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-rw-r--r--util/cutils.c98
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: