diff options
Diffstat (limited to 'util/cutils.c')
-rw-r--r-- | util/cutils.c | 98 |
1 files changed, 77 insertions, 21 deletions
diff --git a/util/cutils.c b/util/cutils.c index 70c7d6efbd..d89a40a8c3 100644 --- a/util/cutils.c +++ b/util/cutils.c @@ -241,52 +241,108 @@ static int64_t suffix_mul(char suffix, int64_t unit) } /* - * Convert string to bytes, allowing either B/b for bytes, K/k for KB, - * M/m for MB, G/g for GB or T/t for TB. End pointer will be returned - * in *end, if not NULL. Return -ERANGE on overflow, and -EINVAL on - * other error. + * Convert size string to bytes. + * + * The size parsing supports the following syntaxes + * - 12345 - decimal, scale determined by @default_suffix and @unit + * - 12345{bBkKmMgGtTpPeE} - decimal, scale determined by suffix and @unit + * - 12345.678{kKmMgGtTpPeE} - decimal, scale determined by suffix, and + * fractional portion is truncated to byte + * - 0x7fEE - hexadecimal, unit determined by @default_suffix + * + * The following cause a deprecation warning, and may be removed in the future + * - 0xabc{kKmMgGtTpP} - hex with scaling suffix + * + * The following are intentionally not supported + * - octal, such as 08 + * - fractional hex, such as 0x1.8 + * - floating point exponents, such as 1e3 + * + * The end pointer will be returned in *end, if not NULL. If there is + * no fraction, the input can be decimal or hexadecimal; if there is a + * fraction, then the input must be decimal and there must be a suffix + * (possibly by @default_suffix) larger than Byte, and the fractional + * portion may suffer from precision loss or rounding. The input must + * be positive. + * + * Return -ERANGE on overflow (with *@end advanced), and -EINVAL on + * other error (with *@end left unchanged). */ static int do_strtosz(const char *nptr, const char **end, const char default_suffix, int64_t unit, uint64_t *result) { int retval; - const char *endptr; + const char *endptr, *f; unsigned char c; - int mul_required = 0; - double val, mul, integral, fraction; + bool mul_required = false, hex = false; + uint64_t val; + int64_t mul; + double fraction = 0.0; - retval = qemu_strtod_finite(nptr, &endptr, &val); + /* Parse integral portion as decimal. */ + retval = qemu_strtou64(nptr, &endptr, 10, &val); if (retval) { goto out; } - fraction = modf(val, &integral); - if (fraction != 0) { - mul_required = 1; + if (memchr(nptr, '-', endptr - nptr) != NULL) { + endptr = nptr; + retval = -EINVAL; + goto out; + } + if (val == 0 && (*endptr == 'x' || *endptr == 'X')) { + /* Input looks like hex, reparse, and insist on no fraction. */ + retval = qemu_strtou64(nptr, &endptr, 16, &val); + if (retval) { + goto out; + } + if (*endptr == '.') { + endptr = nptr; + retval = -EINVAL; + goto out; + } + hex = true; + } else if (*endptr == '.') { + /* + * Input looks like a fraction. Make sure even 1.k works + * without fractional digits. If we see an exponent, treat + * the entire input as invalid instead. + */ + f = endptr; + retval = qemu_strtod_finite(f, &endptr, &fraction); + if (retval) { + fraction = 0.0; + endptr++; + } else if (memchr(f, 'e', endptr - f) || memchr(f, 'E', endptr - f)) { + endptr = nptr; + retval = -EINVAL; + goto out; + } else if (fraction != 0) { + mul_required = true; + } } c = *endptr; mul = suffix_mul(c, unit); - if (mul >= 0) { + if (mul > 0) { + if (hex) { + warn_report("Using a multiplier suffix on hex numbers " + "is deprecated: %s", nptr); + } endptr++; } else { mul = suffix_mul(default_suffix, unit); - assert(mul >= 0); + assert(mul > 0); } if (mul == 1 && mul_required) { + endptr = nptr; retval = -EINVAL; goto out; } - /* - * Values near UINT64_MAX overflow to 2**64 when converting to double - * precision. Compare against the maximum representable double precision - * value below 2**64, computed as "the next value after 2**64 (0x1p64) in - * the direction of 0". - */ - if ((val * mul > nextafter(0x1p64, 0)) || val < 0) { + if (val > (UINT64_MAX - ((uint64_t) (fraction * mul))) / mul) { retval = -ERANGE; goto out; } - *result = val * mul; + *result = val * mul + (uint64_t) (fraction * mul); retval = 0; out: |