const syscall.IP_ADD_MEMBERSHIP

2 uses

	syscall (current package)
		zerrors_linux_amd64.go#L425: 	IP_ADD_MEMBERSHIP                = 0x23

	net
		sockoptip4_linux.go#L17: 	err := fd.pfd.SetsockoptIPMreqn(syscall.IPPROTO_IP, syscall.IP_ADD_MEMBERSHIP, mreq)