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/types.h>
14 #include <linux/string.h>
15 #include <linux/errno.h>
16 #include <linux/skbuff.h>
17 #include <linux/cgroup.h>
18 #include <net/rtnetlink.h>
19 #include <net/pkt_cls.h>
21 struct cgroup_cls_state
23 struct cgroup_subsys_state css;
27 static inline struct cgroup_cls_state *net_cls_state(struct cgroup *cgrp)
29 return (struct cgroup_cls_state *)
30 cgroup_subsys_state(cgrp, net_cls_subsys_id);
33 static struct cgroup_subsys_state *cgrp_create(struct cgroup_subsys *ss,
36 struct cgroup_cls_state *cs;
38 if (!(cs = kzalloc(sizeof(*cs), GFP_KERNEL)))
39 return ERR_PTR(-ENOMEM);
42 cs->classid = net_cls_state(cgrp->parent)->classid;
47 static void cgrp_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
52 static u64 read_classid(struct cgroup *cgrp, struct cftype *cft)
54 return net_cls_state(cgrp)->classid;
57 static int write_classid(struct cgroup *cgrp, struct cftype *cft, u64 value)
59 if (!cgroup_lock_live_group(cgrp))
62 net_cls_state(cgrp)->classid = (u32) value;
69 static struct cftype ss_files[] = {
72 .read_u64 = read_classid,
73 .write_u64 = write_classid,
77 static int cgrp_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
79 return cgroup_add_files(cgrp, ss, ss_files, ARRAY_SIZE(ss_files));
82 struct cgroup_subsys net_cls_subsys = {
84 .create = cgrp_create,
85 .destroy = cgrp_destroy,
86 .populate = cgrp_populate,
87 .subsys_id = net_cls_subsys_id,
90 struct cls_cgroup_head
94 struct tcf_ematch_tree ematches;
97 static int cls_cgroup_classify(struct sk_buff *skb, struct tcf_proto *tp,
98 struct tcf_result *res)
100 struct cls_cgroup_head *head = tp->root;
101 struct cgroup_cls_state *cs;
105 * Due to the nature of the classifier it is required to ignore all
106 * packets originating from softirq context as accessing `current'
107 * would lead to false results.
109 * This test assumes that all callers of dev_queue_xmit() explicitely
110 * disable bh. Knowing this, it is possible to detect softirq based
111 * calls by looking at the number of nested bh disable calls because
112 * softirqs always disables bh.
114 if (softirq_count() != SOFTIRQ_OFFSET)
118 cs = (struct cgroup_cls_state *) task_subsys_state(current,
120 if (cs->classid && tcf_em_tree_match(skb, &head->ematches, NULL)) {
121 res->classid = cs->classid;
123 ret = tcf_exts_exec(skb, &head->exts, res);
132 static unsigned long cls_cgroup_get(struct tcf_proto *tp, u32 handle)
137 static void cls_cgroup_put(struct tcf_proto *tp, unsigned long f)
141 static int cls_cgroup_init(struct tcf_proto *tp)
146 static const struct tcf_ext_map cgroup_ext_map = {
147 .action = TCA_CGROUP_ACT,
148 .police = TCA_CGROUP_POLICE,
151 static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = {
152 [TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED },
155 static int cls_cgroup_change(struct tcf_proto *tp, unsigned long base,
156 u32 handle, struct nlattr **tca,
159 struct nlattr *tb[TCA_CGROUP_MAX+1];
160 struct cls_cgroup_head *head = tp->root;
161 struct tcf_ematch_tree t;
169 head = kzalloc(sizeof(*head), GFP_KERNEL);
173 head->handle = handle;
180 if (handle != head->handle)
183 err = nla_parse_nested(tb, TCA_CGROUP_MAX, tca[TCA_OPTIONS],
188 err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &cgroup_ext_map);
192 err = tcf_em_tree_validate(tp, tb[TCA_CGROUP_EMATCHES], &t);
196 tcf_exts_change(tp, &head->exts, &e);
197 tcf_em_tree_change(tp, &head->ematches, &t);
202 static void cls_cgroup_destroy(struct tcf_proto *tp)
204 struct cls_cgroup_head *head = tp->root;
207 tcf_exts_destroy(tp, &head->exts);
208 tcf_em_tree_destroy(tp, &head->ematches);
213 static int cls_cgroup_delete(struct tcf_proto *tp, unsigned long arg)
218 static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg)
220 struct cls_cgroup_head *head = tp->root;
222 if (arg->count < arg->skip)
225 if (arg->fn(tp, (unsigned long) head, arg) < 0) {
233 static int cls_cgroup_dump(struct tcf_proto *tp, unsigned long fh,
234 struct sk_buff *skb, struct tcmsg *t)
236 struct cls_cgroup_head *head = tp->root;
237 unsigned char *b = skb_tail_pointer(skb);
240 t->tcm_handle = head->handle;
242 nest = nla_nest_start(skb, TCA_OPTIONS);
244 goto nla_put_failure;
246 if (tcf_exts_dump(skb, &head->exts, &cgroup_ext_map) < 0 ||
247 tcf_em_tree_dump(skb, &head->ematches, TCA_CGROUP_EMATCHES) < 0)
248 goto nla_put_failure;
250 nla_nest_end(skb, nest);
252 if (tcf_exts_dump_stats(skb, &head->exts, &cgroup_ext_map) < 0)
253 goto nla_put_failure;
262 static struct tcf_proto_ops cls_cgroup_ops __read_mostly = {
264 .init = cls_cgroup_init,
265 .change = cls_cgroup_change,
266 .classify = cls_cgroup_classify,
267 .destroy = cls_cgroup_destroy,
268 .get = cls_cgroup_get,
269 .put = cls_cgroup_put,
270 .delete = cls_cgroup_delete,
271 .walk = cls_cgroup_walk,
272 .dump = cls_cgroup_dump,
273 .owner = THIS_MODULE,
276 static int __init init_cgroup_cls(void)
278 return register_tcf_proto_ops(&cls_cgroup_ops);
281 static void __exit exit_cgroup_cls(void)
283 unregister_tcf_proto_ops(&cls_cgroup_ops);
286 module_init(init_cgroup_cls);
287 module_exit(exit_cgroup_cls);
288 MODULE_LICENSE("GPL");