ULLA provides a database abtraction of link layer information. Hence, the ULLA Query Language (UQL) is particulary important because the all ULLA Tools make use of its syntax to specify a query. These queries have a a from_clause specifying the table the attribute should be retrived from, a select_clause, which specifies the attribute of interest by name, and optionally a condition clause, which has to be fulfilled by the entry in the database.
The ullaReflection(1) tool allows the display of the available tables providing the link layer information. It is a simple reflection interface showing the tables and their attributes and commands. A description for each attribute and command is exposed as well.
The attribute values can be retrieved using the ullaAttribute(1) tool in an instantaneous manner. The specified query is evaluated once and the result is printed on the screen or optionally logged to a file.
For continuous evaluations the ullaSamples(1) tool can be utilized. ullaSamples(1) evaluates the query with a given period and returns the information on time, even if the set of returned entries is empty because the UQL-condition may not be met for any entry in the database.
The ullaNotification(1) tool evaluates the given condition upon update of the mentioned attribute values only. Hence, the overhead is reduced to the minimum. The Link Layer Adapter (LLA), or device driver supporting ULLA, updates the attributes values with the ULLA Core when appropriate.
LLAs may also implement commands for configuration purposes. To issue a command use the ullaCommand(1) utility. The UQL syntax allows to select a set of commands executed within a single call.
In addition to the reflection interface tool but also from the proc-file
system.
Please use cat /proc/net/ulla/reflection.xml cat /proc/net/ulla/reflection.dtd
cat /proc/net/ulla/notification cat /proc/net/ulla/lock to monitor the
internal status of the ULLA Core and learn about registered classes, objects
and pending notifications.
ulla(2) , uql(2) , ullaRequestReflection(2) , ullaRequestAttribute(2) , ullaRequestCommand(2) , ullaRequestNotification(2) , ullaRequestSample(2)