xref: /openbmc/linux/include/linux/ipc_namespace.h (revision 6dfcd296)
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 
11 struct user_namespace;
12 
13 struct 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 
21 struct 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 	struct ucounts *ucounts;
62 
63 	struct ns_common ns;
64 };
65 
66 extern struct ipc_namespace init_ipc_ns;
67 extern spinlock_t mq_lock;
68 
69 #ifdef CONFIG_SYSVIPC
70 extern void shm_destroy_orphaned(struct ipc_namespace *ns);
71 #else /* CONFIG_SYSVIPC */
72 static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
73 #endif /* CONFIG_SYSVIPC */
74 
75 #ifdef CONFIG_POSIX_MQUEUE
76 extern int mq_init_ns(struct ipc_namespace *ns);
77 /*
78  * POSIX Message Queue default values:
79  *
80  * MIN_*: Lowest value an admin can set the maximum unprivileged limit to
81  * DFLT_*MAX: Default values for the maximum unprivileged limits
82  * DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply
83  *   an attribute to the open call and the queue must be created
84  * HARD_*: Highest value the maximums can be set to.  These are enforced
85  *   on CAP_SYS_RESOURCE apps as well making them inviolate (so make them
86  *   suitably high)
87  *
88  * POSIX Requirements:
89  *   Per app minimum openable message queues - 8.  This does not map well
90  *     to the fact that we limit the number of queues on a per namespace
91  *     basis instead of a per app basis.  So, make the default high enough
92  *     that no given app should have a hard time opening 8 queues.
93  *   Minimum maximum for HARD_MSGMAX - 32767.  I bumped this to 65536.
94  *   Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this.  However,
95  *     we have run into a situation where running applications in the wild
96  *     require this to be at least 5MB, and preferably 10MB, so I set the
97  *     value to 16MB in hopes that this user is the worst of the bunch and
98  *     the new maximum will handle anyone else.  I may have to revisit this
99  *     in the future.
100  */
101 #define DFLT_QUEUESMAX		      256
102 #define MIN_MSGMAX			1
103 #define DFLT_MSG		       10U
104 #define DFLT_MSGMAX		       10
105 #define HARD_MSGMAX		    65536
106 #define MIN_MSGSIZEMAX		      128
107 #define DFLT_MSGSIZE		     8192U
108 #define DFLT_MSGSIZEMAX		     8192
109 #define HARD_MSGSIZEMAX	    (16*1024*1024)
110 #else
111 static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
112 #endif
113 
114 #if defined(CONFIG_IPC_NS)
115 extern struct ipc_namespace *copy_ipcs(unsigned long flags,
116 	struct user_namespace *user_ns, struct ipc_namespace *ns);
117 
118 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
119 {
120 	if (ns)
121 		atomic_inc(&ns->count);
122 	return ns;
123 }
124 
125 extern void put_ipc_ns(struct ipc_namespace *ns);
126 #else
127 static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
128 	struct user_namespace *user_ns, struct ipc_namespace *ns)
129 {
130 	if (flags & CLONE_NEWIPC)
131 		return ERR_PTR(-EINVAL);
132 
133 	return ns;
134 }
135 
136 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
137 {
138 	return ns;
139 }
140 
141 static inline void put_ipc_ns(struct ipc_namespace *ns)
142 {
143 }
144 #endif
145 
146 #ifdef CONFIG_POSIX_MQUEUE_SYSCTL
147 
148 struct ctl_table_header;
149 extern struct ctl_table_header *mq_register_sysctl_table(void);
150 
151 #else /* CONFIG_POSIX_MQUEUE_SYSCTL */
152 
153 static inline struct ctl_table_header *mq_register_sysctl_table(void)
154 {
155 	return NULL;
156 }
157 
158 #endif /* CONFIG_POSIX_MQUEUE_SYSCTL */
159 #endif
160