18c2ecf20Sopenharmony_ci========================= 28c2ecf20Sopenharmony_ciNetwork classifier cgroup 38c2ecf20Sopenharmony_ci========================= 48c2ecf20Sopenharmony_ci 58c2ecf20Sopenharmony_ciThe Network classifier cgroup provides an interface to 68c2ecf20Sopenharmony_citag network packets with a class identifier (classid). 78c2ecf20Sopenharmony_ci 88c2ecf20Sopenharmony_ciThe Traffic Controller (tc) can be used to assign 98c2ecf20Sopenharmony_cidifferent priorities to packets from different cgroups. 108c2ecf20Sopenharmony_ciAlso, Netfilter (iptables) can use this tag to perform 118c2ecf20Sopenharmony_ciactions on such packets. 128c2ecf20Sopenharmony_ci 138c2ecf20Sopenharmony_ciCreating a net_cls cgroups instance creates a net_cls.classid file. 148c2ecf20Sopenharmony_ciThis net_cls.classid value is initialized to 0. 158c2ecf20Sopenharmony_ci 168c2ecf20Sopenharmony_ciYou can write hexadecimal values to net_cls.classid; the format for these 178c2ecf20Sopenharmony_civalues is 0xAAAABBBB; AAAA is the major handle number and BBBB 188c2ecf20Sopenharmony_ciis the minor handle number. 198c2ecf20Sopenharmony_ciReading net_cls.classid yields a decimal result. 208c2ecf20Sopenharmony_ci 218c2ecf20Sopenharmony_ciExample:: 228c2ecf20Sopenharmony_ci 238c2ecf20Sopenharmony_ci mkdir /sys/fs/cgroup/net_cls 248c2ecf20Sopenharmony_ci mount -t cgroup -onet_cls net_cls /sys/fs/cgroup/net_cls 258c2ecf20Sopenharmony_ci mkdir /sys/fs/cgroup/net_cls/0 268c2ecf20Sopenharmony_ci echo 0x100001 > /sys/fs/cgroup/net_cls/0/net_cls.classid 278c2ecf20Sopenharmony_ci 288c2ecf20Sopenharmony_ci- setting a 10:1 handle:: 298c2ecf20Sopenharmony_ci 308c2ecf20Sopenharmony_ci cat /sys/fs/cgroup/net_cls/0/net_cls.classid 318c2ecf20Sopenharmony_ci 1048577 328c2ecf20Sopenharmony_ci 338c2ecf20Sopenharmony_ci- configuring tc:: 348c2ecf20Sopenharmony_ci 358c2ecf20Sopenharmony_ci tc qdisc add dev eth0 root handle 10: htb 368c2ecf20Sopenharmony_ci tc class add dev eth0 parent 10: classid 10:1 htb rate 40mbit 378c2ecf20Sopenharmony_ci 388c2ecf20Sopenharmony_ci- creating traffic class 10:1:: 398c2ecf20Sopenharmony_ci 408c2ecf20Sopenharmony_ci tc filter add dev eth0 parent 10: protocol ip prio 10 handle 1: cgroup 418c2ecf20Sopenharmony_ci 428c2ecf20Sopenharmony_ciconfiguring iptables, basic example:: 438c2ecf20Sopenharmony_ci 448c2ecf20Sopenharmony_ci iptables -A OUTPUT -m cgroup ! --cgroup 0x100001 -j DROP 45