| /* |
| * linux/ipc/util.h |
| * Copyright (C) 1999 Christoph Rohland |
| * |
| * ipc helper functions (c) 1999 Manfred Spraul <manfred@colorfullife.com> |
| * namespaces support. 2006 OpenVZ, SWsoft Inc. |
| * Pavel Emelianov <xemul@openvz.org> |
| */ |
| |
| #ifndef _IPC_UTIL_H |
| #define _IPC_UTIL_H |
| |
| #include <linux/idr.h> |
| #include <linux/err.h> |
| |
| #define USHRT_MAX 0xffff |
| #define SEQ_MULTIPLIER (IPCMNI) |
| |
| void sem_init (void); |
| void msg_init (void); |
| void shm_init (void); |
| |
| int sem_init_ns(struct ipc_namespace *ns); |
| int msg_init_ns(struct ipc_namespace *ns); |
| int shm_init_ns(struct ipc_namespace *ns); |
| |
| void sem_exit_ns(struct ipc_namespace *ns); |
| void msg_exit_ns(struct ipc_namespace *ns); |
| void shm_exit_ns(struct ipc_namespace *ns); |
| |
| struct ipc_ids { |
| int in_use; |
| unsigned short seq; |
| unsigned short seq_max; |
| struct mutex mutex; |
| struct idr ipcs_idr; |
| }; |
| |
| /* |
| * Structure that holds the parameters needed by the ipc operations |
| * (see after) |
| */ |
| struct ipc_params { |
| key_t key; |
| int flg; |
| union { |
| size_t size; /* for shared memories */ |
| int nsems; /* for semaphores */ |
| } u; /* holds the getnew() specific param */ |
| }; |
| |
| /* |
| * Structure that holds some ipc operations. This structure is used to unify |
| * the calls to sys_msgget(), sys_semget(), sys_shmget() |
| * . routine to call to create a new ipc object. Can be one of newque, |
| * newary, newseg |
| * . routine to call to check permissions for a new ipc object. |
| * Can be one of security_msg_associate, security_sem_associate, |
| * security_shm_associate |
| * . routine to call for an extra check if needed |
| */ |
| struct ipc_ops { |
| int (*getnew) (struct ipc_namespace *, struct ipc_params *); |
| int (*associate) (struct kern_ipc_perm *, int); |
| int (*more_checks) (struct kern_ipc_perm *, struct ipc_params *); |
| }; |
| |
| struct seq_file; |
| |
| void ipc_init_ids(struct ipc_ids *); |
| #ifdef CONFIG_PROC_FS |
| void __init ipc_init_proc_interface(const char *path, const char *header, |
| int ids, int (*show)(struct seq_file *, void *)); |
| #else |
| #define ipc_init_proc_interface(path, header, ids, show) do {} while (0) |
| #endif |
| |
| #define IPC_SEM_IDS 0 |
| #define IPC_MSG_IDS 1 |
| #define IPC_SHM_IDS 2 |
| |
| #define ipcid_to_idx(id) ((id) % SEQ_MULTIPLIER) |
| |
| /* must be called with ids->mutex acquired.*/ |
| int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int); |
| int ipc_get_maxid(struct ipc_ids *); |
| |
| /* must be called with both locks acquired. */ |
| void ipc_rmid(struct ipc_ids *, struct kern_ipc_perm *); |
| |
| /* must be called with ipcp locked */ |
| int ipcperms(struct kern_ipc_perm *ipcp, short flg); |
| |
| /* for rare, potentially huge allocations. |
| * both function can sleep |
| */ |
| void* ipc_alloc(int size); |
| void ipc_free(void* ptr, int size); |
| |
| /* |
| * For allocation that need to be freed by RCU. |
| * Objects are reference counted, they start with reference count 1. |
| * getref increases the refcount, the putref call that reduces the recount |
| * to 0 schedules the rcu destruction. Caller must guarantee locking. |
| */ |
| void* ipc_rcu_alloc(int size); |
| void ipc_rcu_getref(void *ptr); |
| void ipc_rcu_putref(void *ptr); |
| |
| struct kern_ipc_perm *ipc_lock(struct ipc_ids *, int); |
| |
| void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out); |
| void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out); |
| |
| #if defined(__ia64__) || defined(__x86_64__) || defined(__hppa__) || defined(__XTENSA__) |
| /* On IA-64, we always use the "64-bit version" of the IPC structures. */ |
| # define ipc_parse_version(cmd) IPC_64 |
| #else |
| int ipc_parse_version (int *cmd); |
| #endif |
| |
| extern void free_msg(struct msg_msg *msg); |
| extern struct msg_msg *load_msg(const void __user *src, int len); |
| extern int store_msg(void __user *dest, struct msg_msg *msg, int len); |
| extern int ipcget_new(struct ipc_namespace *, struct ipc_ids *, |
| struct ipc_ops *, struct ipc_params *); |
| extern int ipcget_public(struct ipc_namespace *, struct ipc_ids *, |
| struct ipc_ops *, struct ipc_params *); |
| |
| static inline int ipc_buildid(struct ipc_ids *ids, int id, int seq) |
| { |
| return SEQ_MULTIPLIER * seq + id; |
| } |
| |
| /* |
| * Must be called with ipcp locked |
| */ |
| static inline int ipc_checkid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp, |
| int uid) |
| { |
| if (uid / SEQ_MULTIPLIER != ipcp->seq) |
| return 1; |
| return 0; |
| } |
| |
| static inline void ipc_lock_by_ptr(struct kern_ipc_perm *perm) |
| { |
| rcu_read_lock(); |
| spin_lock(&perm->lock); |
| } |
| |
| static inline void ipc_unlock(struct kern_ipc_perm *perm) |
| { |
| spin_unlock(&perm->lock); |
| rcu_read_unlock(); |
| } |
| |
| static inline struct kern_ipc_perm *ipc_lock_check(struct ipc_ids *ids, |
| int id) |
| { |
| struct kern_ipc_perm *out; |
| |
| out = ipc_lock(ids, id); |
| if (IS_ERR(out)) |
| return out; |
| |
| if (ipc_checkid(ids, out, id)) { |
| ipc_unlock(out); |
| return ERR_PTR(-EIDRM); |
| } |
| |
| return out; |
| } |
| |
| /** |
| * ipcget - Common sys_*get() code |
| * @ns : namsepace |
| * @ids : IPC identifier set |
| * @ops : operations to be called on ipc object creation, permission checks |
| * and further checks |
| * @params : the parameters needed by the previous operations. |
| * |
| * Common routine called by sys_msgget(), sys_semget() and sys_shmget(). |
| */ |
| static inline int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids, |
| struct ipc_ops *ops, struct ipc_params *params) |
| { |
| if (params->key == IPC_PRIVATE) |
| return ipcget_new(ns, ids, ops, params); |
| else |
| return ipcget_public(ns, ids, ops, params); |
| } |
| |
| #endif |