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> |
6a328d8c | 20 | #include <linux/fdtable.h> |
f4009237 TG |
21 | #include <net/rtnetlink.h> |
22 | #include <net/pkt_cls.h> | |
f8451725 HX |
23 | #include <net/sock.h> |
24 | #include <net/cls_cgroup.h> | |
f4009237 | 25 | |
a7c6d554 TH |
26 | static inline struct cgroup_cls_state *css_cls_state(struct cgroup_subsys_state *css) |
27 | { | |
28 | return css ? container_of(css, struct cgroup_cls_state, css) : NULL; | |
29 | } | |
30 | ||
8e8ba854 LZ |
31 | static inline struct cgroup_cls_state *task_cls_state(struct task_struct *p) |
32 | { | |
a7c6d554 | 33 | return css_cls_state(task_css(p, net_cls_subsys_id)); |
f4009237 TG |
34 | } |
35 | ||
eb95419b TH |
36 | static struct cgroup_subsys_state * |
37 | cgrp_css_alloc(struct cgroup_subsys_state *parent_css) | |
f4009237 TG |
38 | { |
39 | struct cgroup_cls_state *cs; | |
40 | ||
cc7ec456 ED |
41 | cs = kzalloc(sizeof(*cs), GFP_KERNEL); |
42 | if (!cs) | |
f4009237 | 43 | return ERR_PTR(-ENOMEM); |
0ba18f7a TH |
44 | return &cs->css; |
45 | } | |
f4009237 | 46 | |
eb95419b | 47 | static int cgrp_css_online(struct cgroup_subsys_state *css) |
0ba18f7a | 48 | { |
eb95419b TH |
49 | struct cgroup_cls_state *cs = css_cls_state(css); |
50 | struct cgroup_cls_state *parent = css_cls_state(css_parent(css)); | |
63876986 TH |
51 | |
52 | if (parent) | |
53 | cs->classid = parent->classid; | |
0ba18f7a | 54 | return 0; |
f4009237 TG |
55 | } |
56 | ||
eb95419b | 57 | static void cgrp_css_free(struct cgroup_subsys_state *css) |
f4009237 | 58 | { |
eb95419b | 59 | kfree(css_cls_state(css)); |
f4009237 TG |
60 | } |
61 | ||
6a328d8c DW |
62 | static int update_classid(const void *v, struct file *file, unsigned n) |
63 | { | |
64 | int err; | |
65 | struct socket *sock = sock_from_file(file, &err); | |
66 | if (sock) | |
67 | sock->sk->sk_classid = (u32)(unsigned long)v; | |
68 | return 0; | |
69 | } | |
70 | ||
eb95419b TH |
71 | static void cgrp_attach(struct cgroup_subsys_state *css, |
72 | struct cgroup_taskset *tset) | |
6a328d8c DW |
73 | { |
74 | struct task_struct *p; | |
ff0bfad6 G |
75 | struct cgroup_cls_state *cs = css_cls_state(css); |
76 | void *v = (void *)(unsigned long)cs->classid; | |
6a328d8c | 77 | |
d99c8727 | 78 | cgroup_taskset_for_each(p, css, tset) { |
6a328d8c | 79 | task_lock(p); |
6a328d8c DW |
80 | iterate_fd(p->files, 0, update_classid, v); |
81 | task_unlock(p); | |
82 | } | |
83 | } | |
84 | ||
182446d0 | 85 | static u64 read_classid(struct cgroup_subsys_state *css, struct cftype *cft) |
f4009237 | 86 | { |
182446d0 | 87 | return css_cls_state(css)->classid; |
f4009237 TG |
88 | } |
89 | ||
182446d0 TH |
90 | static int write_classid(struct cgroup_subsys_state *css, struct cftype *cft, |
91 | u64 value) | |
f4009237 | 92 | { |
182446d0 | 93 | css_cls_state(css)->classid = (u32) value; |
f4009237 TG |
94 | return 0; |
95 | } | |
96 | ||
97 | static struct cftype ss_files[] = { | |
98 | { | |
99 | .name = "classid", | |
100 | .read_u64 = read_classid, | |
101 | .write_u64 = write_classid, | |
102 | }, | |
4baf6e33 | 103 | { } /* terminate */ |
f4009237 TG |
104 | }; |
105 | ||
676f7c8f TH |
106 | struct cgroup_subsys net_cls_subsys = { |
107 | .name = "net_cls", | |
92fb9748 | 108 | .css_alloc = cgrp_css_alloc, |
0ba18f7a | 109 | .css_online = cgrp_css_online, |
92fb9748 | 110 | .css_free = cgrp_css_free, |
6a328d8c | 111 | .attach = cgrp_attach, |
676f7c8f | 112 | .subsys_id = net_cls_subsys_id, |
4baf6e33 | 113 | .base_cftypes = ss_files, |
676f7c8f TH |
114 | .module = THIS_MODULE, |
115 | }; | |
116 | ||
cc7ec456 | 117 | struct cls_cgroup_head { |
f4009237 TG |
118 | u32 handle; |
119 | struct tcf_exts exts; | |
120 | struct tcf_ematch_tree ematches; | |
121 | }; | |
122 | ||
dc7f9f6e | 123 | static int cls_cgroup_classify(struct sk_buff *skb, const struct tcf_proto *tp, |
f4009237 TG |
124 | struct tcf_result *res) |
125 | { | |
126 | struct cls_cgroup_head *head = tp->root; | |
e65fcfd6 | 127 | u32 classid; |
f4009237 | 128 | |
f8451725 HX |
129 | rcu_read_lock(); |
130 | classid = task_cls_state(current)->classid; | |
131 | rcu_read_unlock(); | |
132 | ||
f4009237 TG |
133 | /* |
134 | * Due to the nature of the classifier it is required to ignore all | |
135 | * packets originating from softirq context as accessing `current' | |
136 | * would lead to false results. | |
137 | * | |
138 | * This test assumes that all callers of dev_queue_xmit() explicitely | |
139 | * disable bh. Knowing this, it is possible to detect softirq based | |
140 | * calls by looking at the number of nested bh disable calls because | |
141 | * softirqs always disables bh. | |
142 | */ | |
75e1056f | 143 | if (in_serving_softirq()) { |
f8451725 HX |
144 | /* If there is an sk_classid we'll use that. */ |
145 | if (!skb->sk) | |
146 | return -1; | |
147 | classid = skb->sk->sk_classid; | |
148 | } | |
f4009237 | 149 | |
e65fcfd6 PM |
150 | if (!classid) |
151 | return -1; | |
152 | ||
153 | if (!tcf_em_tree_match(skb, &head->ematches, NULL)) | |
154 | return -1; | |
155 | ||
156 | res->classid = classid; | |
157 | res->class = 0; | |
158 | return tcf_exts_exec(skb, &head->exts, res); | |
f4009237 TG |
159 | } |
160 | ||
161 | static unsigned long cls_cgroup_get(struct tcf_proto *tp, u32 handle) | |
162 | { | |
163 | return 0UL; | |
164 | } | |
165 | ||
166 | static void cls_cgroup_put(struct tcf_proto *tp, unsigned long f) | |
167 | { | |
168 | } | |
169 | ||
170 | static int cls_cgroup_init(struct tcf_proto *tp) | |
171 | { | |
172 | return 0; | |
173 | } | |
174 | ||
f4009237 TG |
175 | static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = { |
176 | [TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED }, | |
177 | }; | |
178 | ||
c1b52739 | 179 | static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb, |
af4c6641 | 180 | struct tcf_proto *tp, unsigned long base, |
f4009237 TG |
181 | u32 handle, struct nlattr **tca, |
182 | unsigned long *arg) | |
183 | { | |
cc7ec456 | 184 | struct nlattr *tb[TCA_CGROUP_MAX + 1]; |
f4009237 TG |
185 | struct cls_cgroup_head *head = tp->root; |
186 | struct tcf_ematch_tree t; | |
187 | struct tcf_exts e; | |
188 | int err; | |
189 | ||
52ea3a56 MU |
190 | if (!tca[TCA_OPTIONS]) |
191 | return -EINVAL; | |
192 | ||
f4009237 TG |
193 | if (head == NULL) { |
194 | if (!handle) | |
195 | return -EINVAL; | |
196 | ||
197 | head = kzalloc(sizeof(*head), GFP_KERNEL); | |
198 | if (head == NULL) | |
199 | return -ENOBUFS; | |
200 | ||
5da57f42 | 201 | tcf_exts_init(&head->exts, TCA_CGROUP_ACT, TCA_CGROUP_POLICE); |
f4009237 TG |
202 | head->handle = handle; |
203 | ||
204 | tcf_tree_lock(tp); | |
205 | tp->root = head; | |
206 | tcf_tree_unlock(tp); | |
207 | } | |
208 | ||
209 | if (handle != head->handle) | |
210 | return -ENOENT; | |
211 | ||
212 | err = nla_parse_nested(tb, TCA_CGROUP_MAX, tca[TCA_OPTIONS], | |
213 | cgroup_policy); | |
214 | if (err < 0) | |
215 | return err; | |
216 | ||
5da57f42 WC |
217 | tcf_exts_init(&e, TCA_CGROUP_ACT, TCA_CGROUP_POLICE); |
218 | err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e); | |
f4009237 TG |
219 | if (err < 0) |
220 | return err; | |
221 | ||
222 | err = tcf_em_tree_validate(tp, tb[TCA_CGROUP_EMATCHES], &t); | |
223 | if (err < 0) | |
224 | return err; | |
225 | ||
226 | tcf_exts_change(tp, &head->exts, &e); | |
227 | tcf_em_tree_change(tp, &head->ematches, &t); | |
228 | ||
229 | return 0; | |
230 | } | |
231 | ||
232 | static void cls_cgroup_destroy(struct tcf_proto *tp) | |
233 | { | |
47a1a1d4 | 234 | struct cls_cgroup_head *head = tp->root; |
f4009237 TG |
235 | |
236 | if (head) { | |
237 | tcf_exts_destroy(tp, &head->exts); | |
238 | tcf_em_tree_destroy(tp, &head->ematches); | |
239 | kfree(head); | |
240 | } | |
241 | } | |
242 | ||
243 | static int cls_cgroup_delete(struct tcf_proto *tp, unsigned long arg) | |
244 | { | |
245 | return -EOPNOTSUPP; | |
246 | } | |
247 | ||
248 | static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg) | |
249 | { | |
250 | struct cls_cgroup_head *head = tp->root; | |
251 | ||
252 | if (arg->count < arg->skip) | |
253 | goto skip; | |
254 | ||
255 | if (arg->fn(tp, (unsigned long) head, arg) < 0) { | |
256 | arg->stop = 1; | |
257 | return; | |
258 | } | |
259 | skip: | |
260 | arg->count++; | |
261 | } | |
262 | ||
263 | static int cls_cgroup_dump(struct tcf_proto *tp, unsigned long fh, | |
264 | struct sk_buff *skb, struct tcmsg *t) | |
265 | { | |
266 | struct cls_cgroup_head *head = tp->root; | |
267 | unsigned char *b = skb_tail_pointer(skb); | |
268 | struct nlattr *nest; | |
269 | ||
270 | t->tcm_handle = head->handle; | |
271 | ||
272 | nest = nla_nest_start(skb, TCA_OPTIONS); | |
273 | if (nest == NULL) | |
274 | goto nla_put_failure; | |
275 | ||
5da57f42 | 276 | if (tcf_exts_dump(skb, &head->exts) < 0 || |
f4009237 TG |
277 | tcf_em_tree_dump(skb, &head->ematches, TCA_CGROUP_EMATCHES) < 0) |
278 | goto nla_put_failure; | |
279 | ||
280 | nla_nest_end(skb, nest); | |
281 | ||
5da57f42 | 282 | if (tcf_exts_dump_stats(skb, &head->exts) < 0) |
f4009237 TG |
283 | goto nla_put_failure; |
284 | ||
285 | return skb->len; | |
286 | ||
287 | nla_put_failure: | |
288 | nlmsg_trim(skb, b); | |
289 | return -1; | |
290 | } | |
291 | ||
292 | static struct tcf_proto_ops cls_cgroup_ops __read_mostly = { | |
293 | .kind = "cgroup", | |
294 | .init = cls_cgroup_init, | |
295 | .change = cls_cgroup_change, | |
296 | .classify = cls_cgroup_classify, | |
297 | .destroy = cls_cgroup_destroy, | |
298 | .get = cls_cgroup_get, | |
299 | .put = cls_cgroup_put, | |
300 | .delete = cls_cgroup_delete, | |
301 | .walk = cls_cgroup_walk, | |
302 | .dump = cls_cgroup_dump, | |
303 | .owner = THIS_MODULE, | |
304 | }; | |
305 | ||
306 | static int __init init_cgroup_cls(void) | |
307 | { | |
f8451725 HX |
308 | int ret; |
309 | ||
8e039d84 BB |
310 | ret = cgroup_load_subsys(&net_cls_subsys); |
311 | if (ret) | |
f8451725 HX |
312 | goto out; |
313 | ||
f8451725 HX |
314 | ret = register_tcf_proto_ops(&cls_cgroup_ops); |
315 | if (ret) | |
316 | cgroup_unload_subsys(&net_cls_subsys); | |
317 | ||
318 | out: | |
8e039d84 | 319 | return ret; |
f4009237 TG |
320 | } |
321 | ||
322 | static void __exit exit_cgroup_cls(void) | |
323 | { | |
324 | unregister_tcf_proto_ops(&cls_cgroup_ops); | |
f8451725 | 325 | |
8e039d84 | 326 | cgroup_unload_subsys(&net_cls_subsys); |
f4009237 TG |
327 | } |
328 | ||
329 | module_init(init_cgroup_cls); | |
330 | module_exit(exit_cgroup_cls); | |
331 | MODULE_LICENSE("GPL"); |