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 45 void ipc_init_ids(struct ipc_ids *ids, int size); 46 #ifdef CONFIG_PROC_FS 47 void __init ipc_init_proc_interface(const char *path, const char *header, 48 int ids, int (*show)(struct seq_file *, void *)); 49 #else 50 #define ipc_init_proc_interface(path, header, ids, show) do {} while (0) 51 #endif 52 53 #define IPC_SEM_IDS 0 54 #define IPC_MSG_IDS 1 55 #define IPC_SHM_IDS 2 56 57 /* must be called with ids->mutex acquired.*/ 58 int ipc_findkey(struct ipc_ids* ids, key_t key); 59 int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size); 60 61 /* must be called with both locks acquired. */ 62 struct kern_ipc_perm* ipc_rmid(struct ipc_ids* ids, int id); 63 64 int ipcperms (struct kern_ipc_perm *ipcp, short flg); 65 66 /* for rare, potentially huge allocations. 67 * both function can sleep 68 */ 69 void* ipc_alloc(int size); 70 void ipc_free(void* ptr, int size); 71 72 /* 73 * For allocation that need to be freed by RCU. 74 * Objects are reference counted, they start with reference count 1. 75 * getref increases the refcount, the putref call that reduces the recount 76 * to 0 schedules the rcu destruction. Caller must guarantee locking. 77 */ 78 void* ipc_rcu_alloc(int size); 79 void ipc_rcu_getref(void *ptr); 80 void ipc_rcu_putref(void *ptr); 81 82 static inline void __ipc_fini_ids(struct ipc_ids *ids, 83 struct ipc_id_ary *entries) 84 { 85 if (entries != &ids->nullentry) 86 ipc_rcu_putref(entries); 87 } 88 89 static inline void ipc_fini_ids(struct ipc_ids *ids) 90 { 91 __ipc_fini_ids(ids, ids->entries); 92 } 93 94 struct kern_ipc_perm* ipc_get(struct ipc_ids* ids, int id); 95 struct kern_ipc_perm* ipc_lock(struct ipc_ids* ids, int id); 96 void ipc_lock_by_ptr(struct kern_ipc_perm *ipcp); 97 void ipc_unlock(struct kern_ipc_perm* perm); 98 int ipc_buildid(struct ipc_ids* ids, int id, int seq); 99 int ipc_checkid(struct ipc_ids* ids, struct kern_ipc_perm* ipcp, int uid); 100 101 void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out); 102 void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out); 103 104 #if defined(__ia64__) || defined(__x86_64__) || defined(__hppa__) || defined(__XTENSA__) 105 /* On IA-64, we always use the "64-bit version" of the IPC structures. */ 106 # define ipc_parse_version(cmd) IPC_64 107 #else 108 int ipc_parse_version (int *cmd); 109 #endif 110 111 extern void free_msg(struct msg_msg *msg); 112 extern struct msg_msg *load_msg(const void __user *src, int len); 113 extern int store_msg(void __user *dest, struct msg_msg *msg, int len); 114 115 #endif 116