IP4_SRC
offload_pedit(fs, val, mask, IP4_SRC);
SYS(fail, "ip addr add " IP4_SRC "/32 dev src");
SYS(fail, "ip route add " IP4_SRC "/32 dev src_fwd scope global");
SYS(fail, "ip neigh add " IP4_SRC " dev src_fwd lladdr %s", src_addr);
SYS(fail, "ip route add " IP4_SRC "/32 dev dst scope global");
SYS(fail, "ip neigh add " IP4_SRC " dev dst lladdr " MAC_DST_FWD);