:INPUT,FORWARD,OUTPUT -m length --length 1;=;OK -m length --length :2;-m length --length 0:2;OK -m length --length 0:3;=;OK -m length --length 4:;=;OK -m length --length 0:65535;=;OK -m length ! --length 0:65535;=;OK -m length --length 0:65536;;FAIL -m length --length -1:65535;;FAIL -m length;;FAIL