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actions in tc

Section: Linux (8)
Updated: 4 Jul 2017
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NAME

actions - independently defined actions in tc

SYNOPSIS

tc [ TC_OPTIONS ] actions add | change | replace ACTSPEC

tc [ TC_OPTIONS ] actions get | delete ACTISPEC

tc [ TC_OPTIONS ] actions flush ACTNAMESPEC

tc [ TC_OPTIONS ] actions ls | list ACTNAMESPEC

ACTSPEC := action ACTDETAIL [ INDEXSPEC ] [ COOKIESPEC ] [ CONTROL ]

ACTISPEC := ACTNAMESPEC INDEXSPEC

ACTNAMESPEC := action ACTNAME

INDEXSPEC := index INDEX

COOKIESPEC := cookie COOKIE

ACTDETAIL := ACTNAME ACTPARAMS

ACTNAME may be any valid action type: gact, mirred, bpf, connmark, csum, police, etc.

ACTPARAMS are the action-specific parameters; see the man page for the specific action type to be used for details.

CONTROL := { reclassify | pipe | drop | continue | ok }

TC_OPTIONS These are the options that are specific to tc and not only the options. Refer to tc(8) for more information.

DESCRIPTION

The actions object in tc allows a user to define actions independently of a classifier (filter). These actions can then be assigned to one or more filters, with any packets matching the classifier's criteria having that action performed on them.

Each action type (mirred, police, etc.) will have its own table to store all created actions.

OPERATIONS

add: Create a new action in that action's table.
change: replace Make modifications to an existing action.
get: Display the action with the specified index value. When combined with the -s option for tc, display the statistics for that action.
delete: Delete the action with the specified index value. If the action is already associated with a classifier, it does not delete the classifier.
ls: list List all the actions in the specified table. When combined with the -s option for tc, display the statistics for all actions in the specified table.
flush: Delete all actions stored in the specified table.

ACTION OPTIONS

Note that these options are available to all action types.

index INDEX

Specify the table index value of an action. INDEX is a 32-bit value that is unique to the specific type of action referenced.

: For add, change, and replace operations, the index is optional. When adding a new action, specifying an index value will assign the action to that index unless that index value has already been assigned. Omitting the index value for an add operation will cause the kernel to assign a value to the new action.

: For get and delete operations, the index is required to identify the specific action to be displayed or deleted.

cookie COOKIE

In addition to the specific action, mark the matching packet with the value specified by COOKIE. The COOKIE is a 128-bit value that will not be interpreted by the kernel whatsoever. As such, it can be used as a correlating value for maintaining user state. The value to be stored is completely arbitrary and does not require a specific format. It is stored inside the action structure itself.

CONTROL

The CONTROL indicates how tc should proceed after executing the action. Any of the following are valid:

reclassify: Restart the classifiction by jumping back to the first filter attached to the action's parent.
pipe: Continue with the next action. This is the default control.
drop: Drop the packed without running any further actions.
continue: Continue the classification with the next filter.
pass: Return to the calling qdisc for packet processing, and end classification of this packet.