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
  33 void strpadcpy(char *buf, int buf_size, const char *str, char pad)
  34 {
  35     int len = qemu_strnlen(str, buf_size);
  36     memcpy(buf, str, len);
  37     memset(buf + len, pad, buf_size - len);
  38 }
  39
  40 void pstrcpy(char *buf, int buf_size, const char *str)
  41 {
  42     int c;
  43     char *q = buf;
  44
  45     if (buf_size <= 0)
  46         return;
  47
  48     for(;;) {
  49         c = *str++;
  50         if (c == 0 || q >= buf + buf_size - 1)
  51             break;
  52         *q++ = c;
  53     }
  54     *q = '\0';
  55 }
  56
  57 /* strcat and truncate. */
  58 char *pstrcat(char *buf, int buf_size, const char *s)
  59 {
  60     int len;
  61     len = strlen(buf);
  62     if (len < buf_size)
  63         pstrcpy(buf + len, buf_size - len, s);
  64     return buf;
  65 }
  66
  67 int strstart(const char *str, const char *val, const char **ptr)
  68 {
  69     const char *p, *q;
  70     p = str;
  71     q = val;
  72     while (*q != '\0') {
  73         if (*p != *q)
  74             return 0;
  75         p++;
  76         q++;
  77     }
  78     if (ptr)
  79         *ptr = p;
  80     return 1;
  81 }
  82
  83 int stristart(const char *str, const char *val, const char **ptr)
  84 {
  85     const char *p, *q;
  86     p = str;
  87     q = val;
  88     while (*q != '\0') {
  89         if (qemu_toupper(*p) != qemu_toupper(*q))
  90             return 0;
  91         p++;
  92         q++;
  93     }
  94     if (ptr)
  95         *ptr = p;
  96     return 1;
  97 }
  98
  99 /* XXX: use host strnlen if available ? */
 100 int qemu_strnlen(const char *s, int max_len)
 101 {
 102     int i;
 103
 104     for(i = 0; i < max_len; i++) {
 105         if (s[i] == '\0') {
 106             break;
 107         }
 108     }
 109     return i;
 110 }
 111
 112 char *qemu_strsep(char **input, const char *delim)
 113 {
 114     char *result = *input;
 115     if (result != NULL) {
 116         char *p;
 117
 118         for (p = result; *p != '\0'; p++) {
 119             if (strchr(delim, *p)) {
 120                 break;
 121             }
 122         }
 123         if (*p == '\0') {
 124             *input = NULL;
 125         } else {
 126             *p = '\0';
 127             *input = p + 1;
 128         }
 129     }
 130     return result;
 131 }
 132
 133 time_t mktimegm(struct tm *tm)
 134 {
 135     time_t t;
 136     int y = tm->tm_year + 1900, m = tm->tm_mon + 1, d = tm->tm_mday;
 137     if (m < 3) {
 138         m += 12;
 139         y--;
 140     }
 141     t = 86400ULL * (d + (153 * m - 457) / 5 + 365 * y + y / 4 - y / 100 +
 142                  y / 400 - 719469);
 143     t += 3600 * tm->tm_hour + 60 * tm->tm_min + tm->tm_sec;
 144     return t;
 145 }
 146
 147 /*
 148  * Make sure data goes on disk, but if possible do not bother to
 149  * write out the inode just for timestamp updates.
 150  *
 151  * Unfortunately even in 2009 many operating systems do not support
 152  * fdatasync and have to fall back to fsync.
 153  */
 154 int qemu_fdatasync(int fd)
 155 {
 156 #ifdef CONFIG_FDATASYNC
 157     return fdatasync(fd);
 158 #else
 159     return fsync(fd);
 160 #endif
 161 }
 162
 163 static bool
 164 can_use_buffer_find_nonzero_offset_inner(const void *buf, size_t len)
 165 {
 166     return (len % (BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR
 167                    * sizeof(VECTYPE)) == 0
 168             && ((uintptr_t) buf) % sizeof(VECTYPE) == 0);
 169 }
 170
 171 /*
 172  * Searches for an area with non-zero content in a buffer
 173  *
 174  * Attention! The len must be a multiple of
 175  * BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR * sizeof(VECTYPE)
 176  * and addr must be a multiple of sizeof(VECTYPE) due to
 177  * restriction of optimizations in this function.
 178  *
 179  * can_use_buffer_find_nonzero_offset_inner() can be used to
 180  * check these requirements.
 181  *
 182  * The return value is the offset of the non-zero area rounded
 183  * down to a multiple of sizeof(VECTYPE) for the first
 184  * BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR chunks and down to
 185  * BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR * sizeof(VECTYPE)
 186  * afterwards.
 187  *
 188  * If the buffer is all zero the return value is equal to len.
 189  */
 190
 191 static size_t buffer_find_nonzero_offset_inner(const void *buf, size_t len)
 192 {
 193     const VECTYPE *p = buf;
 194     const VECTYPE zero = (VECTYPE){0};
 195     size_t i;
 196
 197     assert(can_use_buffer_find_nonzero_offset_inner(buf, len));
 198
 199     if (!len) {
 200         return 0;
 201     }
 202
 203     for (i = 0; i < BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR; i++) {
 204         if (!ALL_EQ(p[i], zero)) {
 205             return i * sizeof(VECTYPE);
 206         }
 207     }
 208
 209     for (i = BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR;
 210          i < len / sizeof(VECTYPE);
 211          i += BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR) {
 212         VECTYPE tmp0 = VEC_OR(p[i + 0], p[i + 1]);
 213         VECTYPE tmp1 = VEC_OR(p[i + 2], p[i + 3]);
 214         VECTYPE tmp2 = VEC_OR(p[i + 4], p[i + 5]);
 215         VECTYPE tmp3 = VEC_OR(p[i + 6], p[i + 7]);
 216         VECTYPE tmp01 = VEC_OR(tmp0, tmp1);
 217         VECTYPE tmp23 = VEC_OR(tmp2, tmp3);
 218         if (!ALL_EQ(VEC_OR(tmp01, tmp23), zero)) {
 219             break;
 220         }
 221     }
 222
 223     return i * sizeof(VECTYPE);
 224 }
 225
 226 /*
 227  * GCC before version 4.9 has a bug which will cause the target
 228  * attribute work incorrectly and failed to compile in some case,
 229  * restrict the gcc version to 4.9+ to prevent the failure.
 230  */
 231
 232 #if defined CONFIG_AVX2_OPT && QEMU_GNUC_PREREQ(4, 9)
 233 #pragma GCC push_options
 234 #pragma GCC target("avx2")
 235 #include <cpuid.h>
 236 #include <immintrin.h>
 237
 238 #define AVX2_VECTYPE        __m256i
 239 #define AVX2_SPLAT(p)       _mm256_set1_epi8(*(p))
 240 #define AVX2_ALL_EQ(v1, v2) \
 241     (_mm256_movemask_epi8(_mm256_cmpeq_epi8(v1, v2)) == 0xFFFFFFFF)
 242 #define AVX2_VEC_OR(v1, v2) (_mm256_or_si256(v1, v2))
 243
 244 static bool
 245 can_use_buffer_find_nonzero_offset_avx2(const void *buf, size_t len)
 246 {
 247     return (len % (BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR
 248                    * sizeof(AVX2_VECTYPE)) == 0
 249             && ((uintptr_t) buf) % sizeof(AVX2_VECTYPE) == 0);
 250 }
 251
 252 static size_t buffer_find_nonzero_offset_avx2(const void *buf, size_t len)
 253 {
 254     const AVX2_VECTYPE *p = buf;
 255     const AVX2_VECTYPE zero = (AVX2_VECTYPE){0};
 256     size_t i;
 257
 258     assert(can_use_buffer_find_nonzero_offset_avx2(buf, len));
 259
 260     if (!len) {
 261         return 0;
 262     }
 263
 264     for (i = 0; i < BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR; i++) {
 265         if (!AVX2_ALL_EQ(p[i], zero)) {
 266             return i * sizeof(AVX2_VECTYPE);
 267         }
 268     }
 269
 270     for (i = BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR;
 271          i < len / sizeof(AVX2_VECTYPE);
 272          i += BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR) {
 273         AVX2_VECTYPE tmp0 = AVX2_VEC_OR(p[i + 0], p[i + 1]);
 274         AVX2_VECTYPE tmp1 = AVX2_VEC_OR(p[i + 2], p[i + 3]);
 275         AVX2_VECTYPE tmp2 = AVX2_VEC_OR(p[i + 4], p[i + 5]);
 276         AVX2_VECTYPE tmp3 = AVX2_VEC_OR(p[i + 6], p[i + 7]);
 277         AVX2_VECTYPE tmp01 = AVX2_VEC_OR(tmp0, tmp1);
 278         AVX2_VECTYPE tmp23 = AVX2_VEC_OR(tmp2, tmp3);
 279         if (!AVX2_ALL_EQ(AVX2_VEC_OR(tmp01, tmp23), zero)) {
 280             break;
 281         }
 282     }
 283
 284     return i * sizeof(AVX2_VECTYPE);
 285 }
 286
 287 static bool avx2_support(void)
 288 {
 289     int a, b, c, d;
 290
 291     if (__get_cpuid_max(0, NULL) < 7) {
 292         return false;
 293     }
 294
 295     __cpuid_count(7, 0, a, b, c, d);
 296
 297     return b & bit_AVX2;
 298 }
 299
 300 bool can_use_buffer_find_nonzero_offset(const void *buf, size_t len) \
 301          __attribute__ ((ifunc("can_use_buffer_find_nonzero_offset_ifunc")));
 302 size_t buffer_find_nonzero_offset(const void *buf, size_t len) \
 303          __attribute__ ((ifunc("buffer_find_nonzero_offset_ifunc")));
 304
 305 static void *buffer_find_nonzero_offset_ifunc(void)
 306 {
 307     typeof(buffer_find_nonzero_offset) *func = (avx2_support()) ?
 308         buffer_find_nonzero_offset_avx2 : buffer_find_nonzero_offset_inner;
 309
 310     return func;
 311 }
 312
 313 static void *can_use_buffer_find_nonzero_offset_ifunc(void)
 314 {
 315     typeof(can_use_buffer_find_nonzero_offset) *func = (avx2_support()) ?
 316         can_use_buffer_find_nonzero_offset_avx2 :
 317         can_use_buffer_find_nonzero_offset_inner;
 318
 319     return func;
 320 }
 321 #pragma GCC pop_options
 322 #else
 323 bool can_use_buffer_find_nonzero_offset(const void *buf, size_t len)
 324 {
 325     return can_use_buffer_find_nonzero_offset_inner(buf, len);
 326 }
 327
 328 size_t buffer_find_nonzero_offset(const void *buf, size_t len)
 329 {
 330     return buffer_find_nonzero_offset_inner(buf, len);
 331 }
 332 #endif
 333
 334 /*
 335  * Checks if a buffer is all zeroes
 336  *
 337  * Attention! The len must be a multiple of 4 * sizeof(long) due to
 338  * restriction of optimizations in this function.
 339  */
 340 bool buffer_is_zero(const void *buf, size_t len)
 341 {
 342     /*
 343      * Use long as the biggest available internal data type that fits into the
 344      * CPU register and unroll the loop to smooth out the effect of memory
 345      * latency.
 346      */
 347
 348     size_t i;
 349     long d0, d1, d2, d3;
 350     const long * const data = buf;
 351
 352     /* use vector optimized zero check if possible */
 353     if (can_use_buffer_find_nonzero_offset(buf, len)) {
 354         return buffer_find_nonzero_offset(buf, len) == len;
 355     }
 356
 357     assert(len % (4 * sizeof(long)) == 0);
 358     len /= sizeof(long);
 359
 360     for (i = 0; i < len; i += 4) {
 361         d0 = data[i + 0];
 362         d1 = data[i + 1];
 363         d2 = data[i + 2];
 364         d3 = data[i + 3];
 365
 366         if (d0 || d1 || d2 || d3) {
 367             return false;
 368         }
 369     }
 370
 371     return true;
 372 }
 373
 374 #ifndef _WIN32
 375 /* Sets a specific flag */
 376 int fcntl_setfl(int fd, int flag)
 377 {
 378     int flags;
 379
 380     flags = fcntl(fd, F_GETFL);
 381     if (flags == -1)
 382         return -errno;
 383
 384     if (fcntl(fd, F_SETFL, flags | flag) == -1)
 385         return -errno;
 386
 387     return 0;
 388 }
 389 #endif
 390
 391 static int64_t suffix_mul(char suffix, int64_t unit)
 392 {
 393     switch (qemu_toupper(suffix)) {
 394     case QEMU_STRTOSZ_DEFSUFFIX_B:
 395         return 1;
 396     case QEMU_STRTOSZ_DEFSUFFIX_KB:
 397         return unit;
 398     case QEMU_STRTOSZ_DEFSUFFIX_MB:
 399         return unit * unit;
 400     case QEMU_STRTOSZ_DEFSUFFIX_GB:
 401         return unit * unit * unit;
 402     case QEMU_STRTOSZ_DEFSUFFIX_TB:
 403         return unit * unit * unit * unit;
 404     case QEMU_STRTOSZ_DEFSUFFIX_PB:
 405         return unit * unit * unit * unit * unit;
 406     case QEMU_STRTOSZ_DEFSUFFIX_EB:
 407         return unit * unit * unit * unit * unit * unit;
 408     }
 409     return -1;
 410 }
 411
 412 /*
 413  * Convert string to bytes, allowing either B/b for bytes, K/k for KB,
 414  * M/m for MB, G/g for GB or T/t for TB. End pointer will be returned
 415  * in *end, if not NULL. Return -ERANGE on overflow, Return -EINVAL on
 416  * other error.
 417  */
 418 int64_t qemu_strtosz_suffix_unit(const char *nptr, char **end,
 419                             const char default_suffix, int64_t unit)
 420 {
 421     int64_t retval = -EINVAL;
 422     char *endptr;
 423     unsigned char c;
 424     int mul_required = 0;
 425     double val, mul, integral, fraction;
 426
 427     errno = 0;
 428     val = strtod(nptr, &endptr);
 429     if (isnan(val) || endptr == nptr || errno != 0) {
 430         goto fail;
 431     }
 432     fraction = modf(val, &integral);
 433     if (fraction != 0) {
 434         mul_required = 1;
 435     }
 436     c = *endptr;
 437     mul = suffix_mul(c, unit);
 438     if (mul >= 0) {
 439         endptr++;
 440     } else {
 441         mul = suffix_mul(default_suffix, unit);
 442         assert(mul >= 0);
 443     }
 444     if (mul == 1 && mul_required) {
 445         goto fail;
 446     }
 447     if ((val * mul >= INT64_MAX) || val < 0) {
 448         retval = -ERANGE;
 449         goto fail;
 450     }
 451     retval = val * mul;
 452
 453 fail:
 454     if (end) {
 455         *end = endptr;
 456     }
 457
 458     return retval;
 459 }
 460
 461 int64_t qemu_strtosz_suffix(const char *nptr, char **end,
 462                             const char default_suffix)
 463 {
 464     return qemu_strtosz_suffix_unit(nptr, end, default_suffix, 1024);
 465 }
 466
 467 int64_t qemu_strtosz(const char *nptr, char **end)
 468 {
 469     return qemu_strtosz_suffix(nptr, end, QEMU_STRTOSZ_DEFSUFFIX_MB);
 470 }
 471
 472 /**
 473  * Helper function for qemu_strto*l() functions.
 474  */
 475 static int check_strtox_error(const char *p, char *endptr, const char **next,
 476                               int err)
 477 {
 478     /* If no conversion was performed, prefer BSD behavior over glibc
 479      * behavior.
 480      */
 481     if (err == 0 && endptr == p) {
 482         err = EINVAL;
 483     }
 484     if (!next && *endptr) {
 485         return -EINVAL;
 486     }
 487     if (next) {
 488         *next = endptr;
 489     }
 490     return -err;
 491 }
 492
 493 /**
 494  * QEMU wrappers for strtol(), strtoll(), strtoul(), strotull() C functions.
 495  *
 496  * Convert ASCII string @nptr to a long integer value
 497  * from the given @base. Parameters @nptr, @endptr, @base
 498  * follows same semantics as strtol() C function.
 499  *
 500  * Unlike from strtol() function, if @endptr is not NULL, this
 501  * function will return -EINVAL whenever it cannot fully convert
 502  * the string in @nptr with given @base to a long. This function returns
 503  * the result of the conversion only through the @result parameter.
 504  *
 505  * If NULL is passed in @endptr, then the whole string in @ntpr
 506  * is a number otherwise it returns -EINVAL.
 507  *
 508  * RETURN VALUE
 509  * Unlike from strtol() function, this wrapper returns either
 510  * -EINVAL or the errno set by strtol() function (e.g -ERANGE).
 511  * If the conversion overflows, -ERANGE is returned, and @result
 512  * is set to the max value of the desired type
 513  * (e.g. LONG_MAX, LLONG_MAX, ULONG_MAX, ULLONG_MAX). If the case
 514  * of underflow, -ERANGE is returned, and @result is set to the min
 515  * value of the desired type. For strtol(), strtoll(), @result is set to
 516  * LONG_MIN, LLONG_MIN, respectively, and for strtoul(), strtoull() it
 517  * is set to 0.
 518  */
 519 int qemu_strtol(const char *nptr, const char **endptr, int base,
 520                 long *result)
 521 {
 522     char *p;
 523     int err = 0;
 524     if (!nptr) {
 525         if (endptr) {
 526             *endptr = nptr;
 527         }
 528         err = -EINVAL;
 529     } else {
 530         errno = 0;
 531         *result = strtol(nptr, &p, base);
 532         err = check_strtox_error(nptr, p, endptr, errno);
 533     }
 534     return err;
 535 }
 536
 537 /**
 538  * Converts ASCII string to an unsigned long integer.
 539  *
 540  * If string contains a negative number, value will be converted to
 541  * the unsigned representation of the signed value, unless the original
 542  * (nonnegated) value would overflow, in this case, it will set @result
 543  * to ULONG_MAX, and return ERANGE.
 544  *
 545  * The same behavior holds, for qemu_strtoull() but sets @result to
 546  * ULLONG_MAX instead of ULONG_MAX.
 547  *
 548  * See qemu_strtol() documentation for more info.
 549  */
 550 int qemu_strtoul(const char *nptr, const char **endptr, int base,
 551                  unsigned long *result)
 552 {
 553     char *p;
 554     int err = 0;
 555     if (!nptr) {
 556         if (endptr) {
 557             *endptr = nptr;
 558         }
 559         err = -EINVAL;
 560     } else {
 561         errno = 0;
 562         *result = strtoul(nptr, &p, base);
 563         /* Windows returns 1 for negative out-of-range values.  */
 564         if (errno == ERANGE) {
 565             *result = -1;
 566         }
 567         err = check_strtox_error(nptr, p, endptr, errno);
 568     }
 569     return err;
 570 }
 571
 572 /**
 573  * Converts ASCII string to a long long integer.
 574  *
 575  * See qemu_strtol() documentation for more info.
 576  */
 577 int qemu_strtoll(const char *nptr, const char **endptr, int base,
 578                  int64_t *result)
 579 {
 580     char *p;
 581     int err = 0;
 582     if (!nptr) {
 583         if (endptr) {
 584             *endptr = nptr;
 585         }
 586         err = -EINVAL;
 587     } else {
 588         errno = 0;
 589         *result = strtoll(nptr, &p, base);
 590         err = check_strtox_error(nptr, p, endptr, errno);
 591     }
 592     return err;
 593 }
 594
 595 /**
 596  * Converts ASCII string to an unsigned long long integer.
 597  *
 598  * See qemu_strtol() documentation for more info.
 599  */
 600 int qemu_strtoull(const char *nptr, const char **endptr, int base,
 601                   uint64_t *result)
 602 {
 603     char *p;
 604     int err = 0;
 605     if (!nptr) {
 606         if (endptr) {
 607             *endptr = nptr;
 608         }
 609         err = -EINVAL;
 610     } else {
 611         errno = 0;
 612         *result = strtoull(nptr, &p, base);
 613         /* Windows returns 1 for negative out-of-range values.  */
 614         if (errno == ERANGE) {
 615             *result = -1;
 616         }
 617         err = check_strtox_error(nptr, p, endptr, errno);
 618     }
 619     return err;
 620 }
 621
 622 /**
 623  * parse_uint:
 624  *
 625  * @s: String to parse
 626  * @value: Destination for parsed integer value
 627  * @endptr: Destination for pointer to first character not consumed
 628  * @base: integer base, between 2 and 36 inclusive, or 0
 629  *
 630  * Parse unsigned integer
 631  *
 632  * Parsed syntax is like strtoull()'s: arbitrary whitespace, a single optional
 633  * '+' or '-', an optional "0x" if @base is 0 or 16, one or more digits.
 634  *
 635  * If @s is null, or @base is invalid, or @s doesn't start with an
 636  * integer in the syntax above, set *@value to 0, *@endptr to @s, and
 637  * return -EINVAL.
 638  *
 639  * Set *@endptr to point right beyond the parsed integer (even if the integer
 640  * overflows or is negative, all digits will be parsed and *@endptr will
 641  * point right beyond them).
 642  *
 643  * If the integer is negative, set *@value to 0, and return -ERANGE.
 644  *
 645  * If the integer overflows unsigned long long, set *@value to
 646  * ULLONG_MAX, and return -ERANGE.
 647  *
 648  * Else, set *@value to the parsed integer, and return 0.
 649  */
 650 int parse_uint(const char *s, unsigned long long *value, char **endptr,
 651                int base)
 652 {
 653     int r = 0;
 654     char *endp = (char *)s;
 655     unsigned long long val = 0;
 656
 657     if (!s) {
 658         r = -EINVAL;
 659         goto out;
 660     }
 661
 662     errno = 0;
 663     val = strtoull(s, &endp, base);
 664     if (errno) {
 665         r = -errno;
 666         goto out;
 667     }
 668
 669     if (endp == s) {
 670         r = -EINVAL;
 671         goto out;
 672     }
 673
 674     /* make sure we reject negative numbers: */
 675     while (isspace((unsigned char)*s)) {
 676         s++;
 677     }
 678     if (*s == '-') {
 679         val = 0;
 680         r = -ERANGE;
 681         goto out;
 682     }
 683
 684 out:
 685     *value = val;
 686     *endptr = endp;
 687     return r;
 688 }
 689
 690 /**
 691  * parse_uint_full:
 692  *
 693  * @s: String to parse
 694  * @value: Destination for parsed integer value
 695  * @base: integer base, between 2 and 36 inclusive, or 0
 696  *
 697  * Parse unsigned integer from entire string
 698  *
 699  * Have the same behavior of parse_uint(), but with an additional check
 700  * for additional data after the parsed number. If extra characters are present
 701  * after the parsed number, the function will return -EINVAL, and *@v will
 702  * be set to 0.
 703  */
 704 int parse_uint_full(const char *s, unsigned long long *value, int base)
 705 {
 706     char *endp;
 707     int r;
 708
 709     r = parse_uint(s, value, &endp, base);
 710     if (r < 0) {
 711         return r;
 712     }
 713     if (*endp) {
 714         *value = 0;
 715         return -EINVAL;
 716     }
 717
 718     return 0;
 719 }
 720
 721 int qemu_parse_fd(const char *param)
 722 {
 723     long fd;
 724     char *endptr;
 725
 726     errno = 0;
 727     fd = strtol(param, &endptr, 10);
 728     if (param == endptr /* no conversion performed */                    ||
 729         errno != 0      /* not representable as long; possibly others */ ||
 730         *endptr != '\0' /* final string not empty */                     ||
 731         fd < 0          /* invalid as file descriptor */                 ||
 732         fd > INT_MAX    /* not representable as int */) {
 733         return -1;
 734     }
 735     return fd;
 736 }
 737
 738 /*
 739  * Implementation of  ULEB128 (http://en.wikipedia.org/wiki/LEB128)
 740  * Input is limited to 14-bit numbers
 741  */
 742 int uleb128_encode_small(uint8_t *out, uint32_t n)
 743 {
 744     g_assert(n <= 0x3fff);
 745     if (n < 0x80) {
 746         *out++ = n;
 747         return 1;
 748     } else {
 749         *out++ = (n & 0x7f) | 0x80;
 750         *out++ = n >> 7;
 751         return 2;
 752     }
 753 }
 754
 755 int uleb128_decode_small(const uint8_t *in, uint32_t *n)
 756 {
 757     if (!(*in & 0x80)) {
 758         *n = *in++;
 759         return 1;
 760     } else {
 761         *n = *in++ & 0x7f;
 762         /* we exceed 14 bit number */
 763         if (*in & 0x80) {
 764             return -1;
 765         }
 766         *n |= *in++ << 7;
 767         return 2;
 768     }
 769 }
 770
 771 /*
 772  * helper to parse debug environment variables
 773  */
 774 int parse_debug_env(const char *name, int max, int initial)
 775 {
 776     char *debug_env = getenv(name);
 777     char *inv = NULL;
 778     long debug;
 779
 780     if (!debug_env) {
 781         return initial;
 782     }
 783     errno = 0;
 784     debug = strtol(debug_env, &inv, 10);
 785     if (inv == debug_env) {
 786         return initial;
 787     }
 788     if (debug < 0 || debug > max || errno != 0) {
 789         fprintf(stderr, "warning: %s not in [0, %d]", name, max);
 790         return initial;
 791     }
 792     return debug;
 793 }
 794
 795 /*
 796  * Helper to print ethernet mac address
 797  */
 798 const char *qemu_ether_ntoa(const MACAddr *mac)
 799 {
 800     static char ret[18];
 801
 802     snprintf(ret, sizeof(ret), "%02x:%02x:%02x:%02x:%02x:%02x",
 803              mac->a[0], mac->a[1], mac->a[2], mac->a[3], mac->a[4], mac->a[5]);
 804
 805     return ret;
 806 }