tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
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_check(p, net_cls_cgrp_id,
27 rcu_read_lock_bh_held()));
28}
29EXPORT_SYMBOL_GPL(task_cls_state);
30
31static struct cgroup_subsys_state *
32cgrp_css_alloc(struct cgroup_subsys_state *parent_css)
33{
34 struct cgroup_cls_state *cs;
35
36 cs = kzalloc(sizeof(*cs), GFP_KERNEL);
37 if (!cs)
38 return ERR_PTR(-ENOMEM);
39
40 return &cs->css;
41}
42
43static int cgrp_css_online(struct cgroup_subsys_state *css)
44{
45 struct cgroup_cls_state *cs = css_cls_state(css);
46 struct cgroup_cls_state *parent = css_cls_state(css->parent);
47
48 if (parent)
49 cs->classid = parent->classid;
50
51 return 0;
52}
53
54static void cgrp_css_free(struct cgroup_subsys_state *css)
55{
56 kfree(css_cls_state(css));
57}
58
59static int update_classid_sock(const void *v, struct file *file, unsigned n)
60{
61 int err;
62 struct socket *sock = sock_from_file(file, &err);
63
64 if (sock)
65 sock->sk->sk_classid = (u32)(unsigned long)v;
66
67 return 0;
68}
69
70static void update_classid(struct cgroup_subsys_state *css, void *v)
71{
72 struct css_task_iter it;
73 struct task_struct *p;
74
75 css_task_iter_start(css, &it);
76 while ((p = css_task_iter_next(&it))) {
77 task_lock(p);
78 iterate_fd(p->files, 0, update_classid_sock, v);
79 task_unlock(p);
80 }
81 css_task_iter_end(&it);
82}
83
84static void cgrp_attach(struct cgroup_taskset *tset)
85{
86 struct cgroup_subsys_state *css;
87
88 cgroup_taskset_first(tset, &css);
89 update_classid(css,
90 (void *)(unsigned long)css_cls_state(css)->classid);
91}
92
93static u64 read_classid(struct cgroup_subsys_state *css, struct cftype *cft)
94{
95 return css_cls_state(css)->classid;
96}
97
98static int write_classid(struct cgroup_subsys_state *css, struct cftype *cft,
99 u64 value)
100{
101 struct cgroup_cls_state *cs = css_cls_state(css);
102
103 cs->classid = (u32)value;
104
105 update_classid(css, (void *)(unsigned long)cs->classid);
106 return 0;
107}
108
109static struct cftype ss_files[] = {
110 {
111 .name = "classid",
112 .read_u64 = read_classid,
113 .write_u64 = write_classid,
114 },
115 { } /* terminate */
116};
117
118struct cgroup_subsys net_cls_cgrp_subsys = {
119 .css_alloc = cgrp_css_alloc,
120 .css_online = cgrp_css_online,
121 .css_free = cgrp_css_free,
122 .attach = cgrp_attach,
123 .legacy_cftypes = ss_files,
124};