IPV6_FW_TCPF_ACK
rule.fw_tcpnf |= IPV6_FW_TCPF_ACK;
chain->fw_tcpnf == IPV6_FW_TCPF_ACK)
if (chain->fw_tcpf & IPV6_FW_TCPF_ACK) PRINTFLG("ack");
if (chain->fw_tcpnf & IPV6_FW_TCPF_ACK) PRINTFLG("!ack");
{ "ack", IPV6_FW_TCPF_ACK },
((tcp6->th_flags & (IPV6_FW_TCPF_RST | IPV6_FW_TCPF_ACK |