1 /* 2 * linux/ipc/util.h 3 * Copyright (C) 1999 Christoph Rohland 4 * 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 */ 9 10 #ifndef _IPC_UTIL_H 11 #define _IPC_UTIL_H 12 13 #define USHRT_MAX 0xffff 14 #define SEQ_MULTIPLIER (IPCMNI) 15 16 void sem_init (void); 17 void msg_init (void); 18 void shm_init (void); 19 20 int sem_init_ns(struct ipc_namespace *ns); 21 int msg_init_ns(struct ipc_namespace *ns); 22 int shm_init_ns(struct ipc_namespace *ns); 23 24 void sem_exit_ns(struct ipc_namespace *ns); 25 void msg_exit_ns(struct ipc_namespace *ns); 26 void shm_exit_ns(struct ipc_namespace *ns); 27 28 struct ipc_id_ary { 29 int size; 30 struct kern_ipc_perm *p[0]; 31 }; 32 33 struct ipc_ids { 34 int in_use; 35 int max_id; 36 unsigned short seq; 37 unsigned short seq_max; 38 struct mutex mutex; 39 struct ipc_id_ary nullentry; 40 struct ipc_id_ary* entries; 41 }; 42 43 struct seq_file; 44 #ifdef CONFIG_IPC_NS 45 #define __ipc_init 46 #else 47 #define __ipc_init __init 48 #endif 49 void __ipc_init ipc_init_ids(struct ipc_ids *ids, int size); 50 #ifdef CONFIG_PROC_FS 51 void __init ipc_init_proc_interface(const char *path, const char *header, 52 int ids, int (*show)(struct seq_file *, void *)); 53 #else 54 #define ipc_init_proc_interface(path, header, ids, show) do {} while (0) 55 #endif 56 57 #define IPC_SEM_IDS 0 58 #define IPC_MSG_IDS 1 59 #define IPC_SHM_IDS 2 60 61 /* must be called with ids->mutex acquired.*/ 62 int ipc_findkey(struct ipc_ids* ids, key_t key); 63 int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size); 64 65 /* must be called with both locks acquired. */ 66 struct kern_ipc_perm* ipc_rmid(struct ipc_ids* ids, int id); 67 68 int ipcperms (struct kern_ipc_perm *ipcp, short flg); 69 70 /* for rare, potentially huge allocations. 71 * both function can sleep 72 */ 73 void* ipc_alloc(int size); 74 void ipc_free(void* ptr, int size); 75 76 /* 77 * For allocation that need to be freed by RCU. 78 * Objects are reference counted, they start with reference count 1. 79 * getref increases the refcount, the putref call that reduces the recount 80 * to 0 schedules the rcu destruction. Caller must guarantee locking. 81 */ 82 void* ipc_rcu_alloc(int size); 83 void ipc_rcu_getref(void *ptr); 84 void ipc_rcu_putref(void *ptr); 85 86 static inline void __ipc_fini_ids(struct ipc_ids *ids, 87 struct ipc_id_ary *entries) 88 { 89 if (entries != &ids->nullentry) 90 ipc_rcu_putref(entries); 91 } 92 93 static inline void ipc_fini_ids(struct ipc_ids *ids) 94 { 95 __ipc_fini_ids(ids, ids->entries); 96 } 97 98 struct kern_ipc_perm* ipc_get(struct ipc_ids* ids, int id); 99 struct kern_ipc_perm* ipc_lock(struct ipc_ids* ids, int id); 100 void ipc_lock_by_ptr(struct kern_ipc_perm *ipcp); 101 void ipc_unlock(struct kern_ipc_perm* perm); 102 int ipc_buildid(struct ipc_ids* ids, int id, int seq); 103 int ipc_checkid(struct ipc_ids* ids, struct kern_ipc_perm* ipcp, int uid); 104 105 void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out); 106 void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out); 107 108 #if defined(__ia64__) || defined(__x86_64__) || defined(__hppa__) || defined(__XTENSA__) 109 /* On IA-64, we always use the "64-bit version" of the IPC structures. */ 110 # define ipc_parse_version(cmd) IPC_64 111 #else 112 int ipc_parse_version (int *cmd); 113 #endif 114 115 extern void free_msg(struct msg_msg *msg); 116 extern struct msg_msg *load_msg(const void __user *src, int len); 117 extern int store_msg(void __user *dest, struct msg_msg *msg, int len); 118 119 #endif 120