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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 struct rcu_head rcu;
27};
28
29static int cls_cgroup_classify(struct sk_buff *skb, const struct tcf_proto *tp,
30 struct tcf_result *res)
31{
32 struct cls_cgroup_head *head = rcu_dereference_bh(tp->root);
33 u32 classid;
34
35 classid = task_cls_state(current)->classid;
36
37
38
39
40
41
42
43
44
45
46
47 if (in_serving_softirq()) {
48
49 if (!skb->sk)
50 return -1;
51 classid = skb->sk->sk_classid;
52 }
53
54 if (!classid)
55 return -1;
56
57 if (!tcf_em_tree_match(skb, &head->ematches, NULL))
58 return -1;
59
60 res->classid = classid;
61 res->class = 0;
62 return tcf_exts_exec(skb, &head->exts, res);
63}
64
65static unsigned long cls_cgroup_get(struct tcf_proto *tp, u32 handle)
66{
67 return 0UL;
68}
69
70static int cls_cgroup_init(struct tcf_proto *tp)
71{
72 return 0;
73}
74
75static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = {
76 [TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED },
77};
78
79static void cls_cgroup_destroy_rcu(struct rcu_head *root)
80{
81 struct cls_cgroup_head *head = container_of(root,
82 struct cls_cgroup_head,
83 rcu);
84
85 tcf_exts_destroy(&head->exts);
86 tcf_em_tree_destroy(&head->ematches);
87 kfree(head);
88}
89
90static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb,
91 struct tcf_proto *tp, unsigned long base,
92 u32 handle, struct nlattr **tca,
93 unsigned long *arg, bool ovr)
94{
95 struct nlattr *tb[TCA_CGROUP_MAX + 1];
96 struct cls_cgroup_head *head = rtnl_dereference(tp->root);
97 struct cls_cgroup_head *new;
98 struct tcf_ematch_tree t;
99 struct tcf_exts e;
100 int err;
101
102 if (!tca[TCA_OPTIONS])
103 return -EINVAL;
104
105 if (!head && !handle)
106 return -EINVAL;
107
108 if (head && handle != head->handle)
109 return -ENOENT;
110
111 new = kzalloc(sizeof(*head), GFP_KERNEL);
112 if (!new)
113 return -ENOBUFS;
114
115 tcf_exts_init(&new->exts, TCA_CGROUP_ACT, TCA_CGROUP_POLICE);
116 new->handle = handle;
117 new->tp = tp;
118 err = nla_parse_nested(tb, TCA_CGROUP_MAX, tca[TCA_OPTIONS],
119 cgroup_policy);
120 if (err < 0)
121 goto errout;
122
123 tcf_exts_init(&e, TCA_CGROUP_ACT, TCA_CGROUP_POLICE);
124 err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e, ovr);
125 if (err < 0)
126 goto errout;
127
128 err = tcf_em_tree_validate(tp, tb[TCA_CGROUP_EMATCHES], &t);
129 if (err < 0) {
130 tcf_exts_destroy(&e);
131 goto errout;
132 }
133
134 tcf_exts_change(tp, &new->exts, &e);
135 tcf_em_tree_change(tp, &new->ematches, &t);
136
137 rcu_assign_pointer(tp->root, new);
138 if (head)
139 call_rcu(&head->rcu, cls_cgroup_destroy_rcu);
140 return 0;
141errout:
142 kfree(new);
143 return err;
144}
145
146static bool cls_cgroup_destroy(struct tcf_proto *tp, bool force)
147{
148 struct cls_cgroup_head *head = rtnl_dereference(tp->root);
149
150 if (!force)
151 return false;
152
153 if (head) {
154 RCU_INIT_POINTER(tp->root, NULL);
155 call_rcu(&head->rcu, cls_cgroup_destroy_rcu);
156 }
157 return true;
158}
159
160static int cls_cgroup_delete(struct tcf_proto *tp, unsigned long arg)
161{
162 return -EOPNOTSUPP;
163}
164
165static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg)
166{
167 struct cls_cgroup_head *head = rtnl_dereference(tp->root);
168
169 if (arg->count < arg->skip)
170 goto skip;
171
172 if (arg->fn(tp, (unsigned long) head, arg) < 0) {
173 arg->stop = 1;
174 return;
175 }
176skip:
177 arg->count++;
178}
179
180static int cls_cgroup_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
181 struct sk_buff *skb, struct tcmsg *t)
182{
183 struct cls_cgroup_head *head = rtnl_dereference(tp->root);
184 struct nlattr *nest;
185
186 t->tcm_handle = head->handle;
187
188 nest = nla_nest_start(skb, TCA_OPTIONS);
189 if (nest == NULL)
190 goto nla_put_failure;
191
192 if (tcf_exts_dump(skb, &head->exts) < 0 ||
193 tcf_em_tree_dump(skb, &head->ematches, TCA_CGROUP_EMATCHES) < 0)
194 goto nla_put_failure;
195
196 nla_nest_end(skb, nest);
197
198 if (tcf_exts_dump_stats(skb, &head->exts) < 0)
199 goto nla_put_failure;
200
201 return skb->len;
202
203nla_put_failure:
204 nla_nest_cancel(skb, nest);
205 return -1;
206}
207
208static struct tcf_proto_ops cls_cgroup_ops __read_mostly = {
209 .kind = "cgroup",
210 .init = cls_cgroup_init,
211 .change = cls_cgroup_change,
212 .classify = cls_cgroup_classify,
213 .destroy = cls_cgroup_destroy,
214 .get = cls_cgroup_get,
215 .delete = cls_cgroup_delete,
216 .walk = cls_cgroup_walk,
217 .dump = cls_cgroup_dump,
218 .owner = THIS_MODULE,
219};
220
221static int __init init_cgroup_cls(void)
222{
223 return register_tcf_proto_ops(&cls_cgroup_ops);
224}
225
226static void __exit exit_cgroup_cls(void)
227{
228 unregister_tcf_proto_ops(&cls_cgroup_ops);
229}
230
231module_init(init_cgroup_cls);
232module_exit(exit_cgroup_cls);
233MODULE_LICENSE("GPL");
234
