On 9/2/25 11:19, Rong Tao wrote:
> From: Rong Tao <rong...@cestc.cn>
>
> bpf_strcasecmp() function performs same like bpf_strcmp() except ignoring
> the case of the characters.
>
> Signed-off-by: Rong Tao <rong...@cestc.cn>
For the series:
Acked-by: Viktor Malik <vma...@redhat.com>
> ---
> kernel/bpf/helpers.c | 68 +++++++++++++++++++++++++++++++-------------
> 1 file changed, 48 insertions(+), 20 deletions(-)
>
> diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
> index 401b4932cc49..238fd992c786 100644
> --- a/kernel/bpf/helpers.c
> +++ b/kernel/bpf/helpers.c
> @@ -3349,45 +3349,72 @@ __bpf_kfunc void __bpf_trap(void)
> * __get_kernel_nofault instead of plain dereference to make them safe.
> */
>
> -/**
> - * bpf_strcmp - Compare two strings
> - * @s1__ign: One string
> - * @s2__ign: Another string
> - *
> - * Return:
> - * * %0 - Strings are equal
> - * * %-1 - @s1__ign is smaller
> - * * %1 - @s2__ign is smaller
> - * * %-EFAULT - Cannot read one of the strings
> - * * %-E2BIG - One of strings is too large
> - * * %-ERANGE - One of strings is outside of kernel address space
> - */
> -__bpf_kfunc int bpf_strcmp(const char *s1__ign, const char *s2__ign)
> +int __bpf_strcasecmp(const char *s1, const char *s2, bool ignore_case)
> {
> char c1, c2;
> int i;
>
> - if (!copy_from_kernel_nofault_allowed(s1__ign, 1) ||
> - !copy_from_kernel_nofault_allowed(s2__ign, 1)) {
> + if (!copy_from_kernel_nofault_allowed(s1, 1) ||
> + !copy_from_kernel_nofault_allowed(s2, 1)) {
> return -ERANGE;
> }
>
> guard(pagefault)();
> for (i = 0; i < XATTR_SIZE_MAX; i++) {
> - __get_kernel_nofault(&c1, s1__ign, char, err_out);
> - __get_kernel_nofault(&c2, s2__ign, char, err_out);
> + __get_kernel_nofault(&c1, s1, char, err_out);
> + __get_kernel_nofault(&c2, s2, char, err_out);
> + if (ignore_case) {
> + c1 = tolower(c1);
> + c2 = tolower(c2);
> + }
> if (c1 != c2)
> return c1 < c2 ? -1 : 1;
> if (c1 == '\0')
> return 0;
> - s1__ign++;
> - s2__ign++;
> + s1++;
> + s2++;
> }
> return -E2BIG;
> err_out:
> return -EFAULT;
> }
>
> +/**
> + * bpf_strcmp - Compare two strings
> + * @s1__ign: One string
> + * @s2__ign: Another string
> + *
> + * Return:
> + * * %0 - Strings are equal
> + * * %-1 - @s1__ign is smaller
> + * * %1 - @s2__ign is smaller
> + * * %-EFAULT - Cannot read one of the strings
> + * * %-E2BIG - One of strings is too large
> + * * %-ERANGE - One of strings is outside of kernel address space
> + */
> +__bpf_kfunc int bpf_strcmp(const char *s1__ign, const char *s2__ign)
> +{
> + return __bpf_strcasecmp(s1__ign, s2__ign, false);
> +}
> +
> +/**
> + * bpf_strcasecmp - Compare two strings, ignoring the case of the characters
> + * @s1__ign: One string
> + * @s2__ign: Another string
> + *
> + * Return:
> + * * %0 - Strings are equal
> + * * %-1 - @s1__ign is smaller
> + * * %1 - @s2__ign is smaller
> + * * %-EFAULT - Cannot read one of the strings
> + * * %-E2BIG - One of strings is too large
> + * * %-ERANGE - One of strings is outside of kernel address space
> + */
> +__bpf_kfunc int bpf_strcasecmp(const char *s1__ign, const char *s2__ign)
> +{
> + return __bpf_strcasecmp(s1__ign, s2__ign, true);
> +}
> +
> /**
> * bpf_strnchr - Find a character in a length limited string
> * @s__ign: The string to be searched
> @@ -3832,6 +3859,7 @@ BTF_ID_FLAGS(func, bpf_iter_dmabuf_destroy,
> KF_ITER_DESTROY | KF_SLEEPABLE)
> #endif
> BTF_ID_FLAGS(func, __bpf_trap)
> BTF_ID_FLAGS(func, bpf_strcmp);
> +BTF_ID_FLAGS(func, bpf_strcasecmp);
> BTF_ID_FLAGS(func, bpf_strchr);
> BTF_ID_FLAGS(func, bpf_strchrnul);
> BTF_ID_FLAGS(func, bpf_strnchr);
