netfilter: cleanup netfilter_ipv6.h userspace header
[linux-2.6/mini2440.git] / ipc / util.h
blobcdb966aebe0716e8375617431d5734ed45aa639f
1 /*
2 * linux/ipc/util.h
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>
8 */
10 #ifndef _IPC_UTIL_H
11 #define _IPC_UTIL_H
13 #include <linux/err.h>
15 #define SEQ_MULTIPLIER (IPCMNI)
17 void sem_init (void);
18 void msg_init (void);
19 void shm_init (void);
21 struct ipc_namespace;
23 void sem_init_ns(struct ipc_namespace *ns);
24 void msg_init_ns(struct ipc_namespace *ns);
25 void 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);
32 * Structure that holds the parameters needed by the ipc operations
33 * (see after)
35 struct ipc_params {
36 key_t key;
37 int flg;
38 union {
39 size_t size; /* for shared memories */
40 int nsems; /* for semaphores */
41 } u; /* holds the getnew() specific param */
45 * Structure that holds some ipc operations. This structure is used to unify
46 * the calls to sys_msgget(), sys_semget(), sys_shmget()
47 * . routine to call to create a new ipc object. Can be one of newque,
48 * newary, newseg
49 * . routine to call to check permissions for a new ipc object.
50 * Can be one of security_msg_associate, security_sem_associate,
51 * security_shm_associate
52 * . routine to call for an extra check if needed
54 struct ipc_ops {
55 int (*getnew) (struct ipc_namespace *, struct ipc_params *);
56 int (*associate) (struct kern_ipc_perm *, int);
57 int (*more_checks) (struct kern_ipc_perm *, struct ipc_params *);
60 struct seq_file;
61 struct ipc_ids;
63 void ipc_init_ids(struct ipc_ids *);
64 #ifdef CONFIG_PROC_FS
65 void __init ipc_init_proc_interface(const char *path, const char *header,
66 int ids, int (*show)(struct seq_file *, void *));
67 #else
68 #define ipc_init_proc_interface(path, header, ids, show) do {} while (0)
69 #endif
71 #define IPC_SEM_IDS 0
72 #define IPC_MSG_IDS 1
73 #define IPC_SHM_IDS 2
75 #define ipcid_to_idx(id) ((id) % SEQ_MULTIPLIER)
77 /* must be called with ids->rw_mutex acquired for writing */
78 int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int);
80 /* must be called with ids->rw_mutex acquired for reading */
81 int ipc_get_maxid(struct ipc_ids *);
83 /* must be called with both locks acquired. */
84 void ipc_rmid(struct ipc_ids *, struct kern_ipc_perm *);
86 /* must be called with ipcp locked */
87 int ipcperms(struct kern_ipc_perm *ipcp, short flg);
89 /* for rare, potentially huge allocations.
90 * both function can sleep
92 void* ipc_alloc(int size);
93 void ipc_free(void* ptr, int size);
96 * For allocation that need to be freed by RCU.
97 * Objects are reference counted, they start with reference count 1.
98 * getref increases the refcount, the putref call that reduces the recount
99 * to 0 schedules the rcu destruction. Caller must guarantee locking.
101 void* ipc_rcu_alloc(int size);
102 void ipc_rcu_getref(void *ptr);
103 void ipc_rcu_putref(void *ptr);
106 * ipc_lock_down: called with rw_mutex held
107 * ipc_lock: called without that lock held
109 struct kern_ipc_perm *ipc_lock_down(struct ipc_ids *, int);
110 struct kern_ipc_perm *ipc_lock(struct ipc_ids *, int);
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);
114 void ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out);
115 struct kern_ipc_perm *ipcctl_pre_down(struct ipc_ids *ids, int id, int cmd,
116 struct ipc64_perm *perm, int extra_perm);
118 #if defined(__ia64__) || defined(__x86_64__) || defined(__hppa__) || defined(__XTENSA__)
119 /* On IA-64, we always use the "64-bit version" of the IPC structures. */
120 # define ipc_parse_version(cmd) IPC_64
121 #else
122 int ipc_parse_version (int *cmd);
123 #endif
125 extern void free_msg(struct msg_msg *msg);
126 extern struct msg_msg *load_msg(const void __user *src, int len);
127 extern int store_msg(void __user *dest, struct msg_msg *msg, int len);
129 extern void recompute_msgmni(struct ipc_namespace *);
131 static inline int ipc_buildid(int id, int seq)
133 return SEQ_MULTIPLIER * seq + id;
137 * Must be called with ipcp locked
139 static inline int ipc_checkid(struct kern_ipc_perm *ipcp, int uid)
141 if (uid / SEQ_MULTIPLIER != ipcp->seq)
142 return 1;
143 return 0;
146 static inline void ipc_lock_by_ptr(struct kern_ipc_perm *perm)
148 rcu_read_lock();
149 spin_lock(&perm->lock);
152 static inline void ipc_unlock(struct kern_ipc_perm *perm)
154 spin_unlock(&perm->lock);
155 rcu_read_unlock();
158 struct kern_ipc_perm *ipc_lock_check_down(struct ipc_ids *ids, int id);
159 struct kern_ipc_perm *ipc_lock_check(struct ipc_ids *ids, int id);
160 int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
161 struct ipc_ops *ops, struct ipc_params *params);
163 #endif