aboutsummaryrefslogtreecommitdiffstats
path: root/ipc/ipc_sysctl.c
blob: a88934a1b76906e71663f163cd175ab5bce8c0dd (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
/*
 *  Copyright (C) 2007
 *
 *  Author: Eric Biederman <ebiederm@xmision.com>
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License as
 *  published by the Free Software Foundation, version 2 of the
 *  License.
 */

#include <linux/module.h>
#include <linux/ipc.h>
#include <linux/nsproxy.h>
#include <linux/sysctl.h>
#include <linux/uaccess.h>

#ifdef CONFIG_IPC_NS
static void *get_ipc(ctl_table *table)
{
	char *which = table->data;
	struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
	which = (which - (char *)&init_ipc_ns) + (char *)ipc_ns;
	return which;
}
#else
#define get_ipc(T) ((T)->data)
#endif

#ifdef CONFIG_PROC_FS
static int proc_ipc_dointvec(ctl_table *table, int write, struct file *filp,
	void __user *buffer, size_t *lenp, loff_t *ppos)
{
	struct ctl_table ipc_table;
	memcpy(&ipc_table, table, sizeof(ipc_table));
	ipc_table.data = get_ipc(table);

	return proc_dointvec(&ipc_table, write, filp, buffer, lenp, ppos);
}

static int proc_ipc_doulongvec_minmax(ctl_table *table, int write,
	struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos)
{
	struct ctl_table ipc_table;
	memcpy(&ipc_table, table, sizeof(ipc_table));
	ipc_table.data = get_ipc(table);

	return proc_doulongvec_minmax(&ipc_table, write, filp, buffer,
					lenp, ppos);
}

#else
#define proc_ipc_doulongvec_minmax NULL
#define proc_ipc_dointvec	   NULL
#endif

#ifdef CONFIG_SYSCTL_SYSCALL
/* The generic sysctl ipc data routine. */
static int sysctl_ipc_data(ctl_table *table, int __user *name, int nlen,
		void __user *oldval, size_t __user *oldlenp,
		void __user *newval, size_t newlen)
{
	size_t len;
	void *data;

	/* Get out of I don't have a variable */
	if (!table->data || !table->maxlen)
		return -ENOTDIR;

	data = get_ipc(table);
	if (!data)
		return -ENOTDIR;

	if (oldval && oldlenp) {
		if (get_user(len, oldlenp))
			return -EFAULT;
		if (len) {
			if (len > table->maxlen)
				len = table->maxlen;
			if (copy_to_user(oldval, data, len))
				return -EFAULT;
			if (put_user(len, oldlenp))
				return -EFAULT;
		}
	}

	if (newval && newlen) {
		if (newlen > table->maxlen)
			newlen = table->maxlen;

		if (copy_from_user(data, newval, newlen))
			return -EFAULT;
	}
	return 1;
}
#else
#define sysctl_ipc_data NULL
#endif

static struct ctl_table ipc_kern_table[] = {
	{
		.ctl_name	= KERN_SHMMAX,
		.procname	= "shmmax",
		.data		= &init_ipc_ns.shm_ctlmax,
		.maxlen		= sizeof (init_ipc_ns.shm_ctlmax),
		.mode		= 0644,
		.proc_handler	= proc_ipc_doulongvec_minmax,
		.strategy	= sysctl_ipc_data,
	},
	{
		.ctl_name	= KERN_SHMALL,
		.procname	= "shmall",
		.data		= &init_ipc_ns.shm_ctlall,
		.maxlen		= sizeof (init_ipc_ns.shm_ctlall),
		.mode		= 0644,
		.proc_handler	= proc_ipc_doulongvec_minmax,
		.strategy	= sysctl_ipc_data,
	},
	{
		.ctl_name	= KERN_SHMMNI,
		.procname	= "shmmni",
		.data		= &init_ipc_ns.shm_ctlmni,
		.maxlen		= sizeof (init_ipc_ns.shm_ctlmni),
		.mode		= 0644,
		.proc_handler	= proc_ipc_dointvec,
		.strategy	= sysctl_ipc_data,
	},
	{
		.ctl_name	= KERN_MSGMAX,
		.procname	= "msgmax",
		.data		= &init_ipc_ns.msg_ctlmax,
		.maxlen		= sizeof (init_ipc_ns.msg_ctlmax),
		.mode		= 0644,
		.proc_handler	= proc_ipc_dointvec,
		.strategy	= sysctl_ipc_data,
	},
	{
		.ctl_name	= KERN_MSGMNI,
		.procname	= "msgmni",
		.data		= &init_ipc_ns.msg_ctlmni,
		.maxlen		= sizeof (init_ipc_ns.msg_ctlmni),
		.mode		= 0644,
		.proc_handler	= proc_ipc_dointvec,
		.strategy	= sysctl_ipc_data,
	},
	{
		.ctl_name	= KERN_MSGMNB,
		.procname	=  "msgmnb",
		.data		= &init_ipc_ns.msg_ctlmnb,
		.maxlen		= sizeof (init_ipc_ns.msg_ctlmnb),
		.mode		= 0644,
		.proc_handler	= proc_ipc_dointvec,
		.strategy	= sysctl_ipc_data,
	},
	{
		.ctl_name	= KERN_SEM,
		.procname	= "sem",
		.data		= &init_ipc_ns.sem_ctls,
		.maxlen		= 4*sizeof (int),
		.mode		= 0644,
		.proc_handler	= proc_ipc_dointvec,
		.strategy	= sysctl_ipc_data,
	},
	{}
};

static struct ctl_table ipc_root_table[] = {
	{
		.ctl_name	= CTL_KERN,
		.procname	= "kernel",
		.mode		= 0555,
		.child		= ipc_kern_table,
	},
	{}
};

static int __init ipc_sysctl_init(void)
{
	register_sysctl_table(ipc_root_table);
	return 0;
}

__initcall(ipc_sysctl_init);