tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
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_work rwork;
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 = 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
46static void *cls_cgroup_get(struct tcf_proto *tp, u32 handle)
47{
48 return NULL;
49}
50
51static int cls_cgroup_init(struct tcf_proto *tp)
52{
53 return 0;
54}
55
56static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = {
57 [TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED },
58};
59
60static void __cls_cgroup_destroy(struct cls_cgroup_head *head)
61{
62 tcf_exts_destroy(&head->exts);
63 tcf_em_tree_destroy(&head->ematches);
64 tcf_exts_put_net(&head->exts);
65 kfree(head);
66}
67
68static void cls_cgroup_destroy_work(struct work_struct *work)
69{
70 struct cls_cgroup_head *head = container_of(to_rcu_work(work),
71 struct cls_cgroup_head,
72 rwork);
73 rtnl_lock();
74 __cls_cgroup_destroy(head);
75 rtnl_unlock();
76}
77
78static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb,
79 struct tcf_proto *tp, unsigned long base,
80 u32 handle, struct nlattr **tca,
81 void **arg, bool ovr,
82 struct netlink_ext_ack *extack)
83{
84 struct nlattr *tb[TCA_CGROUP_MAX + 1];
85 struct cls_cgroup_head *head = rtnl_dereference(tp->root);
86 struct cls_cgroup_head *new;
87 int err;
88
89 if (!tca[TCA_OPTIONS])
90 return -EINVAL;
91
92 if (!head && !handle)
93 return -EINVAL;
94
95 if (head && handle != head->handle)
96 return -ENOENT;
97
98 new = kzalloc(sizeof(*head), GFP_KERNEL);
99 if (!new)
100 return -ENOBUFS;
101
102 err = tcf_exts_init(&new->exts, TCA_CGROUP_ACT, TCA_CGROUP_POLICE);
103 if (err < 0)
104 goto errout;
105 new->handle = handle;
106 new->tp = tp;
107 err = nla_parse_nested(tb, TCA_CGROUP_MAX, tca[TCA_OPTIONS],
108 cgroup_policy, NULL);
109 if (err < 0)
110 goto errout;
111
112 err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &new->exts, ovr,
113 extack);
114 if (err < 0)
115 goto errout;
116
117 err = tcf_em_tree_validate(tp, tb[TCA_CGROUP_EMATCHES], &new->ematches);
118 if (err < 0)
119 goto errout;
120
121 rcu_assign_pointer(tp->root, new);
122 if (head) {
123 tcf_exts_get_net(&head->exts);
124 tcf_queue_work(&head->rwork, cls_cgroup_destroy_work);
125 }
126 return 0;
127errout:
128 tcf_exts_destroy(&new->exts);
129 kfree(new);
130 return err;
131}
132
133static void cls_cgroup_destroy(struct tcf_proto *tp,
134 struct netlink_ext_ack *extack)
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 if (tcf_exts_get_net(&head->exts))
141 tcf_queue_work(&head->rwork, cls_cgroup_destroy_work);
142 else
143 __cls_cgroup_destroy(head);
144 }
145}
146
147static int cls_cgroup_delete(struct tcf_proto *tp, void *arg, bool *last,
148 struct netlink_ext_ack *extack)
149{
150 return -EOPNOTSUPP;
151}
152
153static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg)
154{
155 struct cls_cgroup_head *head = rtnl_dereference(tp->root);
156
157 if (arg->count < arg->skip)
158 goto skip;
159
160 if (arg->fn(tp, head, arg) < 0) {
161 arg->stop = 1;
162 return;
163 }
164skip:
165 arg->count++;
166}
167
168static int cls_cgroup_dump(struct net *net, struct tcf_proto *tp, void *fh,
169 struct sk_buff *skb, struct tcmsg *t)
170{
171 struct cls_cgroup_head *head = rtnl_dereference(tp->root);
172 struct nlattr *nest;
173
174 t->tcm_handle = head->handle;
175
176 nest = nla_nest_start(skb, TCA_OPTIONS);
177 if (nest == NULL)
178 goto nla_put_failure;
179
180 if (tcf_exts_dump(skb, &head->exts) < 0 ||
181 tcf_em_tree_dump(skb, &head->ematches, TCA_CGROUP_EMATCHES) < 0)
182 goto nla_put_failure;
183
184 nla_nest_end(skb, nest);
185
186 if (tcf_exts_dump_stats(skb, &head->exts) < 0)
187 goto nla_put_failure;
188
189 return skb->len;
190
191nla_put_failure:
192 nla_nest_cancel(skb, nest);
193 return -1;
194}
195
196static struct tcf_proto_ops cls_cgroup_ops __read_mostly = {
197 .kind = "cgroup",
198 .init = cls_cgroup_init,
199 .change = cls_cgroup_change,
200 .classify = cls_cgroup_classify,
201 .destroy = cls_cgroup_destroy,
202 .get = cls_cgroup_get,
203 .delete = cls_cgroup_delete,
204 .walk = cls_cgroup_walk,
205 .dump = cls_cgroup_dump,
206 .owner = THIS_MODULE,
207};
208
209static int __init init_cgroup_cls(void)
210{
211 return register_tcf_proto_ops(&cls_cgroup_ops);
212}
213
214static void __exit exit_cgroup_cls(void)
215{
216 unregister_tcf_proto_ops(&cls_cgroup_ops);
217}
218
219module_init(init_cgroup_cls);
220module_exit(exit_cgroup_cls);
221MODULE_LICENSE("GPL");