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
  28 #include "qemu/sockets.h"
  29 #include "qemu/iov.h"
  30 #include "net/net.h"
  31
  32 void strpadcpy(char *buf, int buf_size, const char *str, char pad)
  33 {
  34     int len = qemu_strnlen(str, buf_size);
  35     memcpy(buf, str, len);
  36     memset(buf + len, pad, buf_size - len);
  37 }
  38
  39 void pstrcpy(char *buf, int buf_size, const char *str)
  40 {
  41     int c;
  42     char *q = buf;
  43
  44     if (buf_size <= 0)
  45         return;
  46
  47     for(;;) {
  48         c = *str++;
  49         if (c == 0 || q >= buf + buf_size - 1)
  50             break;
  51         *q++ = c;
  52     }
  53     *q = '\0';
  54 }
  55
  56 /* strcat and truncate. */
  57 char *pstrcat(char *buf, int buf_size, const char *s)
  58 {
  59     int len;
  60     len = strlen(buf);
  61     if (len < buf_size)
  62         pstrcpy(buf + len, buf_size - len, s);
  63     return buf;
  64 }
  65
  66 int strstart(const char *str, const char *val, const char **ptr)
  67 {
  68     const char *p, *q;
  69     p = str;
  70     q = val;
  71     while (*q != '\0') {
  72         if (*p != *q)
  73             return 0;
  74         p++;
  75         q++;
  76     }
  77     if (ptr)
  78         *ptr = p;
  79     return 1;
  80 }
  81
  82 int stristart(const char *str, const char *val, const char **ptr)
  83 {
  84     const char *p, *q;
  85     p = str;
  86     q = val;
  87     while (*q != '\0') {
  88         if (qemu_toupper(*p) != qemu_toupper(*q))
  89             return 0;
  90         p++;
  91         q++;
  92     }
  93     if (ptr)
  94         *ptr = p;
  95     return 1;
  96 }
  97
  98 /* XXX: use host strnlen if available ? */
  99 int qemu_strnlen(const char *s, int max_len)
 100 {
 101     int i;
 102
 103     for(i = 0; i < max_len; i++) {
 104         if (s[i] == '\0') {
 105             break;
 106         }
 107     }
 108     return i;
 109 }
 110
 111 char *qemu_strsep(char **input, const char *delim)
 112 {
 113     char *result = *input;
 114     if (result != NULL) {
 115         char *p;
 116
 117         for (p = result; *p != '\0'; p++) {
 118             if (strchr(delim, *p)) {
 119                 break;
 120             }
 121         }
 122         if (*p == '\0') {
 123             *input = NULL;
 124         } else {
 125             *p = '\0';
 126             *input = p + 1;
 127         }
 128     }
 129     return result;
 130 }
 131
 132 time_t mktimegm(struct tm *tm)
 133 {
 134     time_t t;
 135     int y = tm->tm_year + 1900, m = tm->tm_mon + 1, d = tm->tm_mday;
 136     if (m < 3) {
 137         m += 12;
 138         y--;
 139     }
 140     t = 86400ULL * (d + (153 * m - 457) / 5 + 365 * y + y / 4 - y / 100 +
 141                  y / 400 - 719469);
 142     t += 3600 * tm->tm_hour + 60 * tm->tm_min + tm->tm_sec;
 143     return t;
 144 }
 145
 146 int qemu_fls(int i)
 147 {
 148     return 32 - clz32(i);
 149 }
 150
 151 /*
 152  * Make sure data goes on disk, but if possible do not bother to
 153  * write out the inode just for timestamp updates.
 154  *
 155  * Unfortunately even in 2009 many operating systems do not support
 156  * fdatasync and have to fall back to fsync.
 157  */
 158 int qemu_fdatasync(int fd)
 159 {
 160 #ifdef CONFIG_FDATASYNC
 161     return fdatasync(fd);
 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 = p[i + 0] | p[i + 1];
 209         VECTYPE tmp1 = p[i + 2] | p[i + 3];
 210         VECTYPE tmp2 = p[i + 4] | p[i + 5];
 211         VECTYPE tmp3 = p[i + 6] | p[i + 7];
 212         VECTYPE tmp01 = tmp0 | tmp1;
 213         VECTYPE tmp23 = tmp2 | tmp3;
 214         if (!ALL_EQ(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 STRTOSZ_DEFSUFFIX_B:
 283         return 1;
 284     case STRTOSZ_DEFSUFFIX_KB:
 285         return unit;
 286     case STRTOSZ_DEFSUFFIX_MB:
 287         return unit * unit;
 288     case STRTOSZ_DEFSUFFIX_GB:
 289         return unit * unit * unit;
 290     case STRTOSZ_DEFSUFFIX_TB:
 291         return unit * unit * unit * unit;
 292     case STRTOSZ_DEFSUFFIX_PB:
 293         return unit * unit * unit * unit * unit;
 294     case 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 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 strtosz_suffix(const char *nptr, char **end, const char default_suffix)
 350 {
 351     return strtosz_suffix_unit(nptr, end, default_suffix, 1024);
 352 }
 353
 354 int64_t strtosz(const char *nptr, char **end)
 355 {
 356     return strtosz_suffix(nptr, end, STRTOSZ_DEFSUFFIX_MB);
 357 }
 358
 359 /**
 360  * parse_uint:
 361  *
 362  * @s: String to parse
 363  * @value: Destination for parsed integer value
 364  * @endptr: Destination for pointer to first character not consumed
 365  * @base: integer base, between 2 and 36 inclusive, or 0
 366  *
 367  * Parse unsigned integer
 368  *
 369  * Parsed syntax is like strtoull()'s: arbitrary whitespace, a single optional
 370  * '+' or '-', an optional "0x" if @base is 0 or 16, one or more digits.
 371  *
 372  * If @s is null, or @base is invalid, or @s doesn't start with an
 373  * integer in the syntax above, set *@value to 0, *@endptr to @s, and
 374  * return -EINVAL.
 375  *
 376  * Set *@endptr to point right beyond the parsed integer (even if the integer
 377  * overflows or is negative, all digits will be parsed and *@endptr will
 378  * point right beyond them).
 379  *
 380  * If the integer is negative, set *@value to 0, and return -ERANGE.
 381  *
 382  * If the integer overflows unsigned long long, set *@value to
 383  * ULLONG_MAX, and return -ERANGE.
 384  *
 385  * Else, set *@value to the parsed integer, and return 0.
 386  */
 387 int parse_uint(const char *s, unsigned long long *value, char **endptr,
 388                int base)
 389 {
 390     int r = 0;
 391     char *endp = (char *)s;
 392     unsigned long long val = 0;
 393
 394     if (!s) {
 395         r = -EINVAL;
 396         goto out;
 397     }
 398
 399     errno = 0;
 400     val = strtoull(s, &endp, base);
 401     if (errno) {
 402         r = -errno;
 403         goto out;
 404     }
 405
 406     if (endp == s) {
 407         r = -EINVAL;
 408         goto out;
 409     }
 410
 411     /* make sure we reject negative numbers: */
 412     while (isspace((unsigned char)*s)) {
 413         s++;
 414     }
 415     if (*s == '-') {
 416         val = 0;
 417         r = -ERANGE;
 418         goto out;
 419     }
 420
 421 out:
 422     *value = val;
 423     *endptr = endp;
 424     return r;
 425 }
 426
 427 /**
 428  * parse_uint_full:
 429  *
 430  * @s: String to parse
 431  * @value: Destination for parsed integer value
 432  * @base: integer base, between 2 and 36 inclusive, or 0
 433  *
 434  * Parse unsigned integer from entire string
 435  *
 436  * Have the same behavior of parse_uint(), but with an additional check
 437  * for additional data after the parsed number. If extra characters are present
 438  * after the parsed number, the function will return -EINVAL, and *@v will
 439  * be set to 0.
 440  */
 441 int parse_uint_full(const char *s, unsigned long long *value, int base)
 442 {
 443     char *endp;
 444     int r;
 445
 446     r = parse_uint(s, value, &endp, base);
 447     if (r < 0) {
 448         return r;
 449     }
 450     if (*endp) {
 451         *value = 0;
 452         return -EINVAL;
 453     }
 454
 455     return 0;
 456 }
 457
 458 int qemu_parse_fd(const char *param)
 459 {
 460     int fd;
 461     char *endptr = NULL;
 462
 463     fd = strtol(param, &endptr, 10);
 464     if (*endptr || (fd == 0 && param == endptr)) {
 465         return -1;
 466     }
 467     return fd;
 468 }
 469
 470 /* round down to the nearest power of 2*/
 471 int64_t pow2floor(int64_t value)
 472 {
 473     if (!is_power_of_2(value)) {
 474         value = 0x8000000000000000ULL >> clz64(value);
 475     }
 476     return value;
 477 }
 478
 479 /*
 480  * Implementation of  ULEB128 (http://en.wikipedia.org/wiki/LEB128)
 481  * Input is limited to 14-bit numbers
 482  */
 483 int uleb128_encode_small(uint8_t *out, uint32_t n)
 484 {
 485     g_assert(n <= 0x3fff);
 486     if (n < 0x80) {
 487         *out++ = n;
 488         return 1;
 489     } else {
 490         *out++ = (n & 0x7f) | 0x80;
 491         *out++ = n >> 7;
 492         return 2;
 493     }
 494 }
 495
 496 int uleb128_decode_small(const uint8_t *in, uint32_t *n)
 497 {
 498     if (!(*in & 0x80)) {
 499         *n = *in++;
 500         return 1;
 501     } else {
 502         *n = *in++ & 0x7f;
 503         /* we exceed 14 bit number */
 504         if (*in & 0x80) {
 505             return -1;
 506         }
 507         *n |= *in++ << 7;
 508         return 2;
 509     }
 510 }
 511
 512 /*
 513  * helper to parse debug environment variables
 514  */
 515 int parse_debug_env(const char *name, int max, int initial)
 516 {
 517     char *debug_env = getenv(name);
 518     char *inv = NULL;
 519     int debug;
 520
 521     if (!debug_env) {
 522         return initial;
 523     }
 524     debug = strtol(debug_env, &inv, 10);
 525     if (inv == debug_env) {
 526         return initial;
 527     }
 528     if (debug < 0 || debug > max) {
 529         fprintf(stderr, "warning: %s not in [0, %d]", name, max);
 530         return initial;
 531     }
 532     return debug;
 533 }
 534
 535 /*
 536  * Helper to print ethernet mac address
 537  */
 538 const char *qemu_ether_ntoa(const MACAddr *mac)
 539 {
 540     static char ret[18];
 541
 542     snprintf(ret, sizeof(ret), "%02x:%02x:%02x:%02x:%02x:%02x",
 543              mac->a[0], mac->a[1], mac->a[2], mac->a[3], mac->a[4], mac->a[5]);
 544
 545     return ret;
 546 }