* [PATCH bpf-next v4 1/2] bpf: add bpf_strcasecmp kfunc
[not found] <cover.1756856613.git.rtoax@foxmail.com>
@ 2025-09-02 23:47 ` Rong Tao
2025-09-03 16:39 ` Yonghong Song
2025-09-04 16:10 ` patchwork-bot+netdevbpf
2025-09-02 23:48 ` [PATCH bpf-next v4 2/2] selftests/bpf: Test kfunc bpf_strcasecmp Rong Tao
1 sibling, 2 replies; 5+ messages in thread
From: Rong Tao @ 2025-09-02 23:47 UTC (permalink / raw)
To: yonghong.song, andrii, ast, vmalik
Cc: rtoax, Rong Tao, Daniel Borkmann, Martin KaFai Lau,
Eduard Zingerman, Song Liu, John Fastabend, KP Singh,
Stanislav Fomichev, Hao Luo, Jiri Olsa, Mykola Lysenko,
Shuah Khan,
open list:BPF [GENERAL] (Safe Dynamic Programs and Tools),
open list, open list:KERNEL SELFTEST FRAMEWORK
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);
--
2.51.0
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH bpf-next v4 2/2] selftests/bpf: Test kfunc bpf_strcasecmp
[not found] <cover.1756856613.git.rtoax@foxmail.com>
2025-09-02 23:47 ` [PATCH bpf-next v4 1/2] bpf: add bpf_strcasecmp kfunc Rong Tao
@ 2025-09-02 23:48 ` Rong Tao
1 sibling, 0 replies; 5+ messages in thread
From: Rong Tao @ 2025-09-02 23:48 UTC (permalink / raw)
To: yonghong.song, andrii, ast, vmalik
Cc: rtoax, Rong Tao, Daniel Borkmann, Martin KaFai Lau,
Eduard Zingerman, Song Liu, John Fastabend, KP Singh,
Stanislav Fomichev, Hao Luo, Jiri Olsa, Mykola Lysenko,
Shuah Khan,
open list:BPF [GENERAL] (Safe Dynamic Programs and Tools),
open list, open list:KERNEL SELFTEST FRAMEWORK
From: Rong Tao <rongtao@cestc.cn>
Add testsuites for kfunc bpf_strcasecmp.
Signed-off-by: Rong Tao <rongtao@cestc.cn>
---
tools/testing/selftests/bpf/prog_tests/string_kfuncs.c | 1 +
tools/testing/selftests/bpf/progs/string_kfuncs_failure1.c | 6 ++++++
tools/testing/selftests/bpf/progs/string_kfuncs_failure2.c | 1 +
tools/testing/selftests/bpf/progs/string_kfuncs_success.c | 5 +++++
4 files changed, 13 insertions(+)
diff --git a/tools/testing/selftests/bpf/prog_tests/string_kfuncs.c b/tools/testing/selftests/bpf/prog_tests/string_kfuncs.c
index 35af8044d059..4d66fad3c8bd 100644
--- a/tools/testing/selftests/bpf/prog_tests/string_kfuncs.c
+++ b/tools/testing/selftests/bpf/prog_tests/string_kfuncs.c
@@ -8,6 +8,7 @@
static const char * const test_cases[] = {
"strcmp",
+ "strcasecmp",
"strchr",
"strchrnul",
"strnchr",
diff --git a/tools/testing/selftests/bpf/progs/string_kfuncs_failure1.c b/tools/testing/selftests/bpf/progs/string_kfuncs_failure1.c
index 53af438bd998..99d72c68f76a 100644
--- a/tools/testing/selftests/bpf/progs/string_kfuncs_failure1.c
+++ b/tools/testing/selftests/bpf/progs/string_kfuncs_failure1.c
@@ -31,6 +31,8 @@ char *invalid_kern_ptr = (char *)-1;
/* Passing NULL to string kfuncs (treated as a userspace ptr) */
SEC("syscall") __retval(USER_PTR_ERR) int test_strcmp_null1(void *ctx) { return bpf_strcmp(NULL, "hello"); }
SEC("syscall") __retval(USER_PTR_ERR)int test_strcmp_null2(void *ctx) { return bpf_strcmp("hello", NULL); }
+SEC("syscall") __retval(USER_PTR_ERR) int test_strcasecmp_null1(void *ctx) { return bpf_strcasecmp(NULL, "HELLO"); }
+SEC("syscall") __retval(USER_PTR_ERR)int test_strcasecmp_null2(void *ctx) { return bpf_strcasecmp("HELLO", NULL); }
SEC("syscall") __retval(USER_PTR_ERR)int test_strchr_null(void *ctx) { return bpf_strchr(NULL, 'a'); }
SEC("syscall") __retval(USER_PTR_ERR)int test_strchrnul_null(void *ctx) { return bpf_strchrnul(NULL, 'a'); }
SEC("syscall") __retval(USER_PTR_ERR)int test_strnchr_null(void *ctx) { return bpf_strnchr(NULL, 1, 'a'); }
@@ -49,6 +51,8 @@ SEC("syscall") __retval(USER_PTR_ERR)int test_strnstr_null2(void *ctx) { return
/* Passing userspace ptr to string kfuncs */
SEC("syscall") __retval(USER_PTR_ERR) int test_strcmp_user_ptr1(void *ctx) { return bpf_strcmp(user_ptr, "hello"); }
SEC("syscall") __retval(USER_PTR_ERR) int test_strcmp_user_ptr2(void *ctx) { return bpf_strcmp("hello", user_ptr); }
+SEC("syscall") __retval(USER_PTR_ERR) int test_strcasecmp_user_ptr1(void *ctx) { return bpf_strcasecmp(user_ptr, "HELLO"); }
+SEC("syscall") __retval(USER_PTR_ERR) int test_strcasecmp_user_ptr2(void *ctx) { return bpf_strcasecmp("HELLO", user_ptr); }
SEC("syscall") __retval(USER_PTR_ERR) int test_strchr_user_ptr(void *ctx) { return bpf_strchr(user_ptr, 'a'); }
SEC("syscall") __retval(USER_PTR_ERR) int test_strchrnul_user_ptr(void *ctx) { return bpf_strchrnul(user_ptr, 'a'); }
SEC("syscall") __retval(USER_PTR_ERR) int test_strnchr_user_ptr(void *ctx) { return bpf_strnchr(user_ptr, 1, 'a'); }
@@ -69,6 +73,8 @@ SEC("syscall") __retval(USER_PTR_ERR) int test_strnstr_user_ptr2(void *ctx) { re
/* Passing invalid kernel ptr to string kfuncs should always return -EFAULT */
SEC("syscall") __retval(-EFAULT) int test_strcmp_pagefault1(void *ctx) { return bpf_strcmp(invalid_kern_ptr, "hello"); }
SEC("syscall") __retval(-EFAULT) int test_strcmp_pagefault2(void *ctx) { return bpf_strcmp("hello", invalid_kern_ptr); }
+SEC("syscall") __retval(-EFAULT) int test_strcasecmp_pagefault1(void *ctx) { return bpf_strcasecmp(invalid_kern_ptr, "HELLO"); }
+SEC("syscall") __retval(-EFAULT) int test_strcasecmp_pagefault2(void *ctx) { return bpf_strcasecmp("HELLO", invalid_kern_ptr); }
SEC("syscall") __retval(-EFAULT) int test_strchr_pagefault(void *ctx) { return bpf_strchr(invalid_kern_ptr, 'a'); }
SEC("syscall") __retval(-EFAULT) int test_strchrnul_pagefault(void *ctx) { return bpf_strchrnul(invalid_kern_ptr, 'a'); }
SEC("syscall") __retval(-EFAULT) int test_strnchr_pagefault(void *ctx) { return bpf_strnchr(invalid_kern_ptr, 1, 'a'); }
diff --git a/tools/testing/selftests/bpf/progs/string_kfuncs_failure2.c b/tools/testing/selftests/bpf/progs/string_kfuncs_failure2.c
index 89fb4669b0e9..e41cc5601994 100644
--- a/tools/testing/selftests/bpf/progs/string_kfuncs_failure2.c
+++ b/tools/testing/selftests/bpf/progs/string_kfuncs_failure2.c
@@ -7,6 +7,7 @@
char long_str[XATTR_SIZE_MAX + 1];
SEC("syscall") int test_strcmp_too_long(void *ctx) { return bpf_strcmp(long_str, long_str); }
+SEC("syscall") int test_strcasecmp_too_long(void *ctx) { return bpf_strcasecmp(long_str, long_str); }
SEC("syscall") int test_strchr_too_long(void *ctx) { return bpf_strchr(long_str, 'b'); }
SEC("syscall") int test_strchrnul_too_long(void *ctx) { return bpf_strchrnul(long_str, 'b'); }
SEC("syscall") int test_strnchr_too_long(void *ctx) { return bpf_strnchr(long_str, sizeof(long_str), 'b'); }
diff --git a/tools/testing/selftests/bpf/progs/string_kfuncs_success.c b/tools/testing/selftests/bpf/progs/string_kfuncs_success.c
index 46697f381878..67830456637b 100644
--- a/tools/testing/selftests/bpf/progs/string_kfuncs_success.c
+++ b/tools/testing/selftests/bpf/progs/string_kfuncs_success.c
@@ -12,6 +12,11 @@ char str[] = "hello world";
/* Functional tests */
__test(0) int test_strcmp_eq(void *ctx) { return bpf_strcmp(str, "hello world"); }
__test(1) int test_strcmp_neq(void *ctx) { return bpf_strcmp(str, "hello"); }
+__test(0) int test_strcasecmp_eq1(void *ctx) { return bpf_strcasecmp(str, "hello world"); }
+__test(0) int test_strcasecmp_eq2(void *ctx) { return bpf_strcasecmp(str, "HELLO WORLD"); }
+__test(0) int test_strcasecmp_eq3(void *ctx) { return bpf_strcasecmp(str, "HELLO world"); }
+__test(1) int test_strcasecmp_neq1(void *ctx) { return bpf_strcasecmp(str, "hello"); }
+__test(1) int test_strcasecmp_neq2(void *ctx) { return bpf_strcasecmp(str, "HELLO"); }
__test(1) int test_strchr_found(void *ctx) { return bpf_strchr(str, 'e'); }
__test(11) int test_strchr_null(void *ctx) { return bpf_strchr(str, '\0'); }
__test(-ENOENT) int test_strchr_notfound(void *ctx) { return bpf_strchr(str, 'x'); }
--
2.51.0
^ permalink raw reply related [flat|nested] 5+ messages in thread