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12#include <linux/module.h>
13#include <linux/slab.h>
14#include <linux/skbuff.h>
15#include <linux/rcupdate.h>
16#include <net/rtnetlink.h>
17#include <net/pkt_cls.h>
18#include <net/sock.h>
19#include <net/cls_cgroup.h>
20
21struct cls_cgroup_head {
22 u32 handle;
23 struct tcf_exts exts;
24 struct tcf_ematch_tree ematches;
25 struct tcf_proto *tp;
26 union {
27 struct work_struct work;
28 struct rcu_head rcu;
29 };
30};
31
32static int cls_cgroup_classify(struct sk_buff *skb, const struct tcf_proto *tp,
33 struct tcf_result *res)
34{
35 struct cls_cgroup_head *head = rcu_dereference_bh(tp->root);
36 u32 classid = task_get_classid(skb);
37
38 if (!classid)
39 return -1;
40 if (!tcf_em_tree_match(skb, &head->ematches, NULL))
41 return -1;
42
43 res->classid = classid;
44 res->class = 0;
45
46 return tcf_exts_exec(skb, &head->exts, res);
47}
48
49static void *cls_cgroup_get(struct tcf_proto *tp, u32 handle)
50{
51 return NULL;
52}
53
54static int cls_cgroup_init(struct tcf_proto *tp)
55{
56 return 0;
57}
58
59static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = {
60 [TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED },
61};
62
63static void __cls_cgroup_destroy(struct cls_cgroup_head *head)
64{
65 tcf_exts_destroy(&head->exts);
66 tcf_em_tree_destroy(&head->ematches);
67 tcf_exts_put_net(&head->exts);
68 kfree(head);
69}
70
71static void cls_cgroup_destroy_work(struct work_struct *work)
72{
73 struct cls_cgroup_head *head = container_of(work,
74 struct cls_cgroup_head,
75 work);
76 rtnl_lock();
77 __cls_cgroup_destroy(head);
78 rtnl_unlock();
79}
80
81static void cls_cgroup_destroy_rcu(struct rcu_head *root)
82{
83 struct cls_cgroup_head *head = container_of(root,
84 struct cls_cgroup_head,
85 rcu);
86
87 INIT_WORK(&head->work, cls_cgroup_destroy_work);
88 tcf_queue_work(&head->work);
89}
90
91static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb,
92 struct tcf_proto *tp, unsigned long base,
93 u32 handle, struct nlattr **tca,
94 void **arg, bool ovr)
95{
96 struct nlattr *tb[TCA_CGROUP_MAX + 1];
97 struct cls_cgroup_head *head = rtnl_dereference(tp->root);
98 struct cls_cgroup_head *new;
99 int err;
100
101 if (!tca[TCA_OPTIONS])
102 return -EINVAL;
103
104 if (!head && !handle)
105 return -EINVAL;
106
107 if (head && handle != head->handle)
108 return -ENOENT;
109
110 new = kzalloc(sizeof(*head), GFP_KERNEL);
111 if (!new)
112 return -ENOBUFS;
113
114 err = tcf_exts_init(&new->exts, TCA_CGROUP_ACT, TCA_CGROUP_POLICE);
115 if (err < 0)
116 goto errout;
117 new->handle = handle;
118 new->tp = tp;
119 err = nla_parse_nested(tb, TCA_CGROUP_MAX, tca[TCA_OPTIONS],
120 cgroup_policy, NULL);
121 if (err < 0)
122 goto errout;
123
124 err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &new->exts, ovr);
125 if (err < 0)
126 goto errout;
127
128 err = tcf_em_tree_validate(tp, tb[TCA_CGROUP_EMATCHES], &new->ematches);
129 if (err < 0)
130 goto errout;
131
132 rcu_assign_pointer(tp->root, new);
133 if (head) {
134 tcf_exts_get_net(&head->exts);
135 call_rcu(&head->rcu, cls_cgroup_destroy_rcu);
136 }
137 return 0;
138errout:
139 tcf_exts_destroy(&new->exts);
140 kfree(new);
141 return err;
142}
143
144static void cls_cgroup_destroy(struct tcf_proto *tp)
145{
146 struct cls_cgroup_head *head = rtnl_dereference(tp->root);
147
148
149 if (head) {
150 if (tcf_exts_get_net(&head->exts))
151 call_rcu(&head->rcu, cls_cgroup_destroy_rcu);
152 else
153 __cls_cgroup_destroy(head);
154 }
155}
156
157static int cls_cgroup_delete(struct tcf_proto *tp, void *arg, bool *last)
158{
159 return -EOPNOTSUPP;
160}
161
162static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg)
163{
164 struct cls_cgroup_head *head = rtnl_dereference(tp->root);
165
166 if (arg->count < arg->skip)
167 goto skip;
168
169 if (arg->fn(tp, head, arg) < 0) {
170 arg->stop = 1;
171 return;
172 }
173skip:
174 arg->count++;
175}
176
177static int cls_cgroup_dump(struct net *net, struct tcf_proto *tp, void *fh,
178 struct sk_buff *skb, struct tcmsg *t)
179{
180 struct cls_cgroup_head *head = rtnl_dereference(tp->root);
181 struct nlattr *nest;
182
183 t->tcm_handle = head->handle;
184
185 nest = nla_nest_start(skb, TCA_OPTIONS);
186 if (nest == NULL)
187 goto nla_put_failure;
188
189 if (tcf_exts_dump(skb, &head->exts) < 0 ||
190 tcf_em_tree_dump(skb, &head->ematches, TCA_CGROUP_EMATCHES) < 0)
191 goto nla_put_failure;
192
193 nla_nest_end(skb, nest);
194
195 if (tcf_exts_dump_stats(skb, &head->exts) < 0)
196 goto nla_put_failure;
197
198 return skb->len;
199
200nla_put_failure:
201 nla_nest_cancel(skb, nest);
202 return -1;
203}
204
205static struct tcf_proto_ops cls_cgroup_ops __read_mostly = {
206 .kind = "cgroup",
207 .init = cls_cgroup_init,
208 .change = cls_cgroup_change,
209 .classify = cls_cgroup_classify,
210 .destroy = cls_cgroup_destroy,
211 .get = cls_cgroup_get,
212 .delete = cls_cgroup_delete,
213 .walk = cls_cgroup_walk,
214 .dump = cls_cgroup_dump,
215 .owner = THIS_MODULE,
216};
217
218static int __init init_cgroup_cls(void)
219{
220 return register_tcf_proto_ops(&cls_cgroup_ops);
221}
222
223static void __exit exit_cgroup_cls(void)
224{
225 unregister_tcf_proto_ops(&cls_cgroup_ops);
226}
227
228module_init(init_cgroup_cls);
229module_exit(exit_cgroup_cls);
230MODULE_LICENSE("GPL");
231
