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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>
20
21struct cgroup_cls_state
22{
23 struct cgroup_subsys_state css;
24 u32 classid;
25};
26
27static inline struct cgroup_cls_state *cgrp_cls_state(struct cgroup *cgrp)
28{
29 return container_of(cgroup_subsys_state(cgrp, net_cls_subsys_id),
30 struct cgroup_cls_state, css);
31}
32
33static inline struct cgroup_cls_state *task_cls_state(struct task_struct *p)
34{
35 return container_of(task_subsys_state(p, net_cls_subsys_id),
36 struct cgroup_cls_state, css);
37}
38
39static struct cgroup_subsys_state *cgrp_create(struct cgroup_subsys *ss,
40 struct cgroup *cgrp)
41{
42 struct cgroup_cls_state *cs;
43
44 if (!(cs = kzalloc(sizeof(*cs), GFP_KERNEL)))
45 return ERR_PTR(-ENOMEM);
46
47 if (cgrp->parent)
48 cs->classid = cgrp_cls_state(cgrp->parent)->classid;
49
50 return &cs->css;
51}
52
53static void cgrp_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
54{
55 kfree(cgrp_cls_state(cgrp));
56}
57
58static u64 read_classid(struct cgroup *cgrp, struct cftype *cft)
59{
60 return cgrp_cls_state(cgrp)->classid;
61}
62
63static int write_classid(struct cgroup *cgrp, struct cftype *cft, u64 value)
64{
65 if (!cgroup_lock_live_group(cgrp))
66 return -ENODEV;
67
68 cgrp_cls_state(cgrp)->classid = (u32) value;
69
70 cgroup_unlock();
71
72 return 0;
73}
74
75static struct cftype ss_files[] = {
76 {
77 .name = "classid",
78 .read_u64 = read_classid,
79 .write_u64 = write_classid,
80 },
81};
82
83static int cgrp_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
84{
85 return cgroup_add_files(cgrp, ss, ss_files, ARRAY_SIZE(ss_files));
86}
87
88struct cgroup_subsys net_cls_subsys = {
89 .name = "net_cls",
90 .create = cgrp_create,
91 .destroy = cgrp_destroy,
92 .populate = cgrp_populate,
93 .subsys_id = net_cls_subsys_id,
94};
95
96struct cls_cgroup_head
97{
98 u32 handle;
99 struct tcf_exts exts;
100 struct tcf_ematch_tree ematches;
101};
102
103static int cls_cgroup_classify(struct sk_buff *skb, struct tcf_proto *tp,
104 struct tcf_result *res)
105{
106 struct cls_cgroup_head *head = tp->root;
107 u32 classid;
108
109
110
111
112
113
114
115
116
117
118
119 if (softirq_count() != SOFTIRQ_OFFSET)
120 return -1;
121
122 rcu_read_lock();
123 classid = task_cls_state(current)->classid;
124 rcu_read_unlock();
125
126 if (!classid)
127 return -1;
128
129 if (!tcf_em_tree_match(skb, &head->ematches, NULL))
130 return -1;
131
132 res->classid = classid;
133 res->class = 0;
134 return tcf_exts_exec(skb, &head->exts, res);
135}
136
137static unsigned long cls_cgroup_get(struct tcf_proto *tp, u32 handle)
138{
139 return 0UL;
140}
141
142static void cls_cgroup_put(struct tcf_proto *tp, unsigned long f)
143{
144}
145
146static int cls_cgroup_init(struct tcf_proto *tp)
147{
148 return 0;
149}
150
151static const struct tcf_ext_map cgroup_ext_map = {
152 .action = TCA_CGROUP_ACT,
153 .police = TCA_CGROUP_POLICE,
154};
155
156static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = {
157 [TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED },
158};
159
160static int cls_cgroup_change(struct tcf_proto *tp, unsigned long base,
161 u32 handle, struct nlattr **tca,
162 unsigned long *arg)
163{
164 struct nlattr *tb[TCA_CGROUP_MAX+1];
165 struct cls_cgroup_head *head = tp->root;
166 struct tcf_ematch_tree t;
167 struct tcf_exts e;
168 int err;
169
170 if (!tca[TCA_OPTIONS])
171 return -EINVAL;
172
173 if (head == NULL) {
174 if (!handle)
175 return -EINVAL;
176
177 head = kzalloc(sizeof(*head), GFP_KERNEL);
178 if (head == NULL)
179 return -ENOBUFS;
180
181 head->handle = handle;
182
183 tcf_tree_lock(tp);
184 tp->root = head;
185 tcf_tree_unlock(tp);
186 }
187
188 if (handle != head->handle)
189 return -ENOENT;
190
191 err = nla_parse_nested(tb, TCA_CGROUP_MAX, tca[TCA_OPTIONS],
192 cgroup_policy);
193 if (err < 0)
194 return err;
195
196 err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &cgroup_ext_map);
197 if (err < 0)
198 return err;
199
200 err = tcf_em_tree_validate(tp, tb[TCA_CGROUP_EMATCHES], &t);
201 if (err < 0)
202 return err;
203
204 tcf_exts_change(tp, &head->exts, &e);
205 tcf_em_tree_change(tp, &head->ematches, &t);
206
207 return 0;
208}
209
210static void cls_cgroup_destroy(struct tcf_proto *tp)
211{
212 struct cls_cgroup_head *head = tp->root;
213
214 if (head) {
215 tcf_exts_destroy(tp, &head->exts);
216 tcf_em_tree_destroy(tp, &head->ematches);
217 kfree(head);
218 }
219}
220
221static int cls_cgroup_delete(struct tcf_proto *tp, unsigned long arg)
222{
223 return -EOPNOTSUPP;
224}
225
226static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg)
227{
228 struct cls_cgroup_head *head = tp->root;
229
230 if (arg->count < arg->skip)
231 goto skip;
232
233 if (arg->fn(tp, (unsigned long) head, arg) < 0) {
234 arg->stop = 1;
235 return;
236 }
237skip:
238 arg->count++;
239}
240
241static int cls_cgroup_dump(struct tcf_proto *tp, unsigned long fh,
242 struct sk_buff *skb, struct tcmsg *t)
243{
244 struct cls_cgroup_head *head = tp->root;
245 unsigned char *b = skb_tail_pointer(skb);
246 struct nlattr *nest;
247
248 t->tcm_handle = head->handle;
249
250 nest = nla_nest_start(skb, TCA_OPTIONS);
251 if (nest == NULL)
252 goto nla_put_failure;
253
254 if (tcf_exts_dump(skb, &head->exts, &cgroup_ext_map) < 0 ||
255 tcf_em_tree_dump(skb, &head->ematches, TCA_CGROUP_EMATCHES) < 0)
256 goto nla_put_failure;
257
258 nla_nest_end(skb, nest);
259
260 if (tcf_exts_dump_stats(skb, &head->exts, &cgroup_ext_map) < 0)
261 goto nla_put_failure;
262
263 return skb->len;
264
265nla_put_failure:
266 nlmsg_trim(skb, b);
267 return -1;
268}
269
270static struct tcf_proto_ops cls_cgroup_ops __read_mostly = {
271 .kind = "cgroup",
272 .init = cls_cgroup_init,
273 .change = cls_cgroup_change,
274 .classify = cls_cgroup_classify,
275 .destroy = cls_cgroup_destroy,
276 .get = cls_cgroup_get,
277 .put = cls_cgroup_put,
278 .delete = cls_cgroup_delete,
279 .walk = cls_cgroup_walk,
280 .dump = cls_cgroup_dump,
281 .owner = THIS_MODULE,
282};
283
284static int __init init_cgroup_cls(void)
285{
286 return register_tcf_proto_ops(&cls_cgroup_ops);
287}
288
289static void __exit exit_cgroup_cls(void)
290{
291 unregister_tcf_proto_ops(&cls_cgroup_ops);
292}
293
294module_init(init_cgroup_cls);
295module_exit(exit_cgroup_cls);
296MODULE_LICENSE("GPL");
297
