tc-actions (8)
NAME
actions - independently defined actions in tcSYNOPSIS
tc [ TC_OPTIONS ] actions add | change | replace ACTSPECtc [ TC_OPTIONS ] actions get | delete ACTISPEC
tc [ TC_OPTIONS ] actions flush ACTNAMESPEC
tc [ TC_OPTIONS ] actions ls | list ACTNAMESPEC [ ACTFILTER ]
ACTSPEC := action ACTDETAIL [ INDEXSPEC ] [ COOKIESPEC ] [ CONTROL ]
ACTISPEC := ACTNAMESPEC INDEXSPEC
ACTNAMESPEC := action ACTNAME
INDEXSPEC := index INDEX
ACTFILTER := since MSTIME
COOKIESPEC := cookie COOKIE
ACTDETAIL := ACTNAME ACTPARAMS
ACTNAME may be any valid action type: gact, mirred, bpf, connmark, csum, police, etc.
MSTIME Time since last update.
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. When combined with the option since allows doing a millisecond time-filter since the last time an action was used in the datapath.
- 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.
- since MSTIME
-
When dumping large number of actions, a millisecond time-filter can be
specified
MSTIME.
The
MSTIME
is a millisecond count since last time a packet hit the action.
As an example specifying "since 20000" implies to dump all actions
that have seen packets in the last 20 seconds. This option is useful
when the kernel has a large number of actions and you are only interested
in recently used actions.
- 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.
-