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a5494dcd EB |
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> | |
ae5e1b22 | 17 | #include <linux/ipc_namespace.h> |
6546bc42 ND |
18 | #include <linux/msg.h> |
19 | #include "util.h" | |
a5494dcd | 20 | |
a5494dcd EB |
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 | } | |
a5494dcd | 28 | |
6546bc42 ND |
29 | /* |
30 | * Routine that is called when a tunable has successfully been changed by | |
31 | * hand and it has a callback routine registered on the ipc namespace notifier | |
32 | * chain: we don't want such tunables to be recomputed anymore upon memory | |
33 | * add/remove or ipc namespace creation/removal. | |
34 | * They can come back to a recomputable state by being set to a <0 value. | |
35 | */ | |
36 | static void tunable_set_callback(int val) | |
37 | { | |
38 | if (val >= 0) | |
39 | unregister_ipcns_notifier(current->nsproxy->ipc_ns); | |
40 | else { | |
41 | /* | |
42 | * Re-enable automatic recomputing only if not already | |
43 | * enabled. | |
44 | */ | |
45 | recompute_msgmni(current->nsproxy->ipc_ns); | |
46 | cond_register_ipcns_notifier(current->nsproxy->ipc_ns); | |
47 | } | |
48 | } | |
49 | ||
a5494dcd EB |
50 | #ifdef CONFIG_PROC_FS |
51 | static int proc_ipc_dointvec(ctl_table *table, int write, struct file *filp, | |
52 | void __user *buffer, size_t *lenp, loff_t *ppos) | |
53 | { | |
54 | struct ctl_table ipc_table; | |
55 | memcpy(&ipc_table, table, sizeof(ipc_table)); | |
56 | ipc_table.data = get_ipc(table); | |
57 | ||
58 | return proc_dointvec(&ipc_table, write, filp, buffer, lenp, ppos); | |
59 | } | |
60 | ||
91cfb2b4 ND |
61 | static int proc_ipc_callback_dointvec(ctl_table *table, int write, |
62 | struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos) | |
63 | { | |
6546bc42 | 64 | struct ctl_table ipc_table; |
91cfb2b4 ND |
65 | size_t lenp_bef = *lenp; |
66 | int rc; | |
67 | ||
6546bc42 ND |
68 | memcpy(&ipc_table, table, sizeof(ipc_table)); |
69 | ipc_table.data = get_ipc(table); | |
70 | ||
71 | rc = proc_dointvec(&ipc_table, write, filp, buffer, lenp, ppos); | |
91cfb2b4 ND |
72 | |
73 | if (write && !rc && lenp_bef == *lenp) | |
6546bc42 | 74 | tunable_set_callback(*((int *)(ipc_table.data))); |
91cfb2b4 ND |
75 | |
76 | return rc; | |
77 | } | |
78 | ||
a5494dcd EB |
79 | static int proc_ipc_doulongvec_minmax(ctl_table *table, int write, |
80 | struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos) | |
81 | { | |
82 | struct ctl_table ipc_table; | |
83 | memcpy(&ipc_table, table, sizeof(ipc_table)); | |
84 | ipc_table.data = get_ipc(table); | |
85 | ||
86 | return proc_doulongvec_minmax(&ipc_table, write, filp, buffer, | |
87 | lenp, ppos); | |
88 | } | |
89 | ||
90 | #else | |
91 | #define proc_ipc_doulongvec_minmax NULL | |
92 | #define proc_ipc_dointvec NULL | |
91cfb2b4 | 93 | #define proc_ipc_callback_dointvec NULL |
a5494dcd EB |
94 | #endif |
95 | ||
96 | #ifdef CONFIG_SYSCTL_SYSCALL | |
97 | /* The generic sysctl ipc data routine. */ | |
98 | static int sysctl_ipc_data(ctl_table *table, int __user *name, int nlen, | |
99 | void __user *oldval, size_t __user *oldlenp, | |
100 | void __user *newval, size_t newlen) | |
101 | { | |
102 | size_t len; | |
103 | void *data; | |
104 | ||
105 | /* Get out of I don't have a variable */ | |
106 | if (!table->data || !table->maxlen) | |
107 | return -ENOTDIR; | |
108 | ||
109 | data = get_ipc(table); | |
110 | if (!data) | |
111 | return -ENOTDIR; | |
112 | ||
113 | if (oldval && oldlenp) { | |
114 | if (get_user(len, oldlenp)) | |
115 | return -EFAULT; | |
116 | if (len) { | |
117 | if (len > table->maxlen) | |
118 | len = table->maxlen; | |
119 | if (copy_to_user(oldval, data, len)) | |
120 | return -EFAULT; | |
121 | if (put_user(len, oldlenp)) | |
122 | return -EFAULT; | |
123 | } | |
124 | } | |
125 | ||
126 | if (newval && newlen) { | |
127 | if (newlen > table->maxlen) | |
128 | newlen = table->maxlen; | |
129 | ||
130 | if (copy_from_user(data, newval, newlen)) | |
131 | return -EFAULT; | |
132 | } | |
133 | return 1; | |
134 | } | |
91cfb2b4 ND |
135 | |
136 | static int sysctl_ipc_registered_data(ctl_table *table, int __user *name, | |
137 | int nlen, void __user *oldval, size_t __user *oldlenp, | |
138 | void __user *newval, size_t newlen) | |
139 | { | |
140 | int rc; | |
141 | ||
142 | rc = sysctl_ipc_data(table, name, nlen, oldval, oldlenp, newval, | |
143 | newlen); | |
144 | ||
6546bc42 | 145 | if (newval && newlen && rc > 0) { |
91cfb2b4 | 146 | /* |
6546bc42 | 147 | * Tunable has successfully been changed from userland |
91cfb2b4 | 148 | */ |
6546bc42 ND |
149 | int *data = get_ipc(table); |
150 | ||
151 | tunable_set_callback(*data); | |
152 | } | |
91cfb2b4 ND |
153 | |
154 | return rc; | |
155 | } | |
a5494dcd EB |
156 | #else |
157 | #define sysctl_ipc_data NULL | |
91cfb2b4 | 158 | #define sysctl_ipc_registered_data NULL |
a5494dcd EB |
159 | #endif |
160 | ||
161 | static struct ctl_table ipc_kern_table[] = { | |
162 | { | |
163 | .ctl_name = KERN_SHMMAX, | |
164 | .procname = "shmmax", | |
165 | .data = &init_ipc_ns.shm_ctlmax, | |
166 | .maxlen = sizeof (init_ipc_ns.shm_ctlmax), | |
167 | .mode = 0644, | |
168 | .proc_handler = proc_ipc_doulongvec_minmax, | |
169 | .strategy = sysctl_ipc_data, | |
170 | }, | |
171 | { | |
172 | .ctl_name = KERN_SHMALL, | |
173 | .procname = "shmall", | |
174 | .data = &init_ipc_ns.shm_ctlall, | |
175 | .maxlen = sizeof (init_ipc_ns.shm_ctlall), | |
176 | .mode = 0644, | |
177 | .proc_handler = proc_ipc_doulongvec_minmax, | |
178 | .strategy = sysctl_ipc_data, | |
179 | }, | |
180 | { | |
181 | .ctl_name = KERN_SHMMNI, | |
182 | .procname = "shmmni", | |
183 | .data = &init_ipc_ns.shm_ctlmni, | |
184 | .maxlen = sizeof (init_ipc_ns.shm_ctlmni), | |
185 | .mode = 0644, | |
186 | .proc_handler = proc_ipc_dointvec, | |
187 | .strategy = sysctl_ipc_data, | |
188 | }, | |
189 | { | |
190 | .ctl_name = KERN_MSGMAX, | |
191 | .procname = "msgmax", | |
192 | .data = &init_ipc_ns.msg_ctlmax, | |
193 | .maxlen = sizeof (init_ipc_ns.msg_ctlmax), | |
194 | .mode = 0644, | |
195 | .proc_handler = proc_ipc_dointvec, | |
196 | .strategy = sysctl_ipc_data, | |
197 | }, | |
198 | { | |
199 | .ctl_name = KERN_MSGMNI, | |
200 | .procname = "msgmni", | |
201 | .data = &init_ipc_ns.msg_ctlmni, | |
202 | .maxlen = sizeof (init_ipc_ns.msg_ctlmni), | |
203 | .mode = 0644, | |
91cfb2b4 ND |
204 | .proc_handler = proc_ipc_callback_dointvec, |
205 | .strategy = sysctl_ipc_registered_data, | |
a5494dcd EB |
206 | }, |
207 | { | |
208 | .ctl_name = KERN_MSGMNB, | |
209 | .procname = "msgmnb", | |
210 | .data = &init_ipc_ns.msg_ctlmnb, | |
211 | .maxlen = sizeof (init_ipc_ns.msg_ctlmnb), | |
212 | .mode = 0644, | |
213 | .proc_handler = proc_ipc_dointvec, | |
214 | .strategy = sysctl_ipc_data, | |
215 | }, | |
216 | { | |
217 | .ctl_name = KERN_SEM, | |
218 | .procname = "sem", | |
219 | .data = &init_ipc_ns.sem_ctls, | |
220 | .maxlen = 4*sizeof (int), | |
221 | .mode = 0644, | |
222 | .proc_handler = proc_ipc_dointvec, | |
223 | .strategy = sysctl_ipc_data, | |
224 | }, | |
225 | {} | |
226 | }; | |
227 | ||
228 | static struct ctl_table ipc_root_table[] = { | |
229 | { | |
230 | .ctl_name = CTL_KERN, | |
231 | .procname = "kernel", | |
232 | .mode = 0555, | |
233 | .child = ipc_kern_table, | |
234 | }, | |
235 | {} | |
236 | }; | |
237 | ||
238 | static int __init ipc_sysctl_init(void) | |
239 | { | |
0b4d4147 | 240 | register_sysctl_table(ipc_root_table); |
a5494dcd EB |
241 | return 0; |
242 | } | |
243 | ||
244 | __initcall(ipc_sysctl_init); |