From: Rong Tao rongtao@cestc.cn

bpf_strcasecmp() function performs same like bpf_strcmp() except ignoring the case of the characters.

Signed-off-by: Rong Tao rongtao@cestc.cn --- 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..588bc7e36436 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) +static 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);