2 * net/sched/cls_cgroup.c Control Group Classifier
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
9 * Authors: Thomas Graf <tgraf@suug.ch>
12 #include <linux/module.h>
13 #include <linux/types.h>
14 #include <linux/string.h>
15 #include <linux/errno.h>
16 #include <linux/skbuff.h>
17 #include <linux/cgroup.h>
18 #include <net/rtnetlink.h>
19 #include <net/pkt_cls.h>
21 struct cgroup_cls_state
23 struct cgroup_subsys_state css;
27 static inline struct cgroup_cls_state *cgrp_cls_state(struct cgroup *cgrp)
29 return container_of(cgroup_subsys_state(cgrp, net_cls_subsys_id),
30 struct cgroup_cls_state, css);
33 static inline struct cgroup_cls_state *task_cls_state(struct task_struct *p)
35 return container_of(task_subsys_state(p, net_cls_subsys_id),
36 struct cgroup_cls_state, css);
39 static struct cgroup_subsys_state *cgrp_create(struct cgroup_subsys *ss,
42 struct cgroup_cls_state *cs;
44 if (!(cs = kzalloc(sizeof(*cs), GFP_KERNEL)))
45 return ERR_PTR(-ENOMEM);
48 cs->classid = cgrp_cls_state(cgrp->parent)->classid;
53 static void cgrp_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
55 kfree(cgrp_cls_state(cgrp));
58 static u64 read_classid(struct cgroup *cgrp, struct cftype *cft)
60 return cgrp_cls_state(cgrp)->classid;
63 static int write_classid(struct cgroup *cgrp, struct cftype *cft, u64 value)
65 if (!cgroup_lock_live_group(cgrp))
68 cgrp_cls_state(cgrp)->classid = (u32) value;
75 static struct cftype ss_files[] = {
78 .read_u64 = read_classid,
79 .write_u64 = write_classid,
83 static int cgrp_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
85 return cgroup_add_files(cgrp, ss, ss_files, ARRAY_SIZE(ss_files));
88 struct cgroup_subsys net_cls_subsys = {
90 .create = cgrp_create,
91 .destroy = cgrp_destroy,
92 .populate = cgrp_populate,
93 .subsys_id = net_cls_subsys_id,
96 struct cls_cgroup_head
100 struct tcf_ematch_tree ematches;
103 static int cls_cgroup_classify(struct sk_buff *skb, struct tcf_proto *tp,
104 struct tcf_result *res)
106 struct cls_cgroup_head *head = tp->root;
107 struct cgroup_cls_state *cs;
111 * Due to the nature of the classifier it is required to ignore all
112 * packets originating from softirq context as accessing `current'
113 * would lead to false results.
115 * This test assumes that all callers of dev_queue_xmit() explicitely
116 * disable bh. Knowing this, it is possible to detect softirq based
117 * calls by looking at the number of nested bh disable calls because
118 * softirqs always disables bh.
120 if (softirq_count() != SOFTIRQ_OFFSET)
124 cs = task_cls_state(current);
125 if (cs->classid && tcf_em_tree_match(skb, &head->ematches, NULL)) {
126 res->classid = cs->classid;
128 ret = tcf_exts_exec(skb, &head->exts, res);
137 static unsigned long cls_cgroup_get(struct tcf_proto *tp, u32 handle)
142 static void cls_cgroup_put(struct tcf_proto *tp, unsigned long f)
146 static int cls_cgroup_init(struct tcf_proto *tp)
151 static const struct tcf_ext_map cgroup_ext_map = {
152 .action = TCA_CGROUP_ACT,
153 .police = TCA_CGROUP_POLICE,
156 static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = {
157 [TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED },
160 static int cls_cgroup_change(struct tcf_proto *tp, unsigned long base,
161 u32 handle, struct nlattr **tca,
164 struct nlattr *tb[TCA_CGROUP_MAX+1];
165 struct cls_cgroup_head *head = tp->root;
166 struct tcf_ematch_tree t;
174 head = kzalloc(sizeof(*head), GFP_KERNEL);
178 head->handle = handle;
185 if (handle != head->handle)
188 err = nla_parse_nested(tb, TCA_CGROUP_MAX, tca[TCA_OPTIONS],
193 err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &cgroup_ext_map);
197 err = tcf_em_tree_validate(tp, tb[TCA_CGROUP_EMATCHES], &t);
201 tcf_exts_change(tp, &head->exts, &e);
202 tcf_em_tree_change(tp, &head->ematches, &t);
207 static void cls_cgroup_destroy(struct tcf_proto *tp)
209 struct cls_cgroup_head *head = tp->root;
212 tcf_exts_destroy(tp, &head->exts);
213 tcf_em_tree_destroy(tp, &head->ematches);
218 static int cls_cgroup_delete(struct tcf_proto *tp, unsigned long arg)
223 static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg)
225 struct cls_cgroup_head *head = tp->root;
227 if (arg->count < arg->skip)
230 if (arg->fn(tp, (unsigned long) head, arg) < 0) {
238 static int cls_cgroup_dump(struct tcf_proto *tp, unsigned long fh,
239 struct sk_buff *skb, struct tcmsg *t)
241 struct cls_cgroup_head *head = tp->root;
242 unsigned char *b = skb_tail_pointer(skb);
245 t->tcm_handle = head->handle;
247 nest = nla_nest_start(skb, TCA_OPTIONS);
249 goto nla_put_failure;
251 if (tcf_exts_dump(skb, &head->exts, &cgroup_ext_map) < 0 ||
252 tcf_em_tree_dump(skb, &head->ematches, TCA_CGROUP_EMATCHES) < 0)
253 goto nla_put_failure;
255 nla_nest_end(skb, nest);
257 if (tcf_exts_dump_stats(skb, &head->exts, &cgroup_ext_map) < 0)
258 goto nla_put_failure;
267 static struct tcf_proto_ops cls_cgroup_ops __read_mostly = {
269 .init = cls_cgroup_init,
270 .change = cls_cgroup_change,
271 .classify = cls_cgroup_classify,
272 .destroy = cls_cgroup_destroy,
273 .get = cls_cgroup_get,
274 .put = cls_cgroup_put,
275 .delete = cls_cgroup_delete,
276 .walk = cls_cgroup_walk,
277 .dump = cls_cgroup_dump,
278 .owner = THIS_MODULE,
281 static int __init init_cgroup_cls(void)
283 return register_tcf_proto_ops(&cls_cgroup_ops);
286 static void __exit exit_cgroup_cls(void)
288 unregister_tcf_proto_ops(&cls_cgroup_ops);
291 module_init(init_cgroup_cls);
292 module_exit(exit_cgroup_cls);
293 MODULE_LICENSE("GPL");