From 7c749893bfcf9f1a117ee6a2d35a6c8f0f05909d Mon Sep 17 00:00:00 2001 From: Neels Hofmeyr Date: Fri, 7 Sep 2018 03:01:38 +0200 Subject: add osmo_str_tolower() and _toupper() with test We already have osmo_str2lower() and osmo_str2upper(), but these lack: * proper destination buffer bounds checking, * ability to call directly as printf() argument. Deprecate osmo_str2upper() and osmo_str2lower() because of missing bounds checking. Introduce osmo_str_tolower_buf(), osmo_str_toupper_buf() to provide bounds-safe conversion, also able to safely convert a buffer in-place. Introduce osmo_str_tolower(), osmo_str_toupper() that call the above _buf() equivalents using a static buffer[128] and returning the resulting string directly, convenient for direct printing. Possibly truncated but always safe. Add unit tests to utils_test.c. Replace all libosmocore uses of now deprecated osmo_str2lower(). Naming: the ctype.h API is called tolower() and toupper(), so just prepend 'osmo_str_' and don't separate 'to_lower'. Change-Id: Ib0ee1206b9f31d7ba25c31f8008119ac55440797 --- src/utils.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 86 insertions(+) (limited to 'src/utils.c') diff --git a/src/utils.c b/src/utils.c index 3f40f2ef..e6adcf86 100644 --- a/src/utils.c +++ b/src/utils.c @@ -638,4 +638,90 @@ uint32_t osmo_isqrt32(uint32_t x) return g0; } +/*! Convert a string to lowercase, while checking buffer size boundaries. + * The result written to \a dest is guaranteed to be nul terminated if \a dest_len > 0. + * If dest == src, the string is converted in-place, if necessary truncated at dest_len - 1 characters + * length as well as nul terminated. + * Note: similar osmo_str2lower(), but safe to use for src strings of arbitrary length. + * \param[out] dest Target buffer to write lowercase string. + * \param[in] dest_len Maximum buffer size of dest (e.g. sizeof(dest)). + * \param[in] src String to convert to lowercase. + * \returns Length of \a src, like osmo_strlcpy(), but if \a dest == \a src at most \a dest_len - 1. + */ +size_t osmo_str_tolower_buf(char *dest, size_t dest_len, const char *src) +{ + size_t rc; + if (dest == src) { + if (dest_len < 1) + return 0; + dest[dest_len - 1] = '\0'; + rc = strlen(dest); + } else { + if (dest_len < 1) + return strlen(src); + rc = osmo_strlcpy(dest, src, dest_len); + } + for (; *dest; dest++) + *dest = tolower(*dest); + return rc; +} + +/*! Convert a string to lowercase, using a static buffer. + * The resulting string may be truncated if the internally used static buffer is shorter than src. + * The internal buffer is at least 128 bytes long, i.e. guaranteed to hold at least 127 characters and a + * terminating nul. + * See also osmo_str_tolower_buf(). + * \param[in] src String to convert to lowercase. + * \returns Resulting lowercase string in a static buffer, always nul terminated. + */ +const char *osmo_str_tolower(const char *src) +{ + static char buf[128]; + osmo_str_tolower_buf(buf, sizeof(buf), src); + return buf; +} + +/*! Convert a string to uppercase, while checking buffer size boundaries. + * The result written to \a dest is guaranteed to be nul terminated if \a dest_len > 0. + * If dest == src, the string is converted in-place, if necessary truncated at dest_len - 1 characters + * length as well as nul terminated. + * Note: similar osmo_str2upper(), but safe to use for src strings of arbitrary length. + * \param[out] dest Target buffer to write uppercase string. + * \param[in] dest_len Maximum buffer size of dest (e.g. sizeof(dest)). + * \param[in] src String to convert to uppercase. + * \returns Length of \a src, like osmo_strlcpy(), but if \a dest == \a src at most \a dest_len - 1. + */ +size_t osmo_str_toupper_buf(char *dest, size_t dest_len, const char *src) +{ + size_t rc; + if (dest == src) { + if (dest_len < 1) + return 0; + dest[dest_len - 1] = '\0'; + rc = strlen(dest); + } else { + if (dest_len < 1) + return strlen(src); + rc = osmo_strlcpy(dest, src, dest_len); + } + for (; *dest; dest++) + *dest = toupper(*dest); + return rc; +} + +/*! Convert a string to uppercase, using a static buffer. + * The resulting string may be truncated if the internally used static buffer is shorter than src. + * The internal buffer is at least 128 bytes long, i.e. guaranteed to hold at least 127 characters and a + * terminating nul. + * See also osmo_str_toupper_buf(). + * \param[in] src String to convert to uppercase. + * \returns Resulting uppercase string in a static buffer, always nul terminated. + */ +const char *osmo_str_toupper(const char *src) +{ + static char buf[128]; + osmo_str_toupper_buf(buf, sizeof(buf), src); + return buf; +} + /*! @} */ -- cgit v1.2.3