3 * Copyright (C) 1999 Christoph Rohland
5 * ipc helper functions (c) 1999 Manfred Spraul <manfred@colorfullife.com>
6 * namespaces support. 2006 OpenVZ, SWsoft Inc.
7 * Pavel Emelianov <xemul@openvz.org>
13 #include <linux/idr.h>
14 #include <linux/err.h>
16 #define USHRT_MAX 0xffff
17 #define SEQ_MULTIPLIER (IPCMNI)
23 int sem_init_ns(struct ipc_namespace *ns);
24 int msg_init_ns(struct ipc_namespace *ns);
25 int shm_init_ns(struct ipc_namespace *ns);
27 void sem_exit_ns(struct ipc_namespace *ns);
28 void msg_exit_ns(struct ipc_namespace *ns);
29 void shm_exit_ns(struct ipc_namespace *ns);
34 unsigned short seq_max;
40 * Structure that holds the parameters needed by the ipc operations
47 size_t size; /* for shared memories */
48 int nsems; /* for semaphores */
49 } u; /* holds the getnew() specific param */
53 * Structure that holds some ipc operations. This structure is used to unify
54 * the calls to sys_msgget(), sys_semget(), sys_shmget()
55 * . routine to call to create a new ipc object. Can be one of newque,
57 * . routine to call to call to check permissions for a new ipc object.
58 * Can be one of security_msg_associate, security_sem_associate,
59 * security_shm_associate
60 * . routine to call for an extra check if needed
63 int (*getnew) (struct ipc_namespace *, struct ipc_params *);
64 int (*associate) (struct kern_ipc_perm *, int);
65 int (*more_checks) (struct kern_ipc_perm *, struct ipc_params *);
70 void ipc_init_ids(struct ipc_ids *);
72 void __init ipc_init_proc_interface(const char *path, const char *header,
73 int ids, int (*show)(struct seq_file *, void *));
75 #define ipc_init_proc_interface(path, header, ids, show) do {} while (0)
82 #define ipcid_to_idx(id) ((id) % SEQ_MULTIPLIER)
84 /* must be called with ids->mutex acquired.*/
85 int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int);
86 int ipc_get_maxid(struct ipc_ids *);
88 /* must be called with both locks acquired. */
89 void ipc_rmid(struct ipc_ids *, struct kern_ipc_perm *);
91 int ipcperms (struct kern_ipc_perm *ipcp, short flg);
93 /* for rare, potentially huge allocations.
94 * both function can sleep
96 void* ipc_alloc(int size);
97 void ipc_free(void* ptr, int size);
100 * For allocation that need to be freed by RCU.
101 * Objects are reference counted, they start with reference count 1.
102 * getref increases the refcount, the putref call that reduces the recount
103 * to 0 schedules the rcu destruction. Caller must guarantee locking.
105 void* ipc_rcu_alloc(int size);
106 void ipc_rcu_getref(void *ptr);
107 void ipc_rcu_putref(void *ptr);
109 struct kern_ipc_perm *ipc_lock(struct ipc_ids *, int);
110 int ipc_buildid(struct ipc_ids* ids, int id, int seq);
112 void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out);
113 void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out);
115 #if defined(__ia64__) || defined(__x86_64__) || defined(__hppa__) || defined(__XTENSA__)
116 /* On IA-64, we always use the "64-bit version" of the IPC structures. */
117 # define ipc_parse_version(cmd) IPC_64
119 int ipc_parse_version (int *cmd);
122 extern void free_msg(struct msg_msg *msg);
123 extern struct msg_msg *load_msg(const void __user *src, int len);
124 extern int store_msg(void __user *dest, struct msg_msg *msg, int len);
125 extern int ipcget_new(struct ipc_namespace *, struct ipc_ids *,
126 struct ipc_ops *, struct ipc_params *);
127 extern int ipcget_public(struct ipc_namespace *, struct ipc_ids *,
128 struct ipc_ops *, struct ipc_params *);
130 static inline int ipc_checkid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp,
133 if (uid / SEQ_MULTIPLIER != ipcp->seq)
138 static inline void ipc_lock_by_ptr(struct kern_ipc_perm *perm)
141 spin_lock(&perm->lock);
144 static inline void ipc_unlock(struct kern_ipc_perm *perm)
146 spin_unlock(&perm->lock);
150 static inline struct kern_ipc_perm *ipc_lock_check(struct ipc_ids *ids,
153 struct kern_ipc_perm *out;
155 out = ipc_lock(ids, id);
159 if (ipc_checkid(ids, out, id)) {
161 return ERR_PTR(-EIDRM);
167 static inline int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
168 struct ipc_ops *ops, struct ipc_params *params)
170 if (params->key == IPC_PRIVATE)
171 return ipcget_new(ns, ids, ops, params);
173 return ipcget_public(ns, ids, ops, params);