System cAll Wrapping 하는 방법을.... 찾아야 합니다 ㅠㅠ

[bushi@rose net]$ cat wrap.c
#include <stdio.h>
#include <sys/types.h>
#include <dlfcn.h>
#include <errno.h>
 
#define LIB "libc.so.6"
 
ssize_t read(int fd, void *buf, size_t count)
{
        ssize_t (*orig_func) (int fd, void *buf, size_t count);
        void *dl_handle;
        ssize_t ret;
 
        printf("fd = %d, buf = %p, count = %d\n",
                        fd, buf, count);
 
        dl_handle = dlopen(LIB, RTLD_NOW);
        if (!dl_handle) {
                printf("%s: %s\n", LIB, dlerror());
                return -EINVAL;
        }
 
        orig_func = dlsym(dl_handle, __func__);
        if (!orig_func) {
                printf("%s: %s\n", __func__, dlerror());
                dlclose(dl_handle);
                return -EINVAL;
        }
 
        ret = (orig_func)(fd, buf, count);
        dlclose(dl_handle);
        return ret;
}
[bushi@rose net]$
[bushi@rose net]$ gcc -shared -o libwrap.so wrap.c -ldl -Wall
[bushi@rose net]$

[bushi@rose net]$ cat wrap_test.c
#include <unistd.h>
 
int main(int argc, char **argv)
{
        return read(-1, NULL, 0);
}
[bushi@rose net]$
[bushi@rose net]$ gcc -s -o wrap_test wrap_test.c -Wall
[bushi@rose net]$
[bushi@rose net]$ ./wrap_test
[bushi@rose net]$
[bushi@rose net]$ LD_PRELOAD=`pwd`/libwrap.so ./wrap_test
fd = -1, buf = (nil), count = 0
[bushi@rose net]$