1Network classifier cgroup 2------------------------- 3 4The Network classifier cgroup provides an interface to 5tag network packets with a class identifier (classid). 6 7The Traffic Controller (tc) can be used to assign 8different priorities to packets from different cgroups. 9 10Creating a net_cls cgroups instance creates a net_cls.classid file. 11This net_cls.classid value is initialized to 0. 12 13You can write hexadecimal values to net_cls.classid; the format for these 14values is 0xAAAABBBB; AAAA is the major handle number and BBBB 15is the minor handle number. 16Reading net_cls.classid yields a decimal result. 17 18Example: 19mkdir /sys/fs/cgroup/net_cls 20mount -t cgroup -onet_cls net_cls /sys/fs/cgroup/net_cls 21mkdir /sys/fs/cgroup/net_cls/0 22echo 0x100001 > /sys/fs/cgroup/net_cls/0/net_cls.classid 23 - setting a 10:1 handle. 24 25cat /sys/fs/cgroup/net_cls/0/net_cls.classid 261048577 27 28configuring tc: 29tc qdisc add dev eth0 root handle 10: htb 30 31tc class add dev eth0 parent 10: classid 10:1 htb rate 40mbit 32 - creating traffic class 10:1 33 34tc filter add dev eth0 parent 10: protocol ip prio 10 handle 1: cgroup 35