On 9/2/25 2:19 AM, 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>
---
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)
The function __bpf_strcasecmp should be a static function.
{
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);
