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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/ipc/util.h
3 * Copyright (C) 1999 Christoph Rohland
4 *
Christian Kujau624dffc2006-01-15 02:43:54 +01005 * ipc helper functions (c) 1999 Manfred Spraul <manfred@colorfullife.com>
Kirill Korotaev73ea4132006-10-02 02:18:20 -07006 * namespaces support. 2006 OpenVZ, SWsoft Inc.
7 * Pavel Emelianov <xemul@openvz.org>
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 */
9
10#ifndef _IPC_UTIL_H
11#define _IPC_UTIL_H
12
Nadia Derbey023a5352007-10-18 23:40:51 -070013#include <linux/err.h>
Nadia Derbey7ca7e562007-10-18 23:40:48 -070014
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#define SEQ_MULTIPLIER (IPCMNI)
16
17void sem_init (void);
18void msg_init (void);
19void shm_init (void);
20
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -080021struct ipc_namespace;
22
Serge E. Hallyn614b84c2009-04-06 19:01:08 -070023#ifdef CONFIG_POSIX_MQUEUE
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -070024extern void mq_clear_sbinfo(struct ipc_namespace *ns);
25extern void mq_put_mnt(struct ipc_namespace *ns);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -070026#else
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -070027static inline void mq_clear_sbinfo(struct ipc_namespace *ns) { }
28static inline void mq_put_mnt(struct ipc_namespace *ns) { }
Serge E. Hallyn614b84c2009-04-06 19:01:08 -070029#endif
30
31#ifdef CONFIG_SYSVIPC
Pierre Peiffered2ddbf2008-02-08 04:18:57 -080032void sem_init_ns(struct ipc_namespace *ns);
33void msg_init_ns(struct ipc_namespace *ns);
34void shm_init_ns(struct ipc_namespace *ns);
Kirill Korotaev73ea4132006-10-02 02:18:20 -070035
36void sem_exit_ns(struct ipc_namespace *ns);
37void msg_exit_ns(struct ipc_namespace *ns);
38void shm_exit_ns(struct ipc_namespace *ns);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -070039#else
40static inline void sem_init_ns(struct ipc_namespace *ns) { }
41static inline void msg_init_ns(struct ipc_namespace *ns) { }
42static inline void shm_init_ns(struct ipc_namespace *ns) { }
43
44static inline void sem_exit_ns(struct ipc_namespace *ns) { }
45static inline void msg_exit_ns(struct ipc_namespace *ns) { }
46static inline void shm_exit_ns(struct ipc_namespace *ns) { }
47#endif
Kirill Korotaev73ea4132006-10-02 02:18:20 -070048
Nadia Derbey7748dbf2007-10-18 23:40:49 -070049/*
50 * Structure that holds the parameters needed by the ipc operations
51 * (see after)
52 */
53struct ipc_params {
54 key_t key;
55 int flg;
56 union {
57 size_t size; /* for shared memories */
58 int nsems; /* for semaphores */
59 } u; /* holds the getnew() specific param */
60};
61
62/*
63 * Structure that holds some ipc operations. This structure is used to unify
64 * the calls to sys_msgget(), sys_semget(), sys_shmget()
65 * . routine to call to create a new ipc object. Can be one of newque,
66 * newary, newseg
Nadia Derbeyf4566f02007-10-18 23:40:53 -070067 * . routine to call to check permissions for a new ipc object.
Nadia Derbey7748dbf2007-10-18 23:40:49 -070068 * Can be one of security_msg_associate, security_sem_associate,
69 * security_shm_associate
70 * . routine to call for an extra check if needed
71 */
72struct ipc_ops {
73 int (*getnew) (struct ipc_namespace *, struct ipc_params *);
Nadia Derbey03f02c72007-10-18 23:40:51 -070074 int (*associate) (struct kern_ipc_perm *, int);
75 int (*more_checks) (struct kern_ipc_perm *, struct ipc_params *);
Nadia Derbey7748dbf2007-10-18 23:40:49 -070076};
77
Mike Waychisonae781772005-09-06 15:17:09 -070078struct seq_file;
Pierre Peiffered2ddbf2008-02-08 04:18:57 -080079struct ipc_ids;
Cedric Le Goater7d69a1f2007-07-15 23:40:58 -070080
Nadia Derbey7ca7e562007-10-18 23:40:48 -070081void ipc_init_ids(struct ipc_ids *);
Mike Waychisonae781772005-09-06 15:17:09 -070082#ifdef CONFIG_PROC_FS
83void __init ipc_init_proc_interface(const char *path, const char *header,
Kirill Korotaev73ea4132006-10-02 02:18:20 -070084 int ids, int (*show)(struct seq_file *, void *));
Mike Waychisonae781772005-09-06 15:17:09 -070085#else
86#define ipc_init_proc_interface(path, header, ids, show) do {} while (0)
87#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070088
Kirill Korotaev73ea4132006-10-02 02:18:20 -070089#define IPC_SEM_IDS 0
90#define IPC_MSG_IDS 1
91#define IPC_SHM_IDS 2
92
Nadia Derbeyce621f52007-10-18 23:40:52 -070093#define ipcid_to_idx(id) ((id) % SEQ_MULTIPLIER)
94
Nadia Derbey3e148c72007-10-18 23:40:54 -070095/* must be called with ids->rw_mutex acquired for writing */
Nadia Derbey7ca7e562007-10-18 23:40:48 -070096int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int);
Nadia Derbey3e148c72007-10-18 23:40:54 -070097
98/* must be called with ids->rw_mutex acquired for reading */
Nadia Derbey7ca7e562007-10-18 23:40:48 -070099int ipc_get_maxid(struct ipc_ids *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100
101/* must be called with both locks acquired. */
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700102void ipc_rmid(struct ipc_ids *, struct kern_ipc_perm *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700104/* must be called with ipcp locked */
105int ipcperms(struct kern_ipc_perm *ipcp, short flg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106
107/* for rare, potentially huge allocations.
108 * both function can sleep
109 */
110void* ipc_alloc(int size);
111void ipc_free(void* ptr, int size);
112
113/*
114 * For allocation that need to be freed by RCU.
115 * Objects are reference counted, they start with reference count 1.
116 * getref increases the refcount, the putref call that reduces the recount
117 * to 0 schedules the rcu destruction. Caller must guarantee locking.
118 */
119void* ipc_rcu_alloc(int size);
120void ipc_rcu_getref(void *ptr);
121void ipc_rcu_putref(void *ptr);
122
Nadia Derbey023a5352007-10-18 23:40:51 -0700123struct kern_ipc_perm *ipc_lock(struct ipc_ids *, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124
125void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out);
126void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out);
Pierre Peiffer8f4a3802008-04-29 01:00:51 -0700127void ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out);
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700128struct kern_ipc_perm *ipcctl_pre_down(struct ipc_ids *ids, int id, int cmd,
129 struct ipc64_perm *perm, int extra_perm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130
Chris Zankel813e6782005-07-12 13:58:25 -0700131#if defined(__ia64__) || defined(__x86_64__) || defined(__hppa__) || defined(__XTENSA__)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 /* On IA-64, we always use the "64-bit version" of the IPC structures. */
133# define ipc_parse_version(cmd) IPC_64
134#else
135int ipc_parse_version (int *cmd);
136#endif
137
138extern void free_msg(struct msg_msg *msg);
139extern struct msg_msg *load_msg(const void __user *src, int len);
140extern int store_msg(void __user *dest, struct msg_msg *msg, int len);
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700141
Nadia Derbeyb6b337a2008-04-29 01:00:42 -0700142extern void recompute_msgmni(struct ipc_namespace *);
143
Nadia Derbey1b531f22007-10-18 23:40:55 -0700144static inline int ipc_buildid(int id, int seq)
Nadia Derbey28028312007-10-18 23:40:52 -0700145{
146 return SEQ_MULTIPLIER * seq + id;
147}
148
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700149/*
150 * Must be called with ipcp locked
151 */
Nadia Derbey1b531f22007-10-18 23:40:55 -0700152static inline int ipc_checkid(struct kern_ipc_perm *ipcp, int uid)
Nadia Derbey023a5352007-10-18 23:40:51 -0700153{
154 if (uid / SEQ_MULTIPLIER != ipcp->seq)
155 return 1;
156 return 0;
157}
158
159static inline void ipc_lock_by_ptr(struct kern_ipc_perm *perm)
160{
161 rcu_read_lock();
162 spin_lock(&perm->lock);
163}
164
165static inline void ipc_unlock(struct kern_ipc_perm *perm)
166{
167 spin_unlock(&perm->lock);
168 rcu_read_unlock();
169}
170
Pavel Emelyanovb2d75cd2008-02-08 04:18:54 -0800171struct kern_ipc_perm *ipc_lock_check(struct ipc_ids *ids, int id);
172int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
173 struct ipc_ops *ops, struct ipc_params *params);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174
175#endif