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;
30 static int proc_ipc_dointvec(ctl_table *table, int write, struct file *filp,
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, filp, buffer, lenp, ppos);
40 static int proc_ipc_callback_dointvec(ctl_table *table, int write,
41 struct file *filp, 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, filp, 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 struct file *filp, 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, filp, 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 struct file *filp, 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, filp, 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);