xref: /openbmc/linux/ipc/mq_sysctl.c (revision 90cb380f9ceb811059340d06ff5fd0c0e93ecbe1)
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  
69  static struct ctl_table_set *set_lookup(struct ctl_table_root *root)
70  {
71  	return &current->nsproxy->ipc_ns->mq_set;
72  }
73  
74  static int set_is_seen(struct ctl_table_set *set)
75  {
76  	return &current->nsproxy->ipc_ns->mq_set == set;
77  }
78  
79  static struct ctl_table_root set_root = {
80  	.lookup = set_lookup,
81  };
82  
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, "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  
123  void 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