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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
Johannes Weiner232086b2009-06-20 02:23:29 +020013#include <linux/unistd.h>
Nadia Derbey023a5352007-10-18 23:40:51 -070014#include <linux/err.h>
Nadia Derbey7ca7e562007-10-18 23:40:48 -070015
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#define SEQ_MULTIPLIER (IPCMNI)
17
18void sem_init (void);
19void msg_init (void);
20void shm_init (void);
21
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -080022struct ipc_namespace;
23
Serge E. Hallyn614b84c2009-04-06 19:01:08 -070024#ifdef CONFIG_POSIX_MQUEUE
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -070025extern void mq_clear_sbinfo(struct ipc_namespace *ns);
26extern void mq_put_mnt(struct ipc_namespace *ns);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -070027#else
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -070028static inline void mq_clear_sbinfo(struct ipc_namespace *ns) { }
29static inline void mq_put_mnt(struct ipc_namespace *ns) { }
Serge E. Hallyn614b84c2009-04-06 19:01:08 -070030#endif
31
32#ifdef CONFIG_SYSVIPC
Pierre Peiffered2ddbf2008-02-08 04:18:57 -080033void sem_init_ns(struct ipc_namespace *ns);
34void msg_init_ns(struct ipc_namespace *ns);
35void shm_init_ns(struct ipc_namespace *ns);
Kirill Korotaev73ea4132006-10-02 02:18:20 -070036
37void sem_exit_ns(struct ipc_namespace *ns);
38void msg_exit_ns(struct ipc_namespace *ns);
39void shm_exit_ns(struct ipc_namespace *ns);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -070040#else
41static inline void sem_init_ns(struct ipc_namespace *ns) { }
42static inline void msg_init_ns(struct ipc_namespace *ns) { }
43static inline void shm_init_ns(struct ipc_namespace *ns) { }
44
45static inline void sem_exit_ns(struct ipc_namespace *ns) { }
46static inline void msg_exit_ns(struct ipc_namespace *ns) { }
47static inline void shm_exit_ns(struct ipc_namespace *ns) { }
48#endif
Kirill Korotaev73ea4132006-10-02 02:18:20 -070049
Nadia Derbey7748dbf2007-10-18 23:40:49 -070050/*
51 * Structure that holds the parameters needed by the ipc operations
52 * (see after)
53 */
54struct ipc_params {
55 key_t key;
56 int flg;
57 union {
58 size_t size; /* for shared memories */
59 int nsems; /* for semaphores */
60 } u; /* holds the getnew() specific param */
61};
62
63/*
64 * Structure that holds some ipc operations. This structure is used to unify
65 * the calls to sys_msgget(), sys_semget(), sys_shmget()
66 * . routine to call to create a new ipc object. Can be one of newque,
67 * newary, newseg
Nadia Derbeyf4566f02007-10-18 23:40:53 -070068 * . routine to call to check permissions for a new ipc object.
Nadia Derbey7748dbf2007-10-18 23:40:49 -070069 * Can be one of security_msg_associate, security_sem_associate,
70 * security_shm_associate
71 * . routine to call for an extra check if needed
72 */
73struct ipc_ops {
74 int (*getnew) (struct ipc_namespace *, struct ipc_params *);
Nadia Derbey03f02c72007-10-18 23:40:51 -070075 int (*associate) (struct kern_ipc_perm *, int);
76 int (*more_checks) (struct kern_ipc_perm *, struct ipc_params *);
Nadia Derbey7748dbf2007-10-18 23:40:49 -070077};
78
Mike Waychisonae781772005-09-06 15:17:09 -070079struct seq_file;
Pierre Peiffered2ddbf2008-02-08 04:18:57 -080080struct ipc_ids;
Cedric Le Goater7d69a1f2007-07-15 23:40:58 -070081
Nadia Derbey7ca7e562007-10-18 23:40:48 -070082void ipc_init_ids(struct ipc_ids *);
Mike Waychisonae781772005-09-06 15:17:09 -070083#ifdef CONFIG_PROC_FS
84void __init ipc_init_proc_interface(const char *path, const char *header,
Kirill Korotaev73ea4132006-10-02 02:18:20 -070085 int ids, int (*show)(struct seq_file *, void *));
Mike Waychisonae781772005-09-06 15:17:09 -070086#else
87#define ipc_init_proc_interface(path, header, ids, show) do {} while (0)
88#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070089
Kirill Korotaev73ea4132006-10-02 02:18:20 -070090#define IPC_SEM_IDS 0
91#define IPC_MSG_IDS 1
92#define IPC_SHM_IDS 2
93
Nadia Derbeyce621f52007-10-18 23:40:52 -070094#define ipcid_to_idx(id) ((id) % SEQ_MULTIPLIER)
Stanislav Kinsbursky03f59562013-01-04 15:34:50 -080095#define ipcid_to_seqx(id) ((id) / SEQ_MULTIPLIER)
Nadia Derbeyce621f52007-10-18 23:40:52 -070096
Nadia Derbey3e148c72007-10-18 23:40:54 -070097/* must be called with ids->rw_mutex acquired for writing */
Nadia Derbey7ca7e562007-10-18 23:40:48 -070098int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int);
Nadia Derbey3e148c72007-10-18 23:40:54 -070099
100/* must be called with ids->rw_mutex acquired for reading */
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700101int ipc_get_maxid(struct ipc_ids *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102
103/* must be called with both locks acquired. */
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700104void ipc_rmid(struct ipc_ids *, struct kern_ipc_perm *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700106/* must be called with ipcp locked */
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700107int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108
109/* for rare, potentially huge allocations.
110 * both function can sleep
111 */
112void* ipc_alloc(int size);
113void ipc_free(void* ptr, int size);
114
115/*
116 * For allocation that need to be freed by RCU.
117 * Objects are reference counted, they start with reference count 1.
118 * getref increases the refcount, the putref call that reduces the recount
119 * to 0 schedules the rcu destruction. Caller must guarantee locking.
120 */
121void* ipc_rcu_alloc(int size);
Rik van Riel6062a8d2013-04-30 19:15:44 -0700122int ipc_rcu_getref(void *ptr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123void ipc_rcu_putref(void *ptr);
124
Nadia Derbey023a5352007-10-18 23:40:51 -0700125struct kern_ipc_perm *ipc_lock(struct ipc_ids *, int);
Davidlohr Bueso4d2bff52013-04-30 19:15:19 -0700126struct kern_ipc_perm *ipc_obtain_object(struct ipc_ids *ids, int id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127
128void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out);
129void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out);
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800130int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out);
Davidlohr Bueso444d0f62013-04-30 19:15:24 -0700131struct kern_ipc_perm *ipcctl_pre_down_nolock(struct ipc_namespace *ns,
132 struct ipc_ids *ids, int id, int cmd,
133 struct ipc64_perm *perm, int extra_perm);
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700134struct kern_ipc_perm *ipcctl_pre_down(struct ipc_namespace *ns,
135 struct ipc_ids *ids, int id, int cmd,
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700136 struct ipc64_perm *perm, int extra_perm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137
Will Deaconc1d7e012012-07-30 14:42:46 -0700138#ifndef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 /* On IA-64, we always use the "64-bit version" of the IPC structures. */
140# define ipc_parse_version(cmd) IPC_64
141#else
142int ipc_parse_version (int *cmd);
143#endif
144
145extern void free_msg(struct msg_msg *msg);
146extern struct msg_msg *load_msg(const void __user *src, int len);
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800147extern struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148extern int store_msg(void __user *dest, struct msg_msg *msg, int len);
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700149
Nadia Derbeyb6b337a2008-04-29 01:00:42 -0700150extern void recompute_msgmni(struct ipc_namespace *);
151
Nadia Derbey1b531f22007-10-18 23:40:55 -0700152static inline int ipc_buildid(int id, int seq)
Nadia Derbey28028312007-10-18 23:40:52 -0700153{
154 return SEQ_MULTIPLIER * seq + id;
155}
156
Nadia Derbey1b531f22007-10-18 23:40:55 -0700157static inline int ipc_checkid(struct kern_ipc_perm *ipcp, int uid)
Nadia Derbey023a5352007-10-18 23:40:51 -0700158{
Davidlohr Bueso7bb4def2013-04-30 19:15:14 -0700159 return uid / SEQ_MULTIPLIER != ipcp->seq;
Nadia Derbey023a5352007-10-18 23:40:51 -0700160}
161
162static inline void ipc_lock_by_ptr(struct kern_ipc_perm *perm)
163{
164 rcu_read_lock();
165 spin_lock(&perm->lock);
166}
167
168static inline void ipc_unlock(struct kern_ipc_perm *perm)
169{
170 spin_unlock(&perm->lock);
171 rcu_read_unlock();
172}
173
Davidlohr Bueso16df3672013-04-30 19:15:29 -0700174static inline void ipc_lock_object(struct kern_ipc_perm *perm)
175{
176 spin_lock(&perm->lock);
177}
178
Pavel Emelyanovb2d75cd2008-02-08 04:18:54 -0800179struct kern_ipc_perm *ipc_lock_check(struct ipc_ids *ids, int id);
Davidlohr Bueso4d2bff52013-04-30 19:15:19 -0700180struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id);
Pavel Emelyanovb2d75cd2008-02-08 04:18:54 -0800181int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
182 struct ipc_ops *ops, struct ipc_params *params);
Alexey Dobriyan665c7742009-06-17 16:27:57 -0700183void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
184 void (*free)(struct ipc_namespace *, struct kern_ipc_perm *));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185#endif