root/include/linux/ipc.h

INCLUDED FROM

#ifndef _LINUX_IPC_H
#define _LINUX_IPC_H

#include <linux/types.h>

#define IPC_PRIVATE ((__kernel_key_t) 0)  

/* Obsolete, used only for backwards compatibility and libc5 compiles */
struct ipc_perm
{
        __kernel_key_t  key;
        __kernel_uid_t  uid;
        __kernel_gid_t  gid;
        __kernel_uid_t  cuid;
        __kernel_gid_t  cgid;
        __kernel_mode_t mode; 
        unsigned short  seq;
};

/* Include the definition of ipc64_perm */
#include <asm/ipcbuf.h>

/* resource get request flags */
#define IPC_CREAT  00001000   /* create if key is nonexistent */
#define IPC_EXCL   00002000   /* fail if key exists */
#define IPC_NOWAIT 00004000   /* return error on wait */

/* these fields are used by the DIPC package so the kernel as standard
   should avoid using them if possible */
   
#define IPC_DIPC 00010000  /* make it distributed */
#define IPC_OWN  00020000  /* this machine is the DIPC owner */

/* 
 * Control commands used with semctl, msgctl and shmctl 
 * see also specific commands in sem.h, msg.h and shm.h
 */
#define IPC_RMID 0     /* remove resource */
#define IPC_SET  1     /* set ipc_perm options */
#define IPC_STAT 2     /* get ipc_perm options */
#define IPC_INFO 3     /* see ipcs */

/*
 * Version flags for semctl, msgctl, and shmctl commands
 * These are passed as bitflags or-ed with the actual command
 */
#define IPC_OLD 0       /* Old version (no 32-bit UID support on many
                           architectures) */
#define IPC_64  0x0100  /* New version (support 32-bit UIDs, bigger
                           message sizes, etc. */

/*
 * These are used to wrap system calls.
 *
 * See architecture code for ugly details..
 */
struct ipc_kludge {
        struct msgbuf __user *msgp;
        long msgtyp;
};

#define SEMOP            1
#define SEMGET           2
#define SEMCTL           3
#define SEMTIMEDOP       4
#define MSGSND          11
#define MSGRCV          12
#define MSGGET          13
#define MSGCTL          14
#define SHMAT           21
#define SHMDT           22
#define SHMGET          23
#define SHMCTL          24

/* Used by the DIPC package, try and avoid reusing it */
#define DIPC            25

#define IPCCALL(version,op)     ((version)<<16 | (op))

#ifdef __KERNEL__

#include <linux/kref.h>
#include <linux/spinlock.h>

#define IPCMNI 32768  /* <= MAX_INT limit for ipc arrays (including sysctl changes) */

/* used by in-kernel data structures */
struct kern_ipc_perm
{
        spinlock_t      lock;
        int             deleted;
        int             id;
        key_t           key;
        uid_t           uid;
        gid_t           gid;
        uid_t           cuid;
        gid_t           cgid;
        mode_t          mode; 
        unsigned long   seq;
        void            *security;
};

#endif /* __KERNEL__ */

#endif /* _LINUX_IPC_H */