1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __IPC_NAMESPACE_H__
3 #define __IPC_NAMESPACE_H__
4
5 #include <linux/err.h>
6 #include <linux/idr.h>
7 #include <linux/rwsem.h>
8 #include <linux/notifier.h>
9 #include <linux/nsproxy.h>
10 #include <linux/ns_common.h>
11 #include <linux/refcount.h>
12 #include <linux/rhashtable-types.h>
13 #include <linux/sysctl.h>
14
15 struct user_namespace;
16
17 struct ipc_ids {
18 int in_use;
19 unsigned short seq;
20 struct rw_semaphore rwsem;
21 struct idr ipcs_idr;
22 int max_idx;
23 int last_idx; /* For wrap around detection */
24 #ifdef CONFIG_CHECKPOINT_RESTORE
25 int next_id;
26 #endif
27 struct rhashtable key_ht;
28 };
29
30 struct ipc_namespace {
31 struct ipc_ids ids[3];
32
33 int sem_ctls[4];
34 int used_sems;
35
36 unsigned int msg_ctlmax;
37 unsigned int msg_ctlmnb;
38 unsigned int msg_ctlmni;
39 atomic_t msg_bytes;
40 atomic_t msg_hdrs;
41
42 size_t shm_ctlmax;
43 size_t shm_ctlall;
44 unsigned long shm_tot;
45 int shm_ctlmni;
46 /*
47 * Defines whether IPC_RMID is forced for _all_ shm segments regardless
48 * of shmctl()
49 */
50 int shm_rmid_forced;
51
52 struct notifier_block ipcns_nb;
53
54 /* The kern_mount of the mqueuefs sb. We take a ref on it */
55 struct vfsmount *mq_mnt;
56
57 /* # queues in this ns, protected by mq_lock */
58 unsigned int mq_queues_count;
59
60 /* next fields are set through sysctl */
61 unsigned int mq_queues_max; /* initialized to DFLT_QUEUESMAX */
62 unsigned int mq_msg_max; /* initialized to DFLT_MSGMAX */
63 unsigned int mq_msgsize_max; /* initialized to DFLT_MSGSIZEMAX */
64 unsigned int mq_msg_default;
65 unsigned int mq_msgsize_default;
66
67 struct ctl_table_set mq_set;
68 struct ctl_table_header *mq_sysctls;
69
70 struct ctl_table_set ipc_set;
71 struct ctl_table_header *ipc_sysctls;
72
73 /* user_ns which owns the ipc ns */
74 struct user_namespace *user_ns;
75 struct ucounts *ucounts;
76
77 struct llist_node mnt_llist;
78
79 struct ns_common ns;
80 } __randomize_layout;
81
82 extern struct ipc_namespace init_ipc_ns;
83 extern spinlock_t mq_lock;
84
85 #ifdef CONFIG_SYSVIPC
86 extern void shm_destroy_orphaned(struct ipc_namespace *ns);
87 #else /* CONFIG_SYSVIPC */
shm_destroy_orphaned(struct ipc_namespace * ns)88 static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
89 #endif /* CONFIG_SYSVIPC */
90
91 #ifdef CONFIG_POSIX_MQUEUE
92 extern int mq_init_ns(struct ipc_namespace *ns);
93 /*
94 * POSIX Message Queue default values:
95 *
96 * MIN_*: Lowest value an admin can set the maximum unprivileged limit to
97 * DFLT_*MAX: Default values for the maximum unprivileged limits
98 * DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply
99 * an attribute to the open call and the queue must be created
100 * HARD_*: Highest value the maximums can be set to. These are enforced
101 * on CAP_SYS_RESOURCE apps as well making them inviolate (so make them
102 * suitably high)
103 *
104 * POSIX Requirements:
105 * Per app minimum openable message queues - 8. This does not map well
106 * to the fact that we limit the number of queues on a per namespace
107 * basis instead of a per app basis. So, make the default high enough
108 * that no given app should have a hard time opening 8 queues.
109 * Minimum maximum for HARD_MSGMAX - 32767. I bumped this to 65536.
110 * Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this. However,
111 * we have run into a situation where running applications in the wild
112 * require this to be at least 5MB, and preferably 10MB, so I set the
113 * value to 16MB in hopes that this user is the worst of the bunch and
114 * the new maximum will handle anyone else. I may have to revisit this
115 * in the future.
116 */
117 #define DFLT_QUEUESMAX 256
118 #define MIN_MSGMAX 1
119 #define DFLT_MSG 10U
120 #define DFLT_MSGMAX 10
121 #define HARD_MSGMAX 65536
122 #define MIN_MSGSIZEMAX 128
123 #define DFLT_MSGSIZE 8192U
124 #define DFLT_MSGSIZEMAX 8192
125 #define HARD_MSGSIZEMAX (16*1024*1024)
126 #else
mq_init_ns(struct ipc_namespace * ns)127 static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
128 #endif
129
130 #if defined(CONFIG_IPC_NS)
131 extern struct ipc_namespace *copy_ipcs(unsigned long flags,
132 struct user_namespace *user_ns, struct ipc_namespace *ns);
133
get_ipc_ns(struct ipc_namespace * ns)134 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
135 {
136 if (ns)
137 refcount_inc(&ns->ns.count);
138 return ns;
139 }
140
get_ipc_ns_not_zero(struct ipc_namespace * ns)141 static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns)
142 {
143 if (ns) {
144 if (refcount_inc_not_zero(&ns->ns.count))
145 return ns;
146 }
147
148 return NULL;
149 }
150
151 extern void put_ipc_ns(struct ipc_namespace *ns);
152 #else
copy_ipcs(unsigned long flags,struct user_namespace * user_ns,struct ipc_namespace * ns)153 static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
154 struct user_namespace *user_ns, struct ipc_namespace *ns)
155 {
156 if (flags & CLONE_NEWIPC)
157 return ERR_PTR(-EINVAL);
158
159 return ns;
160 }
161
get_ipc_ns(struct ipc_namespace * ns)162 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
163 {
164 return ns;
165 }
166
get_ipc_ns_not_zero(struct ipc_namespace * ns)167 static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns)
168 {
169 return ns;
170 }
171
put_ipc_ns(struct ipc_namespace * ns)172 static inline void put_ipc_ns(struct ipc_namespace *ns)
173 {
174 }
175 #endif
176
177 #ifdef CONFIG_POSIX_MQUEUE_SYSCTL
178
179 void retire_mq_sysctls(struct ipc_namespace *ns);
180 bool setup_mq_sysctls(struct ipc_namespace *ns);
181
182 #else /* CONFIG_POSIX_MQUEUE_SYSCTL */
183
retire_mq_sysctls(struct ipc_namespace * ns)184 static inline void retire_mq_sysctls(struct ipc_namespace *ns)
185 {
186 }
187
setup_mq_sysctls(struct ipc_namespace * ns)188 static inline bool setup_mq_sysctls(struct ipc_namespace *ns)
189 {
190 return true;
191 }
192
193 #endif /* CONFIG_POSIX_MQUEUE_SYSCTL */
194
195 #ifdef CONFIG_SYSVIPC_SYSCTL
196
197 bool setup_ipc_sysctls(struct ipc_namespace *ns);
198 void retire_ipc_sysctls(struct ipc_namespace *ns);
199
200 #else /* CONFIG_SYSVIPC_SYSCTL */
201
retire_ipc_sysctls(struct ipc_namespace * ns)202 static inline void retire_ipc_sysctls(struct ipc_namespace *ns)
203 {
204 }
205
setup_ipc_sysctls(struct ipc_namespace * ns)206 static inline bool setup_ipc_sysctls(struct ipc_namespace *ns)
207 {
208 return true;
209 }
210
211 #endif /* CONFIG_SYSVIPC_SYSCTL */
212 #endif
213