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
|
/*
* Copyright (C) 2004 IBM Corporation
*
* Author: Serge Hallyn <serue@us.ibm.com>
*
* 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, version 2 of the
* License.
*/
#include <linux/export.h>
#include <linux/uts.h>
#include <linux/utsname.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/user_namespace.h>
#include <linux/proc_ns.h>
static struct uts_namespace *create_uts_ns(void)
{
struct uts_namespace *uts_ns;
uts_ns = kmalloc(sizeof(struct uts_namespace), GFP_KERNEL);
if (uts_ns)
kref_init(&uts_ns->kref);
return uts_ns;
}
/*
* Clone a new ns copying an original utsname, setting refcount to 1
* @old_ns: namespace to clone
* Return ERR_PTR(-ENOMEM) on error (failure to kmalloc), new ns otherwise
*/
static struct uts_namespace *clone_uts_ns(struct user_namespace *user_ns,
struct uts_namespace *old_ns)
{
struct uts_namespace *ns;
int err;
ns = create_uts_ns();
if (!ns)
return ERR_PTR(-ENOMEM);
err = proc_alloc_inum(&ns->ns.inum);
if (err) {
kfree(ns);
return ERR_PTR(err);
}
down_read(&uts_sem);
memcpy(&ns->name, &old_ns->name, sizeof(ns->name));
ns->user_ns = get_user_ns(user_ns);
up_read(&uts_sem);
return ns;
}
/*
* Copy task tsk's utsname namespace, or clone it if flags
* specifies CLONE_NEWUTS. In latter case, changes to the
* utsname of this process won't be seen by parent, and vice
* versa.
*/
struct uts_namespace *copy_utsname(unsigned long flags,
struct user_namespace *user_ns, struct uts_namespace *old_ns)
{
struct uts_namespace *new_ns;
BUG_ON(!old_ns);
get_uts_ns(old_ns);
if (!(flags & CLONE_NEWUTS))
return old_ns;
new_ns = clone_uts_ns(user_ns, old_ns);
put_uts_ns(old_ns);
return new_ns;
}
void free_uts_ns(struct kref *kref)
{
struct uts_namespace *ns;
ns = container_of(kref, struct uts_namespace, kref);
put_user_ns(ns->user_ns);
proc_free_inum(ns->ns.inum);
kfree(ns);
}
static inline struct uts_namespace *to_uts_ns(struct ns_common *ns)
{
return container_of(ns, struct uts_namespace, ns);
}
static struct ns_common *utsns_get(struct task_struct *task)
{
struct uts_namespace *ns = NULL;
struct nsproxy *nsproxy;
task_lock(task);
nsproxy = task->nsproxy;
if (nsproxy) {
ns = nsproxy->uts_ns;
get_uts_ns(ns);
}
task_unlock(task);
return ns ? &ns->ns : NULL;
}
static void utsns_put(struct ns_common *ns)
{
put_uts_ns(to_uts_ns(ns));
}
static int utsns_install(struct nsproxy *nsproxy, struct ns_common *new)
{
struct uts_namespace *ns = to_uts_ns(new);
if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN) ||
!ns_capable(current_user_ns(), CAP_SYS_ADMIN))
return -EPERM;
get_uts_ns(ns);
put_uts_ns(nsproxy->uts_ns);
nsproxy->uts_ns = ns;
return 0;
}
const struct proc_ns_operations utsns_operations = {
.name = "uts",
.type = CLONE_NEWUTS,
.get = utsns_get,
.put = utsns_put,
.install = utsns_install,
};
|
