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/slab.h>
14 #include <linux/types.h>
15 #include <linux/string.h>
16 #include <linux/errno.h>
17 #include <linux/skbuff.h>
18 #include <linux/cgroup.h>
19 #include <linux/rcupdate.h>
20 #include <net/rtnetlink.h>
21 #include <net/pkt_cls.h>
23 #include <net/cls_cgroup.h>
25 static struct cgroup_subsys_state *cgrp_create(struct cgroup_subsys *ss,
27 static void cgrp_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp);
28 static int cgrp_populate(struct cgroup_subsys *ss, struct cgroup *cgrp);
30 struct cgroup_subsys net_cls_subsys = {
32 .create = cgrp_create,
33 .destroy = cgrp_destroy,
34 .populate = cgrp_populate,
35 #ifdef CONFIG_NET_CLS_CGROUP
36 .subsys_id = net_cls_subsys_id,
38 .module = THIS_MODULE,
42 static inline struct cgroup_cls_state *cgrp_cls_state(struct cgroup *cgrp)
44 return container_of(cgroup_subsys_state(cgrp, net_cls_subsys_id),
45 struct cgroup_cls_state, css);
48 static inline struct cgroup_cls_state *task_cls_state(struct task_struct *p)
50 return container_of(task_subsys_state(p, net_cls_subsys_id),
51 struct cgroup_cls_state, css);
54 static struct cgroup_subsys_state *cgrp_create(struct cgroup_subsys *ss,
57 struct cgroup_cls_state *cs;
59 cs = kzalloc(sizeof(*cs), GFP_KERNEL);
61 return ERR_PTR(-ENOMEM);
64 cs->classid = cgrp_cls_state(cgrp->parent)->classid;
69 static void cgrp_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
71 kfree(cgrp_cls_state(cgrp));
74 static u64 read_classid(struct cgroup *cgrp, struct cftype *cft)
76 return cgrp_cls_state(cgrp)->classid;
79 static int write_classid(struct cgroup *cgrp, struct cftype *cft, u64 value)
81 cgrp_cls_state(cgrp)->classid = (u32) value;
85 static struct cftype ss_files[] = {
88 .read_u64 = read_classid,
89 .write_u64 = write_classid,
93 static int cgrp_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
95 return cgroup_add_files(cgrp, ss, ss_files, ARRAY_SIZE(ss_files));
98 struct cls_cgroup_head {
100 struct tcf_exts exts;
101 struct tcf_ematch_tree ematches;
104 static int cls_cgroup_classify(struct sk_buff *skb, const struct tcf_proto *tp,
105 struct tcf_result *res)
107 struct cls_cgroup_head *head = tp->root;
111 classid = task_cls_state(current)->classid;
115 * Due to the nature of the classifier it is required to ignore all
116 * packets originating from softirq context as accessing `current'
117 * would lead to false results.
119 * This test assumes that all callers of dev_queue_xmit() explicitely
120 * disable bh. Knowing this, it is possible to detect softirq based
121 * calls by looking at the number of nested bh disable calls because
122 * softirqs always disables bh.
124 if (in_serving_softirq()) {
125 /* If there is an sk_classid we'll use that. */
128 classid = skb->sk->sk_classid;
134 if (!tcf_em_tree_match(skb, &head->ematches, NULL))
137 res->classid = classid;
139 return tcf_exts_exec(skb, &head->exts, res);
142 static unsigned long cls_cgroup_get(struct tcf_proto *tp, u32 handle)
147 static void cls_cgroup_put(struct tcf_proto *tp, unsigned long f)
151 static int cls_cgroup_init(struct tcf_proto *tp)
156 static const struct tcf_ext_map cgroup_ext_map = {
157 .action = TCA_CGROUP_ACT,
158 .police = TCA_CGROUP_POLICE,
161 static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = {
162 [TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED },
165 static int cls_cgroup_change(struct tcf_proto *tp, unsigned long base,
166 u32 handle, struct nlattr **tca,
169 struct nlattr *tb[TCA_CGROUP_MAX + 1];
170 struct cls_cgroup_head *head = tp->root;
171 struct tcf_ematch_tree t;
175 if (!tca[TCA_OPTIONS])
182 head = kzalloc(sizeof(*head), GFP_KERNEL);
186 head->handle = handle;
193 if (handle != head->handle)
196 err = nla_parse_nested(tb, TCA_CGROUP_MAX, tca[TCA_OPTIONS],
201 err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &cgroup_ext_map);
205 err = tcf_em_tree_validate(tp, tb[TCA_CGROUP_EMATCHES], &t);
209 tcf_exts_change(tp, &head->exts, &e);
210 tcf_em_tree_change(tp, &head->ematches, &t);
215 static void cls_cgroup_destroy(struct tcf_proto *tp)
217 struct cls_cgroup_head *head = tp->root;
220 tcf_exts_destroy(tp, &head->exts);
221 tcf_em_tree_destroy(tp, &head->ematches);
226 static int cls_cgroup_delete(struct tcf_proto *tp, unsigned long arg)
231 static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg)
233 struct cls_cgroup_head *head = tp->root;
235 if (arg->count < arg->skip)
238 if (arg->fn(tp, (unsigned long) head, arg) < 0) {
246 static int cls_cgroup_dump(struct tcf_proto *tp, unsigned long fh,
247 struct sk_buff *skb, struct tcmsg *t)
249 struct cls_cgroup_head *head = tp->root;
250 unsigned char *b = skb_tail_pointer(skb);
253 t->tcm_handle = head->handle;
255 nest = nla_nest_start(skb, TCA_OPTIONS);
257 goto nla_put_failure;
259 if (tcf_exts_dump(skb, &head->exts, &cgroup_ext_map) < 0 ||
260 tcf_em_tree_dump(skb, &head->ematches, TCA_CGROUP_EMATCHES) < 0)
261 goto nla_put_failure;
263 nla_nest_end(skb, nest);
265 if (tcf_exts_dump_stats(skb, &head->exts, &cgroup_ext_map) < 0)
266 goto nla_put_failure;
275 static struct tcf_proto_ops cls_cgroup_ops __read_mostly = {
277 .init = cls_cgroup_init,
278 .change = cls_cgroup_change,
279 .classify = cls_cgroup_classify,
280 .destroy = cls_cgroup_destroy,
281 .get = cls_cgroup_get,
282 .put = cls_cgroup_put,
283 .delete = cls_cgroup_delete,
284 .walk = cls_cgroup_walk,
285 .dump = cls_cgroup_dump,
286 .owner = THIS_MODULE,
289 static int __init init_cgroup_cls(void)
293 ret = cgroup_load_subsys(&net_cls_subsys);
297 #ifndef CONFIG_NET_CLS_CGROUP
298 /* We can't use rcu_assign_pointer because this is an int. */
300 net_cls_subsys_id = net_cls_subsys.subsys_id;
303 ret = register_tcf_proto_ops(&cls_cgroup_ops);
305 cgroup_unload_subsys(&net_cls_subsys);
311 static void __exit exit_cgroup_cls(void)
313 unregister_tcf_proto_ops(&cls_cgroup_ops);
315 #ifndef CONFIG_NET_CLS_CGROUP
316 net_cls_subsys_id = -1;
320 cgroup_unload_subsys(&net_cls_subsys);
323 module_init(init_cgroup_cls);
324 module_exit(exit_cgroup_cls);
325 MODULE_LICENSE("GPL");