Some users may want to have an ASCII based filter, provided by isascii() function. Here is the addition of a such. Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> --- include/linux/string_helpers.h | 1 + lib/string_helpers.c | 21 +++++++++++++++++---- 2 files changed, 18 insertions(+), 4 deletions(-) diff --git a/include/linux/string_helpers.h b/include/linux/string_helpers.h index bf01e24edd89..d6cf6fe10f74 100644 --- a/include/linux/string_helpers.h +++ b/include/linux/string_helpers.h @@ -52,6 +52,7 @@ static inline int string_unescape_any_inplace(char *buf) #define ESCAPE_NP BIT(4) #define ESCAPE_ANY_NP (ESCAPE_ANY | ESCAPE_NP) #define ESCAPE_HEX BIT(5) +#define ESCAPE_NA BIT(6) int string_escape_mem(const char *src, size_t isz, char *dst, size_t osz, unsigned int flags, const char *only); diff --git a/lib/string_helpers.c b/lib/string_helpers.c index b10a18b4663b..d426163cb446 100644 --- a/lib/string_helpers.c +++ b/lib/string_helpers.c @@ -454,8 +454,8 @@ static bool escape_hex(unsigned char c, char **dst, char *end) * * 1. The character is not matched to the one from @only string and thus * must go as-is to the output. - * 2. The character is matched to the printable class, if asked, and in - * case of match it passes through to the output. + * 2. The character is matched to the printable or ASCII class, if asked, + * and in case of match it passes through to the output. * 3. The character is checked if it falls into the class given by @flags. * %ESCAPE_OCTAL and %ESCAPE_HEX are going last since they cover any * character. Note that they actually can't go together, otherwise @@ -463,7 +463,7 @@ static bool escape_hex(unsigned char c, char **dst, char *end) * * Caller must provide valid source and destination pointers. Be aware that * destination buffer will not be NULL-terminated, thus caller have to append - * it if needs. The supported flags are:: + * it if needs. The supported flags are:: * * %ESCAPE_SPACE: (special white space, not space itself) * '\f' - form feed @@ -482,11 +482,18 @@ static bool escape_hex(unsigned char c, char **dst, char *end) * %ESCAPE_ANY: * all previous together * %ESCAPE_NP: - * escape only non-printable characters (checked by isprint) + * escape only non-printable characters, checked by isprint() * %ESCAPE_ANY_NP: * all previous together * %ESCAPE_HEX: * '\xHH' - byte with hexadecimal value HH (2 digits) + * %ESCAPE_NA: + * escape only non-ascii characters, checked by isascii() + * + * One notable caveat, the %ESCAPE_NP and %ESCAPE_NA have higher priority + * than the rest of the flags (%ESCAPE_NP is higher than %ESCAPE_NA). + * It doesn't make much sense to use either of them without %ESCAPE_OCTAL + * or %ESCAPE_HEX, because they cover most of the other character classes. * * Return: * The total size of the escaped output that would be generated for @@ -510,6 +517,8 @@ int string_escape_mem(const char *src, size_t isz, char *dst, size_t osz, * character under question * - the character is printable, when @flags has * %ESCAPE_NP bit set + * - the character is ASCII, when @flags has + * %ESCAPE_NA bit set * - the character doesn't fall into a class of symbols * defined by given @flags * In these cases we just pass through a character to the @@ -522,6 +531,10 @@ int string_escape_mem(const char *src, size_t isz, char *dst, size_t osz, flags & ESCAPE_NP && escape_passthrough(c, &p, end)) continue; + if (isascii(c) && + flags & ESCAPE_NA && escape_passthrough(c, &p, end)) + continue; + if (flags & ESCAPE_SPACE && escape_space(c, &p, end)) continue; -- 2.30.2
