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git.ipfire.org Git - thirdparty/kernel/linux.git/blob - ipc/mq_sysctl.c
1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2007 IBM Corporation
5 * Author: Cedric Le Goater <clg@fr.ibm.com>
8 #include <linux/nsproxy.h>
9 #include <linux/ipc_namespace.h>
10 #include <linux/sysctl.h>
12 #include <linux/stat.h>
13 #include <linux/capability.h>
14 #include <linux/slab.h>
15 #include <linux/cred.h>
17 static int msg_max_limit_min
= MIN_MSGMAX
;
18 static int msg_max_limit_max
= HARD_MSGMAX
;
20 static int msg_maxsize_limit_min
= MIN_MSGSIZEMAX
;
21 static int msg_maxsize_limit_max
= HARD_MSGSIZEMAX
;
23 static struct ctl_table mq_sysctls
[] = {
25 .procname
= "queues_max",
26 .data
= &init_ipc_ns
.mq_queues_max
,
27 .maxlen
= sizeof(int),
29 .proc_handler
= proc_dointvec
,
32 .procname
= "msg_max",
33 .data
= &init_ipc_ns
.mq_msg_max
,
34 .maxlen
= sizeof(int),
36 .proc_handler
= proc_dointvec_minmax
,
37 .extra1
= &msg_max_limit_min
,
38 .extra2
= &msg_max_limit_max
,
41 .procname
= "msgsize_max",
42 .data
= &init_ipc_ns
.mq_msgsize_max
,
43 .maxlen
= sizeof(int),
45 .proc_handler
= proc_dointvec_minmax
,
46 .extra1
= &msg_maxsize_limit_min
,
47 .extra2
= &msg_maxsize_limit_max
,
50 .procname
= "msg_default",
51 .data
= &init_ipc_ns
.mq_msg_default
,
52 .maxlen
= sizeof(int),
54 .proc_handler
= proc_dointvec_minmax
,
55 .extra1
= &msg_max_limit_min
,
56 .extra2
= &msg_max_limit_max
,
59 .procname
= "msgsize_default",
60 .data
= &init_ipc_ns
.mq_msgsize_default
,
61 .maxlen
= sizeof(int),
63 .proc_handler
= proc_dointvec_minmax
,
64 .extra1
= &msg_maxsize_limit_min
,
65 .extra2
= &msg_maxsize_limit_max
,
70 static struct ctl_table_set
*set_lookup(struct ctl_table_root
*root
)
72 return ¤t
->nsproxy
->ipc_ns
->mq_set
;
75 static int set_is_seen(struct ctl_table_set
*set
)
77 return ¤t
->nsproxy
->ipc_ns
->mq_set
== set
;
80 static void mq_set_ownership(struct ctl_table_header
*head
,
81 struct ctl_table
*table
,
82 kuid_t
*uid
, kgid_t
*gid
)
84 struct ipc_namespace
*ns
=
85 container_of(head
->set
, struct ipc_namespace
, mq_set
);
87 kuid_t ns_root_uid
= make_kuid(ns
->user_ns
, 0);
88 kgid_t ns_root_gid
= make_kgid(ns
->user_ns
, 0);
90 *uid
= uid_valid(ns_root_uid
) ? ns_root_uid
: GLOBAL_ROOT_UID
;
91 *gid
= gid_valid(ns_root_gid
) ? ns_root_gid
: GLOBAL_ROOT_GID
;
94 static int mq_permissions(struct ctl_table_header
*head
, struct ctl_table
*table
)
96 int mode
= table
->mode
;
100 mq_set_ownership(head
, table
, &ns_root_uid
, &ns_root_gid
);
102 if (uid_eq(current_euid(), ns_root_uid
))
105 else if (in_egroup_p(ns_root_gid
))
110 return (mode
<< 6) | (mode
<< 3) | mode
;
113 static struct ctl_table_root set_root
= {
114 .lookup
= set_lookup
,
115 .permissions
= mq_permissions
,
116 .set_ownership
= mq_set_ownership
,
119 bool setup_mq_sysctls(struct ipc_namespace
*ns
)
121 struct ctl_table
*tbl
;
123 setup_sysctl_set(&ns
->mq_set
, &set_root
, set_is_seen
);
125 tbl
= kmemdup(mq_sysctls
, sizeof(mq_sysctls
), GFP_KERNEL
);
129 for (i
= 0; i
< ARRAY_SIZE(mq_sysctls
); i
++) {
130 if (tbl
[i
].data
== &init_ipc_ns
.mq_queues_max
)
131 tbl
[i
].data
= &ns
->mq_queues_max
;
133 else if (tbl
[i
].data
== &init_ipc_ns
.mq_msg_max
)
134 tbl
[i
].data
= &ns
->mq_msg_max
;
136 else if (tbl
[i
].data
== &init_ipc_ns
.mq_msgsize_max
)
137 tbl
[i
].data
= &ns
->mq_msgsize_max
;
139 else if (tbl
[i
].data
== &init_ipc_ns
.mq_msg_default
)
140 tbl
[i
].data
= &ns
->mq_msg_default
;
142 else if (tbl
[i
].data
== &init_ipc_ns
.mq_msgsize_default
)
143 tbl
[i
].data
= &ns
->mq_msgsize_default
;
148 ns
->mq_sysctls
= __register_sysctl_table(&ns
->mq_set
,
150 ARRAY_SIZE(mq_sysctls
));
152 if (!ns
->mq_sysctls
) {
154 retire_sysctl_set(&ns
->mq_set
);
161 void retire_mq_sysctls(struct ipc_namespace
*ns
)
163 struct ctl_table
*tbl
;
165 tbl
= ns
->mq_sysctls
->ctl_table_arg
;
166 unregister_sysctl_table(ns
->mq_sysctls
);
167 retire_sysctl_set(&ns
->mq_set
);