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 TG |
14 | #include <linux/types.h> |
15 | #include <linux/string.h> | |
16 | #include <linux/errno.h> | |
17 | #include <linux/skbuff.h> | |
18 | #include <linux/cgroup.h> | |
f8451725 | 19 | #include <linux/rcupdate.h> |
f4009237 TG |
20 | #include <net/rtnetlink.h> |
21 | #include <net/pkt_cls.h> | |
f8451725 HX |
22 | #include <net/sock.h> |
23 | #include <net/cls_cgroup.h> | |
f4009237 | 24 | |
8e8ba854 | 25 | static inline struct cgroup_cls_state *cgrp_cls_state(struct cgroup *cgrp) |
f4009237 | 26 | { |
8e8ba854 LZ |
27 | return container_of(cgroup_subsys_state(cgrp, net_cls_subsys_id), |
28 | struct cgroup_cls_state, css); | |
29 | } | |
30 | ||
31 | static inline struct cgroup_cls_state *task_cls_state(struct task_struct *p) | |
32 | { | |
33 | return container_of(task_subsys_state(p, net_cls_subsys_id), | |
34 | struct cgroup_cls_state, css); | |
f4009237 TG |
35 | } |
36 | ||
761b3ef5 | 37 | static struct cgroup_subsys_state *cgrp_create(struct cgroup *cgrp) |
f4009237 TG |
38 | { |
39 | struct cgroup_cls_state *cs; | |
40 | ||
cc7ec456 ED |
41 | cs = kzalloc(sizeof(*cs), GFP_KERNEL); |
42 | if (!cs) | |
f4009237 TG |
43 | return ERR_PTR(-ENOMEM); |
44 | ||
45 | if (cgrp->parent) | |
8e8ba854 | 46 | cs->classid = cgrp_cls_state(cgrp->parent)->classid; |
f4009237 TG |
47 | |
48 | return &cs->css; | |
49 | } | |
50 | ||
761b3ef5 | 51 | static void cgrp_destroy(struct cgroup *cgrp) |
f4009237 | 52 | { |
8e8ba854 | 53 | kfree(cgrp_cls_state(cgrp)); |
f4009237 TG |
54 | } |
55 | ||
56 | static u64 read_classid(struct cgroup *cgrp, struct cftype *cft) | |
57 | { | |
8e8ba854 | 58 | return cgrp_cls_state(cgrp)->classid; |
f4009237 TG |
59 | } |
60 | ||
61 | static int write_classid(struct cgroup *cgrp, struct cftype *cft, u64 value) | |
62 | { | |
8e8ba854 | 63 | cgrp_cls_state(cgrp)->classid = (u32) value; |
f4009237 TG |
64 | return 0; |
65 | } | |
66 | ||
67 | static struct cftype ss_files[] = { | |
68 | { | |
69 | .name = "classid", | |
70 | .read_u64 = read_classid, | |
71 | .write_u64 = write_classid, | |
72 | }, | |
4baf6e33 | 73 | { } /* terminate */ |
f4009237 TG |
74 | }; |
75 | ||
676f7c8f TH |
76 | struct cgroup_subsys net_cls_subsys = { |
77 | .name = "net_cls", | |
78 | .create = cgrp_create, | |
79 | .destroy = cgrp_destroy, | |
676f7c8f | 80 | .subsys_id = net_cls_subsys_id, |
4baf6e33 | 81 | .base_cftypes = ss_files, |
676f7c8f | 82 | .module = THIS_MODULE, |
8c7f6edb TH |
83 | |
84 | /* | |
85 | * While net_cls cgroup has the rudimentary hierarchy support of | |
86 | * inheriting the parent's classid on cgroup creation, it doesn't | |
87 | * properly propagates config changes in ancestors to their | |
88 | * descendents. A child should follow the parent's configuration | |
89 | * but be allowed to override it. Fix it and remove the following. | |
90 | */ | |
91 | .broken_hierarchy = true, | |
676f7c8f TH |
92 | }; |
93 | ||
cc7ec456 | 94 | struct cls_cgroup_head { |
f4009237 TG |
95 | u32 handle; |
96 | struct tcf_exts exts; | |
97 | struct tcf_ematch_tree ematches; | |
98 | }; | |
99 | ||
dc7f9f6e | 100 | static int cls_cgroup_classify(struct sk_buff *skb, const struct tcf_proto *tp, |
f4009237 TG |
101 | struct tcf_result *res) |
102 | { | |
103 | struct cls_cgroup_head *head = tp->root; | |
e65fcfd6 | 104 | u32 classid; |
f4009237 | 105 | |
f8451725 HX |
106 | rcu_read_lock(); |
107 | classid = task_cls_state(current)->classid; | |
108 | rcu_read_unlock(); | |
109 | ||
f4009237 TG |
110 | /* |
111 | * Due to the nature of the classifier it is required to ignore all | |
112 | * packets originating from softirq context as accessing `current' | |
113 | * would lead to false results. | |
114 | * | |
115 | * This test assumes that all callers of dev_queue_xmit() explicitely | |
116 | * disable bh. Knowing this, it is possible to detect softirq based | |
117 | * calls by looking at the number of nested bh disable calls because | |
118 | * softirqs always disables bh. | |
119 | */ | |
75e1056f | 120 | if (in_serving_softirq()) { |
f8451725 HX |
121 | /* If there is an sk_classid we'll use that. */ |
122 | if (!skb->sk) | |
123 | return -1; | |
124 | classid = skb->sk->sk_classid; | |
125 | } | |
f4009237 | 126 | |
e65fcfd6 PM |
127 | if (!classid) |
128 | return -1; | |
129 | ||
130 | if (!tcf_em_tree_match(skb, &head->ematches, NULL)) | |
131 | return -1; | |
132 | ||
133 | res->classid = classid; | |
134 | res->class = 0; | |
135 | return tcf_exts_exec(skb, &head->exts, res); | |
f4009237 TG |
136 | } |
137 | ||
138 | static unsigned long cls_cgroup_get(struct tcf_proto *tp, u32 handle) | |
139 | { | |
140 | return 0UL; | |
141 | } | |
142 | ||
143 | static void cls_cgroup_put(struct tcf_proto *tp, unsigned long f) | |
144 | { | |
145 | } | |
146 | ||
147 | static int cls_cgroup_init(struct tcf_proto *tp) | |
148 | { | |
149 | return 0; | |
150 | } | |
151 | ||
152 | static const struct tcf_ext_map cgroup_ext_map = { | |
153 | .action = TCA_CGROUP_ACT, | |
154 | .police = TCA_CGROUP_POLICE, | |
155 | }; | |
156 | ||
157 | static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = { | |
158 | [TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED }, | |
159 | }; | |
160 | ||
af4c6641 EB |
161 | static int cls_cgroup_change(struct sk_buff *in_skb, |
162 | struct tcf_proto *tp, unsigned long base, | |
f4009237 TG |
163 | u32 handle, struct nlattr **tca, |
164 | unsigned long *arg) | |
165 | { | |
cc7ec456 | 166 | struct nlattr *tb[TCA_CGROUP_MAX + 1]; |
f4009237 TG |
167 | struct cls_cgroup_head *head = tp->root; |
168 | struct tcf_ematch_tree t; | |
169 | struct tcf_exts e; | |
170 | int err; | |
171 | ||
52ea3a56 MU |
172 | if (!tca[TCA_OPTIONS]) |
173 | return -EINVAL; | |
174 | ||
f4009237 TG |
175 | if (head == NULL) { |
176 | if (!handle) | |
177 | return -EINVAL; | |
178 | ||
179 | head = kzalloc(sizeof(*head), GFP_KERNEL); | |
180 | if (head == NULL) | |
181 | return -ENOBUFS; | |
182 | ||
183 | head->handle = handle; | |
184 | ||
185 | tcf_tree_lock(tp); | |
186 | tp->root = head; | |
187 | tcf_tree_unlock(tp); | |
188 | } | |
189 | ||
190 | if (handle != head->handle) | |
191 | return -ENOENT; | |
192 | ||
193 | err = nla_parse_nested(tb, TCA_CGROUP_MAX, tca[TCA_OPTIONS], | |
194 | cgroup_policy); | |
195 | if (err < 0) | |
196 | return err; | |
197 | ||
198 | err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &cgroup_ext_map); | |
199 | if (err < 0) | |
200 | return err; | |
201 | ||
202 | err = tcf_em_tree_validate(tp, tb[TCA_CGROUP_EMATCHES], &t); | |
203 | if (err < 0) | |
204 | return err; | |
205 | ||
206 | tcf_exts_change(tp, &head->exts, &e); | |
207 | tcf_em_tree_change(tp, &head->ematches, &t); | |
208 | ||
209 | return 0; | |
210 | } | |
211 | ||
212 | static void cls_cgroup_destroy(struct tcf_proto *tp) | |
213 | { | |
47a1a1d4 | 214 | struct cls_cgroup_head *head = tp->root; |
f4009237 TG |
215 | |
216 | if (head) { | |
217 | tcf_exts_destroy(tp, &head->exts); | |
218 | tcf_em_tree_destroy(tp, &head->ematches); | |
219 | kfree(head); | |
220 | } | |
221 | } | |
222 | ||
223 | static int cls_cgroup_delete(struct tcf_proto *tp, unsigned long arg) | |
224 | { | |
225 | return -EOPNOTSUPP; | |
226 | } | |
227 | ||
228 | static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg) | |
229 | { | |
230 | struct cls_cgroup_head *head = tp->root; | |
231 | ||
232 | if (arg->count < arg->skip) | |
233 | goto skip; | |
234 | ||
235 | if (arg->fn(tp, (unsigned long) head, arg) < 0) { | |
236 | arg->stop = 1; | |
237 | return; | |
238 | } | |
239 | skip: | |
240 | arg->count++; | |
241 | } | |
242 | ||
243 | static int cls_cgroup_dump(struct tcf_proto *tp, unsigned long fh, | |
244 | struct sk_buff *skb, struct tcmsg *t) | |
245 | { | |
246 | struct cls_cgroup_head *head = tp->root; | |
247 | unsigned char *b = skb_tail_pointer(skb); | |
248 | struct nlattr *nest; | |
249 | ||
250 | t->tcm_handle = head->handle; | |
251 | ||
252 | nest = nla_nest_start(skb, TCA_OPTIONS); | |
253 | if (nest == NULL) | |
254 | goto nla_put_failure; | |
255 | ||
256 | if (tcf_exts_dump(skb, &head->exts, &cgroup_ext_map) < 0 || | |
257 | tcf_em_tree_dump(skb, &head->ematches, TCA_CGROUP_EMATCHES) < 0) | |
258 | goto nla_put_failure; | |
259 | ||
260 | nla_nest_end(skb, nest); | |
261 | ||
262 | if (tcf_exts_dump_stats(skb, &head->exts, &cgroup_ext_map) < 0) | |
263 | goto nla_put_failure; | |
264 | ||
265 | return skb->len; | |
266 | ||
267 | nla_put_failure: | |
268 | nlmsg_trim(skb, b); | |
269 | return -1; | |
270 | } | |
271 | ||
272 | static struct tcf_proto_ops cls_cgroup_ops __read_mostly = { | |
273 | .kind = "cgroup", | |
274 | .init = cls_cgroup_init, | |
275 | .change = cls_cgroup_change, | |
276 | .classify = cls_cgroup_classify, | |
277 | .destroy = cls_cgroup_destroy, | |
278 | .get = cls_cgroup_get, | |
279 | .put = cls_cgroup_put, | |
280 | .delete = cls_cgroup_delete, | |
281 | .walk = cls_cgroup_walk, | |
282 | .dump = cls_cgroup_dump, | |
283 | .owner = THIS_MODULE, | |
284 | }; | |
285 | ||
286 | static int __init init_cgroup_cls(void) | |
287 | { | |
f8451725 HX |
288 | int ret; |
289 | ||
8e039d84 BB |
290 | ret = cgroup_load_subsys(&net_cls_subsys); |
291 | if (ret) | |
f8451725 HX |
292 | goto out; |
293 | ||
f8451725 HX |
294 | ret = register_tcf_proto_ops(&cls_cgroup_ops); |
295 | if (ret) | |
296 | cgroup_unload_subsys(&net_cls_subsys); | |
297 | ||
298 | out: | |
8e039d84 | 299 | return ret; |
f4009237 TG |
300 | } |
301 | ||
302 | static void __exit exit_cgroup_cls(void) | |
303 | { | |
304 | unregister_tcf_proto_ops(&cls_cgroup_ops); | |
f8451725 | 305 | |
8e039d84 | 306 | cgroup_unload_subsys(&net_cls_subsys); |
f4009237 TG |
307 | } |
308 | ||
309 | module_init(init_cgroup_cls); | |
310 | module_exit(exit_cgroup_cls); | |
311 | MODULE_LICENSE("GPL"); |