Manual: tc-cgroup

Cgroup classifier in tc(8)				    Linux				  Cgroup classifier in tc(8)

NAME
       cgroup - control group based traffic control filter

SYNOPSIS
       tc filter ... cgroup [ match EMATCH_TREE ] [ action ACTION_SPEC ]

DESCRIPTION
       This  filter  serves  as	 a hint to tc that the assigned class ID of the net_cls control group the process the packet
       originates from belongs to should be used for classification. Obviously, it is useful for locally  generated  packets
       only.

OPTIONS
       action ACTION_SPEC
	      Apply an action from the generic actions framework on matching packets.

       match EMATCH_TREE
	      Match  packets using the extended match infrastructure. See tc-ematch(8) for a detailed description of the al‐
	      lowed syntax in EMATCH_TREE.

EXAMPLES
       In order to use this filter, a net_cls control group has to be created first and class as well as process  ID(s)	 as‐
       signed to it. The following creates a net_cls cgroup named "foobar":

	      modprobe cls_cgroup
	      mkdir /sys/fs/cgroup/net_cls
	      mount -t cgroup -onet_cls net_cls /sys/fs/cgroup/net_cls
	      mkdir /sys/fs/cgroup/net_cls/foobar

       To  assign  a class ID to the created cgroup, a file named net_cls.classid has to be created which contains the class
       ID to be assigned as a hexadecimal, 64bit wide number. The upper 32bits are reserved for the major  handle,  the	 re‐
       maining hold the minor. So a class ID of e.g.  ff:be has to be written like so: 0xff00be (leading zeroes may be omit‐
       ted). To continue the above example, the following assigns class ID 1:2 to foobar cgroup:

	      echo 0x10002 > /sys/fs/cgroup/net_cls/foobar/net_cls.classid

       Finally some PIDs can be assigned to the given cgroup:

	      echo 1234 > /sys/fs/cgroup/net_cls/foobar/tasks
	      echo 5678 > /sys/fs/cgroup/net_cls/foobar/tasks

       Now by simply attaching a cgroup filter to a qdisc makes packets from PIDs 1234 and 5678 be pushed into class 1:2.

SEE ALSO
       tc(8), tc-ematch(8),
       the file Documentation/cgroups/net_cls.txt of the Linux kernel tree

iproute2						 21 Oct 2015				  Cgroup classifier in tc(8)