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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>
22#include <net/sock.h>
23#include <net/cls_cgroup.h>
24
25static struct cgroup_subsys_state *cgrp_create(struct cgroup *cgrp);
26static void cgrp_destroy(struct cgroup *cgrp);
27static int cgrp_populate(struct cgroup_subsys *ss, struct cgroup *cgrp);
28
29struct cgroup_subsys net_cls_subsys = {
30 .name = "net_cls",
31 .create = cgrp_create,
32 .destroy = cgrp_destroy,
33 .populate = cgrp_populate,
34#ifdef CONFIG_NET_CLS_CGROUP
35 .subsys_id = net_cls_subsys_id,
36#endif
37 .module = THIS_MODULE,
38};
39
40
41static inline struct cgroup_cls_state *cgrp_cls_state(struct cgroup *cgrp)
42{
43 return container_of(cgroup_subsys_state(cgrp, net_cls_subsys_id),
44 struct cgroup_cls_state, css);
45}
46
47static inline struct cgroup_cls_state *task_cls_state(struct task_struct *p)
48{
49 return container_of(task_subsys_state(p, net_cls_subsys_id),
50 struct cgroup_cls_state, css);
51}
52
53static struct cgroup_subsys_state *cgrp_create(struct cgroup *cgrp)
54{
55 struct cgroup_cls_state *cs;
56
57 cs = kzalloc(sizeof(*cs), GFP_KERNEL);
58 if (!cs)
59 return ERR_PTR(-ENOMEM);
60
61 if (cgrp->parent)
62 cs->classid = cgrp_cls_state(cgrp->parent)->classid;
63
64 return &cs->css;
65}
66
67static void cgrp_destroy(struct cgroup *cgrp)
68{
69 kfree(cgrp_cls_state(cgrp));
70}
71
72static u64 read_classid(struct cgroup *cgrp, struct cftype *cft)
73{
74 return cgrp_cls_state(cgrp)->classid;
75}
76
77static int write_classid(struct cgroup *cgrp, struct cftype *cft, u64 value)
78{
79 cgrp_cls_state(cgrp)->classid = (u32) value;
80 return 0;
81}
82
83static struct cftype ss_files[] = {
84 {
85 .name = "classid",
86 .read_u64 = read_classid,
87 .write_u64 = write_classid,
88 },
89};
90
91static int cgrp_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
92{
93 return cgroup_add_files(cgrp, ss, ss_files, ARRAY_SIZE(ss_files));
94}
95
96struct cls_cgroup_head {
97 u32 handle;
98 struct tcf_exts exts;
99 struct tcf_ematch_tree ematches;
100};
101
102static int cls_cgroup_classify(struct sk_buff *skb, const struct tcf_proto *tp,
103 struct tcf_result *res)
104{
105 struct cls_cgroup_head *head = tp->root;
106 u32 classid;
107
108 rcu_read_lock();
109 classid = task_cls_state(current)->classid;
110 rcu_read_unlock();
111
112
113
114
115
116
117
118
119
120
121
122 if (in_serving_softirq()) {
123
124 if (!skb->sk)
125 return -1;
126 classid = skb->sk->sk_classid;
127 }
128
129 if (!classid)
130 return -1;
131
132 if (!tcf_em_tree_match(skb, &head->ematches, NULL))
133 return -1;
134
135 res->classid = classid;
136 res->class = 0;
137 return tcf_exts_exec(skb, &head->exts, res);
138}
139
140static unsigned long cls_cgroup_get(struct tcf_proto *tp, u32 handle)
141{
142 return 0UL;
143}
144
145static void cls_cgroup_put(struct tcf_proto *tp, unsigned long f)
146{
147}
148
149static int cls_cgroup_init(struct tcf_proto *tp)
150{
151 return 0;
152}
153
154static const struct tcf_ext_map cgroup_ext_map = {
155 .action = TCA_CGROUP_ACT,
156 .police = TCA_CGROUP_POLICE,
157};
158
159static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = {
160 [TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED },
161};
162
163static int cls_cgroup_change(struct tcf_proto *tp, unsigned long base,
164 u32 handle, struct nlattr **tca,
165 unsigned long *arg)
166{
167 struct nlattr *tb[TCA_CGROUP_MAX + 1];
168 struct cls_cgroup_head *head = tp->root;
169 struct tcf_ematch_tree t;
170 struct tcf_exts e;
171 int err;
172
173 if (!tca[TCA_OPTIONS])
174 return -EINVAL;
175
176 if (head == NULL) {
177 if (!handle)
178 return -EINVAL;
179
180 head = kzalloc(sizeof(*head), GFP_KERNEL);
181 if (head == NULL)
182 return -ENOBUFS;
183
184 head->handle = handle;
185
186 tcf_tree_lock(tp);
187 tp->root = head;
188 tcf_tree_unlock(tp);
189 }
190
191 if (handle != head->handle)
192 return -ENOENT;
193
194 err = nla_parse_nested(tb, TCA_CGROUP_MAX, tca[TCA_OPTIONS],
195 cgroup_policy);
196 if (err < 0)
197 return err;
198
199 err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &cgroup_ext_map);
200 if (err < 0)
201 return err;
202
203 err = tcf_em_tree_validate(tp, tb[TCA_CGROUP_EMATCHES], &t);
204 if (err < 0)
205 return err;
206
207 tcf_exts_change(tp, &head->exts, &e);
208 tcf_em_tree_change(tp, &head->ematches, &t);
209
210 return 0;
211}
212
213static void cls_cgroup_destroy(struct tcf_proto *tp)
214{
215 struct cls_cgroup_head *head = tp->root;
216
217 if (head) {
218 tcf_exts_destroy(tp, &head->exts);
219 tcf_em_tree_destroy(tp, &head->ematches);
220 kfree(head);
221 }
222}
223
224static int cls_cgroup_delete(struct tcf_proto *tp, unsigned long arg)
225{
226 return -EOPNOTSUPP;
227}
228
229static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg)
230{
231 struct cls_cgroup_head *head = tp->root;
232
233 if (arg->count < arg->skip)
234 goto skip;
235
236 if (arg->fn(tp, (unsigned long) head, arg) < 0) {
237 arg->stop = 1;
238 return;
239 }
240skip:
241 arg->count++;
242}
243
244static int cls_cgroup_dump(struct tcf_proto *tp, unsigned long fh,
245 struct sk_buff *skb, struct tcmsg *t)
246{
247 struct cls_cgroup_head *head = tp->root;
248 unsigned char *b = skb_tail_pointer(skb);
249 struct nlattr *nest;
250
251 t->tcm_handle = head->handle;
252
253 nest = nla_nest_start(skb, TCA_OPTIONS);
254 if (nest == NULL)
255 goto nla_put_failure;
256
257 if (tcf_exts_dump(skb, &head->exts, &cgroup_ext_map) < 0 ||
258 tcf_em_tree_dump(skb, &head->ematches, TCA_CGROUP_EMATCHES) < 0)
259 goto nla_put_failure;
260
261 nla_nest_end(skb, nest);
262
263 if (tcf_exts_dump_stats(skb, &head->exts, &cgroup_ext_map) < 0)
264 goto nla_put_failure;
265
266 return skb->len;
267
268nla_put_failure:
269 nlmsg_trim(skb, b);
270 return -1;
271}
272
273static struct tcf_proto_ops cls_cgroup_ops __read_mostly = {
274 .kind = "cgroup",
275 .init = cls_cgroup_init,
276 .change = cls_cgroup_change,
277 .classify = cls_cgroup_classify,
278 .destroy = cls_cgroup_destroy,
279 .get = cls_cgroup_get,
280 .put = cls_cgroup_put,
281 .delete = cls_cgroup_delete,
282 .walk = cls_cgroup_walk,
283 .dump = cls_cgroup_dump,
284 .owner = THIS_MODULE,
285};
286
287static int __init init_cgroup_cls(void)
288{
289 int ret;
290
291 ret = cgroup_load_subsys(&net_cls_subsys);
292 if (ret)
293 goto out;
294
295#ifndef CONFIG_NET_CLS_CGROUP
296
297 smp_wmb();
298 net_cls_subsys_id = net_cls_subsys.subsys_id;
299#endif
300
301 ret = register_tcf_proto_ops(&cls_cgroup_ops);
302 if (ret)
303 cgroup_unload_subsys(&net_cls_subsys);
304
305out:
306 return ret;
307}
308
309static void __exit exit_cgroup_cls(void)
310{
311 unregister_tcf_proto_ops(&cls_cgroup_ops);
312
313#ifndef CONFIG_NET_CLS_CGROUP
314 net_cls_subsys_id = -1;
315 synchronize_rcu();
316#endif
317
318 cgroup_unload_subsys(&net_cls_subsys);
319}
320
321module_init(init_cgroup_cls);
322module_exit(exit_cgroup_cls);
323MODULE_LICENSE("GPL");
324
