Actually, now I am trying to write the rules into some file and reading the rules from user space and set the ip tables rules.
However, I am getting problem in writing and reading from the file. In my code, I am not getting any error and but not able to read and write into the file.
Could you please let me know where I am going wrong in my code?
My code is
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/syscalls.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/fcntl.h>
#include <asm/uaccess.h>
static void write_file(char *filename, char *data)
{
struct file *file;
// mm_segment_t old_fs = get_fs();
// set_fs(KERNEL_DS);
file = filp_open(filename, O_WRONLY|O_CREAT, 0777);
ssize_t wc;
wc = vfs_write(file, data, strlen(data),0);
if(wc < strlen(data))
{
printk(KERN_INFO "Problem in Writing Data\n");
}
filp_close(file,0);
/* if (fd >= 0) {
sys_write(fd, data, strlen(data));
file = fget(fd);
if (file) {
vfs_write(file, data, strlen(data), &pos);
fput(file);
}
// sys_close(fd);
} // set_fs(old_fs); */
}
static void read_file(char *filename)
{
struct file *fd;
// char buf[1];
// mm_segment_t old_fs = get_fs();
// set_fs(KERNEL_DS);
fd = filp_open(filename, O_RDONLY, 0);
char buf[80];
// if (fd >= 0) {
printk(KERN_DEBUG);
vfs_read(fd,buf, 5, 0);
printk("Data Read : %s\n",buf);
// while (sys_read(fd, buf, 1) == 1)
// printk("%c", buf[0]);
// printk("\n");
// sys_close(fd);
// }
filp_close(fd,0);
}
static int __init init(void)
{
write_file("/tmp/test","Hello World\n");
read_file("/tmp/test");
return 0;
}
static void __exit exit(void)
{
}
MODULE_LICENSE("GPL");
module_init(init);
module_exit(exit);
