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
14 struct user_namespace;
15
16 struct ipc_ids {
17 int in_use;
18 unsigned short seq;
19 struct rw_semaphore rwsem;
20 struct idr ipcs_idr;
21 int max_idx;
22 int last_idx; /* For wrap around detection */
23 #ifdef CONFIG_CHECKPOINT_RESTORE
24 int next_id;
25 #endif
26 struct rhashtable key_ht;
27 };
28
29 struct ipc_namespace {
30 refcount_t count;
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 /* user_ns which owns the ipc ns */
68 struct user_namespace *user_ns;
69 struct ucounts *ucounts;
70
71 struct ns_common ns;
72 } __randomize_layout;
73
74 extern struct ipc_namespace init_ipc_ns;
75 extern spinlock_t mq_lock;
76
77 #ifdef CONFIG_SYSVIPC
78 extern void shm_destroy_orphaned(struct ipc_namespace *ns);
79 #else /* CONFIG_SYSVIPC */
shm_destroy_orphaned(struct ipc_namespace * ns)80 static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
81 #endif /* CONFIG_SYSVIPC */
82
83 #ifdef CONFIG_POSIX_MQUEUE
84 extern int mq_init_ns(struct ipc_namespace *ns);
85 /*
86 * POSIX Message Queue default values:
87 *
88 * MIN_*: Lowest value an admin can set the maximum unprivileged limit to
89 * DFLT_*MAX: Default values for the maximum unprivileged limits
90 * DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply
91 * an attribute to the open call and the queue must be created
92 * HARD_*: Highest value the maximums can be set to. These are enforced
93 * on CAP_SYS_RESOURCE apps as well making them inviolate (so make them
94 * suitably high)
95 *
96 * POSIX Requirements:
97 * Per app minimum openable message queues - 8. This does not map well
98 * to the fact that we limit the number of queues on a per namespace
99 * basis instead of a per app basis. So, make the default high enough
100 * that no given app should have a hard time opening 8 queues.
101 * Minimum maximum for HARD_MSGMAX - 32767. I bumped this to 65536.
102 * Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this. However,
103 * we have run into a situation where running applications in the wild
104 * require this to be at least 5MB, and preferably 10MB, so I set the
105 * value to 16MB in hopes that this user is the worst of the bunch and
106 * the new maximum will handle anyone else. I may have to revisit this
107 * in the future.
108 */
109 #define DFLT_QUEUESMAX 256
110 #define MIN_MSGMAX 1
111 #define DFLT_MSG 10U
112 #define DFLT_MSGMAX 10
113 #define HARD_MSGMAX 65536
114 #define MIN_MSGSIZEMAX 128
115 #define DFLT_MSGSIZE 8192U
116 #define DFLT_MSGSIZEMAX 8192
117 #define HARD_MSGSIZEMAX (16*1024*1024)
118 #else
mq_init_ns(struct ipc_namespace * ns)119 static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
120 #endif
121
122 #if defined(CONFIG_IPC_NS)
123 extern struct ipc_namespace *copy_ipcs(unsigned long flags,
124 struct user_namespace *user_ns, struct ipc_namespace *ns);
125
get_ipc_ns(struct ipc_namespace * ns)126 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
127 {
128 if (ns)
129 refcount_inc(&ns->count);
130 return ns;
131 }
132
133 extern void put_ipc_ns(struct ipc_namespace *ns);
134 #else
copy_ipcs(unsigned long flags,struct user_namespace * user_ns,struct ipc_namespace * ns)135 static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
136 struct user_namespace *user_ns, struct ipc_namespace *ns)
137 {
138 if (flags & CLONE_NEWIPC)
139 return ERR_PTR(-EINVAL);
140
141 return ns;
142 }
143
get_ipc_ns(struct ipc_namespace * ns)144 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
145 {
146 return ns;
147 }
148
put_ipc_ns(struct ipc_namespace * ns)149 static inline void put_ipc_ns(struct ipc_namespace *ns)
150 {
151 }
152 #endif
153
154 #ifdef CONFIG_POSIX_MQUEUE_SYSCTL
155
156 struct ctl_table_header;
157 extern struct ctl_table_header *mq_register_sysctl_table(void);
158
159 #else /* CONFIG_POSIX_MQUEUE_SYSCTL */
160
mq_register_sysctl_table(void)161 static inline struct ctl_table_header *mq_register_sysctl_table(void)
162 {
163 return NULL;
164 }
165
166 #endif /* CONFIG_POSIX_MQUEUE_SYSCTL */
167 #endif
168
