Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with
or
.
Download ZIP
Newer
Older
100755 213 lines (189 sloc) 5.21 kB
4fb75bd @glitschi initial commit
authored
1 /*
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>
17 #include <linux/ipc_namespace.h>
18 #include <linux/msg.h>
19 #include "util.h"
20
21 static 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 }
28
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)
32 {
33 struct ctl_table ipc_table;
34 memcpy(&ipc_table, table, sizeof(ipc_table));
35 ipc_table.data = get_ipc(table);
36
37 return proc_dointvec(&ipc_table, write, buffer, lenp, ppos);
38 }
39
40 static int proc_ipc_callback_dointvec(ctl_table *table, int write,
41 void __user *buffer, size_t *lenp, loff_t *ppos)
42 {
43 struct ctl_table ipc_table;
44 size_t lenp_bef = *lenp;
45 int rc;
46
47 memcpy(&ipc_table, table, sizeof(ipc_table));
48 ipc_table.data = get_ipc(table);
49
50 rc = proc_dointvec(&ipc_table, write, buffer, lenp, ppos);
51
52 if (write && !rc && lenp_bef == *lenp)
53 /*
54 * Tunable has successfully been changed by hand. Disable its
55 * automatic adjustment. This simply requires unregistering
56 * the notifiers that trigger recalculation.
57 */
58 unregister_ipcns_notifier(current->nsproxy->ipc_ns);
59
60 return rc;
61 }
62
63 static int proc_ipc_doulongvec_minmax(ctl_table *table, int write,
64 void __user *buffer, size_t *lenp, loff_t *ppos)
65 {
66 struct ctl_table ipc_table;
67 memcpy(&ipc_table, table, sizeof(ipc_table));
68 ipc_table.data = get_ipc(table);
69
70 return proc_doulongvec_minmax(&ipc_table, write, buffer,
71 lenp, ppos);
72 }
73
74 /*
75 * Routine that is called when the file "auto_msgmni" has successfully been
76 * written.
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.
82 */
83 static void ipc_auto_callback(int val)
84 {
85 if (!val)
86 unregister_ipcns_notifier(current->nsproxy->ipc_ns);
87 else {
88 /*
89 * Re-enable automatic recomputing only if not already
90 * enabled.
91 */
92 recompute_msgmni(current->nsproxy->ipc_ns);
93 cond_register_ipcns_notifier(current->nsproxy->ipc_ns);
94 }
95 }
96
97 static int proc_ipcauto_dointvec_minmax(ctl_table *table, int write,
98 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, 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
125 #else
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
130 #endif
131
132 static int zero;
133 static int one = 1;
134
135 static struct ctl_table ipc_kern_table[] = {
136 {
137 .procname = "shmmax",
138 .data = &init_ipc_ns.shm_ctlmax,
139 .maxlen = sizeof (init_ipc_ns.shm_ctlmax),
140 .mode = 0644,
141 .proc_handler = proc_ipc_doulongvec_minmax,
142 },
143 {
144 .procname = "shmall",
145 .data = &init_ipc_ns.shm_ctlall,
146 .maxlen = sizeof (init_ipc_ns.shm_ctlall),
147 .mode = 0644,
148 .proc_handler = proc_ipc_doulongvec_minmax,
149 },
150 {
151 .procname = "shmmni",
152 .data = &init_ipc_ns.shm_ctlmni,
153 .maxlen = sizeof (init_ipc_ns.shm_ctlmni),
154 .mode = 0644,
155 .proc_handler = proc_ipc_dointvec,
156 },
157 {
158 .procname = "msgmax",
159 .data = &init_ipc_ns.msg_ctlmax,
160 .maxlen = sizeof (init_ipc_ns.msg_ctlmax),
161 .mode = 0644,
162 .proc_handler = proc_ipc_dointvec,
163 },
164 {
165 .procname = "msgmni",
166 .data = &init_ipc_ns.msg_ctlmni,
167 .maxlen = sizeof (init_ipc_ns.msg_ctlmni),
168 .mode = 0644,
169 .proc_handler = proc_ipc_callback_dointvec,
170 },
171 {
172 .procname = "msgmnb",
173 .data = &init_ipc_ns.msg_ctlmnb,
174 .maxlen = sizeof (init_ipc_ns.msg_ctlmnb),
175 .mode = 0644,
176 .proc_handler = proc_ipc_dointvec,
177 },
178 {
179 .procname = "sem",
180 .data = &init_ipc_ns.sem_ctls,
181 .maxlen = 4*sizeof (int),
182 .mode = 0644,
183 .proc_handler = proc_ipc_dointvec,
184 },
185 {
186 .procname = "auto_msgmni",
187 .data = &init_ipc_ns.auto_msgmni,
188 .maxlen = sizeof(int),
189 .mode = 0644,
190 .proc_handler = proc_ipcauto_dointvec_minmax,
191 .extra1 = &zero,
192 .extra2 = &one,
193 },
194 {}
195 };
196
197 static struct ctl_table ipc_root_table[] = {
198 {
199 .procname = "kernel",
200 .mode = 0555,
201 .child = ipc_kern_table,
202 },
203 {}
204 };
205
206 static int __init ipc_sysctl_init(void)
207 {
208 register_sysctl_table(ipc_root_table);
209 return 0;
210 }
211
212 __initcall(ipc_sysctl_init);
Something went wrong with that request. Please try again.