2 * net/sched/cls_cgroup.c Control Group Classifier
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.
9 * Authors: Thomas Graf <tgraf@suug.ch>
12 #include <linux/module.h>
13 #include <linux/slab.h>
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>
19 #include <linux/rcupdate.h>
20 #include <net/rtnetlink.h>
21 #include <net/pkt_cls.h>
23 #include <net/cls_cgroup.h>
25 static struct cgroup_subsys_state
*cgrp_create(struct cgroup
*cgrp
);
26 static void cgrp_destroy(struct cgroup
*cgrp
);
27 static int cgrp_populate(struct cgroup_subsys
*ss
, struct cgroup
*cgrp
);
29 struct cgroup_subsys net_cls_subsys
= {
31 .create
= cgrp_create
,
32 .destroy
= cgrp_destroy
,
33 .populate
= cgrp_populate
,
34 #ifdef CONFIG_NET_CLS_CGROUP
35 .subsys_id
= net_cls_subsys_id
,
37 .module
= THIS_MODULE
,
41 static inline struct cgroup_cls_state
*cgrp_cls_state(struct cgroup
*cgrp
)
43 return container_of(cgroup_subsys_state(cgrp
, net_cls_subsys_id
),
44 struct cgroup_cls_state
, css
);
47 static inline struct cgroup_cls_state
*task_cls_state(struct task_struct
*p
)
49 return container_of(task_subsys_state(p
, net_cls_subsys_id
),
50 struct cgroup_cls_state
, css
);
53 static struct cgroup_subsys_state
*cgrp_create(struct cgroup
*cgrp
)
55 struct cgroup_cls_state
*cs
;
57 cs
= kzalloc(sizeof(*cs
), GFP_KERNEL
);
59 return ERR_PTR(-ENOMEM
);
62 cs
->classid
= cgrp_cls_state(cgrp
->parent
)->classid
;
67 static void cgrp_destroy(struct cgroup
*cgrp
)
69 kfree(cgrp_cls_state(cgrp
));
72 static u64
read_classid(struct cgroup
*cgrp
, struct cftype
*cft
)
74 return cgrp_cls_state(cgrp
)->classid
;
77 static int write_classid(struct cgroup
*cgrp
, struct cftype
*cft
, u64 value
)
79 cgrp_cls_state(cgrp
)->classid
= (u32
) value
;
83 static struct cftype ss_files
[] = {
86 .read_u64
= read_classid
,
87 .write_u64
= write_classid
,
91 static int cgrp_populate(struct cgroup_subsys
*ss
, struct cgroup
*cgrp
)
93 return cgroup_add_files(cgrp
, ss
, ss_files
, ARRAY_SIZE(ss_files
));
96 struct cls_cgroup_head
{
99 struct tcf_ematch_tree ematches
;
102 static int cls_cgroup_classify(struct sk_buff
*skb
, const struct tcf_proto
*tp
,
103 struct tcf_result
*res
)
105 struct cls_cgroup_head
*head
= tp
->root
;
109 classid
= task_cls_state(current
)->classid
;
113 * Due to the nature of the classifier it is required to ignore all
114 * packets originating from softirq context as accessing `current'
115 * would lead to false results.
117 * This test assumes that all callers of dev_queue_xmit() explicitely
118 * disable bh. Knowing this, it is possible to detect softirq based
119 * calls by looking at the number of nested bh disable calls because
120 * softirqs always disables bh.
122 if (in_serving_softirq()) {
123 /* If there is an sk_classid we'll use that. */
126 classid
= skb
->sk
->sk_classid
;
132 if (!tcf_em_tree_match(skb
, &head
->ematches
, NULL
))
135 res
->classid
= classid
;
137 return tcf_exts_exec(skb
, &head
->exts
, res
);
140 static unsigned long cls_cgroup_get(struct tcf_proto
*tp
, u32 handle
)
145 static void cls_cgroup_put(struct tcf_proto
*tp
, unsigned long f
)
149 static int cls_cgroup_init(struct tcf_proto
*tp
)
154 static const struct tcf_ext_map cgroup_ext_map
= {
155 .action
= TCA_CGROUP_ACT
,
156 .police
= TCA_CGROUP_POLICE
,
159 static const struct nla_policy cgroup_policy
[TCA_CGROUP_MAX
+ 1] = {
160 [TCA_CGROUP_EMATCHES
] = { .type
= NLA_NESTED
},
163 static int cls_cgroup_change(struct tcf_proto
*tp
, unsigned long base
,
164 u32 handle
, struct nlattr
**tca
,
167 struct nlattr
*tb
[TCA_CGROUP_MAX
+ 1];
168 struct cls_cgroup_head
*head
= tp
->root
;
169 struct tcf_ematch_tree t
;
173 if (!tca
[TCA_OPTIONS
])
180 head
= kzalloc(sizeof(*head
), GFP_KERNEL
);
184 head
->handle
= handle
;
191 if (handle
!= head
->handle
)
194 err
= nla_parse_nested(tb
, TCA_CGROUP_MAX
, tca
[TCA_OPTIONS
],
199 err
= tcf_exts_validate(tp
, tb
, tca
[TCA_RATE
], &e
, &cgroup_ext_map
);
203 err
= tcf_em_tree_validate(tp
, tb
[TCA_CGROUP_EMATCHES
], &t
);
207 tcf_exts_change(tp
, &head
->exts
, &e
);
208 tcf_em_tree_change(tp
, &head
->ematches
, &t
);
213 static void cls_cgroup_destroy(struct tcf_proto
*tp
)
215 struct cls_cgroup_head
*head
= tp
->root
;
218 tcf_exts_destroy(tp
, &head
->exts
);
219 tcf_em_tree_destroy(tp
, &head
->ematches
);
224 static int cls_cgroup_delete(struct tcf_proto
*tp
, unsigned long arg
)
229 static void cls_cgroup_walk(struct tcf_proto
*tp
, struct tcf_walker
*arg
)
231 struct cls_cgroup_head
*head
= tp
->root
;
233 if (arg
->count
< arg
->skip
)
236 if (arg
->fn(tp
, (unsigned long) head
, arg
) < 0) {
244 static int cls_cgroup_dump(struct tcf_proto
*tp
, unsigned long fh
,
245 struct sk_buff
*skb
, struct tcmsg
*t
)
247 struct cls_cgroup_head
*head
= tp
->root
;
248 unsigned char *b
= skb_tail_pointer(skb
);
251 t
->tcm_handle
= head
->handle
;
253 nest
= nla_nest_start(skb
, TCA_OPTIONS
);
255 goto nla_put_failure
;
257 if (tcf_exts_dump(skb
, &head
->exts
, &cgroup_ext_map
) < 0 ||
258 tcf_em_tree_dump(skb
, &head
->ematches
, TCA_CGROUP_EMATCHES
) < 0)
259 goto nla_put_failure
;
261 nla_nest_end(skb
, nest
);
263 if (tcf_exts_dump_stats(skb
, &head
->exts
, &cgroup_ext_map
) < 0)
264 goto nla_put_failure
;
273 static struct tcf_proto_ops cls_cgroup_ops __read_mostly
= {
275 .init
= cls_cgroup_init
,
276 .change
= cls_cgroup_change
,
277 .classify
= cls_cgroup_classify
,
278 .destroy
= cls_cgroup_destroy
,
279 .get
= cls_cgroup_get
,
280 .put
= cls_cgroup_put
,
281 .delete = cls_cgroup_delete
,
282 .walk
= cls_cgroup_walk
,
283 .dump
= cls_cgroup_dump
,
284 .owner
= THIS_MODULE
,
287 static int __init
init_cgroup_cls(void)
291 ret
= cgroup_load_subsys(&net_cls_subsys
);
295 #ifndef CONFIG_NET_CLS_CGROUP
296 /* We can't use rcu_assign_pointer because this is an int. */
298 net_cls_subsys_id
= net_cls_subsys
.subsys_id
;
301 ret
= register_tcf_proto_ops(&cls_cgroup_ops
);
303 cgroup_unload_subsys(&net_cls_subsys
);
309 static void __exit
exit_cgroup_cls(void)
311 unregister_tcf_proto_ops(&cls_cgroup_ops
);
313 #ifndef CONFIG_NET_CLS_CGROUP
314 net_cls_subsys_id
= -1;
318 cgroup_unload_subsys(&net_cls_subsys
);
321 module_init(init_cgroup_cls
);
322 module_exit(exit_cgroup_cls
);
323 MODULE_LICENSE("GPL");