul_required = 1;
 323     }
 324     c = *endptr;
 325     mul = suffix_mul(c, unit);
 326     if (mul >= 0) {
 327         endptr++;
 328     } else {
 329         mul = suffix_mul(default_suffix, unit);
 330         assert(mul >= 0);
 331     }
 332     if (mul == 1 && mul_required) {
 333         goto fail;
 334     }
 335     if ((val * mul >= INT64_MAX) || val < 0) {
 336         retval = -ERANGE;
 337         goto fail;
 338     }
 339     retval = val * mul;
 340
 341 fail:
 342     if (end) {
 343         *end = endptr;
 344     }
 345
 346     return retval;
 347 }
 348
 349 int64_t qemu_strtosz_suffix(const char *nptr, char **end,
 350                             const char default_suffix)
 351 {
 352     return qemu_strtosz_suffix_unit(nptr, end, default_suffix, 1024);
 353 }
 354
 355 int64_t qemu_strtosz(const char *nptr, char **end)
 356 {
 357     return qemu_strtosz_suffix(nptr, end, QEMU_STRTOSZ_DEFSUFFIX_MB);
 358 }
 359
 360 /**
 361  * Helper function for qemu_strto*l() functions.
 362  */
 363 static int check_strtox_error(const char *p, char *endptr, const char **next,
 364                               int err)
 365 {
 366     /* If no conversion was performed, prefer BSD behavior over glibc
 367      * behavior.
 368      */
 369     if (err == 0 && endptr == p) {
 370         err = EINVAL;
 371     }
 372     if (!next && *endptr) {
 373         return -EINVAL;
 374     }
 375     if (next) {
 376         *next = endptr;
 377     }
 378     return -err;
 379 }
 380
 381 /**
 382  * QEMU wrappers for strtol(), strtoll(), strtoul(), strotull() C functions.
 383  *
 384  * Convert ASCII string @nptr to a long integer value
 385  * from the given @base. Parameters @nptr, @endptr, @base
 386  * follows same semantics as strtol() C function.
 387  *
 388  * Unlike from strtol() function, if @endptr is not NULL, this
 389  * function will return -EINVAL whenever it cannot fully convert
 390  * the string in @nptr with given @base to a long. This function returns
 391  * the result of the conversion only through the @result parameter.
 392  *
 393  * If NULL is passed in @endptr, then the whole string in @ntpr
 394  * is a number otherwise it returns -EINVAL.
 395  *
 396  * RETURN VALUE
 397  * Unlike from strtol() function, this wrapper returns either
 398  * -EINVAL or the errno set by strtol() function (e.g -ERANGE).
 399  * If the conversion overflows, -ERANGE is returned, and @result
 400  * is set to the max value of the desired type
 401  * (e.g. LONG_MAX, LLONG_MAX, ULONG_MAX, ULLONG_MAX). If the case
 402  * of underflow, -ERANGE is returned, and @result is set to the min
 403  * value of the desired type. For strtol(), strtoll(), @result is set to
 404  * LONG_MIN, LLONG_MIN, respectively, and for strtoul(), strtoull() it
 405  * is set to 0.
 406  */
 407 int qemu_strtol(const char *nptr, const char **endptr, int base,
 408                 long *result)
 409 {
 410     char *p;
 411     int err = 0;
 412     if (!nptr) {
 413         if (endptr) {
 414             *endptr = nptr;
 415         }
 416         err = -EINVAL;
 417     } else {
 418         errno = 0;
 419         *result = strtol(nptr, &p, base);
 420         err = check_strtox_error(nptr, p, endptr, errno);
 421     }
 422     return err;
 423 }
 424
 425 /**
 426  * Converts ASCII string to an unsigned long integer.
 427  *
 428  * If string contains a negative number, value will be converted to
 429  * the unsigned representation of the signed value, unless the original
 430  * (nonnegated) value would overflow, in this case, it will set @result
 431  * to ULONG_MAX, and return ERANGE.
 432  *
 433  * The same behavior holds, for qemu_strtoull() but sets @result to
 434  * ULLONG_MAX instead of ULONG_MAX.
 435  *
 436  * See qemu_strtol() documentation for more info.
 437  */
 438 int qemu_strtoul(const char *nptr, const char **endptr, int base,
 439                  unsigned long *result)
 440 {
 441     char *p;
 442     int err = 0;
 443     if (!nptr) {
 444         if (endptr) {
 445             *endptr = nptr;
 446         }
 447         err = -EINVAL;
 448     } else {
 449         errno = 0;
 450         *result = strtoul(nptr, &p, base);
 451         /* Windows returns 1 for negative out-of-range values.  */
 452         if (errno == ERANGE) {
 453             *result = -1;
 454         }
 455         err = check_strtox_error(nptr, p, endptr, errno);
 456     }
 457     return err;
 458 }
 459
 460 /**
 461  * Converts ASCII string to a long long integer.
 462  *
 463  * See qemu_strtol() documentation for more info.
 464  */
 465 int qemu_strtoll(const char *nptr, const char **endptr, int base,
 466                  int64_t *result)
 467 {
 468     char *p;
 469     int err = 0;
 470     if (!nptr) {
 471         if (endptr) {
 472             *endptr = nptr;
 473         }
 474         err = -EINVAL;
 475     } else {
 476         errno = 0;
 477         *result = strtoll(nptr, &p, base);
 478         err = check_strtox_error(nptr, p, endptr, errno);
 479     }
 480     return err;
 481 }
 482
 483 /**
 484  * Converts ASCII string to an unsigned long long integer.
 485  *
 486  * See qemu_strtol() documentation for more info.
 487  */
 488 int qemu_strtoull(const char *nptr, const char **endptr, int base,
 489                   uint64_t *result)
 490 {
 491     char *p;
 492     int err = 0;
 493     if (!nptr) {
 494         if (endptr) {
 495             *endptr = nptr;
 496         }
 497         err = -EINVAL;
 498     } else {
 499         errno = 0;
 500         *result = strtoull(nptr, &p, base);
 501         /* Windows returns 1 for negative out-of-range values.  */
 502         if (errno == ERANGE) {
 503             *result = -1;
 504         }
 505         err = check_strtox_error(nptr, p, endptr, errno);
 506     }
 507     return err;
 508 }
 509
 510 /**
 511  * parse_uint:
 512  *
 513  * @s: String to parse
 514  * @value: Destination for parsed integer value
 515  * @endptr: Destination for pointer to first character not consumed
 516  * @base: integer base, between 2 and 36 inclusive, or 0
 517  *
 518  * Parse unsigned integer
 519  *
 520  * Parsed syntax is like strtoull()'s: arbitrary whitespace, a single optional
 521  * '+' or '-', an optional "0x" if @base is 0 or 16, one or more digits.
 522  *
 523  * If @s is null, or @base is invalid, or @s doesn't start with an
 524  * integer in the syntax above, set *@value to 0, *@endptr to @s, and
 525  * return -EINVAL.
 526  *
 527  * Set *@endptr to point right beyond the parsed integer (even if the integer
 528  * overflows or is negative, all digits will be parsed and *@endptr will
 529  * point right beyond them).
 530  *
 531  * If the integer is negative, set *@value to 0, and return -ERANGE.
 532  *
 533  * If the integer overflows unsigned long long, set *@value to
 534  * ULLONG_MAX, and return -ERANGE.
 535  *
 536  * Else, set *@value to the parsed integer, and return 0.
 537  */
 538 int parse_uint(const char *s, unsigned long long *value, char **endptr,
 539                int base)
 540 {
 541     int r = 0;
 542     char *endp = (char *)s;
 543     unsigned long long val = 0;
 544
 545     if (!s) {
 546         r = -EINVAL;
 547         goto out;
 548     }
 549
 550     errno = 0;
 551     val = strtoull(s, &endp, base);
 552     if (errno) {
 553         r = -errno;
 554         goto out;
 555     }
 556
 557     if (endp == s) {
 558         r = -EINVAL;
 559         goto out;
 560     }
 561
 562     /* make sure we reject negative numbers: */
 563     while (isspace((unsigned char)*s)) {
 564         s++;
 565     }
 566     if (*s == '-') {
 567         val = 0;
 568         r = -ERANGE;
 569         goto out;
 570     }
 571
 572 out:
 573     *value = val;
 574     *endptr = endp;
 575     return r;
 576 }
 577
 578 /**
 579  * parse_uint_full:
 580  *
 581  * @s: String to parse
 582  * @value: Destination for parsed integer value
 583  * @base: integer base, between 2 and 36 inclusive, or 0
 584  *
 585  * Parse unsigned integer from entire string
 586  *
 587  * Have the same behavior of parse_uint(), but with an additional check
 588  * for additional data after the parsed number. If extra characters are present
 589  * after the parsed number, the function will return -EINVAL, and *@v will
 590  * be set to 0.
 591  */
 592 int parse_uint_full(const char *s, unsigned long long *value, int base)
 593 {
 594     char *endp;
 595     int r;
 596
 597     r = parse_uint(s, value, &endp, base);
 598     if (r < 0) {
 599         return r;
 600     }
 601     if (*endp) {
 602         *value = 0;
 603         return -EINVAL;
 604     }
 605
 606     return 0;
 607 }
 608
 609 int qemu_parse_fd(const char *param)
 610 {
 611     long fd;
 612     char *endptr;
 613
 614     errno = 0;
 615     fd = strtol(param, &endptr, 10);
 616     if (param == endptr /* no conversion performed */                    ||
 617         errno != 0      /* not representable as long; possibly others */ ||
 618         *endptr != '\0' /* final string not empty */                     ||
 619         fd < 0          /* invalid as file descriptor */                 ||
 620         fd > INT_MAX    /* not representable as int */) {
 621         return -1;
 622     }
 623     return fd;
 624 }
 625
 626 /*
 627  * Implementation of  ULEB128 (http://en.wikipedia.org/wiki/LEB128)
 628  * Input is limited to 14-bit numbers
 629  */
 630 int uleb128_encode_small(uint8_t *out, uint32_t n)
 631 {
 632     g_assert(n <= 0x3fff);
 633     if (n < 0x80) {
 634         *out++ = n;
 635         return 1;
 636     } else {
 637         *out++ = (n & 0x7f) | 0x80;
 638         *out++ = n >> 7;
 639         return 2;
 640     }
 641 }
 642
 643 int uleb128_decode_small(const uint8_t *in, uint32_t *n)
 644 {
 645     if (!(*in & 0x80)) {
 646         *n = *in++;
 647         return 1;
 648     } else {
 649         *n = *in++ & 0x7f;
 650         /* we exceed 14 bit number */
 651         if (*in & 0x80) {
 652             return -1;
 653         }
 654         *n |= *in++ << 7;
 655         return 2;
 656     }
 657 }
 658
 659 /*
 660  * helper to parse debug environment variables
 661  */
 662 int parse_debug_env(const char *name, int max, int initial)
 663 {
 664     char *debug_env = getenv(name);
 665     char *inv = NULL;
 666     long debug;
 667
 668     if (!debug_env) {
 669         return initial;
 670     }
 671     errno = 0;
 672     debug = strtol(debug_env, &inv, 10);
 673     if (inv == debug_env) {
 674         return initial;
 675     }
 676     if (debug < 0 || debug > max || errno != 0) {
 677         fprintf(stderr, "warning: %s not in [0, %d]", name, max);
 678         return initial;
 679     }
 680     return debug;
 681 }
 682
 683 /*
 684  * Helper to print ethernet mac address
 685  */
 686 const char *qemu_ether_ntoa(const MACAddr *mac)
 687 {
 688     static char ret[18];
 689
 690     snprintf(ret, sizeof(ret), "%02x:%02x:%02x:%02x:%02x:%02x",
 691              mac->a[0], mac->a[1], mac->a[2], mac->a[3], mac->a[4], mac->a[5]);
 692
 693     return ret;
 694 }