blob: 719efd541668c9b91fd79d6faa228c0923dafe24 [file] [log] [blame]
Daniel Borkmannfe1217c2013-12-29 18:27:10 +01001/*
2 * net/core/netclassid_cgroup.c Classid Cgroupfs Handling
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>
13#include <linux/slab.h>
14#include <linux/cgroup.h>
15#include <linux/fdtable.h>
16#include <net/cls_cgroup.h>
17#include <net/sock.h>
18
19static inline struct cgroup_cls_state *css_cls_state(struct cgroup_subsys_state *css)
20{
21 return css ? container_of(css, struct cgroup_cls_state, css) : NULL;
22}
23
24struct cgroup_cls_state *task_cls_state(struct task_struct *p)
25{
26 return css_cls_state(task_css(p, net_cls_subsys_id));
27}
28EXPORT_SYMBOL_GPL(task_cls_state);
29
30static struct cgroup_subsys_state *
31cgrp_css_alloc(struct cgroup_subsys_state *parent_css)
32{
33 struct cgroup_cls_state *cs;
34
35 cs = kzalloc(sizeof(*cs), GFP_KERNEL);
36 if (!cs)
37 return ERR_PTR(-ENOMEM);
38
39 return &cs->css;
40}
41
42static int cgrp_css_online(struct cgroup_subsys_state *css)
43{
44 struct cgroup_cls_state *cs = css_cls_state(css);
45 struct cgroup_cls_state *parent = css_cls_state(css_parent(css));
46
47 if (parent)
48 cs->classid = parent->classid;
49
50 return 0;
51}
52
53static void cgrp_css_free(struct cgroup_subsys_state *css)
54{
55 kfree(css_cls_state(css));
56}
57
58static int update_classid(const void *v, struct file *file, unsigned n)
59{
60 int err;
61 struct socket *sock = sock_from_file(file, &err);
62
63 if (sock)
64 sock->sk->sk_classid = (u32)(unsigned long)v;
65
66 return 0;
67}
68
69static void cgrp_attach(struct cgroup_subsys_state *css,
70 struct cgroup_taskset *tset)
71{
72 struct cgroup_cls_state *cs = css_cls_state(css);
73 void *v = (void *)(unsigned long)cs->classid;
74 struct task_struct *p;
75
76 cgroup_taskset_for_each(p, css, tset) {
77 task_lock(p);
78 iterate_fd(p->files, 0, update_classid, v);
79 task_unlock(p);
80 }
81}
82
83static u64 read_classid(struct cgroup_subsys_state *css, struct cftype *cft)
84{
85 return css_cls_state(css)->classid;
86}
87
88static int write_classid(struct cgroup_subsys_state *css, struct cftype *cft,
89 u64 value)
90{
91 css_cls_state(css)->classid = (u32) value;
92
93 return 0;
94}
95
96static struct cftype ss_files[] = {
97 {
98 .name = "classid",
99 .read_u64 = read_classid,
100 .write_u64 = write_classid,
101 },
102 { } /* terminate */
103};
104
105struct cgroup_subsys net_cls_subsys = {
106 .name = "net_cls",
107 .css_alloc = cgrp_css_alloc,
108 .css_online = cgrp_css_online,
109 .css_free = cgrp_css_free,
110 .attach = cgrp_attach,
111 .subsys_id = net_cls_subsys_id,
112 .base_cftypes = ss_files,
113 .module = THIS_MODULE,
114};
115
116static int __init init_netclassid_cgroup(void)
117{
118 return cgroup_load_subsys(&net_cls_subsys);
119}
120__initcall(init_netclassid_cgroup);