On Thu, Apr 8, 2021 at 11:34 AM Gioh Kim <gi-oh....@ionos.com> wrote:
>
> As the name shows, it checks if strings are equal in case insensitive
> manner.
>
> For example, drivers/infiniband/ulp/rtrs/rtrs-clt-sysfs.c uses
> strncasecmp to check that the input via sysfs is "mi". But it would
> work even-if the input is "min-wrongcommand".
>
> I found some more cases using strncasecmp to check the entire string
> such as rtrs-clt-sysfs.c does. drivers/pnp/interface.c checks
> "disable" command with strncasecmp but it would also work if the
> command is "disable-wrong".
>
> Signed-off-by: Gioh Kim <gi-oh....@ionos.com>
It looks good to me.
Reviewed-by: Jack Wang <jinpu.w...@ionos.com>
> ---
> include/linux/string.h | 1 +
> lib/string.c | 38 ++++++++++++++++++++++++++++++--------
> 2 files changed, 31 insertions(+), 8 deletions(-)
>
> diff --git a/include/linux/string.h b/include/linux/string.h
> index 4fcfb56abcf5..36d00ff8013e 100644
> --- a/include/linux/string.h
> +++ b/include/linux/string.h
> @@ -184,6 +184,7 @@ extern char **argv_split(gfp_t gfp, const char *str, int
> *argcp);
> extern void argv_free(char **argv);
>
> extern bool sysfs_streq(const char *s1, const char *s2);
> +extern bool sysfs_streqcase(const char *s1, const char *s2);
> extern int kstrtobool(const char *s, bool *res);
> static inline int strtobool(const char *s, bool *res)
> {
> diff --git a/lib/string.c b/lib/string.c
> index 7548eb715ddb..cb53845cc4ac 100644
> --- a/lib/string.c
> +++ b/lib/string.c
> @@ -687,6 +687,18 @@ char *strsep(char **s, const char *ct)
> EXPORT_SYMBOL(strsep);
> #endif
>
> +#ifdef CONFIG_SYSFS
> +static inline bool __streq_terminal(const char *s1, const char *s2)
> +{
> + if (*s1 == *s2)
> + return true;
> + if (!*s1 && *s2 == '\n' && !s2[1])
> + return true;
> + if (*s1 == '\n' && !s1[1] && !*s2)
> + return true;
> + return false;
> +}
> +
> /**
> * sysfs_streq - return true if strings are equal, modulo trailing newline
> * @s1: one string
> @@ -703,17 +715,27 @@ bool sysfs_streq(const char *s1, const char *s2)
> s1++;
> s2++;
> }
> -
> - if (*s1 == *s2)
> - return true;
> - if (!*s1 && *s2 == '\n' && !s2[1])
> - return true;
> - if (*s1 == '\n' && !s1[1] && !*s2)
> - return true;
> - return false;
> + return __streq_terminal(s1, s2);
> }
> EXPORT_SYMBOL(sysfs_streq);
>
> +/**
> + * sysfs_streqcase - same to sysfs_streq and case insensitive
> + * @s1: one string
> + * @s2: another string
> + *
> + */
> +bool sysfs_streqcase(const char *s1, const char *s2)
> +{
> + while (*s1 && tolower(*s1) == tolower(*s2)) {
> + s1++;
> + s2++;
> + }
> + return __streq_terminal(s1, s2);
> +}
> +EXPORT_SYMBOL(sysfs_streqcase);
> +#endif
> +
> /**
> * match_string - matches given string in an array
> * @array: array of strings
> --
> 2.25.1
>
