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 16void sem_init (void); 17void msg_init (void); 18void shm_init (void); 19 20int sem_init_ns(struct ipc_namespace *ns); 21int msg_init_ns(struct ipc_namespace *ns); 22int shm_init_ns(struct ipc_namespace *ns); 23 24void sem_exit_ns(struct ipc_namespace *ns); 25void msg_exit_ns(struct ipc_namespace *ns); 26void shm_exit_ns(struct ipc_namespace *ns); 27 28struct ipc_id_ary { 29 int size; 30 struct kern_ipc_perm *p[0]; 31}; 32 33struct 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 43struct seq_file; 44#ifdef CONFIG_IPC_NS 45#define __ipc_init 46#else 47#define __ipc_init __init 48#endif 49void __ipc_init ipc_init_ids(struct ipc_ids *ids, int size); 50#ifdef CONFIG_PROC_FS 51void __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.*/ 62int ipc_findkey(struct ipc_ids* ids, key_t key); 63int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size); 64 65/* must be called with both locks acquired. */ 66struct kern_ipc_perm* ipc_rmid(struct ipc_ids* ids, int id); 67 68int ipcperms (struct kern_ipc_perm *ipcp, short flg); 69 70/* for rare, potentially huge allocations. 71 * both function can sleep 72 */ 73void* ipc_alloc(int size); 74void 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 */ 82void* ipc_rcu_alloc(int size); 83void ipc_rcu_getref(void *ptr); 84void ipc_rcu_putref(void *ptr); 85 86static 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 93static inline void ipc_fini_ids(struct ipc_ids *ids) 94{ 95 __ipc_fini_ids(ids, ids->entries); 96} 97 98struct kern_ipc_perm* ipc_get(struct ipc_ids* ids, int id); 99struct kern_ipc_perm* ipc_lock(struct ipc_ids* ids, int id); 100void ipc_lock_by_ptr(struct kern_ipc_perm *ipcp); 101void ipc_unlock(struct kern_ipc_perm* perm); 102int ipc_buildid(struct ipc_ids* ids, int id, int seq); 103int ipc_checkid(struct ipc_ids* ids, struct kern_ipc_perm* ipcp, int uid); 104 105void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out); 106void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out); 107 108#if defined(__ia64__) || defined(__x86_64__) || defined(__hppa__) || \ 109 defined(__XTENSA__) 110 /* On IA-64, we always use the "64-bit version" of the IPC structures. */ 111# define ipc_parse_version(cmd) IPC_64 112#else 113int ipc_parse_version (int *cmd); 114#endif 115 116extern void free_msg(struct msg_msg *msg); 117extern struct msg_msg *load_msg(const void __user *src, int len); 118extern int store_msg(void __user *dest, struct msg_msg *msg, int len); 119 120#endif 121