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