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
16static int msg_max_limit_min = MIN_MSGMAX;
17static int msg_max_limit_max = HARD_MSGMAX;
18
19static int msg_maxsize_limit_min = MIN_MSGSIZEMAX;
20static int msg_maxsize_limit_max = HARD_MSGSIZEMAX;
21
22static 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
69static struct ctl_table_set *set_lookup(struct ctl_table_root *root)
70{
71	return &current->nsproxy->ipc_ns->mq_set;
72}
73
74static int set_is_seen(struct ctl_table_set *set)
75{
76	return &current->nsproxy->ipc_ns->mq_set == set;
77}
78
79static struct ctl_table_root set_root = {
80	.lookup = set_lookup,
81};
82
83bool 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, "fs/mqueue", tbl);
113	}
114	if (!ns->mq_sysctls) {
115		kfree(tbl);
116		retire_sysctl_set(&ns->mq_set);
117		return false;
118	}
119
120	return true;
121}
122
123void retire_mq_sysctls(struct ipc_namespace *ns)
124{
125	struct ctl_table *tbl;
126
127	tbl = ns->mq_sysctls->ctl_table_arg;
128	unregister_sysctl_table(ns->mq_sysctls);
129	retire_sysctl_set(&ns->mq_set);
130	kfree(tbl);
131}
132