diff options
Diffstat (limited to 'util/cutils.c')
| -rw-r--r-- | util/cutils.c | 263 |
1 files changed, 167 insertions, 96 deletions
diff --git a/util/cutils.c b/util/cutils.c index 5887e74414..25373198ad 100644 --- a/util/cutils.c +++ b/util/cutils.c @@ -194,46 +194,48 @@ static int64_t suffix_mul(char suffix, int64_t unit) * - 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 + * fractional portion is truncated to byte, either side of . may be empty * - 0x7fEE - hexadecimal, unit determined by @default_suffix * * The following are intentionally not supported - * - hex with scaling suffix, such as 0x20M - * - octal, such as 08 - * - fractional hex, such as 0x1.8 - * - floating point exponents, such as 1e3 + * - hex with scaling suffix, such as 0x20M or 0x1p3 (both fail with + * -EINVAL), while 0x1b is 27 (not 1 with byte scale) + * - octal, such as 08 (parsed as decimal instead) + * - binary, such as 0b1000 (parsed as 0b with trailing garbage "1000") + * - fractional hex, such as 0x1.8 (parsed as 0 with trailing garbage "x1.8") + * - negative values, including -0 (fail with -ERANGE) + * - floating point exponents, such as 1e3 (parsed as 1e with trailing + * garbage "3") or 0x1p3 (rejected as hex with scaling suffix) + * - non-finite values, such as inf or NaN (fail with -EINVAL) * * 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. + * non-zero 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). + * other error (with *@end at @nptr). Unlike strtoull, *@result is + * set to 0 on all errors, as returning UINT64_MAX on overflow is less + * likely to be usable as a size. */ 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, *f; + const char *endptr; unsigned char c; - uint64_t val, valf = 0; + uint64_t val = 0, valf = 0; int64_t mul; /* Parse integral portion as decimal. */ - retval = qemu_strtou64(nptr, &endptr, 10, &val); - if (retval) { - goto out; - } - if (memchr(nptr, '-', endptr - nptr) != NULL) { - endptr = nptr; - retval = -EINVAL; + retval = parse_uint(nptr, &endptr, 10, &val); + if (retval == -ERANGE || !nptr) { goto out; } - if (val == 0 && (*endptr == 'x' || *endptr == 'X')) { + if (retval == 0 && val == 0 && (*endptr == 'x' || *endptr == 'X')) { /* Input looks like hex; reparse, and insist on no fraction or suffix. */ retval = qemu_strtou64(nptr, &endptr, 16, &val); if (retval) { @@ -244,27 +246,69 @@ static int do_strtosz(const char *nptr, const char **end, retval = -EINVAL; goto out; } - } else if (*endptr == '.') { + } else if (*endptr == '.' || (endptr == nptr && strchr(nptr, '.'))) { /* * 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. + * without fractional digits. strtod tries to treat 'e' as an + * exponent, but we want to treat it as a scaling suffix; + * doing this requires modifying a copy of the fraction. */ - double fraction; + double fraction = 0.0; - f = endptr; - retval = qemu_strtod_finite(f, &endptr, &fraction); - if (retval) { + if (retval == 0 && *endptr == '.' && !isdigit(endptr[1])) { + /* If we got here, we parsed at least one digit already. */ endptr++; - } else if (memchr(f, 'e', endptr - f) || memchr(f, 'E', endptr - f)) { - endptr = nptr; - retval = -EINVAL; - goto out; } else { - /* Extract into a 64-bit fixed-point fraction. */ + char *e; + const char *tail; + g_autofree char *copy = g_strdup(endptr); + + e = strchr(copy, 'e'); + if (e) { + *e = '\0'; + } + e = strchr(copy, 'E'); + if (e) { + *e = '\0'; + } + /* + * If this is a floating point, we are guaranteed that '.' + * appears before any possible digits in copy. If it is + * not a floating point, strtod will fail. Either way, + * there is now no exponent in copy, so if it parses, we + * know 0.0 <= abs(result) <= 1.0 (after rounding), and + * ERANGE is only possible on underflow which is okay. + */ + retval = qemu_strtod_finite(copy, &tail, &fraction); + endptr += tail - copy; + if (signbit(fraction)) { + retval = -ERANGE; + goto out; + } + } + + /* Extract into a 64-bit fixed-point fraction. */ + if (fraction == 1.0) { + if (val == UINT64_MAX) { + retval = -ERANGE; + goto out; + } + val++; + } else if (retval == -ERANGE) { + /* See comments above about underflow */ + valf = 1; + retval = 0; + } else { + /* We want non-zero valf for any non-zero fraction */ valf = (uint64_t)(fraction * 0x1p64); + if (valf == 0 && fraction > 0.0) { + valf = 1; + } } } + if (retval) { + goto out; + } c = *endptr; mul = suffix_mul(c, unit); if (mul > 0) { @@ -306,11 +350,16 @@ static int do_strtosz(const char *nptr, const char **end, out: if (end) { *end = endptr; - } else if (*endptr) { + } else if (nptr && *endptr) { retval = -EINVAL; } if (retval == 0) { *result = val; + } else { + *result = 0; + if (end && retval == -EINVAL) { + *end = nptr; + } } return retval; @@ -377,12 +426,13 @@ static int check_strtox_error(const char *nptr, char *ep, * * @nptr may be null, and no conversion is performed then. * - * If no conversion is performed, store @nptr in *@endptr and return - * -EINVAL. + * If no conversion is performed, store @nptr in *@endptr, 0 in + * @result, and return -EINVAL. * * If @endptr is null, and the string isn't fully converted, return - * -EINVAL. This is the case when the pointer that would be stored in - * a non-null @endptr points to a character other than '\0'. + * -EINVAL with @result set to the parsed value. This is the case + * when the pointer that would be stored in a non-null @endptr points + * to a character other than '\0'. * * If the conversion overflows @result, store INT_MAX in @result, * and return -ERANGE. @@ -391,6 +441,9 @@ static int check_strtox_error(const char *nptr, char *ep, * and return -ERANGE. * * Else store the converted value in @result, and return zero. + * + * This matches the behavior of strtol() on 32-bit platforms, even on + * platforms where long is 64-bits. */ int qemu_strtoi(const char *nptr, const char **endptr, int base, int *result) @@ -400,6 +453,7 @@ int qemu_strtoi(const char *nptr, const char **endptr, int base, assert((unsigned) base <= 36 && base != 1); if (!nptr) { + *result = 0; if (endptr) { *endptr = nptr; } @@ -429,12 +483,13 @@ int qemu_strtoi(const char *nptr, const char **endptr, int base, * * @nptr may be null, and no conversion is performed then. * - * If no conversion is performed, store @nptr in *@endptr and return - * -EINVAL. + * If no conversion is performed, store @nptr in *@endptr, 0 in + * @result, and return -EINVAL. * * If @endptr is null, and the string isn't fully converted, return - * -EINVAL. This is the case when the pointer that would be stored in - * a non-null @endptr points to a character other than '\0'. + * -EINVAL with @result set to the parsed value. This is the case + * when the pointer that would be stored in a non-null @endptr points + * to a character other than '\0'. * * If the conversion overflows @result, store UINT_MAX in @result, * and return -ERANGE. @@ -443,16 +498,19 @@ int qemu_strtoi(const char *nptr, const char **endptr, int base, * * Note that a number with a leading minus sign gets converted without * the minus sign, checked for overflow (see above), then negated (in - * @result's type). This is exactly how strtoul() works. + * @result's type). This matches the behavior of strtoul() on 32-bit + * platforms, even on platforms where long is 64-bits. */ int qemu_strtoui(const char *nptr, const char **endptr, int base, unsigned int *result) { char *ep; - long long lresult; + unsigned long long lresult; + bool neg; assert((unsigned) base <= 36 && base != 1); if (!nptr) { + *result = 0; if (endptr) { *endptr = nptr; } @@ -466,14 +524,22 @@ int qemu_strtoui(const char *nptr, const char **endptr, int base, if (errno == ERANGE) { *result = -1; } else { + /* + * Note that platforms with 32-bit strtoul only accept input + * in the range [-4294967295, 4294967295]; but we used 64-bit + * strtoull which wraps -18446744073709551615 to 1 instead of + * declaring overflow. So we must check if '-' was parsed, + * and if so, undo the negation before doing our bounds check. + */ + neg = memchr(nptr, '-', ep - nptr) != NULL; + if (neg) { + lresult = -lresult; + } if (lresult > UINT_MAX) { *result = UINT_MAX; errno = ERANGE; - } else if (lresult < INT_MIN) { - *result = UINT_MAX; - errno = ERANGE; } else { - *result = lresult; + *result = neg ? -lresult : lresult; } } return check_strtox_error(nptr, ep, endptr, lresult == 0, errno); @@ -488,12 +554,13 @@ int qemu_strtoui(const char *nptr, const char **endptr, int base, * * @nptr may be null, and no conversion is performed then. * - * If no conversion is performed, store @nptr in *@endptr and return - * -EINVAL. + * If no conversion is performed, store @nptr in *@endptr, 0 in + * @result, and return -EINVAL. * * If @endptr is null, and the string isn't fully converted, return - * -EINVAL. This is the case when the pointer that would be stored in - * a non-null @endptr points to a character other than '\0'. + * -EINVAL with @result set to the parsed value. This is the case + * when the pointer that would be stored in a non-null @endptr points + * to a character other than '\0'. * * If the conversion overflows @result, store LONG_MAX in @result, * and return -ERANGE. @@ -510,6 +577,7 @@ int qemu_strtol(const char *nptr, const char **endptr, int base, assert((unsigned) base <= 36 && base != 1); if (!nptr) { + *result = 0; if (endptr) { *endptr = nptr; } @@ -530,12 +598,13 @@ int qemu_strtol(const char *nptr, const char **endptr, int base, * * @nptr may be null, and no conversion is performed then. * - * If no conversion is performed, store @nptr in *@endptr and return - * -EINVAL. + * If no conversion is performed, store @nptr in *@endptr, 0 in + * @result, and return -EINVAL. * * If @endptr is null, and the string isn't fully converted, return - * -EINVAL. This is the case when the pointer that would be stored in - * a non-null @endptr points to a character other than '\0'. + * -EINVAL with @result set to the parsed value. This is the case + * when the pointer that would be stored in a non-null @endptr points + * to a character other than '\0'. * * If the conversion overflows @result, store ULONG_MAX in @result, * and return -ERANGE. @@ -553,6 +622,7 @@ int qemu_strtoul(const char *nptr, const char **endptr, int base, assert((unsigned) base <= 36 && base != 1); if (!nptr) { + *result = 0; if (endptr) { *endptr = nptr; } @@ -581,6 +651,7 @@ int qemu_strtoi64(const char *nptr, const char **endptr, int base, assert((unsigned) base <= 36 && base != 1); if (!nptr) { + *result = 0; if (endptr) { *endptr = nptr; } @@ -598,6 +669,8 @@ int qemu_strtoi64(const char *nptr, const char **endptr, int base, * Convert string @nptr to an uint64_t. * * Works like qemu_strtoul(), except it stores UINT64_MAX on overflow. + * (If you want to prohibit negative numbers that wrap around to + * positive, use parse_uint()). */ int qemu_strtou64(const char *nptr, const char **endptr, int base, uint64_t *result) @@ -606,6 +679,7 @@ int qemu_strtou64(const char *nptr, const char **endptr, int base, assert((unsigned) base <= 36 && base != 1); if (!nptr) { + *result = 0; if (endptr) { *endptr = nptr; } @@ -632,12 +706,13 @@ int qemu_strtou64(const char *nptr, const char **endptr, int base, * * @nptr may be null, and no conversion is performed then. * - * If no conversion is performed, store @nptr in *@endptr and return - * -EINVAL. + * If no conversion is performed, store @nptr in *@endptr, +0.0 in + * @result, and return -EINVAL. * * If @endptr is null, and the string isn't fully converted, return - * -EINVAL. This is the case when the pointer that would be stored in - * a non-null @endptr points to a character other than '\0'. + * -EINVAL with @result set to the parsed value. This is the case + * when the pointer that would be stored in a non-null @endptr points + * to a character other than '\0'. * * If the conversion overflows, store +/-HUGE_VAL in @result, depending * on the sign, and return -ERANGE. @@ -652,6 +727,7 @@ int qemu_strtod(const char *nptr, const char **endptr, double *result) char *ep; if (!nptr) { + *result = 0.0; if (endptr) { *endptr = nptr; } @@ -666,24 +742,28 @@ int qemu_strtod(const char *nptr, const char **endptr, double *result) /** * Convert string @nptr to a finite double. * - * Works like qemu_strtod(), except that "NaN" and "inf" are rejected - * with -EINVAL and no conversion is performed. + * Works like qemu_strtod(), except that "NaN", "inf", and strings + * that cause ERANGE overflow errors are rejected with -EINVAL as if + * no conversion is performed, storing 0.0 into @result regardless of + * any sign. -ERANGE failures for underflow still preserve the parsed + * sign. */ int qemu_strtod_finite(const char *nptr, const char **endptr, double *result) { - double tmp; + const char *tmp; int ret; - ret = qemu_strtod(nptr, endptr, &tmp); - if (!ret && !isfinite(tmp)) { + ret = qemu_strtod(nptr, &tmp, result); + if (!isfinite(*result)) { if (endptr) { *endptr = nptr; } + *result = 0.0; + ret = -EINVAL; + } else if (endptr) { + *endptr = tmp; + } else if (*tmp) { ret = -EINVAL; - } - - if (ret != -EINVAL) { - *result = tmp; } return ret; } @@ -707,32 +787,33 @@ const char *qemu_strchrnul(const char *s, int c) * parse_uint: * * @s: String to parse - * @value: Destination for parsed integer value * @endptr: Destination for pointer to first character not consumed * @base: integer base, between 2 and 36 inclusive, or 0 + * @value: Destination for parsed integer value * * Parse unsigned integer * * Parsed syntax is like strtoull()'s: arbitrary whitespace, a single optional * '+' or '-', an optional "0x" if @base is 0 or 16, one or more digits. * - * If @s is null, or @base is invalid, or @s doesn't start with an - * integer in the syntax above, set *@value to 0, *@endptr to @s, and - * return -EINVAL. + * If @s is null, or @s doesn't start with an integer in the syntax + * above, set *@value to 0, *@endptr to @s, and return -EINVAL. * * Set *@endptr to point right beyond the parsed integer (even if the integer * overflows or is negative, all digits will be parsed and *@endptr will - * point right beyond them). + * point right beyond them). If @endptr is %NULL, any trailing character + * instead causes a result of -EINVAL with *@value of 0. * * If the integer is negative, set *@value to 0, and return -ERANGE. + * (If you want to allow negative numbers that wrap around within + * bounds, use qemu_strtou64()). * * If the integer overflows unsigned long long, set *@value to * ULLONG_MAX, and return -ERANGE. * * Else, set *@value to the parsed integer, and return 0. */ -int parse_uint(const char *s, unsigned long long *value, char **endptr, - int base) +int parse_uint(const char *s, const char **endptr, int base, uint64_t *value) { int r = 0; char *endp = (char *)s; @@ -768,7 +849,12 @@ int parse_uint(const char *s, unsigned long long *value, char **endptr, out: *value = val; - *endptr = endp; + if (endptr) { + *endptr = endp; + } else if (s && *endp) { + r = -EINVAL; + *value = 0; + } return r; } @@ -776,31 +862,16 @@ out: * parse_uint_full: * * @s: String to parse - * @value: Destination for parsed integer value * @base: integer base, between 2 and 36 inclusive, or 0 + * @value: Destination for parsed integer value * - * Parse unsigned integer from entire string + * Parse unsigned integer from entire string, rejecting any trailing slop. * - * Have the same behavior of parse_uint(), but with an additional check - * for additional data after the parsed number. If extra characters are present - * after the parsed number, the function will return -EINVAL, and *@v will - * be set to 0. + * Shorthand for parse_uint(s, NULL, base, value). */ -int parse_uint_full(const char *s, unsigned long long *value, int base) +int parse_uint_full(const char *s, int base, uint64_t *value) { - char *endp; - int r; - - r = parse_uint(s, value, &endp, base); - if (r < 0) { - return r; - } - if (*endp) { - *value = 0; - return -EINVAL; - } - - return 0; + return parse_uint(s, NULL, base, value); } int qemu_parse_fd(const char *param) |