get socket backlog limit on unix domain socket

Is there any way to get socket backlog limit on unix domain socket? In FreeBSD there is getsockopt() with SO_LISTENQLIMIT, but not in Linux. There is getsockopt() with TCP_INFO that returns such info for tcp socket, but returns 'Not implemented' for UDS. What is the right place to implement such functionality? Is porting SO_LISTENQLIMIT to linux a good idea?

WBR, Artem Germanov.