const syscall.SO_PROTOCOL

2 uses

	syscall (current package)
		zerrors_linux_amd64.go#L1023: 	SO_PROTOCOL                      = 0x26

	net
		mptcpsock_linux.go#L112: 	proto, _ := fd.pfd.GetsockoptInt(syscall.SOL_SOCKET, syscall.SO_PROTOCOL)