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 | 31 | static inline struct cgroup_cls_state *cgrp_cls_state(struct cgroup *cgrp) |
f4009237 | 32 | { |
a7c6d554 | 33 | return css_cls_state(cgroup_css(cgrp, net_cls_subsys_id)); |
8e8ba854 LZ |
34 | } |
35 | ||
36 | static inline struct cgroup_cls_state *task_cls_state(struct task_struct *p) | |
37 | { | |
a7c6d554 | 38 | return css_cls_state(task_css(p, net_cls_subsys_id)); |
f4009237 TG |
39 | } |
40 | ||
92fb9748 | 41 | static struct cgroup_subsys_state *cgrp_css_alloc(struct cgroup *cgrp) |
f4009237 TG |
42 | { |
43 | struct cgroup_cls_state *cs; | |
44 | ||
cc7ec456 ED |
45 | cs = kzalloc(sizeof(*cs), GFP_KERNEL); |
46 | if (!cs) | |
f4009237 | 47 | return ERR_PTR(-ENOMEM); |
0ba18f7a TH |
48 | return &cs->css; |
49 | } | |
f4009237 | 50 | |
0ba18f7a TH |
51 | static int cgrp_css_online(struct cgroup *cgrp) |
52 | { | |
63876986 TH |
53 | struct cgroup_cls_state *cs = cgrp_cls_state(cgrp); |
54 | struct cgroup_cls_state *parent = css_cls_state(css_parent(&cs->css)); | |
55 | ||
56 | if (parent) | |
57 | cs->classid = parent->classid; | |
0ba18f7a | 58 | return 0; |
f4009237 TG |
59 | } |
60 | ||
92fb9748 | 61 | static void cgrp_css_free(struct cgroup *cgrp) |
f4009237 | 62 | { |
8e8ba854 | 63 | kfree(cgrp_cls_state(cgrp)); |
f4009237 TG |
64 | } |
65 | ||
6a328d8c DW |
66 | static int update_classid(const void *v, struct file *file, unsigned n) |
67 | { | |
68 | int err; | |
69 | struct socket *sock = sock_from_file(file, &err); | |
70 | if (sock) | |
71 | sock->sk->sk_classid = (u32)(unsigned long)v; | |
72 | return 0; | |
73 | } | |
74 | ||
75 | static void cgrp_attach(struct cgroup *cgrp, struct cgroup_taskset *tset) | |
76 | { | |
77 | struct task_struct *p; | |
78 | void *v; | |
79 | ||
80 | cgroup_taskset_for_each(p, cgrp, tset) { | |
81 | task_lock(p); | |
82 | v = (void *)(unsigned long)task_cls_classid(p); | |
83 | iterate_fd(p->files, 0, update_classid, v); | |
84 | task_unlock(p); | |
85 | } | |
86 | } | |
87 | ||
f4009237 TG |
88 | static u64 read_classid(struct cgroup *cgrp, struct cftype *cft) |
89 | { | |
8e8ba854 | 90 | return cgrp_cls_state(cgrp)->classid; |
f4009237 TG |
91 | } |
92 | ||
93 | static int write_classid(struct cgroup *cgrp, struct cftype *cft, u64 value) | |
94 | { | |
8e8ba854 | 95 | cgrp_cls_state(cgrp)->classid = (u32) value; |
f4009237 TG |
96 | return 0; |
97 | } | |
98 | ||
99 | static struct cftype ss_files[] = { | |
100 | { | |
101 | .name = "classid", | |
102 | .read_u64 = read_classid, | |
103 | .write_u64 = write_classid, | |
104 | }, | |
4baf6e33 | 105 | { } /* terminate */ |
f4009237 TG |
106 | }; |
107 | ||
676f7c8f TH |
108 | struct cgroup_subsys net_cls_subsys = { |
109 | .name = "net_cls", | |
92fb9748 | 110 | .css_alloc = cgrp_css_alloc, |
0ba18f7a | 111 | .css_online = cgrp_css_online, |
92fb9748 | 112 | .css_free = cgrp_css_free, |
6a328d8c | 113 | .attach = cgrp_attach, |
676f7c8f | 114 | .subsys_id = net_cls_subsys_id, |
4baf6e33 | 115 | .base_cftypes = ss_files, |
676f7c8f TH |
116 | .module = THIS_MODULE, |
117 | }; | |
118 | ||
cc7ec456 | 119 | struct cls_cgroup_head { |
f4009237 TG |
120 | u32 handle; |
121 | struct tcf_exts exts; | |
122 | struct tcf_ematch_tree ematches; | |
123 | }; | |
124 | ||
dc7f9f6e | 125 | static int cls_cgroup_classify(struct sk_buff *skb, const struct tcf_proto *tp, |
f4009237 TG |
126 | struct tcf_result *res) |
127 | { | |
128 | struct cls_cgroup_head *head = tp->root; | |
e65fcfd6 | 129 | u32 classid; |
f4009237 | 130 | |
f8451725 HX |
131 | rcu_read_lock(); |
132 | classid = task_cls_state(current)->classid; | |
133 | rcu_read_unlock(); | |
134 | ||
f4009237 TG |
135 | /* |
136 | * Due to the nature of the classifier it is required to ignore all | |
137 | * packets originating from softirq context as accessing `current' | |
138 | * would lead to false results. | |
139 | * | |
140 | * This test assumes that all callers of dev_queue_xmit() explicitely | |
141 | * disable bh. Knowing this, it is possible to detect softirq based | |
142 | * calls by looking at the number of nested bh disable calls because | |
143 | * softirqs always disables bh. | |
144 | */ | |
75e1056f | 145 | if (in_serving_softirq()) { |
f8451725 HX |
146 | /* If there is an sk_classid we'll use that. */ |
147 | if (!skb->sk) | |
148 | return -1; | |
149 | classid = skb->sk->sk_classid; | |
150 | } | |
f4009237 | 151 | |
e65fcfd6 PM |
152 | if (!classid) |
153 | return -1; | |
154 | ||
155 | if (!tcf_em_tree_match(skb, &head->ematches, NULL)) | |
156 | return -1; | |
157 | ||
158 | res->classid = classid; | |
159 | res->class = 0; | |
160 | return tcf_exts_exec(skb, &head->exts, res); | |
f4009237 TG |
161 | } |
162 | ||
163 | static unsigned long cls_cgroup_get(struct tcf_proto *tp, u32 handle) | |
164 | { | |
165 | return 0UL; | |
166 | } | |
167 | ||
168 | static void cls_cgroup_put(struct tcf_proto *tp, unsigned long f) | |
169 | { | |
170 | } | |
171 | ||
172 | static int cls_cgroup_init(struct tcf_proto *tp) | |
173 | { | |
174 | return 0; | |
175 | } | |
176 | ||
177 | static const struct tcf_ext_map cgroup_ext_map = { | |
178 | .action = TCA_CGROUP_ACT, | |
179 | .police = TCA_CGROUP_POLICE, | |
180 | }; | |
181 | ||
182 | static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = { | |
183 | [TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED }, | |
184 | }; | |
185 | ||
c1b52739 | 186 | static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb, |
af4c6641 | 187 | struct tcf_proto *tp, unsigned long base, |
f4009237 TG |
188 | u32 handle, struct nlattr **tca, |
189 | unsigned long *arg) | |
190 | { | |
cc7ec456 | 191 | struct nlattr *tb[TCA_CGROUP_MAX + 1]; |
f4009237 TG |
192 | struct cls_cgroup_head *head = tp->root; |
193 | struct tcf_ematch_tree t; | |
194 | struct tcf_exts e; | |
195 | int err; | |
196 | ||
52ea3a56 MU |
197 | if (!tca[TCA_OPTIONS]) |
198 | return -EINVAL; | |
199 | ||
f4009237 TG |
200 | if (head == NULL) { |
201 | if (!handle) | |
202 | return -EINVAL; | |
203 | ||
204 | head = kzalloc(sizeof(*head), GFP_KERNEL); | |
205 | if (head == NULL) | |
206 | return -ENOBUFS; | |
207 | ||
208 | head->handle = handle; | |
209 | ||
210 | tcf_tree_lock(tp); | |
211 | tp->root = head; | |
212 | tcf_tree_unlock(tp); | |
213 | } | |
214 | ||
215 | if (handle != head->handle) | |
216 | return -ENOENT; | |
217 | ||
218 | err = nla_parse_nested(tb, TCA_CGROUP_MAX, tca[TCA_OPTIONS], | |
219 | cgroup_policy); | |
220 | if (err < 0) | |
221 | return err; | |
222 | ||
c1b52739 BL |
223 | err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e, |
224 | &cgroup_ext_map); | |
f4009237 TG |
225 | if (err < 0) |
226 | return err; | |
227 | ||
228 | err = tcf_em_tree_validate(tp, tb[TCA_CGROUP_EMATCHES], &t); | |
229 | if (err < 0) | |
230 | return err; | |
231 | ||
232 | tcf_exts_change(tp, &head->exts, &e); | |
233 | tcf_em_tree_change(tp, &head->ematches, &t); | |
234 | ||
235 | return 0; | |
236 | } | |
237 | ||
238 | static void cls_cgroup_destroy(struct tcf_proto *tp) | |
239 | { | |
47a1a1d4 | 240 | struct cls_cgroup_head *head = tp->root; |
f4009237 TG |
241 | |
242 | if (head) { | |
243 | tcf_exts_destroy(tp, &head->exts); | |
244 | tcf_em_tree_destroy(tp, &head->ematches); | |
245 | kfree(head); | |
246 | } | |
247 | } | |
248 | ||
249 | static int cls_cgroup_delete(struct tcf_proto *tp, unsigned long arg) | |
250 | { | |
251 | return -EOPNOTSUPP; | |
252 | } | |
253 | ||
254 | static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg) | |
255 | { | |
256 | struct cls_cgroup_head *head = tp->root; | |
257 | ||
258 | if (arg->count < arg->skip) | |
259 | goto skip; | |
260 | ||
261 | if (arg->fn(tp, (unsigned long) head, arg) < 0) { | |
262 | arg->stop = 1; | |
263 | return; | |
264 | } | |
265 | skip: | |
266 | arg->count++; | |
267 | } | |
268 | ||
269 | static int cls_cgroup_dump(struct tcf_proto *tp, unsigned long fh, | |
270 | struct sk_buff *skb, struct tcmsg *t) | |
271 | { | |
272 | struct cls_cgroup_head *head = tp->root; | |
273 | unsigned char *b = skb_tail_pointer(skb); | |
274 | struct nlattr *nest; | |
275 | ||
276 | t->tcm_handle = head->handle; | |
277 | ||
278 | nest = nla_nest_start(skb, TCA_OPTIONS); | |
279 | if (nest == NULL) | |
280 | goto nla_put_failure; | |
281 | ||
282 | if (tcf_exts_dump(skb, &head->exts, &cgroup_ext_map) < 0 || | |
283 | tcf_em_tree_dump(skb, &head->ematches, TCA_CGROUP_EMATCHES) < 0) | |
284 | goto nla_put_failure; | |
285 | ||
286 | nla_nest_end(skb, nest); | |
287 | ||
288 | if (tcf_exts_dump_stats(skb, &head->exts, &cgroup_ext_map) < 0) | |
289 | goto nla_put_failure; | |
290 | ||
291 | return skb->len; | |
292 | ||
293 | nla_put_failure: | |
294 | nlmsg_trim(skb, b); | |
295 | return -1; | |
296 | } | |
297 | ||
298 | static struct tcf_proto_ops cls_cgroup_ops __read_mostly = { | |
299 | .kind = "cgroup", | |
300 | .init = cls_cgroup_init, | |
301 | .change = cls_cgroup_change, | |
302 | .classify = cls_cgroup_classify, | |
303 | .destroy = cls_cgroup_destroy, | |
304 | .get = cls_cgroup_get, | |
305 | .put = cls_cgroup_put, | |
306 | .delete = cls_cgroup_delete, | |
307 | .walk = cls_cgroup_walk, | |
308 | .dump = cls_cgroup_dump, | |
309 | .owner = THIS_MODULE, | |
310 | }; | |
311 | ||
312 | static int __init init_cgroup_cls(void) | |
313 | { | |
f8451725 HX |
314 | int ret; |
315 | ||
8e039d84 BB |
316 | ret = cgroup_load_subsys(&net_cls_subsys); |
317 | if (ret) | |
f8451725 HX |
318 | goto out; |
319 | ||
f8451725 HX |
320 | ret = register_tcf_proto_ops(&cls_cgroup_ops); |
321 | if (ret) | |
322 | cgroup_unload_subsys(&net_cls_subsys); | |
323 | ||
324 | out: | |
8e039d84 | 325 | return ret; |
f4009237 TG |
326 | } |
327 | ||
328 | static void __exit exit_cgroup_cls(void) | |
329 | { | |
330 | unregister_tcf_proto_ops(&cls_cgroup_ops); | |
f8451725 | 331 | |
8e039d84 | 332 | cgroup_unload_subsys(&net_cls_subsys); |
f4009237 TG |
333 | } |
334 | ||
335 | module_init(init_cgroup_cls); | |
336 | module_exit(exit_cgroup_cls); | |
337 | MODULE_LICENSE("GPL"); |