4 * Author: Eric Biederman <ebiederm@xmision.com>
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
12 #include <linux/module.h>
13 #include <linux/ipc.h>
14 #include <linux/nsproxy.h>
15 #include <linux/sysctl.h>
16 #include <linux/uaccess.h>
17 #include <linux/ipc_namespace.h>
18 #include <linux/msg.h>
21 static void *get_ipc(ctl_table
*table
)
23 char *which
= table
->data
;
24 struct ipc_namespace
*ipc_ns
= current
->nsproxy
->ipc_ns
;
25 which
= (which
- (char *)&init_ipc_ns
) + (char *)ipc_ns
;
29 #ifdef CONFIG_PROC_SYSCTL
30 static int proc_ipc_dointvec(ctl_table
*table
, int write
,
31 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
33 struct ctl_table ipc_table
;
34 memcpy(&ipc_table
, table
, sizeof(ipc_table
));
35 ipc_table
.data
= get_ipc(table
);
37 return proc_dointvec(&ipc_table
, write
, buffer
, lenp
, ppos
);
40 static int proc_ipc_callback_dointvec(ctl_table
*table
, int write
,
41 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
43 struct ctl_table ipc_table
;
44 size_t lenp_bef
= *lenp
;
47 memcpy(&ipc_table
, table
, sizeof(ipc_table
));
48 ipc_table
.data
= get_ipc(table
);
50 rc
= proc_dointvec(&ipc_table
, write
, buffer
, lenp
, ppos
);
52 if (write
&& !rc
&& lenp_bef
== *lenp
)
54 * Tunable has successfully been changed by hand. Disable its
55 * automatic adjustment. This simply requires unregistering
56 * the notifiers that trigger recalculation.
58 unregister_ipcns_notifier(current
->nsproxy
->ipc_ns
);
63 static int proc_ipc_doulongvec_minmax(ctl_table
*table
, int write
,
64 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
66 struct ctl_table ipc_table
;
67 memcpy(&ipc_table
, table
, sizeof(ipc_table
));
68 ipc_table
.data
= get_ipc(table
);
70 return proc_doulongvec_minmax(&ipc_table
, write
, buffer
,
75 * Routine that is called when the file "auto_msgmni" has successfully been
77 * Two values are allowed:
78 * 0: unregister msgmni's callback routine from the ipc namespace notifier
79 * chain. This means that msgmni won't be recomputed anymore upon memory
80 * add/remove or ipc namespace creation/removal.
81 * 1: register back the callback routine.
83 static void ipc_auto_callback(int val
)
86 unregister_ipcns_notifier(current
->nsproxy
->ipc_ns
);
89 * Re-enable automatic recomputing only if not already
92 recompute_msgmni(current
->nsproxy
->ipc_ns
);
93 cond_register_ipcns_notifier(current
->nsproxy
->ipc_ns
);
97 static int proc_ipcauto_dointvec_minmax(ctl_table
*table
, int write
,
98 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
100 struct ctl_table ipc_table
;
101 size_t lenp_bef
= *lenp
;
105 memcpy(&ipc_table
, table
, sizeof(ipc_table
));
106 ipc_table
.data
= get_ipc(table
);
107 oldval
= *((int *)(ipc_table
.data
));
109 rc
= proc_dointvec_minmax(&ipc_table
, write
, buffer
, lenp
, ppos
);
111 if (write
&& !rc
&& lenp_bef
== *lenp
) {
112 int newval
= *((int *)(ipc_table
.data
));
114 * The file "auto_msgmni" has correctly been set.
115 * React by (un)registering the corresponding tunable, if the
118 if (newval
!= oldval
)
119 ipc_auto_callback(newval
);
126 #define proc_ipc_doulongvec_minmax NULL
127 #define proc_ipc_dointvec NULL
128 #define proc_ipc_callback_dointvec NULL
129 #define proc_ipcauto_dointvec_minmax NULL
132 #ifdef CONFIG_SYSCTL_SYSCALL
133 /* The generic sysctl ipc data routine. */
134 static int sysctl_ipc_data(ctl_table
*table
,
135 void __user
*oldval
, size_t __user
*oldlenp
,
136 void __user
*newval
, size_t newlen
)
141 /* Get out of I don't have a variable */
142 if (!table
->data
|| !table
->maxlen
)
145 data
= get_ipc(table
);
149 if (oldval
&& oldlenp
) {
150 if (get_user(len
, oldlenp
))
153 if (len
> table
->maxlen
)
155 if (copy_to_user(oldval
, data
, len
))
157 if (put_user(len
, oldlenp
))
162 if (newval
&& newlen
) {
163 if (newlen
> table
->maxlen
)
164 newlen
= table
->maxlen
;
166 if (copy_from_user(data
, newval
, newlen
))
172 static int sysctl_ipc_registered_data(ctl_table
*table
,
173 void __user
*oldval
, size_t __user
*oldlenp
,
174 void __user
*newval
, size_t newlen
)
178 rc
= sysctl_ipc_data(table
, oldval
, oldlenp
, newval
, newlen
);
180 if (newval
&& newlen
&& rc
> 0)
182 * Tunable has successfully been changed from userland
184 unregister_ipcns_notifier(current
->nsproxy
->ipc_ns
);
189 #define sysctl_ipc_data NULL
190 #define sysctl_ipc_registered_data NULL
196 static struct ctl_table ipc_kern_table
[] = {
198 .ctl_name
= KERN_SHMMAX
,
199 .procname
= "shmmax",
200 .data
= &init_ipc_ns
.shm_ctlmax
,
201 .maxlen
= sizeof (init_ipc_ns
.shm_ctlmax
),
203 .proc_handler
= proc_ipc_doulongvec_minmax
,
204 .strategy
= sysctl_ipc_data
,
207 .ctl_name
= KERN_SHMALL
,
208 .procname
= "shmall",
209 .data
= &init_ipc_ns
.shm_ctlall
,
210 .maxlen
= sizeof (init_ipc_ns
.shm_ctlall
),
212 .proc_handler
= proc_ipc_doulongvec_minmax
,
213 .strategy
= sysctl_ipc_data
,
216 .ctl_name
= KERN_SHMMNI
,
217 .procname
= "shmmni",
218 .data
= &init_ipc_ns
.shm_ctlmni
,
219 .maxlen
= sizeof (init_ipc_ns
.shm_ctlmni
),
221 .proc_handler
= proc_ipc_dointvec
,
222 .strategy
= sysctl_ipc_data
,
225 .ctl_name
= KERN_MSGMAX
,
226 .procname
= "msgmax",
227 .data
= &init_ipc_ns
.msg_ctlmax
,
228 .maxlen
= sizeof (init_ipc_ns
.msg_ctlmax
),
230 .proc_handler
= proc_ipc_dointvec
,
231 .strategy
= sysctl_ipc_data
,
234 .ctl_name
= KERN_MSGMNI
,
235 .procname
= "msgmni",
236 .data
= &init_ipc_ns
.msg_ctlmni
,
237 .maxlen
= sizeof (init_ipc_ns
.msg_ctlmni
),
239 .proc_handler
= proc_ipc_callback_dointvec
,
240 .strategy
= sysctl_ipc_registered_data
,
243 .ctl_name
= KERN_MSGMNB
,
244 .procname
= "msgmnb",
245 .data
= &init_ipc_ns
.msg_ctlmnb
,
246 .maxlen
= sizeof (init_ipc_ns
.msg_ctlmnb
),
248 .proc_handler
= proc_ipc_dointvec
,
249 .strategy
= sysctl_ipc_data
,
252 .ctl_name
= KERN_SEM
,
254 .data
= &init_ipc_ns
.sem_ctls
,
255 .maxlen
= 4*sizeof (int),
257 .proc_handler
= proc_ipc_dointvec
,
258 .strategy
= sysctl_ipc_data
,
261 .ctl_name
= CTL_UNNUMBERED
,
262 .procname
= "auto_msgmni",
263 .data
= &init_ipc_ns
.auto_msgmni
,
264 .maxlen
= sizeof(int),
266 .proc_handler
= proc_ipcauto_dointvec_minmax
,
273 static struct ctl_table ipc_root_table
[] = {
275 .ctl_name
= CTL_KERN
,
276 .procname
= "kernel",
278 .child
= ipc_kern_table
,
283 static int __init
ipc_sysctl_init(void)
285 register_sysctl_table(ipc_root_table
);
289 __initcall(ipc_sysctl_init
);