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 #define net_cls_subsys_id net_cls_subsys.subsys_id
40 .module = THIS_MODULE,
44 static inline struct cgroup_cls_state *cgrp_cls_state(struct cgroup *cgrp)
46 return container_of(cgroup_subsys_state(cgrp, net_cls_subsys_id),
47 struct cgroup_cls_state, css);
50 static inline struct cgroup_cls_state *task_cls_state(struct task_struct *p)
52 return container_of(task_subsys_state(p, net_cls_subsys_id),
53 struct cgroup_cls_state, css);
56 static struct cgroup_subsys_state *cgrp_create(struct cgroup_subsys *ss,
59 struct cgroup_cls_state *cs;
61 if (!(cs = kzalloc(sizeof(*cs), GFP_KERNEL)))
62 return ERR_PTR(-ENOMEM);
65 cs->classid = cgrp_cls_state(cgrp->parent)->classid;
70 static void cgrp_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
72 kfree(cgrp_cls_state(cgrp));
75 static u64 read_classid(struct cgroup *cgrp, struct cftype *cft)
77 return cgrp_cls_state(cgrp)->classid;
80 static int write_classid(struct cgroup *cgrp, struct cftype *cft, u64 value)
82 cgrp_cls_state(cgrp)->classid = (u32) value;
86 static struct cftype ss_files[] = {
89 .read_u64 = read_classid,
90 .write_u64 = write_classid,
94 static int cgrp_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
96 return cgroup_add_files(cgrp, ss, ss_files, ARRAY_SIZE(ss_files));
99 struct cls_cgroup_head
102 struct tcf_exts exts;
103 struct tcf_ematch_tree ematches;
106 static int cls_cgroup_classify(struct sk_buff *skb, struct tcf_proto *tp,
107 struct tcf_result *res)
109 struct cls_cgroup_head *head = tp->root;
113 classid = task_cls_state(current)->classid;
117 * Due to the nature of the classifier it is required to ignore all
118 * packets originating from softirq context as accessing `current'
119 * would lead to false results.
121 * This test assumes that all callers of dev_queue_xmit() explicitely
122 * disable bh. Knowing this, it is possible to detect softirq based
123 * calls by looking at the number of nested bh disable calls because
124 * softirqs always disables bh.
126 if (softirq_count() != SOFTIRQ_OFFSET) {
127 /* If there is an sk_classid we'll use that. */
130 classid = skb->sk->sk_classid;
136 if (!tcf_em_tree_match(skb, &head->ematches, NULL))
139 res->classid = classid;
141 return tcf_exts_exec(skb, &head->exts, res);
144 static unsigned long cls_cgroup_get(struct tcf_proto *tp, u32 handle)
149 static void cls_cgroup_put(struct tcf_proto *tp, unsigned long f)
153 static int cls_cgroup_init(struct tcf_proto *tp)
158 static const struct tcf_ext_map cgroup_ext_map = {
159 .action = TCA_CGROUP_ACT,
160 .police = TCA_CGROUP_POLICE,
163 static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = {
164 [TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED },
167 static int cls_cgroup_change(struct tcf_proto *tp, unsigned long base,
168 u32 handle, struct nlattr **tca,
171 struct nlattr *tb[TCA_CGROUP_MAX+1];
172 struct cls_cgroup_head *head = tp->root;
173 struct tcf_ematch_tree t;
177 if (!tca[TCA_OPTIONS])
184 head = kzalloc(sizeof(*head), GFP_KERNEL);
188 head->handle = handle;
195 if (handle != head->handle)
198 err = nla_parse_nested(tb, TCA_CGROUP_MAX, tca[TCA_OPTIONS],
203 err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &cgroup_ext_map);
207 err = tcf_em_tree_validate(tp, tb[TCA_CGROUP_EMATCHES], &t);
211 tcf_exts_change(tp, &head->exts, &e);
212 tcf_em_tree_change(tp, &head->ematches, &t);
217 static void cls_cgroup_destroy(struct tcf_proto *tp)
219 struct cls_cgroup_head *head = tp->root;
222 tcf_exts_destroy(tp, &head->exts);
223 tcf_em_tree_destroy(tp, &head->ematches);
228 static int cls_cgroup_delete(struct tcf_proto *tp, unsigned long arg)
233 static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg)
235 struct cls_cgroup_head *head = tp->root;
237 if (arg->count < arg->skip)
240 if (arg->fn(tp, (unsigned long) head, arg) < 0) {
248 static int cls_cgroup_dump(struct tcf_proto *tp, unsigned long fh,
249 struct sk_buff *skb, struct tcmsg *t)
251 struct cls_cgroup_head *head = tp->root;
252 unsigned char *b = skb_tail_pointer(skb);
255 t->tcm_handle = head->handle;
257 nest = nla_nest_start(skb, TCA_OPTIONS);
259 goto nla_put_failure;
261 if (tcf_exts_dump(skb, &head->exts, &cgroup_ext_map) < 0 ||
262 tcf_em_tree_dump(skb, &head->ematches, TCA_CGROUP_EMATCHES) < 0)
263 goto nla_put_failure;
265 nla_nest_end(skb, nest);
267 if (tcf_exts_dump_stats(skb, &head->exts, &cgroup_ext_map) < 0)
268 goto nla_put_failure;
277 static struct tcf_proto_ops cls_cgroup_ops __read_mostly = {
279 .init = cls_cgroup_init,
280 .change = cls_cgroup_change,
281 .classify = cls_cgroup_classify,
282 .destroy = cls_cgroup_destroy,
283 .get = cls_cgroup_get,
284 .put = cls_cgroup_put,
285 .delete = cls_cgroup_delete,
286 .walk = cls_cgroup_walk,
287 .dump = cls_cgroup_dump,
288 .owner = THIS_MODULE,
291 static int __init init_cgroup_cls(void)
295 ret = cgroup_load_subsys(&net_cls_subsys);
299 #ifndef CONFIG_NET_CLS_CGROUP
300 /* We can't use rcu_assign_pointer because this is an int. */
302 net_cls_subsys_id = net_cls_subsys.subsys_id;
305 ret = register_tcf_proto_ops(&cls_cgroup_ops);
307 cgroup_unload_subsys(&net_cls_subsys);
313 static void __exit exit_cgroup_cls(void)
315 unregister_tcf_proto_ops(&cls_cgroup_ops);
317 #ifndef CONFIG_NET_CLS_CGROUP
318 net_cls_subsys_id = -1;
322 cgroup_unload_subsys(&net_cls_subsys);
325 module_init(init_cgroup_cls);
326 module_exit(exit_cgroup_cls);
327 MODULE_LICENSE("GPL");