Traffic actions

Traffic actions allow certain predefined operations to be applied to incoming or outgoing packets that are matched by some traffic filter. An example of such an operation is rate policing.

Although traffic actions may exist as standalone objects in the kernel, they must be associated with a traffic filter in order to take effect.

A traffic action is of a certain action kind; police is such an action kind (the terminology action kind is specific to this package). Traffic actions are identified by an action index; this index is per action kind.

This package provides Python classes that correspond to traffic action kinds. They are implemented as subclasses of the TrafficAction class. An instance of a TrafficAction subclass can be created and added to a TrafficFilter instance before the filter is instantiated.

Traffic actions can be shared. This is implemented by creating an instance of a TrafficAction subclass and specifying the action index of an existing action (of the same kind).

Standalone traffic actions are not currently supported.

The linuxnet.qos package supports the following traffic action classes:

Certain classes provide functionality common to all traffic actions.

class ActionDecision(value)

List of decisions for tc(8) actions (see tc-actions(8)); these are also referred-to as controls.

RECLASSIFY = 'reclassify'

Reclassify packet

PIPE = 'pipe'

Pass packet to next action

DROP = 'drop'

Drop packet

CONTINUE = 'continue'

Pass packet to next filter

PASS = 'pass'

End packet classification (packet returned to queuing discipline/class)

classmethod create_from_string(decision_str: str) → ActionDecision

Convert from a string to an ActionDecision member.

Parameters:

decision_str – the string representation of ActionDecision member.

Return type:

a ActionDecision member

Raises a ValueError if no match is found.

Traffic actions support statistics. These statistics are collected in ActionStats instances which are returned from the TrafficAction.get_stats() method.

class ActionStats

An ActionStats instance holds statistics for a traffic action.

property bytes_sent: int

Number of bytes sent.

property packets_sent: int

Number of packets sent.

property dropped_packets: int

Number of packets dropped.

property requeued_packets: int

Number of packets that were requeued for some reason.

property overlimits: int

Number of times a packet was delayed due to rate limits.

get_byte_backlog() → int

Backlog in bytes

get_packet_backlog() → int

Backlog in packets