projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 077f02f1 RR |
1 | Network classifier cgroup |
| 2 | ------------------------- | |
| 3 | ||
| 4 | The Network classifier cgroup provides an interface to | |
| 5 | tag network packets with a class identifier (classid). | |
| 6 | ||
| 7 | The Traffic Controller (tc) can be used to assign | |
| 8 | different priorities to packets from different cgroups. | |
| 82a37132 DB |
9 | Also, Netfilter (iptables) can use this tag to perform |
| 10 | actions on such packets. | |
| 077f02f1 RR |
11 | |
| 12 | Creating a net_cls cgroups instance creates a net_cls.classid file. | |
| 13 | This net_cls.classid value is initialized to 0. | |
| 14 | ||
| 15 | You can write hexadecimal values to net_cls.classid; the format for these | |
| 16 | values is 0xAAAABBBB; AAAA is the major handle number and BBBB | |
| 17 | is the minor handle number. | |
| 18 | Reading net_cls.classid yields a decimal result. | |
| 19 | ||
| 20 | Example: | |
| 21 | mkdir /sys/fs/cgroup/net_cls | |
| 22 | mount -t cgroup -onet_cls net_cls /sys/fs/cgroup/net_cls | |
| 23 | mkdir /sys/fs/cgroup/net_cls/0 | |
| 24 | echo 0x100001 > /sys/fs/cgroup/net_cls/0/net_cls.classid | |
| 25 | - setting a 10:1 handle. | |
| 26 | ||
| 27 | cat /sys/fs/cgroup/net_cls/0/net_cls.classid | |
| 28 | 1048577 | |
| 29 | ||
| 30 | configuring tc: | |
| 31 | tc qdisc add dev eth0 root handle 10: htb | |
| 32 | ||
| 33 | tc class add dev eth0 parent 10: classid 10:1 htb rate 40mbit | |
| 34 | - creating traffic class 10:1 | |
| 35 | ||
| 36 | tc filter add dev eth0 parent 10: protocol ip prio 10 handle 1: cgroup | |
| 82a37132 DB |
37 | |
| 38 | configuring iptables, basic example: | |
| 39 | iptables -A OUTPUT -m cgroup ! --cgroup 0x100001 -j DROP |