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
21static void *get_ipc(struct 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
30static int proc_ipc_dointvec(struct ctl_table *table, int write,
31 void __user *buffer, size_t *lenp, loff_t *ppos)
32{
33 struct ctl_table ipc_table;
34
35 memcpy(&ipc_table, table, sizeof(ipc_table));
36 ipc_table.data = get_ipc(table);
37
38 return proc_dointvec(&ipc_table, write, buffer, lenp, ppos);
39}
40
41static int proc_ipc_dointvec_minmax(struct ctl_table *table, int write,
42 void __user *buffer, size_t *lenp, loff_t *ppos)
43{
44 struct ctl_table ipc_table;
45
46 memcpy(&ipc_table, table, sizeof(ipc_table));
47 ipc_table.data = get_ipc(table);
48
49 return proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
50}
51
52static int proc_ipc_dointvec_minmax_orphans(struct ctl_table *table, int write,
53 void __user *buffer, size_t *lenp, loff_t *ppos)
54{
55 struct ipc_namespace *ns = current->nsproxy->ipc_ns;
56 int err = proc_ipc_dointvec_minmax(table, write, buffer, lenp, ppos);
57
58 if (err < 0)
59 return err;
60 if (ns->shm_rmid_forced)
61 shm_destroy_orphaned(ns);
62 return err;
63}
64
65static int proc_ipc_doulongvec_minmax(struct ctl_table *table, int write,
66 void __user *buffer, size_t *lenp, loff_t *ppos)
67{
68 struct ctl_table ipc_table;
69 memcpy(&ipc_table, table, sizeof(ipc_table));
70 ipc_table.data = get_ipc(table);
71
72 return proc_doulongvec_minmax(&ipc_table, write, buffer,
73 lenp, ppos);
74}
75
76static int proc_ipc_auto_msgmni(struct ctl_table *table, int write,
77 void __user *buffer, size_t *lenp, loff_t *ppos)
78{
79 struct ctl_table ipc_table;
80 int dummy = 0;
81
82 memcpy(&ipc_table, table, sizeof(ipc_table));
83 ipc_table.data = &dummy;
84
85 if (write)
86 pr_info_once("writing to auto_msgmni has no effect");
87
88 return proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
89}
90
91static int proc_ipc_sem_dointvec(struct ctl_table *table, int write,
92 void __user *buffer, size_t *lenp, loff_t *ppos)
93{
94 int ret, semmni;
95 struct ipc_namespace *ns = current->nsproxy->ipc_ns;
96
97 semmni = ns->sem_ctls[3];
98 ret = proc_ipc_dointvec(table, write, buffer, lenp, ppos);
99
100 if (!ret)
101 ret = sem_check_semmni(current->nsproxy->ipc_ns);
102
103 /*
104 * Reset the semmni value if an error happens.
105 */
106 if (ret)
107 ns->sem_ctls[3] = semmni;
108 return ret;
109}
110
111#else
112#define proc_ipc_doulongvec_minmax NULL
113#define proc_ipc_dointvec NULL
114#define proc_ipc_dointvec_minmax NULL
115#define proc_ipc_dointvec_minmax_orphans NULL
116#define proc_ipc_auto_msgmni NULL
117#define proc_ipc_sem_dointvec NULL
118#endif
119
120static int zero;
121static int one = 1;
122static int int_max = INT_MAX;
123static int ipc_mni = IPCMNI;
124
125static struct ctl_table ipc_kern_table[] = {
126 {
127 .procname = "shmmax",
128 .data = &init_ipc_ns.shm_ctlmax,
129 .maxlen = sizeof(init_ipc_ns.shm_ctlmax),
130 .mode = 0644,
131 .proc_handler = proc_ipc_doulongvec_minmax,
132 },
133 {
134 .procname = "shmall",
135 .data = &init_ipc_ns.shm_ctlall,
136 .maxlen = sizeof(init_ipc_ns.shm_ctlall),
137 .mode = 0644,
138 .proc_handler = proc_ipc_doulongvec_minmax,
139 },
140 {
141 .procname = "shmmni",
142 .data = &init_ipc_ns.shm_ctlmni,
143 .maxlen = sizeof(init_ipc_ns.shm_ctlmni),
144 .mode = 0644,
145 .proc_handler = proc_ipc_dointvec_minmax,
146 .extra1 = &zero,
147 .extra2 = &ipc_mni,
148 },
149 {
150 .procname = "shm_rmid_forced",
151 .data = &init_ipc_ns.shm_rmid_forced,
152 .maxlen = sizeof(init_ipc_ns.shm_rmid_forced),
153 .mode = 0644,
154 .proc_handler = proc_ipc_dointvec_minmax_orphans,
155 .extra1 = &zero,
156 .extra2 = &one,
157 },
158 {
159 .procname = "msgmax",
160 .data = &init_ipc_ns.msg_ctlmax,
161 .maxlen = sizeof(init_ipc_ns.msg_ctlmax),
162 .mode = 0644,
163 .proc_handler = proc_ipc_dointvec_minmax,
164 .extra1 = &zero,
165 .extra2 = &int_max,
166 },
167 {
168 .procname = "msgmni",
169 .data = &init_ipc_ns.msg_ctlmni,
170 .maxlen = sizeof(init_ipc_ns.msg_ctlmni),
171 .mode = 0644,
172 .proc_handler = proc_ipc_dointvec_minmax,
173 .extra1 = &zero,
174 .extra2 = &ipc_mni,
175 },
176 {
177 .procname = "auto_msgmni",
178 .data = NULL,
179 .maxlen = sizeof(int),
180 .mode = 0644,
181 .proc_handler = proc_ipc_auto_msgmni,
182 .extra1 = &zero,
183 .extra2 = &one,
184 },
185 {
186 .procname = "msgmnb",
187 .data = &init_ipc_ns.msg_ctlmnb,
188 .maxlen = sizeof(init_ipc_ns.msg_ctlmnb),
189 .mode = 0644,
190 .proc_handler = proc_ipc_dointvec_minmax,
191 .extra1 = &zero,
192 .extra2 = &int_max,
193 },
194 {
195 .procname = "sem",
196 .data = &init_ipc_ns.sem_ctls,
197 .maxlen = 4*sizeof(int),
198 .mode = 0644,
199 .proc_handler = proc_ipc_sem_dointvec,
200 },
201#ifdef CONFIG_CHECKPOINT_RESTORE
202 {
203 .procname = "sem_next_id",
204 .data = &init_ipc_ns.ids[IPC_SEM_IDS].next_id,
205 .maxlen = sizeof(init_ipc_ns.ids[IPC_SEM_IDS].next_id),
206 .mode = 0644,
207 .proc_handler = proc_ipc_dointvec_minmax,
208 .extra1 = &zero,
209 .extra2 = &int_max,
210 },
211 {
212 .procname = "msg_next_id",
213 .data = &init_ipc_ns.ids[IPC_MSG_IDS].next_id,
214 .maxlen = sizeof(init_ipc_ns.ids[IPC_MSG_IDS].next_id),
215 .mode = 0644,
216 .proc_handler = proc_ipc_dointvec_minmax,
217 .extra1 = &zero,
218 .extra2 = &int_max,
219 },
220 {
221 .procname = "shm_next_id",
222 .data = &init_ipc_ns.ids[IPC_SHM_IDS].next_id,
223 .maxlen = sizeof(init_ipc_ns.ids[IPC_SHM_IDS].next_id),
224 .mode = 0644,
225 .proc_handler = proc_ipc_dointvec_minmax,
226 .extra1 = &zero,
227 .extra2 = &int_max,
228 },
229#endif
230 {}
231};
232
233static struct ctl_table ipc_root_table[] = {
234 {
235 .procname = "kernel",
236 .mode = 0555,
237 .child = ipc_kern_table,
238 },
239 {}
240};
241
242static int __init ipc_sysctl_init(void)
243{
244 register_sysctl_table(ipc_root_table);
245 return 0;
246}
247
248device_initcall(ipc_sysctl_init);
249