Messages in this thread Patch in this message | | | Subject | [PATCH 2/3] lib: vsnprintf.c remove macros defining strict string functions | From | Harvey Harrison <> | Date | Tue, 13 May 2008 16:57:44 -0700 |
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Directly code the strict string conversion functions rather than using defining macros. Pull out a small helper to check the strict conditions required at the end of a string (nul-terminated or newline).
Add additional checks in strict_strtol and strict_strtoll for numeric overflow of the signed types.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> --- lib/vsprintf.c | 145 +++++++++++++++++++++++++++++++++++++------------------ 1 files changed, 97 insertions(+), 48 deletions(-)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c index dc5c3ae..3547fb5 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -131,6 +131,19 @@ long long simple_strtoll(const char *cp,char **endp,unsigned int base) return simple_strtoull(cp, endp, base); } +/* + * Strictly check that the string is nul terminated or has a newline + * immediately following len chars. + */ +static int strict_checktail(size_t len, const char *cp, const char *tail) +{ + if ((*tail == '\0') || + ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) + return 1; + else + return 0; +} + /** * strict_strtoul - convert a string to an unsigned long strictly * @cp: The string to be converted @@ -153,7 +166,26 @@ long long simple_strtoll(const char *cp,char **endp,unsigned int base) * simple_strtoul just ignores the successive invalid characters and * return the converted value of prefix part of the string. */ -int strict_strtoul(const char *cp, unsigned int base, unsigned long *res); +int strict_strtoul(const char *cp, unsigned int base, unsigned long *res) +{ + char *tail; + unsigned long val; + size_t len; + + *res = 0; + len = strlen(cp); + if (len == 0) + return -EINVAL; + + val = simple_strtoul(cp, &tail, base); + if (strict_checktail(len, cp, tail)) { + *res = val; + return 0; + } + + return -EINVAL; +} +EXPORT_SYMBOL(strict_strtoul); /** * strict_strtol - convert a string to a long strictly @@ -167,7 +199,29 @@ int strict_strtoul(const char *cp, unsigned int base, unsigned long *res); * It returns 0 if conversion is successful and *res is set to the converted * value, otherwise it returns -EINVAL and *res is set to 0. */ -int strict_strtol(const char *cp, unsigned int base, long *res); +int strict_strtol(const char *cp, unsigned int base, long *res) +{ + int ret; + unsigned long tmp; + + if (*cp == '-') + ret = strict_strtoul(cp + 1, base, &tmp); + else + ret = strict_strtoul(cp, base, &tmp); + + if (ret < 0 || tmp > LONG_MAX) { + *res = 0; + return -EINVAL; + } + + if (*cp == '-') + *res = -tmp; + else + *res = tmp; + + return 0; +} +EXPORT_SYMBOL(strict_strtol); /** * strict_strtoull - convert a string to an unsigned long long strictly @@ -191,7 +245,26 @@ int strict_strtol(const char *cp, unsigned int base, long *res); * simple_strtoull just ignores the successive invalid characters and * return the converted value of prefix part of the string. */ -int strict_strtoull(const char *cp, unsigned int base, unsigned long long *res); +int strict_strtoull(const char *cp, unsigned int base, unsigned long long *res) +{ + char *tail; + unsigned long long val; + size_t len; + + *res = 0; + len = strlen(cp); + if (len == 0) + return -EINVAL; + + val = simple_strtoull(cp, &tail, base); + if (strict_checktail(len, cp, tail)) { + *res = val; + return 0; + } + + return -EINVAL; +} +EXPORT_SYMBOL(strict_strtoull); /** * strict_strtoll - convert a string to a long long strictly @@ -205,53 +278,29 @@ int strict_strtoull(const char *cp, unsigned int base, unsigned long long *res); * It returns 0 if conversion is successful and *res is set to the converted * value, otherwise it returns -EINVAL and *res is set to 0. */ -int strict_strtoll(const char *cp, unsigned int base, long long *res); - -#define define_strict_strtoux(type, valtype) \ -int strict_strtou##type(const char *cp, unsigned int base, valtype *res)\ -{ \ - char *tail; \ - valtype val; \ - size_t len; \ - \ - *res = 0; \ - len = strlen(cp); \ - if (len == 0) \ - return -EINVAL; \ - \ - val = simple_strtoul(cp, &tail, base); \ - if ((*tail == '\0') || \ - ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {\ - *res = val; \ - return 0; \ - } \ - \ - return -EINVAL; \ -} \ - -#define define_strict_strtox(type, valtype) \ -int strict_strto##type(const char *cp, unsigned int base, valtype *res) \ -{ \ - int ret; \ - if (*cp == '-') { \ - ret = strict_strtou##type(cp+1, base, res); \ - if (!ret) \ - *res = -(*res); \ - } else \ - ret = strict_strtou##type(cp, base, res); \ - \ - return ret; \ -} \ - -define_strict_strtoux(l, unsigned long) -define_strict_strtox(l, long) -define_strict_strtoux(ll, unsigned long long) -define_strict_strtox(ll, long long) +int strict_strtoll(const char *cp, unsigned int base, long long *res) +{ + int ret; + unsigned long long tmp; -EXPORT_SYMBOL(strict_strtoul); -EXPORT_SYMBOL(strict_strtol); + if (*cp == '-') + ret = strict_strtoull(cp + 1, base, &tmp); + else + ret = strict_strtoull(cp, base, &tmp); + + if (ret < 0 || tmp > LLONG_MAX) { + *res = 0; + return -EINVAL; + } + + if (*cp == '-') + *res = -tmp; + else + *res = tmp; + + return 0; +} EXPORT_SYMBOL(strict_strtoll); -EXPORT_SYMBOL(strict_strtoull); static int skip_atoi(const char **s) { -- 1.5.5.1.482.g0f174
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