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
get_mq(struct ctl_table * table)17 static 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 
proc_mq_dointvec(struct ctl_table * table,int write,void __user * buffer,size_t * lenp,loff_t * ppos)25 static 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 
proc_mq_dointvec_minmax(struct ctl_table * table,int write,void __user * buffer,size_t * lenp,loff_t * ppos)35 static 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 
50 static int msg_max_limit_min = MIN_MSGMAX;
51 static int msg_max_limit_max = HARD_MSGMAX;
52 
53 static int msg_maxsize_limit_min = MIN_MSGSIZEMAX;
54 static int msg_maxsize_limit_max = HARD_MSGSIZEMAX;
55 
56 static 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 
103 static struct ctl_table mq_sysctl_dir[] = {
104 	{
105 		.procname	= "mqueue",
106 		.mode		= 0555,
107 		.child		= mq_sysctls,
108 	},
109 	{}
110 };
111 
112 static struct ctl_table mq_sysctl_root[] = {
113 	{
114 		.procname	= "fs",
115 		.mode		= 0555,
116 		.child		= mq_sysctl_dir,
117 	},
118 	{}
119 };
120 
mq_register_sysctl_table(void)121 struct ctl_table_header *mq_register_sysctl_table(void)
122 {
123 	return register_sysctl_table(mq_sysctl_root);
124 }
125