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Diffstat (limited to 'ipc/util.h')
-rw-r--r-- | ipc/util.h | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/ipc/util.h b/ipc/util.h new file mode 100644 index 0000000..3646b45 --- /dev/null +++ b/ipc/util.h @@ -0,0 +1,157 @@ +/* + * 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/err.h> + +#define SEQ_MULTIPLIER (IPCMNI) + +void sem_init (void); +void msg_init (void); +void shm_init (void); + +struct ipc_namespace; + +void sem_init_ns(struct ipc_namespace *ns); +void msg_init_ns(struct ipc_namespace *ns); +void 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); + +/* + * 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; +struct ipc_ids; + +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->rw_mutex acquired for writing */ +int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int); + +/* must be called with ids->rw_mutex acquired for reading */ +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); +void ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out); +struct kern_ipc_perm *ipcctl_pre_down(struct ipc_ids *ids, int id, int cmd, + struct ipc64_perm *perm, int extra_perm); + +#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 void recompute_msgmni(struct ipc_namespace *); + +static inline int ipc_buildid(int id, int seq) +{ + return SEQ_MULTIPLIER * seq + id; +} + +/* + * Must be called with ipcp locked + */ +static inline int ipc_checkid(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(); +} + +struct kern_ipc_perm *ipc_lock_check(struct ipc_ids *ids, int id); +int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids, + struct ipc_ops *ops, struct ipc_params *params); + +#endif |