1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2007 IBM Corporation
4 *
5 * Author: Cedric Le Goater <clg@fr.ibm.com>
6 */
7
8 #include <linux/nsproxy.h>
9 #include <linux/ipc_namespace.h>
10 #include <linux/sysctl.h>
11
12 #include <linux/stat.h>
13 #include <linux/capability.h>
14 #include <linux/slab.h>
15
16 static int msg_max_limit_min = MIN_MSGMAX;
17 static int msg_max_limit_max = HARD_MSGMAX;
18
19 static int msg_maxsize_limit_min = MIN_MSGSIZEMAX;
20 static int msg_maxsize_limit_max = HARD_MSGSIZEMAX;
21
22 static struct ctl_table mq_sysctls[] = {
23 {
24 .procname = "queues_max",
25 .data = &init_ipc_ns.mq_queues_max,
26 .maxlen = sizeof(int),
27 .mode = 0644,
28 .proc_handler = proc_dointvec,
29 },
30 {
31 .procname = "msg_max",
32 .data = &init_ipc_ns.mq_msg_max,
33 .maxlen = sizeof(int),
34 .mode = 0644,
35 .proc_handler = proc_dointvec_minmax,
36 .extra1 = &msg_max_limit_min,
37 .extra2 = &msg_max_limit_max,
38 },
39 {
40 .procname = "msgsize_max",
41 .data = &init_ipc_ns.mq_msgsize_max,
42 .maxlen = sizeof(int),
43 .mode = 0644,
44 .proc_handler = proc_dointvec_minmax,
45 .extra1 = &msg_maxsize_limit_min,
46 .extra2 = &msg_maxsize_limit_max,
47 },
48 {
49 .procname = "msg_default",
50 .data = &init_ipc_ns.mq_msg_default,
51 .maxlen = sizeof(int),
52 .mode = 0644,
53 .proc_handler = proc_dointvec_minmax,
54 .extra1 = &msg_max_limit_min,
55 .extra2 = &msg_max_limit_max,
56 },
57 {
58 .procname = "msgsize_default",
59 .data = &init_ipc_ns.mq_msgsize_default,
60 .maxlen = sizeof(int),
61 .mode = 0644,
62 .proc_handler = proc_dointvec_minmax,
63 .extra1 = &msg_maxsize_limit_min,
64 .extra2 = &msg_maxsize_limit_max,
65 },
66 {}
67 };
68
set_lookup(struct ctl_table_root * root)69 static struct ctl_table_set *set_lookup(struct ctl_table_root *root)
70 {
71 return ¤t->nsproxy->ipc_ns->mq_set;
72 }
73
set_is_seen(struct ctl_table_set * set)74 static int set_is_seen(struct ctl_table_set *set)
75 {
76 return ¤t->nsproxy->ipc_ns->mq_set == set;
77 }
78
79 static struct ctl_table_root set_root = {
80 .lookup = set_lookup,
81 };
82
setup_mq_sysctls(struct ipc_namespace * ns)83 bool setup_mq_sysctls(struct ipc_namespace *ns)
84 {
85 struct ctl_table *tbl;
86
87 setup_sysctl_set(&ns->mq_set, &set_root, set_is_seen);
88
89 tbl = kmemdup(mq_sysctls, sizeof(mq_sysctls), GFP_KERNEL);
90 if (tbl) {
91 int i;
92
93 for (i = 0; i < ARRAY_SIZE(mq_sysctls); i++) {
94 if (tbl[i].data == &init_ipc_ns.mq_queues_max)
95 tbl[i].data = &ns->mq_queues_max;
96
97 else if (tbl[i].data == &init_ipc_ns.mq_msg_max)
98 tbl[i].data = &ns->mq_msg_max;
99
100 else if (tbl[i].data == &init_ipc_ns.mq_msgsize_max)
101 tbl[i].data = &ns->mq_msgsize_max;
102
103 else if (tbl[i].data == &init_ipc_ns.mq_msg_default)
104 tbl[i].data = &ns->mq_msg_default;
105
106 else if (tbl[i].data == &init_ipc_ns.mq_msgsize_default)
107 tbl[i].data = &ns->mq_msgsize_default;
108 else
109 tbl[i].data = NULL;
110 }
111
112 ns->mq_sysctls = __register_sysctl_table(&ns->mq_set,
113 "fs/mqueue", tbl,
114 ARRAY_SIZE(mq_sysctls));
115 }
116 if (!ns->mq_sysctls) {
117 kfree(tbl);
118 retire_sysctl_set(&ns->mq_set);
119 return false;
120 }
121
122 return true;
123 }
124
retire_mq_sysctls(struct ipc_namespace * ns)125 void retire_mq_sysctls(struct ipc_namespace *ns)
126 {
127 struct ctl_table *tbl;
128
129 tbl = ns->mq_sysctls->ctl_table_arg;
130 unregister_sysctl_table(ns->mq_sysctls);
131 retire_sysctl_set(&ns->mq_set);
132 kfree(tbl);
133 }
134