Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/ipc/util.h | |
3 | * Copyright (C) 1999 Christoph Rohland | |
4 | * | |
624dffcb | 5 | * ipc helper functions (c) 1999 Manfred Spraul <manfred@colorfullife.com> |
73ea4130 KK |
6 | * namespaces support. 2006 OpenVZ, SWsoft Inc. |
7 | * Pavel Emelianov <xemul@openvz.org> | |
1da177e4 LT |
8 | */ |
9 | ||
10 | #ifndef _IPC_UTIL_H | |
11 | #define _IPC_UTIL_H | |
12 | ||
023a5355 | 13 | #include <linux/err.h> |
7ca7e564 | 14 | |
1da177e4 LT |
15 | #define USHRT_MAX 0xffff |
16 | #define SEQ_MULTIPLIER (IPCMNI) | |
17 | ||
18 | void sem_init (void); | |
19 | void msg_init (void); | |
20 | void shm_init (void); | |
21 | ||
ae5e1b22 PE |
22 | struct ipc_namespace; |
23 | ||
ed2ddbf8 PP |
24 | void sem_init_ns(struct ipc_namespace *ns); |
25 | void msg_init_ns(struct ipc_namespace *ns); | |
26 | void shm_init_ns(struct ipc_namespace *ns); | |
73ea4130 KK |
27 | |
28 | void sem_exit_ns(struct ipc_namespace *ns); | |
29 | void msg_exit_ns(struct ipc_namespace *ns); | |
30 | void shm_exit_ns(struct ipc_namespace *ns); | |
31 | ||
7748dbfa ND |
32 | /* |
33 | * Structure that holds the parameters needed by the ipc operations | |
34 | * (see after) | |
35 | */ | |
36 | struct ipc_params { | |
37 | key_t key; | |
38 | int flg; | |
39 | union { | |
40 | size_t size; /* for shared memories */ | |
41 | int nsems; /* for semaphores */ | |
42 | } u; /* holds the getnew() specific param */ | |
43 | }; | |
44 | ||
45 | /* | |
46 | * Structure that holds some ipc operations. This structure is used to unify | |
47 | * the calls to sys_msgget(), sys_semget(), sys_shmget() | |
48 | * . routine to call to create a new ipc object. Can be one of newque, | |
49 | * newary, newseg | |
f4566f04 | 50 | * . routine to call to check permissions for a new ipc object. |
7748dbfa ND |
51 | * Can be one of security_msg_associate, security_sem_associate, |
52 | * security_shm_associate | |
53 | * . routine to call for an extra check if needed | |
54 | */ | |
55 | struct ipc_ops { | |
56 | int (*getnew) (struct ipc_namespace *, struct ipc_params *); | |
03f02c76 ND |
57 | int (*associate) (struct kern_ipc_perm *, int); |
58 | int (*more_checks) (struct kern_ipc_perm *, struct ipc_params *); | |
7748dbfa ND |
59 | }; |
60 | ||
ae781774 | 61 | struct seq_file; |
ed2ddbf8 | 62 | struct ipc_ids; |
7d69a1f4 | 63 | |
7ca7e564 | 64 | void ipc_init_ids(struct ipc_ids *); |
ae781774 MW |
65 | #ifdef CONFIG_PROC_FS |
66 | void __init ipc_init_proc_interface(const char *path, const char *header, | |
73ea4130 | 67 | int ids, int (*show)(struct seq_file *, void *)); |
ae781774 MW |
68 | #else |
69 | #define ipc_init_proc_interface(path, header, ids, show) do {} while (0) | |
70 | #endif | |
1da177e4 | 71 | |
73ea4130 KK |
72 | #define IPC_SEM_IDS 0 |
73 | #define IPC_MSG_IDS 1 | |
74 | #define IPC_SHM_IDS 2 | |
75 | ||
ce621f5b ND |
76 | #define ipcid_to_idx(id) ((id) % SEQ_MULTIPLIER) |
77 | ||
3e148c79 | 78 | /* must be called with ids->rw_mutex acquired for writing */ |
7ca7e564 | 79 | int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int); |
3e148c79 ND |
80 | |
81 | /* must be called with ids->rw_mutex acquired for reading */ | |
7ca7e564 | 82 | int ipc_get_maxid(struct ipc_ids *); |
1da177e4 LT |
83 | |
84 | /* must be called with both locks acquired. */ | |
7ca7e564 | 85 | void ipc_rmid(struct ipc_ids *, struct kern_ipc_perm *); |
1da177e4 | 86 | |
f4566f04 ND |
87 | /* must be called with ipcp locked */ |
88 | int ipcperms(struct kern_ipc_perm *ipcp, short flg); | |
1da177e4 LT |
89 | |
90 | /* for rare, potentially huge allocations. | |
91 | * both function can sleep | |
92 | */ | |
93 | void* ipc_alloc(int size); | |
94 | void ipc_free(void* ptr, int size); | |
95 | ||
96 | /* | |
97 | * For allocation that need to be freed by RCU. | |
98 | * Objects are reference counted, they start with reference count 1. | |
99 | * getref increases the refcount, the putref call that reduces the recount | |
100 | * to 0 schedules the rcu destruction. Caller must guarantee locking. | |
101 | */ | |
102 | void* ipc_rcu_alloc(int size); | |
103 | void ipc_rcu_getref(void *ptr); | |
104 | void ipc_rcu_putref(void *ptr); | |
105 | ||
3e148c79 ND |
106 | /* |
107 | * ipc_lock_down: called with rw_mutex held | |
108 | * ipc_lock: called without that lock held | |
109 | */ | |
110 | struct kern_ipc_perm *ipc_lock_down(struct ipc_ids *, int); | |
023a5355 | 111 | struct kern_ipc_perm *ipc_lock(struct ipc_ids *, int); |
1da177e4 LT |
112 | |
113 | void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out); | |
114 | void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out); | |
115 | ||
813e6783 | 116 | #if defined(__ia64__) || defined(__x86_64__) || defined(__hppa__) || defined(__XTENSA__) |
1da177e4 LT |
117 | /* On IA-64, we always use the "64-bit version" of the IPC structures. */ |
118 | # define ipc_parse_version(cmd) IPC_64 | |
119 | #else | |
120 | int ipc_parse_version (int *cmd); | |
121 | #endif | |
122 | ||
123 | extern void free_msg(struct msg_msg *msg); | |
124 | extern struct msg_msg *load_msg(const void __user *src, int len); | |
125 | extern int store_msg(void __user *dest, struct msg_msg *msg, int len); | |
7748dbfa | 126 | |
1b531f21 | 127 | static inline int ipc_buildid(int id, int seq) |
28028313 ND |
128 | { |
129 | return SEQ_MULTIPLIER * seq + id; | |
130 | } | |
131 | ||
f4566f04 ND |
132 | /* |
133 | * Must be called with ipcp locked | |
134 | */ | |
1b531f21 | 135 | static inline int ipc_checkid(struct kern_ipc_perm *ipcp, int uid) |
023a5355 ND |
136 | { |
137 | if (uid / SEQ_MULTIPLIER != ipcp->seq) | |
138 | return 1; | |
139 | return 0; | |
140 | } | |
141 | ||
142 | static inline void ipc_lock_by_ptr(struct kern_ipc_perm *perm) | |
143 | { | |
144 | rcu_read_lock(); | |
145 | spin_lock(&perm->lock); | |
146 | } | |
147 | ||
148 | static inline void ipc_unlock(struct kern_ipc_perm *perm) | |
149 | { | |
150 | spin_unlock(&perm->lock); | |
151 | rcu_read_unlock(); | |
152 | } | |
153 | ||
b2d75cdd PE |
154 | struct kern_ipc_perm *ipc_lock_check_down(struct ipc_ids *ids, int id); |
155 | struct kern_ipc_perm *ipc_lock_check(struct ipc_ids *ids, int id); | |
156 | int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids, | |
157 | struct ipc_ops *ops, struct ipc_params *params); | |
1da177e4 LT |
158 | |
159 | #endif |