const syscall.IP_ADD_MEMBERSHIP

2 uses

	syscall (current package)
		zerrors_linux_amd64.go#L449: 	IP_ADD_MEMBERSHIP                = 0x23

	net
		sockoptip_posix.go#L19: 	err := fd.pfd.SetsockoptIPMreq(syscall.IPPROTO_IP, syscall.IP_ADD_MEMBERSHIP, mreq)