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Eric W. Biedermana5494dc2007-02-14 00:34:06 -08001/*
2 * Copyright (C) 2007
3 *
4 * Author: Eric Biederman <ebiederm@xmision.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/module.h>
13#include <linux/ipc.h>
14#include <linux/nsproxy.h>
15#include <linux/sysctl.h>
16#include <linux/uaccess.h>
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -080017#include <linux/ipc_namespace.h>
Nadia Derbey6546bc42008-04-29 01:00:45 -070018#include <linux/msg.h>
19#include "util.h"
Eric W. Biedermana5494dc2007-02-14 00:34:06 -080020
Eric W. Biedermana5494dc2007-02-14 00:34:06 -080021static void *get_ipc(ctl_table *table)
22{
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;
26 return which;
27}
Eric W. Biedermana5494dc2007-02-14 00:34:06 -080028
Nadia Derbey6546bc42008-04-29 01:00:45 -070029/*
Nadia Derbey9eefe522008-07-25 01:48:08 -070030 * Routine that is called when the file "auto_msgmni" has successfully been
31 * written.
32 * Two values are allowed:
33 * 0: unregister msgmni's callback routine from the ipc namespace notifier
34 * chain. This means that msgmni won't be recomputed anymore upon memory
35 * add/remove or ipc namespace creation/removal.
36 * 1: register back the callback routine.
Nadia Derbey6546bc42008-04-29 01:00:45 -070037 */
Nadia Derbey9eefe522008-07-25 01:48:08 -070038static void ipc_auto_callback(int val)
Nadia Derbey6546bc42008-04-29 01:00:45 -070039{
Nadia Derbey9eefe522008-07-25 01:48:08 -070040 if (!val)
Nadia Derbey6546bc42008-04-29 01:00:45 -070041 unregister_ipcns_notifier(current->nsproxy->ipc_ns);
42 else {
43 /*
44 * Re-enable automatic recomputing only if not already
45 * enabled.
46 */
47 recompute_msgmni(current->nsproxy->ipc_ns);
48 cond_register_ipcns_notifier(current->nsproxy->ipc_ns);
49 }
50}
51
Eric W. Biedermana5494dc2007-02-14 00:34:06 -080052#ifdef CONFIG_PROC_FS
53static int proc_ipc_dointvec(ctl_table *table, int write, struct file *filp,
54 void __user *buffer, size_t *lenp, loff_t *ppos)
55{
56 struct ctl_table ipc_table;
57 memcpy(&ipc_table, table, sizeof(ipc_table));
58 ipc_table.data = get_ipc(table);
59
60 return proc_dointvec(&ipc_table, write, filp, buffer, lenp, ppos);
61}
62
Nadia Derbey91cfb2b2008-04-29 01:00:44 -070063static int proc_ipc_callback_dointvec(ctl_table *table, int write,
64 struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos)
65{
Nadia Derbey6546bc42008-04-29 01:00:45 -070066 struct ctl_table ipc_table;
Nadia Derbey91cfb2b2008-04-29 01:00:44 -070067 size_t lenp_bef = *lenp;
68 int rc;
69
Nadia Derbey6546bc42008-04-29 01:00:45 -070070 memcpy(&ipc_table, table, sizeof(ipc_table));
71 ipc_table.data = get_ipc(table);
72
73 rc = proc_dointvec(&ipc_table, write, filp, buffer, lenp, ppos);
Nadia Derbey91cfb2b2008-04-29 01:00:44 -070074
75 if (write && !rc && lenp_bef == *lenp)
Nadia Derbey9eefe522008-07-25 01:48:08 -070076 /*
77 * Tunable has successfully been changed by hand. Disable its
78 * automatic adjustment. This simply requires unregistering
79 * the notifiers that trigger recalculation.
80 */
81 unregister_ipcns_notifier(current->nsproxy->ipc_ns);
Nadia Derbey91cfb2b2008-04-29 01:00:44 -070082
83 return rc;
84}
85
Eric W. Biedermana5494dc2007-02-14 00:34:06 -080086static int proc_ipc_doulongvec_minmax(ctl_table *table, int write,
87 struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos)
88{
89 struct ctl_table ipc_table;
90 memcpy(&ipc_table, table, sizeof(ipc_table));
91 ipc_table.data = get_ipc(table);
92
93 return proc_doulongvec_minmax(&ipc_table, write, filp, buffer,
94 lenp, ppos);
95}
96
Nadia Derbey9eefe522008-07-25 01:48:08 -070097static int proc_ipcauto_dointvec_minmax(ctl_table *table, int write,
98 struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos)
99{
100 struct ctl_table ipc_table;
101 size_t lenp_bef = *lenp;
102 int oldval;
103 int rc;
104
105 memcpy(&ipc_table, table, sizeof(ipc_table));
106 ipc_table.data = get_ipc(table);
107 oldval = *((int *)(ipc_table.data));
108
109 rc = proc_dointvec_minmax(&ipc_table, write, filp, buffer, lenp, ppos);
110
111 if (write && !rc && lenp_bef == *lenp) {
112 int newval = *((int *)(ipc_table.data));
113 /*
114 * The file "auto_msgmni" has correctly been set.
115 * React by (un)registering the corresponding tunable, if the
116 * value has changed.
117 */
118 if (newval != oldval)
119 ipc_auto_callback(newval);
120 }
121
122 return rc;
123}
124
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800125#else
126#define proc_ipc_doulongvec_minmax NULL
127#define proc_ipc_dointvec NULL
Nadia Derbey91cfb2b2008-04-29 01:00:44 -0700128#define proc_ipc_callback_dointvec NULL
Nadia Derbey9eefe522008-07-25 01:48:08 -0700129#define proc_ipcauto_dointvec_minmax NULL
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800130#endif
131
132#ifdef CONFIG_SYSCTL_SYSCALL
133/* The generic sysctl ipc data routine. */
Alexey Dobriyanf221e722008-10-15 22:04:23 -0700134static int sysctl_ipc_data(ctl_table *table,
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800135 void __user *oldval, size_t __user *oldlenp,
136 void __user *newval, size_t newlen)
137{
138 size_t len;
139 void *data;
140
141 /* Get out of I don't have a variable */
142 if (!table->data || !table->maxlen)
143 return -ENOTDIR;
144
145 data = get_ipc(table);
146 if (!data)
147 return -ENOTDIR;
148
149 if (oldval && oldlenp) {
150 if (get_user(len, oldlenp))
151 return -EFAULT;
152 if (len) {
153 if (len > table->maxlen)
154 len = table->maxlen;
155 if (copy_to_user(oldval, data, len))
156 return -EFAULT;
157 if (put_user(len, oldlenp))
158 return -EFAULT;
159 }
160 }
161
162 if (newval && newlen) {
163 if (newlen > table->maxlen)
164 newlen = table->maxlen;
165
166 if (copy_from_user(data, newval, newlen))
167 return -EFAULT;
168 }
169 return 1;
170}
Nadia Derbey91cfb2b2008-04-29 01:00:44 -0700171
Alexey Dobriyanf221e722008-10-15 22:04:23 -0700172static int sysctl_ipc_registered_data(ctl_table *table,
173 void __user *oldval, size_t __user *oldlenp,
Nadia Derbey91cfb2b2008-04-29 01:00:44 -0700174 void __user *newval, size_t newlen)
175{
176 int rc;
177
Alexey Dobriyanf221e722008-10-15 22:04:23 -0700178 rc = sysctl_ipc_data(table, oldval, oldlenp, newval, newlen);
Nadia Derbey91cfb2b2008-04-29 01:00:44 -0700179
Nadia Derbey9eefe522008-07-25 01:48:08 -0700180 if (newval && newlen && rc > 0)
Nadia Derbey91cfb2b2008-04-29 01:00:44 -0700181 /*
Nadia Derbey6546bc42008-04-29 01:00:45 -0700182 * Tunable has successfully been changed from userland
Nadia Derbey91cfb2b2008-04-29 01:00:44 -0700183 */
Nadia Derbey9eefe522008-07-25 01:48:08 -0700184 unregister_ipcns_notifier(current->nsproxy->ipc_ns);
Nadia Derbey91cfb2b2008-04-29 01:00:44 -0700185
186 return rc;
187}
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800188#else
189#define sysctl_ipc_data NULL
Nadia Derbey91cfb2b2008-04-29 01:00:44 -0700190#define sysctl_ipc_registered_data NULL
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800191#endif
192
Nadia Derbey9eefe522008-07-25 01:48:08 -0700193static int zero;
194static int one = 1;
195
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800196static struct ctl_table ipc_kern_table[] = {
197 {
198 .ctl_name = KERN_SHMMAX,
199 .procname = "shmmax",
200 .data = &init_ipc_ns.shm_ctlmax,
201 .maxlen = sizeof (init_ipc_ns.shm_ctlmax),
202 .mode = 0644,
203 .proc_handler = proc_ipc_doulongvec_minmax,
204 .strategy = sysctl_ipc_data,
205 },
206 {
207 .ctl_name = KERN_SHMALL,
208 .procname = "shmall",
209 .data = &init_ipc_ns.shm_ctlall,
210 .maxlen = sizeof (init_ipc_ns.shm_ctlall),
211 .mode = 0644,
212 .proc_handler = proc_ipc_doulongvec_minmax,
213 .strategy = sysctl_ipc_data,
214 },
215 {
216 .ctl_name = KERN_SHMMNI,
217 .procname = "shmmni",
218 .data = &init_ipc_ns.shm_ctlmni,
219 .maxlen = sizeof (init_ipc_ns.shm_ctlmni),
220 .mode = 0644,
221 .proc_handler = proc_ipc_dointvec,
222 .strategy = sysctl_ipc_data,
223 },
224 {
225 .ctl_name = KERN_MSGMAX,
226 .procname = "msgmax",
227 .data = &init_ipc_ns.msg_ctlmax,
228 .maxlen = sizeof (init_ipc_ns.msg_ctlmax),
229 .mode = 0644,
230 .proc_handler = proc_ipc_dointvec,
231 .strategy = sysctl_ipc_data,
232 },
233 {
234 .ctl_name = KERN_MSGMNI,
235 .procname = "msgmni",
236 .data = &init_ipc_ns.msg_ctlmni,
237 .maxlen = sizeof (init_ipc_ns.msg_ctlmni),
238 .mode = 0644,
Nadia Derbey91cfb2b2008-04-29 01:00:44 -0700239 .proc_handler = proc_ipc_callback_dointvec,
240 .strategy = sysctl_ipc_registered_data,
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800241 },
242 {
243 .ctl_name = KERN_MSGMNB,
244 .procname = "msgmnb",
245 .data = &init_ipc_ns.msg_ctlmnb,
246 .maxlen = sizeof (init_ipc_ns.msg_ctlmnb),
247 .mode = 0644,
248 .proc_handler = proc_ipc_dointvec,
249 .strategy = sysctl_ipc_data,
250 },
251 {
252 .ctl_name = KERN_SEM,
253 .procname = "sem",
254 .data = &init_ipc_ns.sem_ctls,
255 .maxlen = 4*sizeof (int),
256 .mode = 0644,
257 .proc_handler = proc_ipc_dointvec,
258 .strategy = sysctl_ipc_data,
259 },
Nadia Derbey9eefe522008-07-25 01:48:08 -0700260 {
261 .ctl_name = CTL_UNNUMBERED,
262 .procname = "auto_msgmni",
263 .data = &init_ipc_ns.auto_msgmni,
264 .maxlen = sizeof(int),
265 .mode = 0644,
266 .proc_handler = proc_ipcauto_dointvec_minmax,
267 .extra1 = &zero,
268 .extra2 = &one,
269 },
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800270 {}
271};
272
273static struct ctl_table ipc_root_table[] = {
274 {
275 .ctl_name = CTL_KERN,
276 .procname = "kernel",
277 .mode = 0555,
278 .child = ipc_kern_table,
279 },
280 {}
281};
282
283static int __init ipc_sysctl_init(void)
284{
Eric W. Biederman0b4d4142007-02-14 00:34:09 -0800285 register_sysctl_table(ipc_root_table);
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800286 return 0;
287}
288
289__initcall(ipc_sysctl_init);