IPFW_KEY_SWAP_ADDRS
#define IPFW_KEY_SWAP_ALL (IPFW_KEY_SWAP_ADDRS | IPFW_KEY_SWAP_PORTS)
key->swap |= IPFW_KEY_SWAP_ADDRS;
if (sport == dport && (key->swap & IPFW_KEY_SWAP_ADDRS))
key->swap |= IPFW_KEY_SWAP_ADDRS;
if (key->swap & IPFW_KEY_SWAP_ADDRS) {