void __user *, size_t *, loff_t *);
static int dn_forwarding_sysctl(ctl_table *table,
void __user *oldval, size_t __user *oldlenp,
void __user *, size_t *, loff_t *);
static int dn_forwarding_sysctl(ctl_table *table,
void __user *oldval, size_t __user *oldlenp,