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/skbuff.h>
15 #include <linux/rcupdate.h>
16 #include <net/rtnetlink.h>
17 #include <net/pkt_cls.h>
19 #include <net/cls_cgroup.h>
21 struct cls_cgroup_head
{
24 struct tcf_ematch_tree ematches
;
29 static int cls_cgroup_classify(struct sk_buff
*skb
, const struct tcf_proto
*tp
,
30 struct tcf_result
*res
)
32 struct cls_cgroup_head
*head
= rcu_dereference_bh(tp
->root
);
35 classid
= task_cls_state(current
)->classid
;
38 * Due to the nature of the classifier it is required to ignore all
39 * packets originating from softirq context as accessing `current'
40 * would lead to false results.
42 * This test assumes that all callers of dev_queue_xmit() explicitely
43 * disable bh. Knowing this, it is possible to detect softirq based
44 * calls by looking at the number of nested bh disable calls because
45 * softirqs always disables bh.
47 if (in_serving_softirq()) {
48 /* If there is an sk_classid we'll use that. */
51 classid
= skb
->sk
->sk_classid
;
57 if (!tcf_em_tree_match(skb
, &head
->ematches
, NULL
))
60 res
->classid
= classid
;
62 return tcf_exts_exec(skb
, &head
->exts
, res
);
65 static unsigned long cls_cgroup_get(struct tcf_proto
*tp
, u32 handle
)
70 static void cls_cgroup_put(struct tcf_proto
*tp
, unsigned long f
)
74 static int cls_cgroup_init(struct tcf_proto
*tp
)
79 static const struct nla_policy cgroup_policy
[TCA_CGROUP_MAX
+ 1] = {
80 [TCA_CGROUP_EMATCHES
] = { .type
= NLA_NESTED
},
83 static void cls_cgroup_destroy_rcu(struct rcu_head
*root
)
85 struct cls_cgroup_head
*head
= container_of(root
,
86 struct cls_cgroup_head
,
89 tcf_exts_destroy(&head
->exts
);
90 tcf_em_tree_destroy(&head
->ematches
);
94 static int cls_cgroup_change(struct net
*net
, struct sk_buff
*in_skb
,
95 struct tcf_proto
*tp
, unsigned long base
,
96 u32 handle
, struct nlattr
**tca
,
97 unsigned long *arg
, bool ovr
)
99 struct nlattr
*tb
[TCA_CGROUP_MAX
+ 1];
100 struct cls_cgroup_head
*head
= rtnl_dereference(tp
->root
);
101 struct cls_cgroup_head
*new;
102 struct tcf_ematch_tree t
;
106 if (!tca
[TCA_OPTIONS
])
109 if (!head
&& !handle
)
112 if (head
&& handle
!= head
->handle
)
115 new = kzalloc(sizeof(*head
), GFP_KERNEL
);
119 tcf_exts_init(&new->exts
, TCA_CGROUP_ACT
, TCA_CGROUP_POLICE
);
121 new->handle
= head
->handle
;
123 new->handle
= handle
;
126 err
= nla_parse_nested(tb
, TCA_CGROUP_MAX
, tca
[TCA_OPTIONS
],
131 tcf_exts_init(&e
, TCA_CGROUP_ACT
, TCA_CGROUP_POLICE
);
132 err
= tcf_exts_validate(net
, tp
, tb
, tca
[TCA_RATE
], &e
, ovr
);
136 err
= tcf_em_tree_validate(tp
, tb
[TCA_CGROUP_EMATCHES
], &t
);
138 tcf_exts_destroy(&e
);
142 tcf_exts_change(tp
, &new->exts
, &e
);
143 tcf_em_tree_change(tp
, &new->ematches
, &t
);
145 rcu_assign_pointer(tp
->root
, new);
147 call_rcu(&head
->rcu
, cls_cgroup_destroy_rcu
);
154 static void cls_cgroup_destroy(struct tcf_proto
*tp
)
156 struct cls_cgroup_head
*head
= rtnl_dereference(tp
->root
);
159 RCU_INIT_POINTER(tp
->root
, NULL
);
160 call_rcu(&head
->rcu
, cls_cgroup_destroy_rcu
);
164 static int cls_cgroup_delete(struct tcf_proto
*tp
, unsigned long arg
)
169 static void cls_cgroup_walk(struct tcf_proto
*tp
, struct tcf_walker
*arg
)
171 struct cls_cgroup_head
*head
= rtnl_dereference(tp
->root
);
173 if (arg
->count
< arg
->skip
)
176 if (arg
->fn(tp
, (unsigned long) head
, arg
) < 0) {
184 static int cls_cgroup_dump(struct net
*net
, struct tcf_proto
*tp
, unsigned long fh
,
185 struct sk_buff
*skb
, struct tcmsg
*t
)
187 struct cls_cgroup_head
*head
= rtnl_dereference(tp
->root
);
188 unsigned char *b
= skb_tail_pointer(skb
);
191 t
->tcm_handle
= head
->handle
;
193 nest
= nla_nest_start(skb
, TCA_OPTIONS
);
195 goto nla_put_failure
;
197 if (tcf_exts_dump(skb
, &head
->exts
) < 0 ||
198 tcf_em_tree_dump(skb
, &head
->ematches
, TCA_CGROUP_EMATCHES
) < 0)
199 goto nla_put_failure
;
201 nla_nest_end(skb
, nest
);
203 if (tcf_exts_dump_stats(skb
, &head
->exts
) < 0)
204 goto nla_put_failure
;
213 static struct tcf_proto_ops cls_cgroup_ops __read_mostly
= {
215 .init
= cls_cgroup_init
,
216 .change
= cls_cgroup_change
,
217 .classify
= cls_cgroup_classify
,
218 .destroy
= cls_cgroup_destroy
,
219 .get
= cls_cgroup_get
,
220 .put
= cls_cgroup_put
,
221 .delete = cls_cgroup_delete
,
222 .walk
= cls_cgroup_walk
,
223 .dump
= cls_cgroup_dump
,
224 .owner
= THIS_MODULE
,
227 static int __init
init_cgroup_cls(void)
229 return register_tcf_proto_ops(&cls_cgroup_ops
);
232 static void __exit
exit_cgroup_cls(void)
234 unregister_tcf_proto_ops(&cls_cgroup_ops
);
237 module_init(init_cgroup_cls
);
238 module_exit(exit_cgroup_cls
);
239 MODULE_LICENSE("GPL");