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fe1217c4 DB |
1 | /* |
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 | ||
19 | static 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 | ||
24 | struct cgroup_cls_state *task_cls_state(struct task_struct *p) | |
25 | { | |
26 | return css_cls_state(task_css(p, net_cls_subsys_id)); | |
27 | } | |
28 | EXPORT_SYMBOL_GPL(task_cls_state); | |
29 | ||
30 | static struct cgroup_subsys_state * | |
31 | cgrp_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 | ||
42 | static 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 | ||
53 | static void cgrp_css_free(struct cgroup_subsys_state *css) | |
54 | { | |
55 | kfree(css_cls_state(css)); | |
56 | } | |
57 | ||
58 | static 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 | ||
69 | static 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 | ||
83 | static u64 read_classid(struct cgroup_subsys_state *css, struct cftype *cft) | |
84 | { | |
85 | return css_cls_state(css)->classid; | |
86 | } | |
87 | ||
88 | static 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 | ||
96 | static struct cftype ss_files[] = { | |
97 | { | |
98 | .name = "classid", | |
99 | .read_u64 = read_classid, | |
100 | .write_u64 = write_classid, | |
101 | }, | |
102 | { } /* terminate */ | |
103 | }; | |
104 | ||
105 | struct 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, | |
fe1217c4 | 113 | }; |