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1/*
2 * Copyright (C) 2007 IBM Corporation
3 *
4 * Author: Cedric Le Goater <clg@fr.ibm.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/nsproxy.h>
13#include <linux/ipc_namespace.h>
14#include <linux/sysctl.h>
15
16#ifdef CONFIG_PROC_SYSCTL
17static void *get_mq(ctl_table *table)
18{
19 char *which = table->data;
20 struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
21 which = (which - (char *)&init_ipc_ns) + (char *)ipc_ns;
22 return which;
23}
24
25static int proc_mq_dointvec_minmax(ctl_table *table, int write,
26 void __user *buffer, size_t *lenp, loff_t *ppos)
27{
28 struct ctl_table mq_table;
29 memcpy(&mq_table, table, sizeof(mq_table));
30 mq_table.data = get_mq(table);
31
32 return proc_dointvec_minmax(&mq_table, write, buffer,
33 lenp, ppos);
34}
35#else
36#define proc_mq_dointvec_minmax NULL
37#endif
38
39static int msg_queues_limit_min = MIN_QUEUESMAX;
40static int msg_queues_limit_max = HARD_QUEUESMAX;
41
42static int msg_max_limit_min = MIN_MSGMAX;
43static int msg_max_limit_max = HARD_MSGMAX;
44
45static int msg_maxsize_limit_min = MIN_MSGSIZEMAX;
46static int msg_maxsize_limit_max = HARD_MSGSIZEMAX;
47
48static ctl_table mq_sysctls[] = {
49 {
50 .procname = "queues_max",
51 .data = &init_ipc_ns.mq_queues_max,
52 .maxlen = sizeof(int),
53 .mode = 0644,
54 .proc_handler = proc_mq_dointvec_minmax,
55 .extra1 = &msg_queues_limit_min,
56 .extra2 = &msg_queues_limit_max,
57 },
58 {
59 .procname = "msg_max",
60 .data = &init_ipc_ns.mq_msg_max,
61 .maxlen = sizeof(int),
62 .mode = 0644,
63 .proc_handler = proc_mq_dointvec_minmax,
64 .extra1 = &msg_max_limit_min,
65 .extra2 = &msg_max_limit_max,
66 },
67 {
68 .procname = "msgsize_max",
69 .data = &init_ipc_ns.mq_msgsize_max,
70 .maxlen = sizeof(int),
71 .mode = 0644,
72 .proc_handler = proc_mq_dointvec_minmax,
73 .extra1 = &msg_maxsize_limit_min,
74 .extra2 = &msg_maxsize_limit_max,
75 },
76 {
77 .procname = "msg_default",
78 .data = &init_ipc_ns.mq_msg_default,
79 .maxlen = sizeof(int),
80 .mode = 0644,
81 .proc_handler = proc_mq_dointvec_minmax,
82 .extra1 = &msg_max_limit_min,
83 .extra2 = &msg_max_limit_max,
84 },
85 {
86 .procname = "msgsize_default",
87 .data = &init_ipc_ns.mq_msgsize_default,
88 .maxlen = sizeof(int),
89 .mode = 0644,
90 .proc_handler = proc_mq_dointvec_minmax,
91 .extra1 = &msg_maxsize_limit_min,
92 .extra2 = &msg_maxsize_limit_max,
93 },
94 {}
95};
96
97static ctl_table mq_sysctl_dir[] = {
98 {
99 .procname = "mqueue",
100 .mode = 0555,
101 .child = mq_sysctls,
102 },
103 {}
104};
105
106static ctl_table mq_sysctl_root[] = {
107 {
108 .procname = "fs",
109 .mode = 0555,
110 .child = mq_sysctl_dir,
111 },
112 {}
113};
114
115struct ctl_table_header *mq_register_sysctl_table(void)
116{
117 return register_sysctl_table(mq_sysctl_root);
118}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2007 IBM Corporation
4 *
5 * Author: Cedric Le Goater <clg@fr.ibm.com>
6 */
7
8#include <linux/nsproxy.h>
9#include <linux/ipc_namespace.h>
10#include <linux/sysctl.h>
11
12#include <linux/stat.h>
13#include <linux/capability.h>
14#include <linux/slab.h>
15#include <linux/cred.h>
16
17static int msg_max_limit_min = MIN_MSGMAX;
18static int msg_max_limit_max = HARD_MSGMAX;
19
20static int msg_maxsize_limit_min = MIN_MSGSIZEMAX;
21static int msg_maxsize_limit_max = HARD_MSGSIZEMAX;
22
23static struct ctl_table mq_sysctls[] = {
24 {
25 .procname = "queues_max",
26 .data = &init_ipc_ns.mq_queues_max,
27 .maxlen = sizeof(int),
28 .mode = 0644,
29 .proc_handler = proc_dointvec,
30 },
31 {
32 .procname = "msg_max",
33 .data = &init_ipc_ns.mq_msg_max,
34 .maxlen = sizeof(int),
35 .mode = 0644,
36 .proc_handler = proc_dointvec_minmax,
37 .extra1 = &msg_max_limit_min,
38 .extra2 = &msg_max_limit_max,
39 },
40 {
41 .procname = "msgsize_max",
42 .data = &init_ipc_ns.mq_msgsize_max,
43 .maxlen = sizeof(int),
44 .mode = 0644,
45 .proc_handler = proc_dointvec_minmax,
46 .extra1 = &msg_maxsize_limit_min,
47 .extra2 = &msg_maxsize_limit_max,
48 },
49 {
50 .procname = "msg_default",
51 .data = &init_ipc_ns.mq_msg_default,
52 .maxlen = sizeof(int),
53 .mode = 0644,
54 .proc_handler = proc_dointvec_minmax,
55 .extra1 = &msg_max_limit_min,
56 .extra2 = &msg_max_limit_max,
57 },
58 {
59 .procname = "msgsize_default",
60 .data = &init_ipc_ns.mq_msgsize_default,
61 .maxlen = sizeof(int),
62 .mode = 0644,
63 .proc_handler = proc_dointvec_minmax,
64 .extra1 = &msg_maxsize_limit_min,
65 .extra2 = &msg_maxsize_limit_max,
66 },
67 {}
68};
69
70static struct ctl_table_set *set_lookup(struct ctl_table_root *root)
71{
72 return ¤t->nsproxy->ipc_ns->mq_set;
73}
74
75static int set_is_seen(struct ctl_table_set *set)
76{
77 return ¤t->nsproxy->ipc_ns->mq_set == set;
78}
79
80static void mq_set_ownership(struct ctl_table_header *head,
81 struct ctl_table *table,
82 kuid_t *uid, kgid_t *gid)
83{
84 struct ipc_namespace *ns =
85 container_of(head->set, struct ipc_namespace, mq_set);
86
87 kuid_t ns_root_uid = make_kuid(ns->user_ns, 0);
88 kgid_t ns_root_gid = make_kgid(ns->user_ns, 0);
89
90 *uid = uid_valid(ns_root_uid) ? ns_root_uid : GLOBAL_ROOT_UID;
91 *gid = gid_valid(ns_root_gid) ? ns_root_gid : GLOBAL_ROOT_GID;
92}
93
94static int mq_permissions(struct ctl_table_header *head, struct ctl_table *table)
95{
96 int mode = table->mode;
97 kuid_t ns_root_uid;
98 kgid_t ns_root_gid;
99
100 mq_set_ownership(head, table, &ns_root_uid, &ns_root_gid);
101
102 if (uid_eq(current_euid(), ns_root_uid))
103 mode >>= 6;
104
105 else if (in_egroup_p(ns_root_gid))
106 mode >>= 3;
107
108 mode &= 7;
109
110 return (mode << 6) | (mode << 3) | mode;
111}
112
113static struct ctl_table_root set_root = {
114 .lookup = set_lookup,
115 .permissions = mq_permissions,
116 .set_ownership = mq_set_ownership,
117};
118
119bool setup_mq_sysctls(struct ipc_namespace *ns)
120{
121 struct ctl_table *tbl;
122
123 setup_sysctl_set(&ns->mq_set, &set_root, set_is_seen);
124
125 tbl = kmemdup(mq_sysctls, sizeof(mq_sysctls), GFP_KERNEL);
126 if (tbl) {
127 int i;
128
129 for (i = 0; i < ARRAY_SIZE(mq_sysctls); i++) {
130 if (tbl[i].data == &init_ipc_ns.mq_queues_max)
131 tbl[i].data = &ns->mq_queues_max;
132
133 else if (tbl[i].data == &init_ipc_ns.mq_msg_max)
134 tbl[i].data = &ns->mq_msg_max;
135
136 else if (tbl[i].data == &init_ipc_ns.mq_msgsize_max)
137 tbl[i].data = &ns->mq_msgsize_max;
138
139 else if (tbl[i].data == &init_ipc_ns.mq_msg_default)
140 tbl[i].data = &ns->mq_msg_default;
141
142 else if (tbl[i].data == &init_ipc_ns.mq_msgsize_default)
143 tbl[i].data = &ns->mq_msgsize_default;
144 else
145 tbl[i].data = NULL;
146 }
147
148 ns->mq_sysctls = __register_sysctl_table(&ns->mq_set,
149 "fs/mqueue", tbl,
150 ARRAY_SIZE(mq_sysctls));
151 }
152 if (!ns->mq_sysctls) {
153 kfree(tbl);
154 retire_sysctl_set(&ns->mq_set);
155 return false;
156 }
157
158 return true;
159}
160
161void retire_mq_sysctls(struct ipc_namespace *ns)
162{
163 struct ctl_table *tbl;
164
165 tbl = ns->mq_sysctls->ctl_table_arg;
166 unregister_sysctl_table(ns->mq_sysctls);
167 retire_sysctl_set(&ns->mq_set);
168 kfree(tbl);
169}