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 #elif defined(_WIN64)
 160     /* TODO: Implement fsync for w64, too. */
 161     return NOERROR;
 162 #else
 163     return fsync(fd);
 164 #endif
 165 }
 166
 167 #ifndef _WIN32
 168 /* Sets a specific flag */
 169 int fcntl_setfl(int fd, int flag)
 170 {
 171     int flags;
 172
 173     flags = fcntl(fd, F_GETFL);
 174     if (flags == -1)
 175         return -errno;
 176
 177     if (fcntl(fd, F_SETFL, flags | flag) == -1)
 178         return -errno;
 179
 180     return 0;
 181 }
 182 #endif
 183
 184 static int64_t suffix_mul(char suffix, int64_t unit)
 185 {
 186     switch (qemu_toupper(suffix)) {
 187     case 'B':
 188         return 1;
 189     case 'K':
 190         return unit;
 191     case 'M':
 192         return unit * unit;
 193     case 'G':
 194         return unit * unit * unit;
 195     case 'T':
 196         return unit * unit * unit * unit;
 197     case 'P':
 198         return unit * unit * unit * unit * unit;
 199     case 'E':
 200         return unit * unit * unit * unit * unit * unit;
 201     }
 202     return -1;
 203 }
 204
 205 /*
 206  * Convert string to bytes, allowing either B/b for bytes, K/k for KB,
 207  * M/m for MB, G/g for GB or T/t for TB. End pointer will be returned
 208  * in *end, if not NULL. Return -ERANGE on overflow, Return -EINVAL on
 209  * other error.
 210  */
 211 static int do_strtosz(const char *nptr, char **end,
 212                       const char default_suffix, int64_t unit,
 213                       uint64_t *result)
 214 {
 215     int retval;
 216     char *endptr;
 217     unsigned char c;
 218     int mul_required = 0;
 219     double val, mul, integral, fraction;
 220
 221     errno = 0;
 222     val = strtod(nptr, &endptr);
 223     if (isnan(val) || endptr == nptr || errno != 0) {
 224         retval = -EINVAL;
 225         goto out;
 226     }
 227     fraction = modf(val, &integral);
 228     if (fraction != 0) {
 229         mul_required = 1;
 230     }
 231     c = *endptr;
 232     mul = suffix_mul(c, unit);
 233     if (mul >= 0) {
 234         endptr++;
 235     } else {
 236         mul = suffix_mul(default_suffix, unit);
 237         assert(mul >= 0);
 238     }
 239     if (mul == 1 && mul_required) {
 240         retval = -EINVAL;
 241         goto out;
 242     }
 243     /*
 244      * Values >= 0xfffffffffffffc00 overflow uint64_t after their trip
 245      * through double (53 bits of precision).
 246      */
 247     if ((val * mul >= 0xfffffffffffffc00) || val < 0) {
 248         retval = -ERANGE;
 249         goto out;
 250     }
 251     *result = val * mul;
 252     retval = 0;
 253
 254 out:
 255     if (end) {
 256         *end = endptr;
 257     } else if (*endptr) {
 258         retval = -EINVAL;
 259     }
 260
 261     return retval;
 262 }
 263
 264 int qemu_strtosz(const char *nptr, char **end, uint64_t *result)
 265 {
 266     return do_strtosz(nptr, end, 'B', 1024, result);
 267 }
 268
 269 int qemu_strtosz_MiB(const char *nptr, char **end, uint64_t *result)
 270 {
 271     return do_strtosz(nptr, end, 'M', 1024, result);
 272 }
 273
 274 int qemu_strtosz_metric(const char *nptr, char **end, uint64_t *result)
 275 {
 276     return do_strtosz(nptr, end, 'B', 1000, result);
 277 }
 278
 279 /**
 280  * Helper function for error checking after strtol() and the like
 281  */
 282 static int check_strtox_error(const char *nptr, char *ep,
 283                               const char **endptr, int libc_errno)
 284 {
 285     if (endptr) {
 286         *endptr = ep;
 287     }
 288
 289     /* Turn "no conversion" into an error */
 290     if (libc_errno == 0 && ep == nptr) {
 291         return -EINVAL;
 292     }
 293
 294     /* Fail when we're expected to consume the string, but didn't */
 295     if (!endptr && *ep) {
 296         return -EINVAL;
 297     }
 298
 299     return -libc_errno;
 300 }
 301
 302 /**
 303  * Convert string @nptr to a long integer, and store it in @result.
 304  *
 305  * This is a wrapper around strtol() that is harder to misuse.
 306  * Semantics of @nptr, @endptr, @base match strtol() with differences
 307  * noted below.
 308  *
 309  * @nptr may be null, and no conversion is performed then.
 310  *
 311  * If no conversion is performed, store @nptr in *@endptr and return
 312  * -EINVAL.
 313  *
 314  * If @endptr is null, and the string isn't fully converted, return
 315  * -EINVAL.  This is the case when the pointer that would be stored in
 316  * a non-null @endptr points to a character other than '\0'.
 317  *
 318  * If the conversion overflows @result, store LONG_MAX in @result,
 319  * and return -ERANGE.
 320  *
 321  * If the conversion underflows @result, store LONG_MIN in @result,
 322  * and return -ERANGE.
 323  *
 324  * Else store the converted value in @result, and return zero.
 325  */
 326 int qemu_strtol(const char *nptr, const char **endptr, int base,
 327                 long *result)
 328 {
 329     char *ep;
 330
 331     if (!nptr) {
 332         if (endptr) {
 333             *endptr = nptr;
 334         }
 335         return -EINVAL;
 336     }
 337
 338     errno = 0;
 339     *result = strtol(nptr, &ep, base);
 340     return check_strtox_error(nptr, ep, endptr, errno);
 341 }
 342
 343 /**
 344  * Convert string @nptr to an unsigned long, and store it in @result.
 345  *
 346  * This is a wrapper around strtoul() that is harder to misuse.
 347  * Semantics of @nptr, @endptr, @base match strtoul() with differences
 348  * noted below.
 349  *
 350  * @nptr may be null, and no conversion is performed then.
 351  *
 352  * If no conversion is performed, store @nptr in *@endptr and return
 353  * -EINVAL.
 354  *
 355  * If @endptr is null, and the string isn't fully converted, return
 356  * -EINVAL.  This is the case when the pointer that would be stored in
 357  * a non-null @endptr points to a character other than '\0'.
 358  *
 359  * If the conversion overflows @result, store ULONG_MAX in @result,
 360  * and return -ERANGE.
 361  *
 362  * Else store the converted value in @result, and return zero.
 363  *
 364  * Note that a number with a leading minus sign gets converted without
 365  * the minus sign, checked for overflow (see above), then negated (in
 366  * @result's type).  This is exactly how strtoul() works.
 367  */
 368 int qemu_strtoul(const char *nptr, const char **endptr, int base,
 369                  unsigned long *result)
 370 {
 371     char *ep;
 372
 373     if (!nptr) {
 374         if (endptr) {
 375             *endptr = nptr;
 376         }
 377         return -EINVAL;
 378     }
 379
 380     errno = 0;
 381     *result = strtoul(nptr, &ep, base);
 382     /* Windows returns 1 for negative out-of-range values.  */
 383     if (errno == ERANGE) {
 384         *result = -1;
 385     }
 386     return check_strtox_error(nptr, ep, endptr, errno);
 387 }
 388
 389 /**
 390  * Convert string @nptr to an int64_t.
 391  *
 392  * Works like qemu_strtol(), except it stores INT64_MAX on overflow,
 393  * and INT_MIN on underflow.
 394  */
 395 int qemu_strtoi64(const char *nptr, const char **endptr, int base,
 396                  int64_t *result)
 397 {
 398     char *ep;
 399
 400     if (!nptr) {
 401         if (endptr) {
 402             *endptr = nptr;
 403         }
 404         return -EINVAL;
 405     }
 406
 407     errno = 0;
 408     /* FIXME This assumes int64_t is long long */
 409     *result = strtoll(nptr, &ep, base);
 410     return check_strtox_error(nptr, ep, endptr, errno);
 411 }
 412
 413 /**
 414  * Convert string @nptr to an uint64_t.
 415  *
 416  * Works like qemu_strtoul(), except it stores UINT64_MAX on overflow.
 417  */
 418 int qemu_strtou64(const char *nptr, const char **endptr, int base,
 419                   uint64_t *result)
 420 {
 421     char *ep;
 422
 423     if (!nptr) {
 424         if (endptr) {
 425             *endptr = nptr;
 426         }
 427         return -EINVAL;
 428     }
 429
 430     errno = 0;
 431     /* FIXME This assumes uint64_t is unsigned long long */
 432     *result = strtoull(nptr, &ep, base);
 433     /* Windows returns 1 for negative out-of-range values.  */
 434     if (errno == ERANGE) {
 435         *result = -1;
 436     }
 437     return check_strtox_error(nptr, ep, endptr, errno);
 438 }
 439
 440 /**
 441  * parse_uint:
 442  *
 443  * @s: String to parse
 444  * @value: Destination for parsed integer value
 445  * @endptr: Destination for pointer to first character not consumed
 446  * @base: integer base, between 2 and 36 inclusive, or 0
 447  *
 448  * Parse unsigned integer
 449  *
 450  * Parsed syntax is like strtoull()'s: arbitrary whitespace, a single optional
 451  * '+' or '-', an optional "0x" if @base is 0 or 16, one or more digits.
 452  *
 453  * If @s is null, or @base is invalid, or @s doesn't start with an
 454  * integer in the syntax above, set *@value to 0, *@endptr to @s, and
 455  * return -EINVAL.
 456  *
 457  * Set *@endptr to point right beyond the parsed integer (even if the integer
 458  * overflows or is negative, all digits will be parsed and *@endptr will
 459  * point right beyond them).
 460  *
 461  * If the integer is negative, set *@value to 0, and return -ERANGE.
 462  *
 463  * If the integer overflows unsigned long long, set *@value to
 464  * ULLONG_MAX, and return -ERANGE.
 465  *
 466  * Else, set *@value to the parsed integer, and return 0.
 467  */
 468 int parse_uint(const char *s, unsigned long long *value, char **endptr,
 469                int base)
 470 {
 471     int r = 0;
 472     char *endp = (char *)s;
 473     unsigned long long val = 0;
 474
 475     if (!s) {
 476         r = -EINVAL;
 477         goto out;
 478     }
 479
 480     errno = 0;
 481     val = strtoull(s, &endp, base);
 482     if (errno) {
 483         r = -errno;
 484         goto out;
 485     }
 486
 487     if (endp == s) {
 488         r = -EINVAL;
 489         goto out;
 490     }
 491
 492     /* make sure we reject negative numbers: */
 493     while (isspace((unsigned char)*s)) {
 494         s++;
 495     }
 496     if (*s == '-') {
 497         val = 0;
 498         r = -ERANGE;
 499         goto out;
 500     }
 501
 502 out:
 503     *value = val;
 504     *endptr = endp;
 505     return r;
 506 }
 507
 508 /**
 509  * parse_uint_full:
 510  *
 511  * @s: String to parse
 512  * @value: Destination for parsed integer value
 513  * @base: integer base, between 2 and 36 inclusive, or 0
 514  *
 515  * Parse unsigned integer from entire string
 516  *
 517  * Have the same behavior of parse_uint(), but with an additional check
 518  * for additional data after the parsed number. If extra characters are present
 519  * after the parsed number, the function will return -EINVAL, and *@v will
 520  * be set to 0.
 521  */
 522 int parse_uint_full(const char *s, unsigned long long *value, int base)
 523 {
 524     char *endp;
 525     int r;
 526
 527     r = parse_uint(s, value, &endp, base);
 528     if (r < 0) {
 529         return r;
 530     }
 531     if (*endp) {
 532         *value = 0;
 533         return -EINVAL;
 534     }
 535
 536     return 0;
 537 }
 538
 539 int qemu_parse_fd(const char *param)
 540 {
 541     long fd;
 542     char *endptr;
 543
 544     errno = 0;
 545     fd = strtol(param, &endptr, 10);
 546     if (param == endptr /* no conversion performed */                    ||
 547         errno != 0      /* not representable as long; possibly others */ ||
 548         *endptr != '\0' /* final string not empty */                     ||
 549         fd < 0          /* invalid as file descriptor */                 ||
 550         fd > INT_MAX    /* not representable as int */) {
 551         return -1;
 552     }
 553     return fd;
 554 }
 555
 556 /*
 557  * Implementation of  ULEB128 (http://en.wikipedia.org/wiki/LEB128)
 558  * Input is limited to 14-bit numbers
 559  */
 560 int uleb128_encode_small(uint8_t *out, uint32_t n)
 561 {
 562     g_assert(n <= 0x3fff);
 563     if (n < 0x80) {
 564         *out++ = n;
 565         return 1;
 566     } else {
 567         *out++ = (n & 0x7f) | 0x80;
 568         *out++ = n >> 7;
 569         return 2;
 570     }
 571 }
 572
 573 int uleb128_decode_small(const uint8_t *in, uint32_t *n)
 574 {
 575     if (!(*in & 0x80)) {
 576         *n = *in++;
 577         return 1;
 578     } else {
 579         *n = *in++ & 0x7f;
 580         /* we exceed 14 bit number */
 581         if (*in & 0x80) {
 582             return -1;
 583         }
 584         *n |= *in++ << 7;
 585         return 2;
 586     }
 587 }
 588
 589 /*
 590  * helper to parse debug environment variables
 591  */
 592 int parse_debug_env(const char *name, int max, int initial)
 593 {
 594     char *debug_env = getenv(name);
 595     char *inv = NULL;
 596     long debug;
 597
 598     if (!debug_env) {
 599         return initial;
 600     }
 601     errno = 0;
 602     debug = strtol(debug_env, &inv, 10);
 603     if (inv == debug_env) {
 604         return initial;
 605     }
 606     if (debug < 0 || debug > max || errno != 0) {
 607         fprintf(stderr, "warning: %s not in [0, %d]", name, max);
 608         return initial;
 609     }
 610     return debug;
 611 }
 612
 613 /*
 614  * Helper to print ethernet mac address
 615  */
 616 const char *qemu_ether_ntoa(const MACAddr *mac)
 617 {
 618     static char ret[18];
 619
 620     snprintf(ret, sizeof(ret), "%02x:%02x:%02x:%02x:%02x:%02x",
 621              mac->a[0], mac->a[1], mac->a[2], mac->a[3], mac->a[4], mac->a[5]);
 622
 623     return ret;
 624 }
 625
 626 /*
 627  * Return human readable string for size @val.
 628  * @val can be anything that uint64_t allows (no more than "16 EiB").
 629  * Use IEC binary units like KiB, MiB, and so forth.
 630  * Caller is responsible for passing it to g_free().
 631  */
 632 char *size_to_str(uint64_t val)
 633 {
 634     static const char *suffixes[] = { "", "Ki", "Mi", "Gi", "Ti", "Pi", "Ei" };
 635     unsigned long div;
 636     int i;
 637
 638     /*
 639      * The exponent (returned in i) minus one gives us
 640      * floor(log2(val * 1024 / 1000).  The correction makes us
 641      * switch to the higher power when the integer part is >= 1000.
 642      * (see e41b509d68afb1f for more info)
 643      */
 644     frexp(val / (1000.0 / 1024.0), &i);
 645     i = (i - 1) / 10;
 646     div = 1ULL << (i * 10);
 647
 648     return g_strdup_printf("%0.3g %sB", (double)val / div, suffixes[i]);
 649 }