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 <linux/fdtable.h>
21 #include <net/rtnetlink.h>
22 #include <net/pkt_cls.h>
24 #include <net/cls_cgroup.h>
26 static inline struct cgroup_cls_state
*css_cls_state(struct cgroup_subsys_state
*css
)
28 return css
? container_of(css
, struct cgroup_cls_state
, css
) : NULL
;
31 static inline struct cgroup_cls_state
*task_cls_state(struct task_struct
*p
)
33 return css_cls_state(task_css(p
, net_cls_subsys_id
));
36 static struct cgroup_subsys_state
*
37 cgrp_css_alloc(struct cgroup_subsys_state
*parent_css
)
39 struct cgroup_cls_state
*cs
;
41 cs
= kzalloc(sizeof(*cs
), GFP_KERNEL
);
43 return ERR_PTR(-ENOMEM
);
47 static int cgrp_css_online(struct cgroup_subsys_state
*css
)
49 struct cgroup_cls_state
*cs
= css_cls_state(css
);
50 struct cgroup_cls_state
*parent
= css_cls_state(css_parent(css
));
53 cs
->classid
= parent
->classid
;
57 static void cgrp_css_free(struct cgroup_subsys_state
*css
)
59 kfree(css_cls_state(css
));
62 static int update_classid(const void *v
, struct file
*file
, unsigned n
)
65 struct socket
*sock
= sock_from_file(file
, &err
);
67 sock
->sk
->sk_classid
= (u32
)(unsigned long)v
;
71 static void cgrp_attach(struct cgroup_subsys_state
*css
,
72 struct cgroup_taskset
*tset
)
74 struct task_struct
*p
;
77 cgroup_taskset_for_each(p
, css
, tset
) {
79 v
= (void *)(unsigned long)task_cls_classid(p
);
80 iterate_fd(p
->files
, 0, update_classid
, v
);
85 static u64
read_classid(struct cgroup_subsys_state
*css
, struct cftype
*cft
)
87 return css_cls_state(css
)->classid
;
90 static int write_classid(struct cgroup_subsys_state
*css
, struct cftype
*cft
,
93 css_cls_state(css
)->classid
= (u32
) value
;
97 static struct cftype ss_files
[] = {
100 .read_u64
= read_classid
,
101 .write_u64
= write_classid
,
106 struct cgroup_subsys net_cls_subsys
= {
108 .css_alloc
= cgrp_css_alloc
,
109 .css_online
= cgrp_css_online
,
110 .css_free
= cgrp_css_free
,
111 .attach
= cgrp_attach
,
112 .subsys_id
= net_cls_subsys_id
,
113 .base_cftypes
= ss_files
,
114 .module
= THIS_MODULE
,
117 struct cls_cgroup_head
{
119 struct tcf_exts exts
;
120 struct tcf_ematch_tree ematches
;
123 static int cls_cgroup_classify(struct sk_buff
*skb
, const struct tcf_proto
*tp
,
124 struct tcf_result
*res
)
126 struct cls_cgroup_head
*head
= tp
->root
;
130 classid
= task_cls_state(current
)->classid
;
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.
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.
143 if (in_serving_softirq()) {
144 /* If there is an sk_classid we'll use that. */
147 classid
= skb
->sk
->sk_classid
;
153 if (!tcf_em_tree_match(skb
, &head
->ematches
, NULL
))
156 res
->classid
= classid
;
158 return tcf_exts_exec(skb
, &head
->exts
, res
);
161 static unsigned long cls_cgroup_get(struct tcf_proto
*tp
, u32 handle
)
166 static void cls_cgroup_put(struct tcf_proto
*tp
, unsigned long f
)
170 static int cls_cgroup_init(struct tcf_proto
*tp
)
175 static const struct tcf_ext_map cgroup_ext_map
= {
176 .action
= TCA_CGROUP_ACT
,
177 .police
= TCA_CGROUP_POLICE
,
180 static const struct nla_policy cgroup_policy
[TCA_CGROUP_MAX
+ 1] = {
181 [TCA_CGROUP_EMATCHES
] = { .type
= NLA_NESTED
},
184 static int cls_cgroup_change(struct net
*net
, struct sk_buff
*in_skb
,
185 struct tcf_proto
*tp
, unsigned long base
,
186 u32 handle
, struct nlattr
**tca
,
189 struct nlattr
*tb
[TCA_CGROUP_MAX
+ 1];
190 struct cls_cgroup_head
*head
= tp
->root
;
191 struct tcf_ematch_tree t
;
195 if (!tca
[TCA_OPTIONS
])
202 head
= kzalloc(sizeof(*head
), GFP_KERNEL
);
206 head
->handle
= handle
;
213 if (handle
!= head
->handle
)
216 err
= nla_parse_nested(tb
, TCA_CGROUP_MAX
, tca
[TCA_OPTIONS
],
221 err
= tcf_exts_validate(net
, tp
, tb
, tca
[TCA_RATE
], &e
,
226 err
= tcf_em_tree_validate(tp
, tb
[TCA_CGROUP_EMATCHES
], &t
);
230 tcf_exts_change(tp
, &head
->exts
, &e
);
231 tcf_em_tree_change(tp
, &head
->ematches
, &t
);
236 static void cls_cgroup_destroy(struct tcf_proto
*tp
)
238 struct cls_cgroup_head
*head
= tp
->root
;
241 tcf_exts_destroy(tp
, &head
->exts
);
242 tcf_em_tree_destroy(tp
, &head
->ematches
);
247 static int cls_cgroup_delete(struct tcf_proto
*tp
, unsigned long arg
)
252 static void cls_cgroup_walk(struct tcf_proto
*tp
, struct tcf_walker
*arg
)
254 struct cls_cgroup_head
*head
= tp
->root
;
256 if (arg
->count
< arg
->skip
)
259 if (arg
->fn(tp
, (unsigned long) head
, arg
) < 0) {
267 static int cls_cgroup_dump(struct tcf_proto
*tp
, unsigned long fh
,
268 struct sk_buff
*skb
, struct tcmsg
*t
)
270 struct cls_cgroup_head
*head
= tp
->root
;
271 unsigned char *b
= skb_tail_pointer(skb
);
274 t
->tcm_handle
= head
->handle
;
276 nest
= nla_nest_start(skb
, TCA_OPTIONS
);
278 goto nla_put_failure
;
280 if (tcf_exts_dump(skb
, &head
->exts
, &cgroup_ext_map
) < 0 ||
281 tcf_em_tree_dump(skb
, &head
->ematches
, TCA_CGROUP_EMATCHES
) < 0)
282 goto nla_put_failure
;
284 nla_nest_end(skb
, nest
);
286 if (tcf_exts_dump_stats(skb
, &head
->exts
, &cgroup_ext_map
) < 0)
287 goto nla_put_failure
;
296 static struct tcf_proto_ops cls_cgroup_ops __read_mostly
= {
298 .init
= cls_cgroup_init
,
299 .change
= cls_cgroup_change
,
300 .classify
= cls_cgroup_classify
,
301 .destroy
= cls_cgroup_destroy
,
302 .get
= cls_cgroup_get
,
303 .put
= cls_cgroup_put
,
304 .delete = cls_cgroup_delete
,
305 .walk
= cls_cgroup_walk
,
306 .dump
= cls_cgroup_dump
,
307 .owner
= THIS_MODULE
,
310 static int __init
init_cgroup_cls(void)
314 ret
= cgroup_load_subsys(&net_cls_subsys
);
318 ret
= register_tcf_proto_ops(&cls_cgroup_ops
);
320 cgroup_unload_subsys(&net_cls_subsys
);
326 static void __exit
exit_cgroup_cls(void)
328 unregister_tcf_proto_ops(&cls_cgroup_ops
);
330 cgroup_unload_subsys(&net_cls_subsys
);
333 module_init(init_cgroup_cls
);
334 module_exit(exit_cgroup_cls
);
335 MODULE_LICENSE("GPL");