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yunwei37
2024-10-09 00:54:15 +00:00
parent 6f7bc37a6a
commit 18c60187b8
2 changed files with 49 additions and 15 deletions
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52
43-kfuncs/module/hello.c
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@@ -1,24 +1,51 @@
#include <linux/init.h> // Macros for module initialization
#include <linux/module.h> // Core header for loading modules
#include <linux/kernel.h> // Kernel logging macros
#include <linux/init.h> // Macros for module initialization
#include <linux/module.h> // Core header for loading modules
#include <linux/kernel.h> // Kernel logging macros
#include <linux/bpf.h>
#include <linux/btf.h>
#include <linux/btf_ids.h>
__bpf_kfunc u64 bpf_kfunc_call_test(u32 a, u64 b, u32 c, u64 d);
__bpf_kfunc int bpf_strstr(const char *str, u32 str__sz, const char *substr, u32 substr__sz);
/* Define a kfunc function */
__bpf_kfunc_start_defs();
__bpf_kfunc u64 bpf_kfunc_call_test(u32 a, u64 b, u32 c, u64 d)
__bpf_kfunc int bpf_strstr(const char *str, u32 str__sz, const char *substr, u32 substr__sz)
{
return a + b + c + d;
// Edge case: if substr is empty, return 0 (assuming empty string is found at the start)
if (substr__sz == 0)
{
return 0;
}
// Edge case: if the substring is longer than the main string, it's impossible to find
if (substr__sz > str__sz)
{
return -1; // Return -1 to indicate not found
}
// Iterate through the main string, considering the size limit
for (size_t i = 0; i <= str__sz - substr__sz; i++)
{
size_t j = 0;
// Compare the substring with the current position in the string
while (j < substr__sz && str[i + j] == substr[j])
{
j++;
}
// If the entire substring was found
if (j == substr__sz)
{
return i; // Return the index of the first match
}
}
// Return -1 if the substring is not found
return -1;
}
__bpf_kfunc_end_defs();
BTF_KFUNCS_START(bpf_kfunc_example_ids_set)
BTF_ID_FLAGS(func, bpf_kfunc_call_test)
BTF_ID_FLAGS(func, bpf_strstr)
BTF_KFUNCS_END(bpf_kfunc_example_ids_set)
// Register the kfunc ID set
@@ -35,12 +62,13 @@ static int __init hello_init(void)
printk(KERN_INFO "Hello, world!\n");
// Register the BTF kfunc ID set
ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_KPROBE, &bpf_kfunc_example_set);
if (ret) {
if (ret)
{
pr_err("bpf_kfunc_example: Failed to register BTF kfunc ID set\n");
return ret;
}
printk(KERN_INFO "bpf_kfunc_example: Module loaded successfully\n");
return 0; // Return 0 if successful
return 0; // Return 0 if successful
}
// Function executed when the module is removed
@@ -55,7 +83,7 @@ static void __exit hello_exit(void)
module_init(hello_init);
module_exit(hello_exit);
MODULE_LICENSE("GPL"); // License type (GPL)
MODULE_AUTHOR("Your Name"); // Module author
MODULE_LICENSE("GPL"); // License type (GPL)
MODULE_AUTHOR("Your Name"); // Module author
MODULE_DESCRIPTION("A simple module"); // Module description
MODULE_VERSION("1.0"); // Module version
MODULE_VERSION("1.0"); // Module version