The external interface

The ``external'' interface of tcc allows the addition of support for hardware accelerators and other traffic control implementations not directly known to tcc, without the need to understand and change tcc itself.

tcc attempts to use external programs for all traffic control elements (i.e. classifiers, queuing disciplines, or combinations thereof) for which such an external program is specified with the -x command line option. -x is used as follows:

-x element:external_target

element

is the name of the element. Currently, only the names if and all are recognized. All other names are treated as if if had been specified. -x all:external_target has the same effect as the external program returning all in the configuration query, as described in section 7.3.1.

external_target

is the name of the external target. This name identifies the (external) program tcc will invoke for configuration.

tcc invokes the external program to probe whether it is able to process the configuration. If it is, tcc may invoke it a second time to request generation of the components that implement the desired configuration.

Note: tcc currently omits the probe and always tries to implement the configuration.