Cgroup classifier in tc(8)( 21 Oct 2015)Cgroup classifier in tc(8)

          cgroup - control group based traffic control filter

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

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

          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
               allowed syntax in EMATCH_TREE.

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

               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 remain-
          ing hold the minor. So a class ID of e.g.  ff:be has to be
          written like so: 0xff00be (leading zeroes may be omitted).
          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

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     Cgroup classifier in tc(8)( 21 Oct 2015)Cgroup classifier in tc(8)

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

          tc(8), tc-ematch(8),
          the file Documentation/cgroups/net_cls.txt of the Linux ker-
          nel tree

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