When the DHCP server doesn't supply the routersOnSubnet option in its
reply, dhcpcd assumes that it can use the giaddr instead, and just goes
ahead and uses it to invent its own static route:

 if ( ! DhcpOptions.val[routersOnSubnet] )
   {
     DhcpOptions.val[routersOnSubnet] = malloc(4);
     if ( DhcpMsgRecv->giaddr )
       memcpy(DhcpOptions.val[routersOnSubnet],&DhcpMsgRecv->giaddr,4);
     else
       memcpy(DhcpOptions.val[routersOnSubnet],
              DhcpOptions.val[dhcpServerIdentifier],4);

I can't find any warrant for doing this in RFC2131, and it's not the
behaviour I want (or expect).  Could it at least be made possible to
disable this behaviour using a command-line option?

Thanks very much,
Chris.