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 <net/rtnetlink.h>
20 #include <net/pkt_cls.h>
22 struct cgroup_cls_state
24 struct cgroup_subsys_state css;
28 static struct cgroup_subsys_state *cgrp_create(struct cgroup_subsys *ss,
30 static void cgrp_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp);
31 static int cgrp_populate(struct cgroup_subsys *ss, struct cgroup *cgrp);
33 struct cgroup_subsys net_cls_subsys = {
35 .create = cgrp_create,
36 .destroy = cgrp_destroy,
37 .populate = cgrp_populate,
38 #ifdef CONFIG_NET_CLS_CGROUP
39 .subsys_id = net_cls_subsys_id,
41 #define net_cls_subsys_id net_cls_subsys.subsys_id
43 .module = THIS_MODULE,
47 static inline struct cgroup_cls_state *cgrp_cls_state(struct cgroup *cgrp)
49 return container_of(cgroup_subsys_state(cgrp, net_cls_subsys_id),
50 struct cgroup_cls_state, css);
53 static inline struct cgroup_cls_state *task_cls_state(struct task_struct *p)
55 return container_of(task_subsys_state(p, net_cls_subsys_id),
56 struct cgroup_cls_state, css);
59 static struct cgroup_subsys_state *cgrp_create(struct cgroup_subsys *ss,
62 struct cgroup_cls_state *cs;
64 if (!(cs = kzalloc(sizeof(*cs), GFP_KERNEL)))
65 return ERR_PTR(-ENOMEM);
68 cs->classid = cgrp_cls_state(cgrp->parent)->classid;
73 static void cgrp_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
75 kfree(cgrp_cls_state(cgrp));
78 static u64 read_classid(struct cgroup *cgrp, struct cftype *cft)
80 return cgrp_cls_state(cgrp)->classid;
83 static int write_classid(struct cgroup *cgrp, struct cftype *cft, u64 value)
85 cgrp_cls_state(cgrp)->classid = (u32) value;
89 static struct cftype ss_files[] = {
92 .read_u64 = read_classid,
93 .write_u64 = write_classid,
97 static int cgrp_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
99 return cgroup_add_files(cgrp, ss, ss_files, ARRAY_SIZE(ss_files));
102 struct cls_cgroup_head
105 struct tcf_exts exts;
106 struct tcf_ematch_tree ematches;
109 static int cls_cgroup_classify(struct sk_buff *skb, struct tcf_proto *tp,
110 struct tcf_result *res)
112 struct cls_cgroup_head *head = tp->root;
116 * Due to the nature of the classifier it is required to ignore all
117 * packets originating from softirq context as accessing `current'
118 * would lead to false results.
120 * This test assumes that all callers of dev_queue_xmit() explicitely
121 * disable bh. Knowing this, it is possible to detect softirq based
122 * calls by looking at the number of nested bh disable calls because
123 * softirqs always disables bh.
125 if (softirq_count() != SOFTIRQ_OFFSET)
129 classid = task_cls_state(current)->classid;
135 if (!tcf_em_tree_match(skb, &head->ematches, NULL))
138 res->classid = classid;
140 return tcf_exts_exec(skb, &head->exts, res);
143 static unsigned long cls_cgroup_get(struct tcf_proto *tp, u32 handle)
148 static void cls_cgroup_put(struct tcf_proto *tp, unsigned long f)
152 static int cls_cgroup_init(struct tcf_proto *tp)
157 static const struct tcf_ext_map cgroup_ext_map = {
158 .action = TCA_CGROUP_ACT,
159 .police = TCA_CGROUP_POLICE,
162 static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = {
163 [TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED },
166 static int cls_cgroup_change(struct tcf_proto *tp, unsigned long base,
167 u32 handle, struct nlattr **tca,
170 struct nlattr *tb[TCA_CGROUP_MAX+1];
171 struct cls_cgroup_head *head = tp->root;
172 struct tcf_ematch_tree t;
176 if (!tca[TCA_OPTIONS])
183 head = kzalloc(sizeof(*head), GFP_KERNEL);
187 head->handle = handle;
194 if (handle != head->handle)
197 err = nla_parse_nested(tb, TCA_CGROUP_MAX, tca[TCA_OPTIONS],
202 err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &cgroup_ext_map);
206 err = tcf_em_tree_validate(tp, tb[TCA_CGROUP_EMATCHES], &t);
210 tcf_exts_change(tp, &head->exts, &e);
211 tcf_em_tree_change(tp, &head->ematches, &t);
216 static void cls_cgroup_destroy(struct tcf_proto *tp)
218 struct cls_cgroup_head *head = tp->root;
221 tcf_exts_destroy(tp, &head->exts);
222 tcf_em_tree_destroy(tp, &head->ematches);
227 static int cls_cgroup_delete(struct tcf_proto *tp, unsigned long arg)
232 static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg)
234 struct cls_cgroup_head *head = tp->root;
236 if (arg->count < arg->skip)
239 if (arg->fn(tp, (unsigned long) head, arg) < 0) {
247 static int cls_cgroup_dump(struct tcf_proto *tp, unsigned long fh,
248 struct sk_buff *skb, struct tcmsg *t)
250 struct cls_cgroup_head *head = tp->root;
251 unsigned char *b = skb_tail_pointer(skb);
254 t->tcm_handle = head->handle;
256 nest = nla_nest_start(skb, TCA_OPTIONS);
258 goto nla_put_failure;
260 if (tcf_exts_dump(skb, &head->exts, &cgroup_ext_map) < 0 ||
261 tcf_em_tree_dump(skb, &head->ematches, TCA_CGROUP_EMATCHES) < 0)
262 goto nla_put_failure;
264 nla_nest_end(skb, nest);
266 if (tcf_exts_dump_stats(skb, &head->exts, &cgroup_ext_map) < 0)
267 goto nla_put_failure;
276 static struct tcf_proto_ops cls_cgroup_ops __read_mostly = {
278 .init = cls_cgroup_init,
279 .change = cls_cgroup_change,
280 .classify = cls_cgroup_classify,
281 .destroy = cls_cgroup_destroy,
282 .get = cls_cgroup_get,
283 .put = cls_cgroup_put,
284 .delete = cls_cgroup_delete,
285 .walk = cls_cgroup_walk,
286 .dump = cls_cgroup_dump,
287 .owner = THIS_MODULE,
290 static int __init init_cgroup_cls(void)
292 int ret = register_tcf_proto_ops(&cls_cgroup_ops);
295 ret = cgroup_load_subsys(&net_cls_subsys);
297 unregister_tcf_proto_ops(&cls_cgroup_ops);
301 static void __exit exit_cgroup_cls(void)
303 unregister_tcf_proto_ops(&cls_cgroup_ops);
304 cgroup_unload_subsys(&net_cls_subsys);
307 module_init(init_cgroup_cls);
308 module_exit(exit_cgroup_cls);
309 MODULE_LICENSE("GPL");