Commit | Line | Data |
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f4009237 TG |
1 | /* |
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> | |
5a0e3ad6 | 13 | #include <linux/slab.h> |
f4009237 | 14 | #include <linux/skbuff.h> |
f8451725 | 15 | #include <linux/rcupdate.h> |
f4009237 TG |
16 | #include <net/rtnetlink.h> |
17 | #include <net/pkt_cls.h> | |
f8451725 HX |
18 | #include <net/sock.h> |
19 | #include <net/cls_cgroup.h> | |
f4009237 | 20 | |
cc7ec456 | 21 | struct cls_cgroup_head { |
f4009237 TG |
22 | u32 handle; |
23 | struct tcf_exts exts; | |
24 | struct tcf_ematch_tree ematches; | |
952313bd JF |
25 | struct tcf_proto *tp; |
26 | struct rcu_head rcu; | |
f4009237 TG |
27 | }; |
28 | ||
dc7f9f6e | 29 | static int cls_cgroup_classify(struct sk_buff *skb, const struct tcf_proto *tp, |
f4009237 TG |
30 | struct tcf_result *res) |
31 | { | |
952313bd | 32 | struct cls_cgroup_head *head = rcu_dereference_bh(tp->root); |
e65fcfd6 | 33 | u32 classid; |
f4009237 | 34 | |
f8451725 | 35 | classid = task_cls_state(current)->classid; |
f8451725 | 36 | |
f4009237 TG |
37 | /* |
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 | */ | |
75e1056f | 47 | if (in_serving_softirq()) { |
f8451725 HX |
48 | /* If there is an sk_classid we'll use that. */ |
49 | if (!skb->sk) | |
50 | return -1; | |
51 | classid = skb->sk->sk_classid; | |
52 | } | |
f4009237 | 53 | |
e65fcfd6 PM |
54 | 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); | |
f4009237 TG |
63 | } |
64 | ||
65 | static unsigned long cls_cgroup_get(struct tcf_proto *tp, u32 handle) | |
66 | { | |
67 | return 0UL; | |
68 | } | |
69 | ||
70 | static void cls_cgroup_put(struct tcf_proto *tp, unsigned long f) | |
71 | { | |
72 | } | |
73 | ||
74 | static int cls_cgroup_init(struct tcf_proto *tp) | |
75 | { | |
76 | return 0; | |
77 | } | |
78 | ||
f4009237 TG |
79 | static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = { |
80 | [TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED }, | |
81 | }; | |
82 | ||
952313bd JF |
83 | static 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 | ||
89 | tcf_exts_destroy(head->tp, &head->exts); | |
90 | tcf_em_tree_destroy(head->tp, &head->ematches); | |
91 | kfree(head); | |
92 | } | |
93 | ||
c1b52739 | 94 | static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb, |
af4c6641 | 95 | struct tcf_proto *tp, unsigned long base, |
f4009237 | 96 | u32 handle, struct nlattr **tca, |
2f7ef2f8 | 97 | unsigned long *arg, bool ovr) |
f4009237 | 98 | { |
cc7ec456 | 99 | struct nlattr *tb[TCA_CGROUP_MAX + 1]; |
952313bd JF |
100 | struct cls_cgroup_head *head = rtnl_dereference(tp->root); |
101 | struct cls_cgroup_head *new; | |
f4009237 TG |
102 | struct tcf_ematch_tree t; |
103 | struct tcf_exts e; | |
104 | int err; | |
105 | ||
52ea3a56 MU |
106 | if (!tca[TCA_OPTIONS]) |
107 | return -EINVAL; | |
108 | ||
952313bd JF |
109 | if (!head && !handle) |
110 | return -EINVAL; | |
f4009237 | 111 | |
952313bd JF |
112 | if (head && handle != head->handle) |
113 | return -ENOENT; | |
f4009237 | 114 | |
952313bd JF |
115 | new = kzalloc(sizeof(*head), GFP_KERNEL); |
116 | if (!new) | |
117 | return -ENOBUFS; | |
f4009237 | 118 | |
952313bd JF |
119 | if (head) { |
120 | new->handle = head->handle; | |
121 | } else { | |
122 | tcf_exts_init(&new->exts, TCA_CGROUP_ACT, TCA_CGROUP_POLICE); | |
123 | new->handle = handle; | |
f4009237 TG |
124 | } |
125 | ||
952313bd | 126 | new->tp = tp; |
f4009237 TG |
127 | err = nla_parse_nested(tb, TCA_CGROUP_MAX, tca[TCA_OPTIONS], |
128 | cgroup_policy); | |
129 | if (err < 0) | |
130 | return err; | |
131 | ||
5da57f42 | 132 | tcf_exts_init(&e, TCA_CGROUP_ACT, TCA_CGROUP_POLICE); |
2f7ef2f8 | 133 | err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e, ovr); |
f4009237 TG |
134 | if (err < 0) |
135 | return err; | |
136 | ||
137 | err = tcf_em_tree_validate(tp, tb[TCA_CGROUP_EMATCHES], &t); | |
138 | if (err < 0) | |
139 | return err; | |
140 | ||
952313bd JF |
141 | tcf_exts_change(tp, &new->exts, &e); |
142 | tcf_em_tree_change(tp, &new->ematches, &t); | |
f4009237 | 143 | |
952313bd JF |
144 | rcu_assign_pointer(tp->root, new); |
145 | if (head) | |
146 | call_rcu(&head->rcu, cls_cgroup_destroy_rcu); | |
f4009237 TG |
147 | return 0; |
148 | } | |
149 | ||
150 | static void cls_cgroup_destroy(struct tcf_proto *tp) | |
151 | { | |
952313bd | 152 | struct cls_cgroup_head *head = rtnl_dereference(tp->root); |
f4009237 TG |
153 | |
154 | if (head) { | |
155 | tcf_exts_destroy(tp, &head->exts); | |
156 | tcf_em_tree_destroy(tp, &head->ematches); | |
952313bd JF |
157 | RCU_INIT_POINTER(tp->root, NULL); |
158 | kfree_rcu(head, rcu); | |
f4009237 TG |
159 | } |
160 | } | |
161 | ||
162 | static int cls_cgroup_delete(struct tcf_proto *tp, unsigned long arg) | |
163 | { | |
164 | return -EOPNOTSUPP; | |
165 | } | |
166 | ||
167 | static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg) | |
168 | { | |
952313bd | 169 | struct cls_cgroup_head *head = rtnl_dereference(tp->root); |
f4009237 TG |
170 | |
171 | if (arg->count < arg->skip) | |
172 | goto skip; | |
173 | ||
174 | if (arg->fn(tp, (unsigned long) head, arg) < 0) { | |
175 | arg->stop = 1; | |
176 | return; | |
177 | } | |
178 | skip: | |
179 | arg->count++; | |
180 | } | |
181 | ||
832d1d5b | 182 | static int cls_cgroup_dump(struct net *net, struct tcf_proto *tp, unsigned long fh, |
f4009237 TG |
183 | struct sk_buff *skb, struct tcmsg *t) |
184 | { | |
952313bd | 185 | struct cls_cgroup_head *head = rtnl_dereference(tp->root); |
f4009237 TG |
186 | unsigned char *b = skb_tail_pointer(skb); |
187 | struct nlattr *nest; | |
188 | ||
189 | t->tcm_handle = head->handle; | |
190 | ||
191 | nest = nla_nest_start(skb, TCA_OPTIONS); | |
192 | if (nest == NULL) | |
193 | goto nla_put_failure; | |
194 | ||
5da57f42 | 195 | if (tcf_exts_dump(skb, &head->exts) < 0 || |
f4009237 TG |
196 | tcf_em_tree_dump(skb, &head->ematches, TCA_CGROUP_EMATCHES) < 0) |
197 | goto nla_put_failure; | |
198 | ||
199 | nla_nest_end(skb, nest); | |
200 | ||
5da57f42 | 201 | if (tcf_exts_dump_stats(skb, &head->exts) < 0) |
f4009237 TG |
202 | goto nla_put_failure; |
203 | ||
204 | return skb->len; | |
205 | ||
206 | nla_put_failure: | |
207 | nlmsg_trim(skb, b); | |
208 | return -1; | |
209 | } | |
210 | ||
211 | static struct tcf_proto_ops cls_cgroup_ops __read_mostly = { | |
212 | .kind = "cgroup", | |
213 | .init = cls_cgroup_init, | |
214 | .change = cls_cgroup_change, | |
215 | .classify = cls_cgroup_classify, | |
216 | .destroy = cls_cgroup_destroy, | |
217 | .get = cls_cgroup_get, | |
218 | .put = cls_cgroup_put, | |
219 | .delete = cls_cgroup_delete, | |
220 | .walk = cls_cgroup_walk, | |
221 | .dump = cls_cgroup_dump, | |
222 | .owner = THIS_MODULE, | |
223 | }; | |
224 | ||
225 | static int __init init_cgroup_cls(void) | |
226 | { | |
fe1217c4 | 227 | return register_tcf_proto_ops(&cls_cgroup_ops); |
f4009237 TG |
228 | } |
229 | ||
230 | static void __exit exit_cgroup_cls(void) | |
231 | { | |
232 | unregister_tcf_proto_ops(&cls_cgroup_ops); | |
233 | } | |
234 | ||
235 | module_init(init_cgroup_cls); | |
236 | module_exit(exit_cgroup_cls); | |
237 | MODULE_LICENSE("GPL"); |