Man page 9 : sk_unattached_filter_create

sk_unattached_filter_create - create an unattached filter

int sk_unattached_filter_create(struct sk_filter **  pfp , struct sock_fprog *  fprog );

pfp
    the unattached filter that is created

fprog
    the filter program

Create a filter independent of any socket. We first run some sanity checks on it to make sure it does not explode on us later. If an error occurs or there is insufficient memory for the filter a negative errno code is returned. On success the return is zero.