* [PATCH bpf-next v2 1/2] bpf: add bpf_strcasestr,bpf_strncasestr kfuncs
[not found] <cover.1759588929.git.rongtao@cestc.cn>
@ 2025-10-04 14:47 ` Rong Tao
2025-10-06 23:23 ` Andrii Nakryiko
2025-10-04 14:47 ` [PATCH bpf-next v2 2/2] selftests/bpf: Test " Rong Tao
1 sibling, 1 reply; 6+ messages in thread
From: Rong Tao @ 2025-10-04 14:47 UTC (permalink / raw)
To: vmalik, ast
Cc: Rong Tao, Daniel Borkmann, Andrii Nakryiko, Martin KaFai Lau,
Eduard Zingerman, Song Liu, Yonghong Song, John Fastabend,
KP Singh, Stanislav Fomichev, Hao Luo, Jiri Olsa, 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_strcasestr() and bpf_strncasestr() functions perform same like
bpf_strstr() and bpf_strnstr() except ignoring the case of the
characters.
Signed-off-by: Rong Tao <rongtao@cestc.cn>
---
kernel/bpf/helpers.c | 96 ++++++++++++++++++++++++++++++++++----------
1 file changed, 75 insertions(+), 21 deletions(-)
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index c9fab9a356df..4df902e5f208 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -3675,34 +3675,20 @@ __bpf_kfunc int bpf_strcspn(const char *s__ign, const char *reject__ign)
return -EFAULT;
}
-/**
- * bpf_strnstr - Find the first substring in a length-limited string
- * @s1__ign: The string to be searched
- * @s2__ign: The string to search for
- * @len: the maximum number of characters to search
- *
- * Return:
- * * >=0 - Index of the first character of the first occurrence of @s2__ign
- * within the first @len characters of @s1__ign
- * * %-ENOENT - @s2__ign not found in the first @len characters of @s1__ign
- * * %-EFAULT - Cannot read one of the strings
- * * %-E2BIG - One of the strings is too large
- * * %-ERANGE - One of the strings is outside of kernel address space
- */
-__bpf_kfunc int bpf_strnstr(const char *s1__ign, const char *s2__ign, size_t len)
+int __bpf_strnstr(const char *s1, const char *s2, size_t len, bool ignore_case)
{
char c1, c2;
int i, j;
- 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++) {
for (j = 0; i + j <= len && j < XATTR_SIZE_MAX; j++) {
- __get_kernel_nofault(&c2, s2__ign + j, char, err_out);
+ __get_kernel_nofault(&c2, s2 + j, char, err_out);
if (c2 == '\0')
return i;
/*
@@ -3712,7 +3698,13 @@ __bpf_kfunc int bpf_strnstr(const char *s1__ign, const char *s2__ign, size_t len
*/
if (i + j == len)
break;
- __get_kernel_nofault(&c1, s1__ign + j, char, err_out);
+ __get_kernel_nofault(&c1, s1 + j, char, err_out);
+
+ if (ignore_case) {
+ c1 = tolower(c1);
+ c2 = tolower(c2);
+ }
+
if (c1 == '\0')
return -ENOENT;
if (c1 != c2)
@@ -3722,7 +3714,7 @@ __bpf_kfunc int bpf_strnstr(const char *s1__ign, const char *s2__ign, size_t len
return -E2BIG;
if (i + j == len)
return -ENOENT;
- s1__ign++;
+ s1++;
}
return -E2BIG;
err_out:
@@ -3744,8 +3736,68 @@ __bpf_kfunc int bpf_strnstr(const char *s1__ign, const char *s2__ign, size_t len
*/
__bpf_kfunc int bpf_strstr(const char *s1__ign, const char *s2__ign)
{
- return bpf_strnstr(s1__ign, s2__ign, XATTR_SIZE_MAX);
+ return __bpf_strnstr(s1__ign, s2__ign, XATTR_SIZE_MAX, false);
+}
+
+/**
+ * bpf_strcasestr - Find the first substring in a string, ignoring the case of
+ * the characters
+ * @s1__ign: The string to be searched
+ * @s2__ign: The string to search for
+ *
+ * Return:
+ * * >=0 - Index of the first character of the first occurrence of @s2__ign
+ * within @s1__ign
+ * * %-ENOENT - @s2__ign is not a substring of @s1__ign
+ * * %-EFAULT - Cannot read one of the strings
+ * * %-E2BIG - One of the strings is too large
+ * * %-ERANGE - One of the strings is outside of kernel address space
+ */
+__bpf_kfunc int bpf_strcasestr(const char *s1__ign, const char *s2__ign)
+{
+ return __bpf_strnstr(s1__ign, s2__ign, XATTR_SIZE_MAX, true);
}
+
+/**
+ * bpf_strnstr - Find the first substring in a length-limited string
+ * @s1__ign: The string to be searched
+ * @s2__ign: The string to search for
+ * @len: the maximum number of characters to search
+ *
+ * Return:
+ * * >=0 - Index of the first character of the first occurrence of @s2__ign
+ * within the first @len characters of @s1__ign
+ * * %-ENOENT - @s2__ign not found in the first @len characters of @s1__ign
+ * * %-EFAULT - Cannot read one of the strings
+ * * %-E2BIG - One of the strings is too large
+ * * %-ERANGE - One of the strings is outside of kernel address space
+ */
+__bpf_kfunc int bpf_strnstr(const char *s1__ign, const char *s2__ign, size_t len)
+{
+ return __bpf_strnstr(s1__ign, s2__ign, len, false);
+}
+
+/**
+ * bpf_strnstr - Find the first substring in a length-limited string, ignoring
+ * the case of the characters
+ * @s1__ign: The string to be searched
+ * @s2__ign: The string to search for
+ * @len: the maximum number of characters to search
+ *
+ * Return:
+ * * >=0 - Index of the first character of the first occurrence of @s2__ign
+ * within the first @len characters of @s1__ign
+ * * %-ENOENT - @s2__ign not found in the first @len characters of @s1__ign
+ * * %-EFAULT - Cannot read one of the strings
+ * * %-E2BIG - One of the strings is too large
+ * * %-ERANGE - One of the strings is outside of kernel address space
+ */
+__bpf_kfunc int bpf_strncasestr(const char *s1__ign, const char *s2__ign,
+ size_t len)
+{
+ return __bpf_strnstr(s1__ign, s2__ign, len, true);
+}
+
#ifdef CONFIG_KEYS
/**
* bpf_lookup_user_key - lookup a key by its serial
@@ -4367,7 +4419,9 @@ BTF_ID_FLAGS(func, bpf_strnlen);
BTF_ID_FLAGS(func, bpf_strspn);
BTF_ID_FLAGS(func, bpf_strcspn);
BTF_ID_FLAGS(func, bpf_strstr);
+BTF_ID_FLAGS(func, bpf_strcasestr);
BTF_ID_FLAGS(func, bpf_strnstr);
+BTF_ID_FLAGS(func, bpf_strncasestr);
#if defined(CONFIG_BPF_LSM) && defined(CONFIG_CGROUPS)
BTF_ID_FLAGS(func, bpf_cgroup_read_xattr, KF_RCU)
#endif
--
2.51.0
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH bpf-next v2 2/2] selftests/bpf: Test bpf_strcasestr,bpf_strncasestr kfuncs
[not found] <cover.1759588929.git.rongtao@cestc.cn>
2025-10-04 14:47 ` [PATCH bpf-next v2 1/2] bpf: add bpf_strcasestr,bpf_strncasestr kfuncs Rong Tao
@ 2025-10-04 14:47 ` Rong Tao
2025-10-07 0:29 ` Eduard Zingerman
1 sibling, 1 reply; 6+ messages in thread
From: Rong Tao @ 2025-10-04 14:47 UTC (permalink / raw)
To: vmalik, ast
Cc: Rong Tao, Daniel Borkmann, Andrii Nakryiko, Martin KaFai Lau,
Eduard Zingerman, Song Liu, Yonghong Song, John Fastabend,
KP Singh, Stanislav Fomichev, Hao Luo, Jiri Olsa, 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 tests for new kfuncs bpf_strcasestr() and bpf_strncasestr().
Signed-off-by: Rong Tao <rongtao@cestc.cn>
---
.../selftests/bpf/prog_tests/string_kfuncs.c | 2 ++
.../selftests/bpf/progs/string_kfuncs_failure1.c | 12 ++++++++++++
.../selftests/bpf/progs/string_kfuncs_failure2.c | 2 ++
.../selftests/bpf/progs/string_kfuncs_success.c | 13 +++++++++++++
4 files changed, 29 insertions(+)
diff --git a/tools/testing/selftests/bpf/prog_tests/string_kfuncs.c b/tools/testing/selftests/bpf/prog_tests/string_kfuncs.c
index 4d66fad3c8bd..0f3bf594e7a5 100644
--- a/tools/testing/selftests/bpf/prog_tests/string_kfuncs.c
+++ b/tools/testing/selftests/bpf/prog_tests/string_kfuncs.c
@@ -20,7 +20,9 @@ static const char * const test_cases[] = {
"strcspn_str",
"strcspn_reject",
"strstr",
+ "strcasestr",
"strnstr",
+ "strncasestr",
};
void run_too_long_tests(void)
diff --git a/tools/testing/selftests/bpf/progs/string_kfuncs_failure1.c b/tools/testing/selftests/bpf/progs/string_kfuncs_failure1.c
index 99d72c68f76a..826e6b6aff7e 100644
--- a/tools/testing/selftests/bpf/progs/string_kfuncs_failure1.c
+++ b/tools/testing/selftests/bpf/progs/string_kfuncs_failure1.c
@@ -45,8 +45,12 @@ SEC("syscall") __retval(USER_PTR_ERR)int test_strcspn_null1(void *ctx) { return
SEC("syscall") __retval(USER_PTR_ERR)int test_strcspn_null2(void *ctx) { return bpf_strcspn("hello", NULL); }
SEC("syscall") __retval(USER_PTR_ERR)int test_strstr_null1(void *ctx) { return bpf_strstr(NULL, "hello"); }
SEC("syscall") __retval(USER_PTR_ERR)int test_strstr_null2(void *ctx) { return bpf_strstr("hello", NULL); }
+SEC("syscall") __retval(USER_PTR_ERR)int test_strcasestr_null1(void *ctx) { return bpf_strcasestr(NULL, "hello"); }
+SEC("syscall") __retval(USER_PTR_ERR)int test_strcasestr_null2(void *ctx) { return bpf_strcasestr("hello", NULL); }
SEC("syscall") __retval(USER_PTR_ERR)int test_strnstr_null1(void *ctx) { return bpf_strnstr(NULL, "hello", 1); }
SEC("syscall") __retval(USER_PTR_ERR)int test_strnstr_null2(void *ctx) { return bpf_strnstr("hello", NULL, 1); }
+SEC("syscall") __retval(USER_PTR_ERR)int test_strncasestr_null1(void *ctx) { return bpf_strncasestr(NULL, "hello", 1); }
+SEC("syscall") __retval(USER_PTR_ERR)int test_strncasestr_null2(void *ctx) { return bpf_strncasestr("hello", NULL, 1); }
/* 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"); }
@@ -65,8 +69,12 @@ SEC("syscall") __retval(USER_PTR_ERR) int test_strcspn_user_ptr1(void *ctx) { re
SEC("syscall") __retval(USER_PTR_ERR) int test_strcspn_user_ptr2(void *ctx) { return bpf_strcspn("hello", user_ptr); }
SEC("syscall") __retval(USER_PTR_ERR) int test_strstr_user_ptr1(void *ctx) { return bpf_strstr(user_ptr, "hello"); }
SEC("syscall") __retval(USER_PTR_ERR) int test_strstr_user_ptr2(void *ctx) { return bpf_strstr("hello", user_ptr); }
+SEC("syscall") __retval(USER_PTR_ERR) int test_strcasestr_user_ptr1(void *ctx) { return bpf_strcasestr(user_ptr, "hello"); }
+SEC("syscall") __retval(USER_PTR_ERR) int test_strcasestr_user_ptr2(void *ctx) { return bpf_strcasestr("hello", user_ptr); }
SEC("syscall") __retval(USER_PTR_ERR) int test_strnstr_user_ptr1(void *ctx) { return bpf_strnstr(user_ptr, "hello", 1); }
SEC("syscall") __retval(USER_PTR_ERR) int test_strnstr_user_ptr2(void *ctx) { return bpf_strnstr("hello", user_ptr, 1); }
+SEC("syscall") __retval(USER_PTR_ERR) int test_strncasestr_user_ptr1(void *ctx) { return bpf_strncasestr(user_ptr, "hello", 1); }
+SEC("syscall") __retval(USER_PTR_ERR) int test_strncasestr_user_ptr2(void *ctx) { return bpf_strncasestr("hello", user_ptr, 1); }
#endif /* __TARGET_ARCH_s390 */
@@ -87,7 +95,11 @@ SEC("syscall") __retval(-EFAULT) int test_strcspn_pagefault1(void *ctx) { return
SEC("syscall") __retval(-EFAULT) int test_strcspn_pagefault2(void *ctx) { return bpf_strcspn("hello", invalid_kern_ptr); }
SEC("syscall") __retval(-EFAULT) int test_strstr_pagefault1(void *ctx) { return bpf_strstr(invalid_kern_ptr, "hello"); }
SEC("syscall") __retval(-EFAULT) int test_strstr_pagefault2(void *ctx) { return bpf_strstr("hello", invalid_kern_ptr); }
+SEC("syscall") __retval(-EFAULT) int test_strcasestr_pagefault1(void *ctx) { return bpf_strcasestr(invalid_kern_ptr, "hello"); }
+SEC("syscall") __retval(-EFAULT) int test_strcasestr_pagefault2(void *ctx) { return bpf_strcasestr("hello", invalid_kern_ptr); }
SEC("syscall") __retval(-EFAULT) int test_strnstr_pagefault1(void *ctx) { return bpf_strnstr(invalid_kern_ptr, "hello", 1); }
SEC("syscall") __retval(-EFAULT) int test_strnstr_pagefault2(void *ctx) { return bpf_strnstr("hello", invalid_kern_ptr, 1); }
+SEC("syscall") __retval(-EFAULT) int test_strncasestr_pagefault1(void *ctx) { return bpf_strncasestr(invalid_kern_ptr, "hello", 1); }
+SEC("syscall") __retval(-EFAULT) int test_strncasestr_pagefault2(void *ctx) { return bpf_strncasestr("hello", invalid_kern_ptr, 1); }
char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/string_kfuncs_failure2.c b/tools/testing/selftests/bpf/progs/string_kfuncs_failure2.c
index e41cc5601994..05e1da1f250f 100644
--- a/tools/testing/selftests/bpf/progs/string_kfuncs_failure2.c
+++ b/tools/testing/selftests/bpf/progs/string_kfuncs_failure2.c
@@ -19,6 +19,8 @@ SEC("syscall") int test_strspn_accept_too_long(void *ctx) { return bpf_strspn("b
SEC("syscall") int test_strcspn_str_too_long(void *ctx) { return bpf_strcspn(long_str, "b"); }
SEC("syscall") int test_strcspn_reject_too_long(void *ctx) { return bpf_strcspn("b", long_str); }
SEC("syscall") int test_strstr_too_long(void *ctx) { return bpf_strstr(long_str, "hello"); }
+SEC("syscall") int test_strcasestr_too_long(void *ctx) { return bpf_strcasestr(long_str, "hello"); }
SEC("syscall") int test_strnstr_too_long(void *ctx) { return bpf_strnstr(long_str, "hello", sizeof(long_str)); }
+SEC("syscall") int test_strncasestr_too_long(void *ctx) { return bpf_strncasestr(long_str, "hello", sizeof(long_str)); }
char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/string_kfuncs_success.c b/tools/testing/selftests/bpf/progs/string_kfuncs_success.c
index 2e3498e37b9c..d21330b4cc3b 100644
--- a/tools/testing/selftests/bpf/progs/string_kfuncs_success.c
+++ b/tools/testing/selftests/bpf/progs/string_kfuncs_success.c
@@ -33,8 +33,12 @@ __test(11) int test_strnlen(void *ctx) { return bpf_strnlen(str, 12); }
__test(5) int test_strspn(void *ctx) { return bpf_strspn(str, "ehlo"); }
__test(2) int test_strcspn(void *ctx) { return bpf_strcspn(str, "lo"); }
__test(6) int test_strstr_found(void *ctx) { return bpf_strstr(str, "world"); }
+__test(6) int test_strcasestr_found1(void *ctx) { return bpf_strcasestr(str, "world"); }
+__test(6) int test_strcasestr_found2(void *ctx) { return bpf_strcasestr(str, "WORLD"); }
__test(-ENOENT) int test_strstr_notfound(void *ctx) { return bpf_strstr(str, "hi"); }
+__test(-ENOENT) int test_strcasestr_notfound(void *ctx) { return bpf_strcasestr(str, "hi"); }
__test(0) int test_strstr_empty(void *ctx) { return bpf_strstr(str, ""); }
+__test(0) int test_strcasestr_empty(void *ctx) { return bpf_strcasestr(str, ""); }
__test(0) int test_strnstr_found1(void *ctx) { return bpf_strnstr("", "", 0); }
__test(0) int test_strnstr_found2(void *ctx) { return bpf_strnstr(str, "hello", 5); }
__test(0) int test_strnstr_found3(void *ctx) { return bpf_strnstr(str, "hello", 6); }
@@ -42,5 +46,14 @@ __test(-ENOENT) int test_strnstr_notfound1(void *ctx) { return bpf_strnstr(str,
__test(-ENOENT) int test_strnstr_notfound2(void *ctx) { return bpf_strnstr(str, "hello", 4); }
__test(-ENOENT) int test_strnstr_notfound3(void *ctx) { return bpf_strnstr("", "a", 0); }
__test(0) int test_strnstr_empty(void *ctx) { return bpf_strnstr(str, "", 1); }
+__test(0) int test_strncasestr_found1(void *ctx) { return bpf_strncasestr("", "", 0); }
+__test(0) int test_strncasestr_found2(void *ctx) { return bpf_strncasestr(str, "hello", 5); }
+__test(0) int test_strncasestr_found3(void *ctx) { return bpf_strncasestr(str, "hello", 6); }
+__test(0) int test_strncasestr_found4(void *ctx) { return bpf_strncasestr(str, "HELLO", 5); }
+__test(0) int test_strncasestr_found5(void *ctx) { return bpf_strncasestr(str, "HELLO", 6); }
+__test(-ENOENT) int test_strncasestr_notfound1(void *ctx) { return bpf_strncasestr(str, "hi", 10); }
+__test(-ENOENT) int test_strncasestr_notfound2(void *ctx) { return bpf_strncasestr(str, "hello", 4); }
+__test(-ENOENT) int test_strncasestr_notfound3(void *ctx) { return bpf_strncasestr("", "a", 0); }
+__test(0) int test_strncasestr_empty(void *ctx) { return bpf_strncasestr(str, "", 1); }
char _license[] SEC("license") = "GPL";
--
2.51.0
^ permalink raw reply [flat|nested] 6+ messages in thread