1 /*
2 * net/sched/cls_cgroup.c Control Group Classifier
3 *
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.
8 *
9 * Authors: Thomas Graf <tgraf@suug.ch>
10 */
11
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
21 struct 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
29 static 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 = task_get_classid(skb);
34
35 if (!classid)
36 return -1;
37 if (!tcf_em_tree_match(skb, &head->ematches, NULL))
38 return -1;
39
40 res->classid = classid;
41 res->class = 0;
42
43 return tcf_exts_exec(skb, &head->exts, res);
44 }
45
46 static unsigned long cls_cgroup_get(struct tcf_proto *tp, u32 handle)
47 {
48 return 0UL;
49 }
50
51 static int cls_cgroup_init(struct tcf_proto *tp)
52 {
53 return 0;
54 }
55
56 static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = {
57 [TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED },
58 };
59
60 static void cls_cgroup_destroy_rcu(struct rcu_head *root)
61 {
62 struct cls_cgroup_head *head = container_of(root,
63 struct cls_cgroup_head,
64 rcu);
65
66 tcf_exts_destroy(&head->exts);
67 tcf_em_tree_destroy(&head->ematches);
68 kfree(head);
69 }
70
71 static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb,
72 struct tcf_proto *tp, unsigned long base,
73 u32 handle, struct nlattr **tca,
74 unsigned long *arg, bool ovr)
75 {
76 struct nlattr *tb[TCA_CGROUP_MAX + 1];
77 struct cls_cgroup_head *head = rtnl_dereference(tp->root);
78 struct cls_cgroup_head *new;
79 struct tcf_ematch_tree t;
80 struct tcf_exts e;
81 int err;
82
83 if (!tca[TCA_OPTIONS])
84 return -EINVAL;
85
86 if (!head && !handle)
87 return -EINVAL;
88
89 if (head && handle != head->handle)
90 return -ENOENT;
91
92 new = kzalloc(sizeof(*head), GFP_KERNEL);
93 if (!new)
94 return -ENOBUFS;
95
96 err = tcf_exts_init(&new->exts, TCA_CGROUP_ACT, TCA_CGROUP_POLICE);
97 if (err < 0)
98 goto errout;
99 new->handle = handle;
100 new->tp = tp;
101 err = nla_parse_nested(tb, TCA_CGROUP_MAX, tca[TCA_OPTIONS],
102 cgroup_policy, NULL);
103 if (err < 0)
104 goto errout;
105
106 err = tcf_exts_init(&e, TCA_CGROUP_ACT, TCA_CGROUP_POLICE);
107 if (err < 0)
108 goto errout;
109 err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e, ovr);
110 if (err < 0) {
111 tcf_exts_destroy(&e);
112 goto errout;
113 }
114
115 err = tcf_em_tree_validate(tp, tb[TCA_CGROUP_EMATCHES], &t);
116 if (err < 0) {
117 tcf_exts_destroy(&e);
118 goto errout;
119 }
120
121 tcf_exts_change(tp, &new->exts, &e);
122 tcf_em_tree_change(tp, &new->ematches, &t);
123
124 rcu_assign_pointer(tp->root, new);
125 if (head)
126 call_rcu(&head->rcu, cls_cgroup_destroy_rcu);
127 return 0;
128 errout:
129 tcf_exts_destroy(&new->exts);
130 kfree(new);
131 return err;
132 }
133
134 static void cls_cgroup_destroy(struct tcf_proto *tp)
135 {
136 struct cls_cgroup_head *head = rtnl_dereference(tp->root);
137
138 /* Head can still be NULL due to cls_cgroup_init(). */
139 if (head)
140 call_rcu(&head->rcu, cls_cgroup_destroy_rcu);
141 }
142
143 static int cls_cgroup_delete(struct tcf_proto *tp, unsigned long arg, bool *last)
144 {
145 return -EOPNOTSUPP;
146 }
147
148 static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg)
149 {
150 struct cls_cgroup_head *head = rtnl_dereference(tp->root);
151
152 if (arg->count < arg->skip)
153 goto skip;
154
155 if (arg->fn(tp, (unsigned long) head, arg) < 0) {
156 arg->stop = 1;
157 return;
158 }
159 skip:
160 arg->count++;
161 }
162
163 static int cls_cgroup_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
164 struct sk_buff *skb, struct tcmsg *t)
165 {
166 struct cls_cgroup_head *head = rtnl_dereference(tp->root);
167 struct nlattr *nest;
168
169 t->tcm_handle = head->handle;
170
171 nest = nla_nest_start(skb, TCA_OPTIONS);
172 if (nest == NULL)
173 goto nla_put_failure;
174
175 if (tcf_exts_dump(skb, &head->exts) < 0 ||
176 tcf_em_tree_dump(skb, &head->ematches, TCA_CGROUP_EMATCHES) < 0)
177 goto nla_put_failure;
178
179 nla_nest_end(skb, nest);
180
181 if (tcf_exts_dump_stats(skb, &head->exts) < 0)
182 goto nla_put_failure;
183
184 return skb->len;
185
186 nla_put_failure:
187 nla_nest_cancel(skb, nest);
188 return -1;
189 }
190
191 static struct tcf_proto_ops cls_cgroup_ops __read_mostly = {
192 .kind = "cgroup",
193 .init = cls_cgroup_init,
194 .change = cls_cgroup_change,
195 .classify = cls_cgroup_classify,
196 .destroy = cls_cgroup_destroy,
197 .get = cls_cgroup_get,
198 .delete = cls_cgroup_delete,
199 .walk = cls_cgroup_walk,
200 .dump = cls_cgroup_dump,
201 .owner = THIS_MODULE,
202 };
203
204 static int __init init_cgroup_cls(void)
205 {
206 return register_tcf_proto_ops(&cls_cgroup_ops);
207 }
208
209 static void __exit exit_cgroup_cls(void)
210 {
211 unregister_tcf_proto_ops(&cls_cgroup_ops);
212 }
213
214 module_init(init_cgroup_cls);
215 module_exit(exit_cgroup_cls);
216 MODULE_LICENSE("GPL");
217
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