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
  31 void strpadcpy(char *buf, int buf_size, const char *str, char pad)
  32 {
  33     int len = qemu_strnlen(str, buf_size);
  34     memcpy(buf, str, len);
  35     memset(buf + len, pad, buf_size - len);
  36 }
  37
  38 void pstrcpy(char *buf, int buf_size, const char *str)
  39 {
  40     int c;
  41     char *q = buf;
  42
  43     if (buf_size <= 0)
  44         return;
  45
  46     for(;;) {
  47         c = *str++;
  48         if (c == 0 || q >= buf + buf_size - 1)
  49             break;
  50         *q++ = c;
  51     }
  52     *q = '\0';
  53 }
  54
  55 /* strcat and truncate. */
  56 char *pstrcat(char *buf, int buf_size, const char *s)
  57 {
  58     int len;
  59     len = strlen(buf);
  60     if (len < buf_size)
  61         pstrcpy(buf + len, buf_size - len, s);
  62     return buf;
  63 }
  64
  65 int strstart(const char *str, const char *val, const char **ptr)
  66 {
  67     const char *p, *q;
  68     p = str;
  69     q = val;
  70     while (*q != '\0') {
  71         if (*p != *q)
  72             return 0;
  73         p++;
  74         q++;
  75     }
  76     if (ptr)
  77         *ptr = p;
  78     return 1;
  79 }
  80
  81 int stristart(const char *str, const char *val, const char **ptr)
  82 {
  83     const char *p, *q;
  84     p = str;
  85     q = val;
  86     while (*q != '\0') {
  87         if (qemu_toupper(*p) != qemu_toupper(*q))
  88             return 0;
  89         p++;
  90         q++;
  91     }
  92     if (ptr)
  93         *ptr = p;
  94     return 1;
  95 }
  96
  97 /* XXX: use host strnlen if available ? */
  98 int qemu_strnlen(const char *s, int max_len)
  99 {
 100     int i;
 101
 102     for(i = 0; i < max_len; i++) {
 103         if (s[i] == '\0') {
 104             break;
 105         }
 106     }
 107     return i;
 108 }
 109
 110 char *qemu_strsep(char **input, const char *delim)
 111 {
 112     char *result = *input;
 113     if (result != NULL) {
 114         char *p;
 115
 116         for (p = result; *p != '\0'; p++) {
 117             if (strchr(delim, *p)) {
 118                 break;
 119             }
 120         }
 121         if (*p == '\0') {
 122             *input = NULL;
 123         } else {
 124             *p = '\0';
 125             *input = p + 1;
 126         }
 127     }
 128     return result;
 129 }
 130
 131 time_t mktimegm(struct tm *tm)
 132 {
 133     time_t t;
 134     int y = tm->tm_year + 1900, m = tm->tm_mon + 1, d = tm->tm_mday;
 135     if (m < 3) {
 136         m += 12;
 137         y--;
 138     }
 139     t = 86400ULL * (d + (153 * m - 457) / 5 + 365 * y + y / 4 - y / 100 +
 140                  y / 400 - 719469);
 141     t += 3600 * tm->tm_hour + 60 * tm->tm_min + tm->tm_sec;
 142     return t;
 143 }
 144
 145 int qemu_fls(int i)
 146 {
 147     return 32 - clz32(i);
 148 }
 149
 150 /*
 151  * Make sure data goes on disk, but if possible do not bother to
 152  * write out the inode just for timestamp updates.
 153  *
 154  * Unfortunately even in 2009 many operating systems do not support
 155  * fdatasync and have to fall back to fsync.
 156  */
 157 int qemu_fdatasync(int fd)
 158 {
 159 #ifdef CONFIG_FDATASYNC
 160     return fdatasync(fd);
 161 #else
 162     return fsync(fd);
 163 #endif
 164 }
 165
 166 /*
 167  * Searches for an area with non-zero content in a buffer
 168  *
 169  * Attention! The len must be a multiple of
 170  * BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR * sizeof(VECTYPE)
 171  * and addr must be a multiple of sizeof(VECTYPE) due to
 172  * restriction of optimizations in this function.
 173  *
 174  * can_use_buffer_find_nonzero_offset() can be used to check
 175  * these requirements.
 176  *
 177  * The return value is the offset of the non-zero area rounded
 178  * down to a multiple of sizeof(VECTYPE) for the first
 179  * BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR chunks and down to
 180  * BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR * sizeof(VECTYPE)
 181  * afterwards.
 182  *
 183  * If the buffer is all zero the return value is equal to len.
 184  */
 185
 186 size_t buffer_find_nonzero_offset(const void *buf, size_t len)
 187 {
 188     const VECTYPE *p = buf;
 189     const VECTYPE zero = (VECTYPE){0};
 190     size_t i;
 191
 192     assert(can_use_buffer_find_nonzero_offset(buf, len));
 193
 194     if (!len) {
 195         return 0;
 196     }
 197
 198     for (i = 0; i < BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR; i++) {
 199         if (!ALL_EQ(p[i], zero)) {
 200             return i * sizeof(VECTYPE);
 201         }
 202     }
 203
 204     for (i = BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR;
 205          i < len / sizeof(VECTYPE);
 206          i += BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR) {
 207         VECTYPE tmp0 = p[i + 0] | p[i + 1];
 208         VECTYPE tmp1 = p[i + 2] | p[i + 3];
 209         VECTYPE tmp2 = p[i + 4] | p[i + 5];
 210         VECTYPE tmp3 = p[i + 6] | p[i + 7];
 211         VECTYPE tmp01 = tmp0 | tmp1;
 212         VECTYPE tmp23 = tmp2 | tmp3;
 213         if (!ALL_EQ(tmp01 | tmp23, zero)) {
 214             break;
 215         }
 216     }
 217
 218     return i * sizeof(VECTYPE);
 219 }
 220
 221 /*
 222  * Checks if a buffer is all zeroes
 223  *
 224  * Attention! The len must be a multiple of 4 * sizeof(long) due to
 225  * restriction of optimizations in this function.
 226  */
 227 bool buffer_is_zero(const void *buf, size_t len)
 228 {
 229     /*
 230      * Use long as the biggest available internal data type that fits into the
 231      * CPU register and unroll the loop to smooth out the effect of memory
 232      * latency.
 233      */
 234
 235     size_t i;
 236     long d0, d1, d2, d3;
 237     const long * const data = buf;
 238
 239     /* use vector optimized zero check if possible */
 240     if (can_use_buffer_find_nonzero_offset(buf, len)) {
 241         return buffer_find_nonzero_offset(buf, len) == len;
 242     }
 243
 244     assert(len % (4 * sizeof(long)) == 0);
 245     len /= sizeof(long);
 246
 247     for (i = 0; i < len; i += 4) {
 248         d0 = data[i + 0];
 249         d1 = data[i + 1];
 250         d2 = data[i + 2];
 251         d3 = data[i + 3];
 252
 253         if (d0 || d1 || d2 || d3) {
 254             return false;
 255         }
 256     }
 257
 258     return true;
 259 }
 260
 261 #ifndef _WIN32
 262 /* Sets a specific flag */
 263 int fcntl_setfl(int fd, int flag)
 264 {
 265     int flags;
 266
 267     flags = fcntl(fd, F_GETFL);
 268     if (flags == -1)
 269         return -errno;
 270
 271     if (fcntl(fd, F_SETFL, flags | flag) == -1)
 272         return -errno;
 273
 274     return 0;
 275 }
 276 #endif
 277
 278 static int64_t suffix_mul(char suffix, int64_t unit)
 279 {
 280     switch (qemu_toupper(suffix)) {
 281     case STRTOSZ_DEFSUFFIX_B:
 282         return 1;
 283     case STRTOSZ_DEFSUFFIX_KB:
 284         return unit;
 285     case STRTOSZ_DEFSUFFIX_MB:
 286         return unit * unit;
 287     case STRTOSZ_DEFSUFFIX_GB:
 288         return unit * unit * unit;
 289     case STRTOSZ_DEFSUFFIX_TB:
 290         return unit * unit * unit * unit;
 291     case STRTOSZ_DEFSUFFIX_PB:
 292         return unit * unit * unit * unit * unit;
 293     case STRTOSZ_DEFSUFFIX_EB:
 294         return unit * unit * unit * unit * unit * unit;
 295     }
 296     return -1;
 297 }
 298
 299 /*
 300  * Convert string to bytes, allowing either B/b for bytes, K/k for KB,
 301  * M/m for MB, G/g for GB or T/t for TB. End pointer will be returned
 302  * in *end, if not NULL. Return -ERANGE on overflow, Return -EINVAL on
 303  * other error.
 304  */
 305 int64_t strtosz_suffix_unit(const char *nptr, char **end,
 306                             const char default_suffix, int64_t unit)
 307 {
 308     int64_t retval = -EINVAL;
 309     char *endptr;
 310     unsigned char c;
 311     int mul_required = 0;
 312     double val, mul, integral, fraction;
 313
 314     errno = 0;
 315     val = strtod(nptr, &endptr);
 316     if (isnan(val) || endptr == nptr || errno != 0) {
 317         goto fail;
 318     }
 319     fraction = modf(val, &integral);
 320     if (fraction != 0) {
 321         mul_required = 1;
 322     }
 323     c = *endptr;
 324     mul = suffix_mul(c, unit);
 325     if (mul >= 0) {
 326         endptr++;
 327     } else {
 328         mul = suffix_mul(default_suffix, unit);
 329         assert(mul >= 0);
 330     }
 331     if (mul == 1 && mul_required) {
 332         goto fail;
 333     }
 334     if ((val * mul >= INT64_MAX) || val < 0) {
 335         retval = -ERANGE;
 336         goto fail;
 337     }
 338     retval = val * mul;
 339
 340 fail:
 341     if (end) {
 342         *end = endptr;
 343     }
 344
 345     return retval;
 346 }
 347
 348 int64_t strtosz_suffix(const char *nptr, char **end, const char default_suffix)
 349 {
 350     return strtosz_suffix_unit(nptr, end, default_suffix, 1024);
 351 }
 352
 353 int64_t strtosz(const char *nptr, char **end)
 354 {
 355     return strtosz_suffix(nptr, end, STRTOSZ_DEFSUFFIX_MB);
 356 }
 357
 358 /**
 359  * parse_uint:
 360  *
 361  * @s: String to parse
 362  * @value: Destination for parsed integer value
 363  * @endptr: Destination for pointer to first character not consumed
 364  * @base: integer base, between 2 and 36 inclusive, or 0
 365  *
 366  * Parse unsigned integer
 367  *
 368  * Parsed syntax is like strtoull()'s: arbitrary whitespace, a single optional
 369  * '+' or '-', an optional "0x" if @base is 0 or 16, one or more digits.
 370  *
 371  * If @s is null, or @base is invalid, or @s doesn't start with an
 372  * integer in the syntax above, set *@value to 0, *@endptr to @s, and
 373  * return -EINVAL.
 374  *
 375  * Set *@endptr to point right beyond the parsed integer (even if the integer
 376  * overflows or is negative, all digits will be parsed and *@endptr will
 377  * point right beyond them).
 378  *
 379  * If the integer is negative, set *@value to 0, and return -ERANGE.
 380  *
 381  * If the integer overflows unsigned long long, set *@value to
 382  * ULLONG_MAX, and return -ERANGE.
 383  *
 384  * Else, set *@value to the parsed integer, and return 0.
 385  */
 386 int parse_uint(const char *s, unsigned long long *value, char **endptr,
 387                int base)
 388 {
 389     int r = 0;
 390     char *endp = (char *)s;
 391     unsigned long long val = 0;
 392
 393     if (!s) {
 394         r = -EINVAL;
 395         goto out;
 396     }
 397
 398     errno = 0;
 399     val = strtoull(s, &endp, base);
 400     if (errno) {
 401         r = -errno;
 402         goto out;
 403     }
 404
 405     if (endp == s) {
 406         r = -EINVAL;
 407         goto out;
 408     }
 409
 410     /* make sure we reject negative numbers: */
 411     while (isspace((unsigned char)*s)) {
 412         s++;
 413     }
 414     if (*s == '-') {
 415         val = 0;
 416         r = -ERANGE;
 417         goto out;
 418     }
 419
 420 out:
 421     *value = val;
 422     *endptr = endp;
 423     return r;
 424 }
 425
 426 /**
 427  * parse_uint_full:
 428  *
 429  * @s: String to parse
 430  * @value: Destination for parsed integer value
 431  * @base: integer base, between 2 and 36 inclusive, or 0
 432  *
 433  * Parse unsigned integer from entire string
 434  *
 435  * Have the same behavior of parse_uint(), but with an additional check
 436  * for additional data after the parsed number. If extra characters are present
 437  * after the parsed number, the function will return -EINVAL, and *@v will
 438  * be set to 0.
 439  */
 440 int parse_uint_full(const char *s, unsigned long long *value, int base)
 441 {
 442     char *endp;
 443     int r;
 444
 445     r = parse_uint(s, value, &endp, base);
 446     if (r < 0) {
 447         return r;
 448     }
 449     if (*endp) {
 450         *value = 0;
 451         return -EINVAL;
 452     }
 453
 454     return 0;
 455 }
 456
 457 int qemu_parse_fd(const char *param)
 458 {
 459     int fd;
 460     char *endptr = NULL;
 461
 462     fd = strtol(param, &endptr, 10);
 463     if (*endptr || (fd == 0 && param == endptr)) {
 464         return -1;
 465     }
 466     return fd;
 467 }
 468
 469 /* round down to the nearest power of 2*/
 470 int64_t pow2floor(int64_t value)
 471 {
 472     if (!is_power_of_2(value)) {
 473         value = 0x8000000000000000ULL >> clz64(value);
 474     }
 475     return value;
 476 }
 477
 478 /*
 479  * Implementation of  ULEB128 (http://en.wikipedia.org/wiki/LEB128)
 480  * Input is limited to 14-bit numbers
 481  */
 482 int uleb128_encode_small(uint8_t *out, uint32_t n)
 483 {
 484     g_assert(n <= 0x3fff);
 485     if (n < 0x80) {
 486         *out++ = n;
 487         return 1;
 488     } else {
 489         *out++ = (n & 0x7f) | 0x80;
 490         *out++ = n >> 7;
 491         return 2;
 492     }
 493 }
 494
 495 int uleb128_decode_small(const uint8_t *in, uint32_t *n)
 496 {
 497     if (!(*in & 0x80)) {
 498         *n = *in++;
 499         return 1;
 500     } else {
 501         *n = *in++ & 0x7f;
 502         /* we exceed 14 bit number */
 503         if (*in & 0x80) {
 504             return -1;
 505         }
 506         *n |= *in++ << 7;
 507         return 2;
 508     }
 509 }
 510
 511 /*
 512  * helper to parse debug environment variables
 513  */
 514 int parse_debug_env(const char *name, int max, int initial)
 515 {
 516     char *debug_env = getenv(name);
 517     char *inv = NULL;
 518     int debug;
 519
 520     if (!debug_env) {
 521         return initial;
 522     }
 523     debug = strtol(debug_env, &inv, 10);
 524     if (inv == debug_env) {
 525         return initial;
 526     }
 527     if (debug < 0 || debug > max) {
 528         fprintf(stderr, "warning: %s not in [0, %d]", name, max);
 529         return initial;
 530     }
 531     return debug;
 532 }