Commit | Line | Data |
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f4009237 TG |
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> | |
5a0e3ad6 | 13 | #include <linux/slab.h> |
f4009237 | 14 | #include <linux/skbuff.h> |
f8451725 | 15 | #include <linux/rcupdate.h> |
f4009237 TG |
16 | #include <net/rtnetlink.h> |
17 | #include <net/pkt_cls.h> | |
f8451725 HX |
18 | #include <net/sock.h> |
19 | #include <net/cls_cgroup.h> | |
f4009237 | 20 | |
cc7ec456 | 21 | struct cls_cgroup_head { |
f4009237 TG |
22 | u32 handle; |
23 | struct tcf_exts exts; | |
24 | struct tcf_ematch_tree ematches; | |
25 | }; | |
26 | ||
dc7f9f6e | 27 | static int cls_cgroup_classify(struct sk_buff *skb, const struct tcf_proto *tp, |
f4009237 TG |
28 | struct tcf_result *res) |
29 | { | |
30 | struct cls_cgroup_head *head = tp->root; | |
e65fcfd6 | 31 | u32 classid; |
f4009237 | 32 | |
f8451725 HX |
33 | rcu_read_lock(); |
34 | classid = task_cls_state(current)->classid; | |
35 | rcu_read_unlock(); | |
36 | ||
f4009237 TG |
37 | /* |
38 | * Due to the nature of the classifier it is required to ignore all | |
39 | * packets originating from softirq context as accessing `current' | |
40 | * would lead to false results. | |
41 | * | |
42 | * This test assumes that all callers of dev_queue_xmit() explicitely | |
43 | * disable bh. Knowing this, it is possible to detect softirq based | |
44 | * calls by looking at the number of nested bh disable calls because | |
45 | * softirqs always disables bh. | |
46 | */ | |
75e1056f | 47 | if (in_serving_softirq()) { |
f8451725 HX |
48 | /* If there is an sk_classid we'll use that. */ |
49 | if (!skb->sk) | |
50 | return -1; | |
51 | classid = skb->sk->sk_classid; | |
52 | } | |
f4009237 | 53 | |
e65fcfd6 PM |
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); | |
f4009237 TG |
63 | } |
64 | ||
65 | static unsigned long cls_cgroup_get(struct tcf_proto *tp, u32 handle) | |
66 | { | |
67 | return 0UL; | |
68 | } | |
69 | ||
70 | static void cls_cgroup_put(struct tcf_proto *tp, unsigned long f) | |
71 | { | |
72 | } | |
73 | ||
74 | static int cls_cgroup_init(struct tcf_proto *tp) | |
75 | { | |
76 | return 0; | |
77 | } | |
78 | ||
f4009237 TG |
79 | static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = { |
80 | [TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED }, | |
81 | }; | |
82 | ||
c1b52739 | 83 | static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb, |
af4c6641 | 84 | struct tcf_proto *tp, unsigned long base, |
f4009237 | 85 | u32 handle, struct nlattr **tca, |
2f7ef2f8 | 86 | unsigned long *arg, bool ovr) |
f4009237 | 87 | { |
cc7ec456 | 88 | struct nlattr *tb[TCA_CGROUP_MAX + 1]; |
f4009237 TG |
89 | struct cls_cgroup_head *head = tp->root; |
90 | struct tcf_ematch_tree t; | |
91 | struct tcf_exts e; | |
92 | int err; | |
93 | ||
52ea3a56 MU |
94 | if (!tca[TCA_OPTIONS]) |
95 | return -EINVAL; | |
96 | ||
f4009237 TG |
97 | if (head == NULL) { |
98 | if (!handle) | |
99 | return -EINVAL; | |
100 | ||
101 | head = kzalloc(sizeof(*head), GFP_KERNEL); | |
102 | if (head == NULL) | |
103 | return -ENOBUFS; | |
104 | ||
5da57f42 | 105 | tcf_exts_init(&head->exts, TCA_CGROUP_ACT, TCA_CGROUP_POLICE); |
f4009237 TG |
106 | head->handle = handle; |
107 | ||
108 | tcf_tree_lock(tp); | |
109 | tp->root = head; | |
110 | tcf_tree_unlock(tp); | |
111 | } | |
112 | ||
113 | if (handle != head->handle) | |
114 | return -ENOENT; | |
115 | ||
116 | err = nla_parse_nested(tb, TCA_CGROUP_MAX, tca[TCA_OPTIONS], | |
117 | cgroup_policy); | |
118 | if (err < 0) | |
119 | return err; | |
120 | ||
5da57f42 | 121 | tcf_exts_init(&e, TCA_CGROUP_ACT, TCA_CGROUP_POLICE); |
2f7ef2f8 | 122 | err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e, ovr); |
f4009237 TG |
123 | if (err < 0) |
124 | return err; | |
125 | ||
126 | err = tcf_em_tree_validate(tp, tb[TCA_CGROUP_EMATCHES], &t); | |
127 | if (err < 0) | |
128 | return err; | |
129 | ||
130 | tcf_exts_change(tp, &head->exts, &e); | |
131 | tcf_em_tree_change(tp, &head->ematches, &t); | |
132 | ||
133 | return 0; | |
134 | } | |
135 | ||
136 | static void cls_cgroup_destroy(struct tcf_proto *tp) | |
137 | { | |
47a1a1d4 | 138 | struct cls_cgroup_head *head = tp->root; |
f4009237 TG |
139 | |
140 | if (head) { | |
141 | tcf_exts_destroy(tp, &head->exts); | |
142 | tcf_em_tree_destroy(tp, &head->ematches); | |
143 | kfree(head); | |
144 | } | |
145 | } | |
146 | ||
147 | static int cls_cgroup_delete(struct tcf_proto *tp, unsigned long arg) | |
148 | { | |
149 | return -EOPNOTSUPP; | |
150 | } | |
151 | ||
152 | static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg) | |
153 | { | |
154 | struct cls_cgroup_head *head = tp->root; | |
155 | ||
156 | if (arg->count < arg->skip) | |
157 | goto skip; | |
158 | ||
159 | if (arg->fn(tp, (unsigned long) head, arg) < 0) { | |
160 | arg->stop = 1; | |
161 | return; | |
162 | } | |
163 | skip: | |
164 | arg->count++; | |
165 | } | |
166 | ||
832d1d5b | 167 | static int cls_cgroup_dump(struct net *net, struct tcf_proto *tp, unsigned long fh, |
f4009237 TG |
168 | struct sk_buff *skb, struct tcmsg *t) |
169 | { | |
170 | struct cls_cgroup_head *head = tp->root; | |
171 | unsigned char *b = skb_tail_pointer(skb); | |
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 | ||
5da57f42 | 180 | if (tcf_exts_dump(skb, &head->exts) < 0 || |
f4009237 TG |
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 | ||
5da57f42 | 186 | if (tcf_exts_dump_stats(skb, &head->exts) < 0) |
f4009237 TG |
187 | goto nla_put_failure; |
188 | ||
189 | return skb->len; | |
190 | ||
191 | nla_put_failure: | |
192 | nlmsg_trim(skb, b); | |
193 | return -1; | |
194 | } | |
195 | ||
196 | static 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 | .put = cls_cgroup_put, | |
204 | .delete = cls_cgroup_delete, | |
205 | .walk = cls_cgroup_walk, | |
206 | .dump = cls_cgroup_dump, | |
207 | .owner = THIS_MODULE, | |
208 | }; | |
209 | ||
210 | static int __init init_cgroup_cls(void) | |
211 | { | |
fe1217c4 | 212 | return register_tcf_proto_ops(&cls_cgroup_ops); |
f4009237 TG |
213 | } |
214 | ||
215 | static void __exit exit_cgroup_cls(void) | |
216 | { | |
217 | unregister_tcf_proto_ops(&cls_cgroup_ops); | |
218 | } | |
219 | ||
220 | module_init(init_cgroup_cls); | |
221 | module_exit(exit_cgroup_cls); | |
222 | MODULE_LICENSE("GPL"); |