Linux Kernel  3.7.1
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ipc_namespace.h
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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 
10 /*
11  * ipc namespace events
12  */
13 #define IPCNS_MEMCHANGED 0x00000001 /* Notify lowmem size changed */
14 #define IPCNS_CREATED 0x00000002 /* Notify new ipc namespace created */
15 #define IPCNS_REMOVED 0x00000003 /* Notify ipc namespace removed */
16 
17 #define IPCNS_CALLBACK_PRI 0
18 
19 struct user_namespace;
20 
21 struct ipc_ids {
22  int in_use;
23  unsigned short seq;
24  unsigned short seq_max;
26  struct idr ipcs_idr;
27 };
28 
29 struct ipc_namespace {
31  struct ipc_ids ids[3];
32 
33  int sem_ctls[4];
34  int used_sems;
35 
42 
43  size_t shm_ctlmax;
44  size_t shm_ctlall;
46  int shm_tot;
47  /*
48  * Defines whether IPC_RMID is forced for _all_ shm segments regardless
49  * of shmctl()
50  */
52 
54 
55  /* The kern_mount of the mqueuefs sb. We take a ref on it */
56  struct vfsmount *mq_mnt;
57 
58  /* # queues in this ns, protected by mq_lock */
59  unsigned int mq_queues_count;
60 
61  /* next fields are set through sysctl */
62  unsigned int mq_queues_max; /* initialized to DFLT_QUEUESMAX */
63  unsigned int mq_msg_max; /* initialized to DFLT_MSGMAX */
64  unsigned int mq_msgsize_max; /* initialized to DFLT_MSGSIZEMAX */
65  unsigned int mq_msg_default;
66  unsigned int mq_msgsize_default;
67 
68  /* user_ns which owns the ipc ns */
70 };
71 
72 extern struct ipc_namespace init_ipc_ns;
73 extern atomic_t nr_ipc_ns;
74 
75 extern spinlock_t mq_lock;
76 
77 #ifdef CONFIG_SYSVIPC
78 extern int register_ipcns_notifier(struct ipc_namespace *);
79 extern int cond_register_ipcns_notifier(struct ipc_namespace *);
80 extern void unregister_ipcns_notifier(struct ipc_namespace *);
81 extern int ipcns_notify(unsigned long);
82 extern void shm_destroy_orphaned(struct ipc_namespace *ns);
83 #else /* CONFIG_SYSVIPC */
84 static inline int register_ipcns_notifier(struct ipc_namespace *ns)
85 { return 0; }
86 static inline int cond_register_ipcns_notifier(struct ipc_namespace *ns)
87 { return 0; }
88 static inline void unregister_ipcns_notifier(struct ipc_namespace *ns) { }
89 static inline int ipcns_notify(unsigned long l) { return 0; }
90 static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
91 #endif /* CONFIG_SYSVIPC */
92 
93 #ifdef CONFIG_POSIX_MQUEUE
94 extern int mq_init_ns(struct ipc_namespace *ns);
95 /*
96  * POSIX Message Queue default values:
97  *
98  * MIN_*: Lowest value an admin can set the maximum unprivileged limit to
99  * DFLT_*MAX: Default values for the maximum unprivileged limits
100  * DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply
101  * an attribute to the open call and the queue must be created
102  * HARD_*: Highest value the maximums can be set to. These are enforced
103  * on CAP_SYS_RESOURCE apps as well making them inviolate (so make them
104  * suitably high)
105  *
106  * POSIX Requirements:
107  * Per app minimum openable message queues - 8. This does not map well
108  * to the fact that we limit the number of queues on a per namespace
109  * basis instead of a per app basis. So, make the default high enough
110  * that no given app should have a hard time opening 8 queues.
111  * Minimum maximum for HARD_MSGMAX - 32767. I bumped this to 65536.
112  * Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this. However,
113  * we have run into a situation where running applications in the wild
114  * require this to be at least 5MB, and preferably 10MB, so I set the
115  * value to 16MB in hopes that this user is the worst of the bunch and
116  * the new maximum will handle anyone else. I may have to revisit this
117  * in the future.
118  */
119 #define MIN_QUEUESMAX 1
120 #define DFLT_QUEUESMAX 256
121 #define HARD_QUEUESMAX 1024
122 #define MIN_MSGMAX 1
123 #define DFLT_MSG 10U
124 #define DFLT_MSGMAX 10
125 #define HARD_MSGMAX 65536
126 #define MIN_MSGSIZEMAX 128
127 #define DFLT_MSGSIZE 8192U
128 #define DFLT_MSGSIZEMAX 8192
129 #define HARD_MSGSIZEMAX (16*1024*1024)
130 #else
131 static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
132 #endif
133 
134 #if defined(CONFIG_IPC_NS)
135 extern struct ipc_namespace *copy_ipcs(unsigned long flags,
136  struct task_struct *tsk);
137 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
138 {
139  if (ns)
140  atomic_inc(&ns->count);
141  return ns;
142 }
143 
144 extern void put_ipc_ns(struct ipc_namespace *ns);
145 #else
146 static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
147  struct task_struct *tsk)
148 {
149  if (flags & CLONE_NEWIPC)
150  return ERR_PTR(-EINVAL);
151 
152  return tsk->nsproxy->ipc_ns;
153 }
154 
155 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
156 {
157  return ns;
158 }
159 
160 static inline void put_ipc_ns(struct ipc_namespace *ns)
161 {
162 }
163 #endif
164 
165 #ifdef CONFIG_POSIX_MQUEUE_SYSCTL
166 
167 struct ctl_table_header;
168 extern struct ctl_table_header *mq_register_sysctl_table(void);
169 
170 #else /* CONFIG_POSIX_MQUEUE_SYSCTL */
171 
172 static inline struct ctl_table_header *mq_register_sysctl_table(void)
173 {
174  return NULL;
175 }
176 
177 #endif /* CONFIG_POSIX_MQUEUE_SYSCTL */
178 #endif