1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
|
/*
* net/core/netclassid_cgroup.c Classid Cgroupfs Handling
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Authors: Thomas Graf <tgraf@suug.ch>
*/
#include <linux/slab.h>
#include <linux/cgroup.h>
#include <linux/fdtable.h>
#include <linux/sched/task.h>
#include <net/cls_cgroup.h>
#include <net/sock.h>
static inline struct cgroup_cls_state *css_cls_state(struct cgroup_subsys_state *css)
{
return css ? container_of(css, struct cgroup_cls_state, css) : NULL;
}
struct cgroup_cls_state *task_cls_state(struct task_struct *p)
{
return css_cls_state(task_css_check(p, net_cls_cgrp_id,
rcu_read_lock_bh_held()));
}
EXPORT_SYMBOL_GPL(task_cls_state);
static struct cgroup_subsys_state *
cgrp_css_alloc(struct cgroup_subsys_state *parent_css)
{
struct cgroup_cls_state *cs;
cs = kzalloc(sizeof(*cs), GFP_KERNEL);
if (!cs)
return ERR_PTR(-ENOMEM);
return &cs->css;
}
static int cgrp_css_online(struct cgroup_subsys_state *css)
{
struct cgroup_cls_state *cs = css_cls_state(css);
struct cgroup_cls_state *parent = css_cls_state(css->parent);
if (parent)
cs->classid = parent->classid;
return 0;
}
static void cgrp_css_free(struct cgroup_subsys_state *css)
{
kfree(css_cls_state(css));
}
/*
* To avoid freezing of sockets creation for tasks with big number of threads
* and opened sockets lets release file_lock every 1000 iterated descriptors.
* New sockets will already have been created with new classid.
*/
struct update_classid_context {
u32 classid;
unsigned int batch;
};
#define UPDATE_CLASSID_BATCH 1000
static int update_classid_sock(const void *v, struct file *file, unsigned n)
{
int err;
struct update_classid_context *ctx = (void *)v;
struct socket *sock = sock_from_file(file, &err);
if (sock) {
spin_lock(&cgroup_sk_update_lock);
sock_cgroup_set_classid(&sock->sk->sk_cgrp_data, ctx->classid);
spin_unlock(&cgroup_sk_update_lock);
}
if (--ctx->batch == 0) {
ctx->batch = UPDATE_CLASSID_BATCH;
return n + 1;
}
return 0;
}
static void update_classid_task(struct task_struct *p, u32 classid)
{
struct update_classid_context ctx = {
.classid = classid,
.batch = UPDATE_CLASSID_BATCH
};
unsigned int fd = 0;
do {
task_lock(p);
fd = iterate_fd(p->files, fd, update_classid_sock, &ctx);
task_unlock(p);
cond_resched();
} while (fd);
}
static void cgrp_attach(struct cgroup_taskset *tset)
{
struct cgroup_subsys_state *css;
struct task_struct *p;
cgroup_taskset_for_each(p, css, tset) {
update_classid_task(p, css_cls_state(css)->classid);
}
}
static u64 read_classid(struct cgroup_subsys_state *css, struct cftype *cft)
{
return css_cls_state(css)->classid;
}
static int write_classid(struct cgroup_subsys_state *css, struct cftype *cft,
u64 value)
{
struct cgroup_cls_state *cs = css_cls_state(css);
struct css_task_iter it;
struct task_struct *p;
cgroup_sk_alloc_disable();
cs->classid = (u32)value;
css_task_iter_start(css, 0, &it);
while ((p = css_task_iter_next(&it)))
update_classid_task(p, cs->classid);
css_task_iter_end(&it);
return 0;
}
static struct cftype ss_files[] = {
{
.name = "classid",
.read_u64 = read_classid,
.write_u64 = write_classid,
},
{ } /* terminate */
};
struct cgroup_subsys net_cls_cgrp_subsys = {
.css_alloc = cgrp_css_alloc,
.css_online = cgrp_css_online,
.css_free = cgrp_css_free,
.attach = cgrp_attach,
.legacy_cftypes = ss_files,
};
|
