blob: 2f77a89655dcdd2bffba27640af7d7c3318a027f [file] [log] [blame]
Thomas Graff4009232008-11-07 22:56:00 -08001/*
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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090013#include <linux/slab.h>
Thomas Graff4009232008-11-07 22:56:00 -080014#include <linux/skbuff.h>
Herbert Xuf8451722010-05-24 00:12:34 -070015#include <linux/rcupdate.h>
Thomas Graff4009232008-11-07 22:56:00 -080016#include <net/rtnetlink.h>
17#include <net/pkt_cls.h>
Herbert Xuf8451722010-05-24 00:12:34 -070018#include <net/sock.h>
19#include <net/cls_cgroup.h>
Thomas Graff4009232008-11-07 22:56:00 -080020
Eric Dumazetcc7ec452011-01-19 19:26:56 +000021struct cls_cgroup_head {
Thomas Graff4009232008-11-07 22:56:00 -080022 u32 handle;
23 struct tcf_exts exts;
24 struct tcf_ematch_tree ematches;
John Fastabend952313b2014-09-12 20:06:26 -070025 struct tcf_proto *tp;
26 struct rcu_head rcu;
Thomas Graff4009232008-11-07 22:56:00 -080027};
28
Eric Dumazetdc7f9f62011-07-05 23:25:42 +000029static int cls_cgroup_classify(struct sk_buff *skb, const struct tcf_proto *tp,
Thomas Graff4009232008-11-07 22:56:00 -080030 struct tcf_result *res)
31{
John Fastabend952313b2014-09-12 20:06:26 -070032 struct cls_cgroup_head *head = rcu_dereference_bh(tp->root);
Paul Menagee65fcfd2009-05-26 20:47:02 -070033 u32 classid;
Thomas Graff4009232008-11-07 22:56:00 -080034
Herbert Xuf8451722010-05-24 00:12:34 -070035 classid = task_cls_state(current)->classid;
Herbert Xuf8451722010-05-24 00:12:34 -070036
Thomas Graff4009232008-11-07 22:56:00 -080037 /*
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.
41 *
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.
46 */
Venkatesh Pallipadi75e10562010-10-04 17:03:16 -070047 if (in_serving_softirq()) {
Herbert Xuf8451722010-05-24 00:12:34 -070048 /* If there is an sk_classid we'll use that. */
49 if (!skb->sk)
50 return -1;
51 classid = skb->sk->sk_classid;
52 }
Thomas Graff4009232008-11-07 22:56:00 -080053
Paul Menagee65fcfd2009-05-26 20:47:02 -070054 if (!classid)
55 return -1;
56
57 if (!tcf_em_tree_match(skb, &head->ematches, NULL))
58 return -1;
59
60 res->classid = classid;
61 res->class = 0;
62 return tcf_exts_exec(skb, &head->exts, res);
Thomas Graff4009232008-11-07 22:56:00 -080063}
64
65static unsigned long cls_cgroup_get(struct tcf_proto *tp, u32 handle)
66{
67 return 0UL;
68}
69
70static void cls_cgroup_put(struct tcf_proto *tp, unsigned long f)
71{
72}
73
74static int cls_cgroup_init(struct tcf_proto *tp)
75{
76 return 0;
77}
78
Thomas Graff4009232008-11-07 22:56:00 -080079static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = {
80 [TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED },
81};
82
John Fastabend952313b2014-09-12 20:06:26 -070083static void cls_cgroup_destroy_rcu(struct rcu_head *root)
84{
85 struct cls_cgroup_head *head = container_of(root,
86 struct cls_cgroup_head,
87 rcu);
88
WANG Cong18d02642014-09-25 10:26:37 -070089 tcf_exts_destroy(&head->exts);
John Fastabend82a470f2014-10-05 21:27:53 -070090 tcf_em_tree_destroy(&head->ematches);
John Fastabend952313b2014-09-12 20:06:26 -070091 kfree(head);
92}
93
Benjamin LaHaisec1b52732013-01-14 05:15:39 +000094static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb,
Eric W. Biedermanaf4c6642012-05-25 13:42:45 -060095 struct tcf_proto *tp, unsigned long base,
Thomas Graff4009232008-11-07 22:56:00 -080096 u32 handle, struct nlattr **tca,
Cong Wang2f7ef2f2014-04-25 13:54:06 -070097 unsigned long *arg, bool ovr)
Thomas Graff4009232008-11-07 22:56:00 -080098{
Eric Dumazetcc7ec452011-01-19 19:26:56 +000099 struct nlattr *tb[TCA_CGROUP_MAX + 1];
John Fastabend952313b2014-09-12 20:06:26 -0700100 struct cls_cgroup_head *head = rtnl_dereference(tp->root);
101 struct cls_cgroup_head *new;
Thomas Graff4009232008-11-07 22:56:00 -0800102 struct tcf_ematch_tree t;
103 struct tcf_exts e;
104 int err;
105
Minoru Usui52ea3a52009-06-09 04:03:09 -0700106 if (!tca[TCA_OPTIONS])
107 return -EINVAL;
108
John Fastabend952313b2014-09-12 20:06:26 -0700109 if (!head && !handle)
110 return -EINVAL;
Thomas Graff4009232008-11-07 22:56:00 -0800111
John Fastabend952313b2014-09-12 20:06:26 -0700112 if (head && handle != head->handle)
Thomas Graff4009232008-11-07 22:56:00 -0800113 return -ENOENT;
114
John Fastabend952313b2014-09-12 20:06:26 -0700115 new = kzalloc(sizeof(*head), GFP_KERNEL);
116 if (!new)
117 return -ENOBUFS;
118
John Fastabend9f6c38e2014-09-16 00:33:42 -0700119 tcf_exts_init(&new->exts, TCA_CGROUP_ACT, TCA_CGROUP_POLICE);
120 if (head)
John Fastabend952313b2014-09-12 20:06:26 -0700121 new->handle = head->handle;
John Fastabend9f6c38e2014-09-16 00:33:42 -0700122 else
John Fastabend952313b2014-09-12 20:06:26 -0700123 new->handle = handle;
John Fastabend952313b2014-09-12 20:06:26 -0700124
125 new->tp = tp;
Thomas Graff4009232008-11-07 22:56:00 -0800126 err = nla_parse_nested(tb, TCA_CGROUP_MAX, tca[TCA_OPTIONS],
127 cgroup_policy);
128 if (err < 0)
John Fastabendd14cbfc82014-09-15 23:31:17 -0700129 goto errout;
Thomas Graff4009232008-11-07 22:56:00 -0800130
WANG Cong5da57f42013-12-15 20:15:07 -0800131 tcf_exts_init(&e, TCA_CGROUP_ACT, TCA_CGROUP_POLICE);
Cong Wang2f7ef2f2014-04-25 13:54:06 -0700132 err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e, ovr);
Thomas Graff4009232008-11-07 22:56:00 -0800133 if (err < 0)
John Fastabendd14cbfc82014-09-15 23:31:17 -0700134 goto errout;
Thomas Graff4009232008-11-07 22:56:00 -0800135
136 err = tcf_em_tree_validate(tp, tb[TCA_CGROUP_EMATCHES], &t);
John Fastabendd14cbfc82014-09-15 23:31:17 -0700137 if (err < 0) {
WANG Cong18d02642014-09-25 10:26:37 -0700138 tcf_exts_destroy(&e);
John Fastabendd14cbfc82014-09-15 23:31:17 -0700139 goto errout;
140 }
Thomas Graff4009232008-11-07 22:56:00 -0800141
John Fastabend952313b2014-09-12 20:06:26 -0700142 tcf_exts_change(tp, &new->exts, &e);
143 tcf_em_tree_change(tp, &new->ematches, &t);
Thomas Graff4009232008-11-07 22:56:00 -0800144
John Fastabend952313b2014-09-12 20:06:26 -0700145 rcu_assign_pointer(tp->root, new);
146 if (head)
147 call_rcu(&head->rcu, cls_cgroup_destroy_rcu);
Thomas Graff4009232008-11-07 22:56:00 -0800148 return 0;
John Fastabendd14cbfc82014-09-15 23:31:17 -0700149errout:
150 kfree(new);
151 return err;
Thomas Graff4009232008-11-07 22:56:00 -0800152}
153
154static void cls_cgroup_destroy(struct tcf_proto *tp)
155{
John Fastabend952313b2014-09-12 20:06:26 -0700156 struct cls_cgroup_head *head = rtnl_dereference(tp->root);
Thomas Graff4009232008-11-07 22:56:00 -0800157
158 if (head) {
WANG Cong18d02642014-09-25 10:26:37 -0700159 tcf_exts_destroy(&head->exts);
John Fastabend82a470f2014-10-05 21:27:53 -0700160 tcf_em_tree_destroy(&head->ematches);
John Fastabend952313b2014-09-12 20:06:26 -0700161 RCU_INIT_POINTER(tp->root, NULL);
162 kfree_rcu(head, rcu);
Thomas Graff4009232008-11-07 22:56:00 -0800163 }
164}
165
166static int cls_cgroup_delete(struct tcf_proto *tp, unsigned long arg)
167{
168 return -EOPNOTSUPP;
169}
170
171static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg)
172{
John Fastabend952313b2014-09-12 20:06:26 -0700173 struct cls_cgroup_head *head = rtnl_dereference(tp->root);
Thomas Graff4009232008-11-07 22:56:00 -0800174
175 if (arg->count < arg->skip)
176 goto skip;
177
178 if (arg->fn(tp, (unsigned long) head, arg) < 0) {
179 arg->stop = 1;
180 return;
181 }
182skip:
183 arg->count++;
184}
185
WANG Cong832d1d52014-01-09 16:14:01 -0800186static int cls_cgroup_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
Thomas Graff4009232008-11-07 22:56:00 -0800187 struct sk_buff *skb, struct tcmsg *t)
188{
John Fastabend952313b2014-09-12 20:06:26 -0700189 struct cls_cgroup_head *head = rtnl_dereference(tp->root);
Thomas Graff4009232008-11-07 22:56:00 -0800190 unsigned char *b = skb_tail_pointer(skb);
191 struct nlattr *nest;
192
193 t->tcm_handle = head->handle;
194
195 nest = nla_nest_start(skb, TCA_OPTIONS);
196 if (nest == NULL)
197 goto nla_put_failure;
198
WANG Cong5da57f42013-12-15 20:15:07 -0800199 if (tcf_exts_dump(skb, &head->exts) < 0 ||
Thomas Graff4009232008-11-07 22:56:00 -0800200 tcf_em_tree_dump(skb, &head->ematches, TCA_CGROUP_EMATCHES) < 0)
201 goto nla_put_failure;
202
203 nla_nest_end(skb, nest);
204
WANG Cong5da57f42013-12-15 20:15:07 -0800205 if (tcf_exts_dump_stats(skb, &head->exts) < 0)
Thomas Graff4009232008-11-07 22:56:00 -0800206 goto nla_put_failure;
207
208 return skb->len;
209
210nla_put_failure:
211 nlmsg_trim(skb, b);
212 return -1;
213}
214
215static struct tcf_proto_ops cls_cgroup_ops __read_mostly = {
216 .kind = "cgroup",
217 .init = cls_cgroup_init,
218 .change = cls_cgroup_change,
219 .classify = cls_cgroup_classify,
220 .destroy = cls_cgroup_destroy,
221 .get = cls_cgroup_get,
222 .put = cls_cgroup_put,
223 .delete = cls_cgroup_delete,
224 .walk = cls_cgroup_walk,
225 .dump = cls_cgroup_dump,
226 .owner = THIS_MODULE,
227};
228
229static int __init init_cgroup_cls(void)
230{
Daniel Borkmannfe1217c2013-12-29 18:27:10 +0100231 return register_tcf_proto_ops(&cls_cgroup_ops);
Thomas Graff4009232008-11-07 22:56:00 -0800232}
233
234static void __exit exit_cgroup_cls(void)
235{
236 unregister_tcf_proto_ops(&cls_cgroup_ops);
Thomas Graff4009232008-11-07 22:56:00 -0800237}
238
239module_init(init_cgroup_cls);
240module_exit(exit_cgroup_cls);
241MODULE_LICENSE("GPL");