xref: /openbmc/linux/ipc/mq_sysctl.c (revision 565d76cb)
1 /*
2  *  Copyright (C) 2007 IBM Corporation
3  *
4  *  Author: Cedric Le Goater <clg@fr.ibm.com>
5  *
6  *  This program is free software; you can redistribute it and/or
7  *  modify it under the terms of the GNU General Public License as
8  *  published by the Free Software Foundation, version 2 of the
9  *  License.
10  */
11 
12 #include <linux/nsproxy.h>
13 #include <linux/ipc_namespace.h>
14 #include <linux/sysctl.h>
15 
16 /*
17  * Define the ranges various user-specified maximum values can
18  * be set to.
19  */
20 #define MIN_MSGMAX	1		/* min value for msg_max */
21 #define MAX_MSGMAX	HARD_MSGMAX	/* max value for msg_max */
22 #define MIN_MSGSIZEMAX	128		/* min value for msgsize_max */
23 #define MAX_MSGSIZEMAX	(8192*128)	/* max value for msgsize_max */
24 
25 #ifdef CONFIG_PROC_SYSCTL
26 static void *get_mq(ctl_table *table)
27 {
28 	char *which = table->data;
29 	struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
30 	which = (which - (char *)&init_ipc_ns) + (char *)ipc_ns;
31 	return which;
32 }
33 
34 static int proc_mq_dointvec(ctl_table *table, int write,
35 	void __user *buffer, size_t *lenp, loff_t *ppos)
36 {
37 	struct ctl_table mq_table;
38 	memcpy(&mq_table, table, sizeof(mq_table));
39 	mq_table.data = get_mq(table);
40 
41 	return proc_dointvec(&mq_table, write, buffer, lenp, ppos);
42 }
43 
44 static int proc_mq_dointvec_minmax(ctl_table *table, int write,
45 	void __user *buffer, size_t *lenp, loff_t *ppos)
46 {
47 	struct ctl_table mq_table;
48 	memcpy(&mq_table, table, sizeof(mq_table));
49 	mq_table.data = get_mq(table);
50 
51 	return proc_dointvec_minmax(&mq_table, write, buffer,
52 					lenp, ppos);
53 }
54 #else
55 #define proc_mq_dointvec NULL
56 #define proc_mq_dointvec_minmax NULL
57 #endif
58 
59 static int msg_max_limit_min = MIN_MSGMAX;
60 static int msg_max_limit_max = MAX_MSGMAX;
61 
62 static int msg_maxsize_limit_min = MIN_MSGSIZEMAX;
63 static int msg_maxsize_limit_max = MAX_MSGSIZEMAX;
64 
65 static ctl_table mq_sysctls[] = {
66 	{
67 		.procname	= "queues_max",
68 		.data		= &init_ipc_ns.mq_queues_max,
69 		.maxlen		= sizeof(int),
70 		.mode		= 0644,
71 		.proc_handler	= proc_mq_dointvec,
72 	},
73 	{
74 		.procname	= "msg_max",
75 		.data		= &init_ipc_ns.mq_msg_max,
76 		.maxlen		= sizeof(int),
77 		.mode		= 0644,
78 		.proc_handler	= proc_mq_dointvec_minmax,
79 		.extra1		= &msg_max_limit_min,
80 		.extra2		= &msg_max_limit_max,
81 	},
82 	{
83 		.procname	= "msgsize_max",
84 		.data		= &init_ipc_ns.mq_msgsize_max,
85 		.maxlen		= sizeof(int),
86 		.mode		= 0644,
87 		.proc_handler	= proc_mq_dointvec_minmax,
88 		.extra1		= &msg_maxsize_limit_min,
89 		.extra2		= &msg_maxsize_limit_max,
90 	},
91 	{}
92 };
93 
94 static ctl_table mq_sysctl_dir[] = {
95 	{
96 		.procname	= "mqueue",
97 		.mode		= 0555,
98 		.child		= mq_sysctls,
99 	},
100 	{}
101 };
102 
103 static ctl_table mq_sysctl_root[] = {
104 	{
105 		.procname	= "fs",
106 		.mode		= 0555,
107 		.child		= mq_sysctl_dir,
108 	},
109 	{}
110 };
111 
112 struct ctl_table_header *mq_register_sysctl_table(void)
113 {
114 	return register_sysctl_table(mq_sysctl_root);
115 }
116