xref: /openbmc/linux/ipc/util.h (revision e868d61272caa648214046a096e5a6bfc068dc8c)
1 /*
2  * linux/ipc/util.h
3  * Copyright (C) 1999 Christoph Rohland
4  *
5  * ipc helper functions (c) 1999 Manfred Spraul <manfred@colorfullife.com>
6  * namespaces support.      2006 OpenVZ, SWsoft Inc.
7  *                               Pavel Emelianov <xemul@openvz.org>
8  */
9 
10 #ifndef _IPC_UTIL_H
11 #define _IPC_UTIL_H
12 
13 #define USHRT_MAX 0xffff
14 #define SEQ_MULTIPLIER	(IPCMNI)
15 
16 void sem_init (void);
17 void msg_init (void);
18 void shm_init (void);
19 
20 int sem_init_ns(struct ipc_namespace *ns);
21 int msg_init_ns(struct ipc_namespace *ns);
22 int shm_init_ns(struct ipc_namespace *ns);
23 
24 void sem_exit_ns(struct ipc_namespace *ns);
25 void msg_exit_ns(struct ipc_namespace *ns);
26 void shm_exit_ns(struct ipc_namespace *ns);
27 
28 struct ipc_id_ary {
29 	int size;
30 	struct kern_ipc_perm *p[0];
31 };
32 
33 struct ipc_ids {
34 	int in_use;
35 	int max_id;
36 	unsigned short seq;
37 	unsigned short seq_max;
38 	struct mutex mutex;
39 	struct ipc_id_ary nullentry;
40 	struct ipc_id_ary* entries;
41 };
42 
43 struct seq_file;
44 #ifdef CONFIG_IPC_NS
45 #define __ipc_init
46 #else
47 #define __ipc_init	__init
48 #endif
49 void __ipc_init ipc_init_ids(struct ipc_ids *ids, int size);
50 #ifdef CONFIG_PROC_FS
51 void __init ipc_init_proc_interface(const char *path, const char *header,
52 		int ids, int (*show)(struct seq_file *, void *));
53 #else
54 #define ipc_init_proc_interface(path, header, ids, show) do {} while (0)
55 #endif
56 
57 #define IPC_SEM_IDS	0
58 #define IPC_MSG_IDS	1
59 #define IPC_SHM_IDS	2
60 
61 /* must be called with ids->mutex acquired.*/
62 int ipc_findkey(struct ipc_ids* ids, key_t key);
63 int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size);
64 
65 /* must be called with both locks acquired. */
66 struct kern_ipc_perm* ipc_rmid(struct ipc_ids* ids, int id);
67 
68 int ipcperms (struct kern_ipc_perm *ipcp, short flg);
69 
70 /* for rare, potentially huge allocations.
71  * both function can sleep
72  */
73 void* ipc_alloc(int size);
74 void ipc_free(void* ptr, int size);
75 
76 /*
77  * For allocation that need to be freed by RCU.
78  * Objects are reference counted, they start with reference count 1.
79  * getref increases the refcount, the putref call that reduces the recount
80  * to 0 schedules the rcu destruction. Caller must guarantee locking.
81  */
82 void* ipc_rcu_alloc(int size);
83 void ipc_rcu_getref(void *ptr);
84 void ipc_rcu_putref(void *ptr);
85 
86 static inline void __ipc_fini_ids(struct ipc_ids *ids,
87 		struct ipc_id_ary *entries)
88 {
89 	if (entries != &ids->nullentry)
90 		ipc_rcu_putref(entries);
91 }
92 
93 static inline void ipc_fini_ids(struct ipc_ids *ids)
94 {
95 	__ipc_fini_ids(ids, ids->entries);
96 }
97 
98 struct kern_ipc_perm* ipc_get(struct ipc_ids* ids, int id);
99 struct kern_ipc_perm* ipc_lock(struct ipc_ids* ids, int id);
100 void ipc_lock_by_ptr(struct kern_ipc_perm *ipcp);
101 void ipc_unlock(struct kern_ipc_perm* perm);
102 int ipc_buildid(struct ipc_ids* ids, int id, int seq);
103 int ipc_checkid(struct ipc_ids* ids, struct kern_ipc_perm* ipcp, int uid);
104 
105 void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out);
106 void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out);
107 
108 #if defined(__ia64__) || defined(__x86_64__) || defined(__hppa__) || defined(__XTENSA__)
109   /* On IA-64, we always use the "64-bit version" of the IPC structures.  */
110 # define ipc_parse_version(cmd)	IPC_64
111 #else
112 int ipc_parse_version (int *cmd);
113 #endif
114 
115 extern void free_msg(struct msg_msg *msg);
116 extern struct msg_msg *load_msg(const void __user *src, int len);
117 extern int store_msg(void __user *dest, struct msg_msg *msg, int len);
118 
119 #endif
120