Understanding the Multilevel Printing Service

Because the printing service accepts requests from processes that operate at different labels, printing must be label-aware. Ordinarily, MAC allows access only to resources that are at the same labels at which the user is operating. Even when print requests are issued only at the same label, printing should be label-aware to enable the printed output to display labels on the printed page.

To handle labels, the printing service must perform these essential functions:

• Determine if the host on which the print process is running is labeled or unlabeled

• If the printing process is running in a labeled environment, obtain the credential of the network connection from which the print request originates (the credential contains the label for that process)

• Extract the label from the network credential

• Obtain the printer's label range, that is, the range of labels for which the printer can accept requests

• Determine if the user's label falls within the acceptable range of labels for the specified printer