nf_conntrack_helper_register
int nf_conntrack_helper_register(struct nf_conntrack_helper *, struct nf_conntrack_helper **);
err = nf_conntrack_helper_register(&snmp_trap_helper, &snmp_trap_helper_ptr);
ret = nf_conntrack_helper_register(&nf_conntrack_helper_h245,
EXPORT_SYMBOL_GPL(nf_conntrack_helper_register);
return nf_conntrack_helper_register(&helper, &helper_ptr);
return nf_conntrack_helper_register(&pptp, &pptp_ptr);
return nf_conntrack_helper_register(&helper, &helper_ptr);