mq_sysctl.c revision a5c5928b
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#ifdef CONFIG_PROC_SYSCTL
17static void *get_mq(struct ctl_table *table)
18{
19	char *which = table->data;
20	struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
21	which = (which - (char *)&init_ipc_ns) + (char *)ipc_ns;
22	return which;
23}
24
25static int proc_mq_dointvec(struct ctl_table *table, int write,
26			    void __user *buffer, size_t *lenp, loff_t *ppos)
27{
28	struct ctl_table mq_table;
29	memcpy(&mq_table, table, sizeof(mq_table));
30	mq_table.data = get_mq(table);
31
32	return proc_dointvec(&mq_table, write, buffer, lenp, ppos);
33}
34
35static int proc_mq_dointvec_minmax(struct ctl_table *table, int write,
36	void __user *buffer, size_t *lenp, loff_t *ppos)
37{
38	struct ctl_table mq_table;
39	memcpy(&mq_table, table, sizeof(mq_table));
40	mq_table.data = get_mq(table);
41
42	return proc_dointvec_minmax(&mq_table, write, buffer,
43					lenp, ppos);
44}
45#else
46#define proc_mq_dointvec NULL
47#define proc_mq_dointvec_minmax NULL
48#endif
49
50static int msg_max_limit_min = MIN_MSGMAX;
51static int msg_max_limit_max = HARD_MSGMAX;
52
53static int msg_maxsize_limit_min = MIN_MSGSIZEMAX;
54static int msg_maxsize_limit_max = HARD_MSGSIZEMAX;
55
56static struct ctl_table mq_sysctls[] = {
57	{
58		.procname	= "queues_max",
59		.data		= &init_ipc_ns.mq_queues_max,
60		.maxlen		= sizeof(int),
61		.mode		= 0644,
62		.proc_handler	= proc_mq_dointvec,
63	},
64	{
65		.procname	= "msg_max",
66		.data		= &init_ipc_ns.mq_msg_max,
67		.maxlen		= sizeof(int),
68		.mode		= 0644,
69		.proc_handler	= proc_mq_dointvec_minmax,
70		.extra1		= &msg_max_limit_min,
71		.extra2		= &msg_max_limit_max,
72	},
73	{
74		.procname	= "msgsize_max",
75		.data		= &init_ipc_ns.mq_msgsize_max,
76		.maxlen		= sizeof(int),
77		.mode		= 0644,
78		.proc_handler	= proc_mq_dointvec_minmax,
79		.extra1		= &msg_maxsize_limit_min,
80		.extra2		= &msg_maxsize_limit_max,
81	},
82	{
83		.procname	= "msg_default",
84		.data		= &init_ipc_ns.mq_msg_default,
85		.maxlen		= sizeof(int),
86		.mode		= 0644,
87		.proc_handler	= proc_mq_dointvec_minmax,
88		.extra1		= &msg_max_limit_min,
89		.extra2		= &msg_max_limit_max,
90	},
91	{
92		.procname	= "msgsize_default",
93		.data		= &init_ipc_ns.mq_msgsize_default,
94		.maxlen		= sizeof(int),
95		.mode		= 0644,
96		.proc_handler	= proc_mq_dointvec_minmax,
97		.extra1		= &msg_maxsize_limit_min,
98		.extra2		= &msg_maxsize_limit_max,
99	},
100	{}
101};
102
103static struct ctl_table mq_sysctl_dir[] = {
104	{
105		.procname	= "mqueue",
106		.mode		= 0555,
107		.child		= mq_sysctls,
108	},
109	{}
110};
111
112static struct ctl_table mq_sysctl_root[] = {
113	{
114		.procname	= "fs",
115		.mode		= 0555,
116		.child		= mq_sysctl_dir,
117	},
118	{}
119};
120
121struct ctl_table_header *mq_register_sysctl_table(void)
122{
123	return register_sysctl_table(mq_sysctl_root);
124}
125