1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * net/sched/cls_cgroup.c Control Group Classifier |
4 | * |
5 | * Authors: Thomas Graf <tgraf@suug.ch> |
6 | */ |
7 | |
8 | #include <linux/module.h> |
9 | #include <linux/slab.h> |
10 | #include <linux/skbuff.h> |
11 | #include <linux/rcupdate.h> |
12 | #include <net/rtnetlink.h> |
13 | #include <net/pkt_cls.h> |
14 | #include <net/sock.h> |
15 | #include <net/cls_cgroup.h> |
16 | #include <net/tc_wrapper.h> |
17 | |
18 | struct cls_cgroup_head { |
19 | u32 handle; |
20 | struct tcf_exts exts; |
21 | struct tcf_ematch_tree ematches; |
22 | struct tcf_proto *tp; |
23 | struct rcu_work rwork; |
24 | }; |
25 | |
26 | TC_INDIRECT_SCOPE int cls_cgroup_classify(struct sk_buff *skb, |
27 | const struct tcf_proto *tp, |
28 | struct tcf_result *res) |
29 | { |
30 | struct cls_cgroup_head *head = rcu_dereference_bh(tp->root); |
31 | u32 classid = task_get_classid(skb); |
32 | |
33 | if (unlikely(!head)) |
34 | return -1; |
35 | if (!classid) |
36 | return -1; |
37 | if (!tcf_em_tree_match(skb, tree: &head->ematches, NULL)) |
38 | return -1; |
39 | |
40 | res->classid = classid; |
41 | res->class = 0; |
42 | |
43 | return tcf_exts_exec(skb, exts: &head->exts, res); |
44 | } |
45 | |
46 | static void *cls_cgroup_get(struct tcf_proto *tp, u32 handle) |
47 | { |
48 | return NULL; |
49 | } |
50 | |
51 | static int cls_cgroup_init(struct tcf_proto *tp) |
52 | { |
53 | return 0; |
54 | } |
55 | |
56 | static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = { |
57 | [TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED }, |
58 | }; |
59 | |
60 | static void __cls_cgroup_destroy(struct cls_cgroup_head *head) |
61 | { |
62 | tcf_exts_destroy(exts: &head->exts); |
63 | tcf_em_tree_destroy(&head->ematches); |
64 | tcf_exts_put_net(exts: &head->exts); |
65 | kfree(objp: head); |
66 | } |
67 | |
68 | static void cls_cgroup_destroy_work(struct work_struct *work) |
69 | { |
70 | struct cls_cgroup_head *head = container_of(to_rcu_work(work), |
71 | struct cls_cgroup_head, |
72 | rwork); |
73 | rtnl_lock(); |
74 | __cls_cgroup_destroy(head); |
75 | rtnl_unlock(); |
76 | } |
77 | |
78 | static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb, |
79 | struct tcf_proto *tp, unsigned long base, |
80 | u32 handle, struct nlattr **tca, |
81 | void **arg, u32 flags, |
82 | struct netlink_ext_ack *extack) |
83 | { |
84 | struct nlattr *tb[TCA_CGROUP_MAX + 1]; |
85 | struct cls_cgroup_head *head = rtnl_dereference(tp->root); |
86 | struct cls_cgroup_head *new; |
87 | int err; |
88 | |
89 | if (!tca[TCA_OPTIONS]) |
90 | return -EINVAL; |
91 | |
92 | if (!head && !handle) |
93 | return -EINVAL; |
94 | |
95 | if (head && handle != head->handle) |
96 | return -ENOENT; |
97 | |
98 | new = kzalloc(size: sizeof(*head), GFP_KERNEL); |
99 | if (!new) |
100 | return -ENOBUFS; |
101 | |
102 | err = tcf_exts_init(exts: &new->exts, net, action: TCA_CGROUP_ACT, police: TCA_CGROUP_POLICE); |
103 | if (err < 0) |
104 | goto errout; |
105 | new->handle = handle; |
106 | new->tp = tp; |
107 | err = nla_parse_nested_deprecated(tb, TCA_CGROUP_MAX, |
108 | nla: tca[TCA_OPTIONS], policy: cgroup_policy, |
109 | NULL); |
110 | if (err < 0) |
111 | goto errout; |
112 | |
113 | err = tcf_exts_validate(net, tp, tb, rate_tlv: tca[TCA_RATE], exts: &new->exts, flags, |
114 | extack); |
115 | if (err < 0) |
116 | goto errout; |
117 | |
118 | err = tcf_em_tree_validate(tp, tb[TCA_CGROUP_EMATCHES], &new->ematches); |
119 | if (err < 0) |
120 | goto errout; |
121 | |
122 | rcu_assign_pointer(tp->root, new); |
123 | if (head) { |
124 | tcf_exts_get_net(exts: &head->exts); |
125 | tcf_queue_work(rwork: &head->rwork, func: cls_cgroup_destroy_work); |
126 | } |
127 | return 0; |
128 | errout: |
129 | tcf_exts_destroy(exts: &new->exts); |
130 | kfree(objp: new); |
131 | return err; |
132 | } |
133 | |
134 | static void cls_cgroup_destroy(struct tcf_proto *tp, bool rtnl_held, |
135 | struct netlink_ext_ack *extack) |
136 | { |
137 | struct cls_cgroup_head *head = rtnl_dereference(tp->root); |
138 | |
139 | /* Head can still be NULL due to cls_cgroup_init(). */ |
140 | if (head) { |
141 | if (tcf_exts_get_net(exts: &head->exts)) |
142 | tcf_queue_work(rwork: &head->rwork, func: cls_cgroup_destroy_work); |
143 | else |
144 | __cls_cgroup_destroy(head); |
145 | } |
146 | } |
147 | |
148 | static int cls_cgroup_delete(struct tcf_proto *tp, void *arg, bool *last, |
149 | bool rtnl_held, struct netlink_ext_ack *extack) |
150 | { |
151 | return -EOPNOTSUPP; |
152 | } |
153 | |
154 | static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg, |
155 | bool rtnl_held) |
156 | { |
157 | struct cls_cgroup_head *head = rtnl_dereference(tp->root); |
158 | |
159 | if (arg->count < arg->skip) |
160 | goto skip; |
161 | |
162 | if (!head) |
163 | return; |
164 | if (arg->fn(tp, head, arg) < 0) { |
165 | arg->stop = 1; |
166 | return; |
167 | } |
168 | skip: |
169 | arg->count++; |
170 | } |
171 | |
172 | static int cls_cgroup_dump(struct net *net, struct tcf_proto *tp, void *fh, |
173 | struct sk_buff *skb, struct tcmsg *t, bool rtnl_held) |
174 | { |
175 | struct cls_cgroup_head *head = rtnl_dereference(tp->root); |
176 | struct nlattr *nest; |
177 | |
178 | t->tcm_handle = head->handle; |
179 | |
180 | nest = nla_nest_start_noflag(skb, attrtype: TCA_OPTIONS); |
181 | if (nest == NULL) |
182 | goto nla_put_failure; |
183 | |
184 | if (tcf_exts_dump(skb, exts: &head->exts) < 0 || |
185 | tcf_em_tree_dump(skb, &head->ematches, TCA_CGROUP_EMATCHES) < 0) |
186 | goto nla_put_failure; |
187 | |
188 | nla_nest_end(skb, start: nest); |
189 | |
190 | if (tcf_exts_dump_stats(skb, exts: &head->exts) < 0) |
191 | goto nla_put_failure; |
192 | |
193 | return skb->len; |
194 | |
195 | nla_put_failure: |
196 | nla_nest_cancel(skb, start: nest); |
197 | return -1; |
198 | } |
199 | |
200 | static struct tcf_proto_ops cls_cgroup_ops __read_mostly = { |
201 | .kind = "cgroup" , |
202 | .init = cls_cgroup_init, |
203 | .change = cls_cgroup_change, |
204 | .classify = cls_cgroup_classify, |
205 | .destroy = cls_cgroup_destroy, |
206 | .get = cls_cgroup_get, |
207 | .delete = cls_cgroup_delete, |
208 | .walk = cls_cgroup_walk, |
209 | .dump = cls_cgroup_dump, |
210 | .owner = THIS_MODULE, |
211 | }; |
212 | |
213 | static int __init init_cgroup_cls(void) |
214 | { |
215 | return register_tcf_proto_ops(ops: &cls_cgroup_ops); |
216 | } |
217 | |
218 | static void __exit exit_cgroup_cls(void) |
219 | { |
220 | unregister_tcf_proto_ops(ops: &cls_cgroup_ops); |
221 | } |
222 | |
223 | module_init(init_cgroup_cls); |
224 | module_exit(exit_cgroup_cls); |
225 | MODULE_LICENSE("GPL" ); |
226 | |