#ifndef _LINUX_MSG_H

#define _LINUX_MSG_H

#include <linux/ipc.h>

/* ipcs ctl commands */

#define MSG_STAT 11

#define MSG_INFO 12

/* msgrcv options */

#define MSG_NOERROR     010000  /* no error if message is too big */

#define MSG_EXCEPT      020000  /* recv any msg except of specified type.*/

/* Obsolete, used only for backwards compatibility and libc5 compiles */

struct msqid_ds {

	struct ipc_perm msg_perm;

	struct msg *msg_first;		/* first message on queue,unused  */

	struct msg *msg_last;		/* last message in queue,unused */

	__kernel_time_t msg_stime;	/* last msgsnd time */

	__kernel_time_t msg_rtime;	/* last msgrcv time */

	__kernel_time_t msg_ctime;	/* last change time */

	unsigned long  msg_lcbytes;	/* Reuse junk fields for 32 bit */

	unsigned long  msg_lqbytes;	/* ditto */

	unsigned short msg_cbytes;	/* current number of bytes on queue */

	unsigned short msg_qnum;	/* number of messages in queue */

	unsigned short msg_qbytes;	/* max number of bytes on queue */

	__kernel_ipc_pid_t msg_lspid;	/* pid of last msgsnd */

	__kernel_ipc_pid_t msg_lrpid;	/* last receive pid */

};

/* Include the definition of msqid64_ds */

#include <asm/msgbuf.h>

/* message buffer for msgsnd and msgrcv calls */

struct msgbuf {

	long mtype;         /* type of message */

	char mtext[1];      /* message text */

};

/* buffer for msgctl calls IPC_INFO, MSG_INFO */

struct msginfo {

	int msgpool;

	int msgmap; 

	int msgmax; 

	int msgmnb; 

	int msgmni; 

	int msgssz; 

	int msgtql; 

	unsigned short  msgseg; 

};

/*

 * Scaling factor to compute msgmni:

 * the memory dedicated to msg queues (msgmni * msgmnb) should occupy

 * at most 1/MSG_MEM_SCALE of the lowmem (see the formula in ipc/msg.c):

 * up to 8MB       : msgmni = 16 (MSGMNI)

 * 4 GB            : msgmni = 8K

 * more than 16 GB : msgmni = 32K (IPCMNI)

 */

#define MSG_MEM_SCALE 32

#define MSGMNI    16   /* <= IPCMNI */     /* max # of msg queue identifiers */

#define MSGMAX  8192   /* <= INT_MAX */   /* max size of message (bytes) */

#define MSGMNB 16384   /* <= INT_MAX */   /* default max size of a message queue */

/* unused */

#define MSGPOOL (MSGMNI * MSGMNB / 1024) /* size in kbytes of message pool */

#define MSGTQL  MSGMNB            /* number of system message headers */

#define MSGMAP  MSGMNB            /* number of entries in message map */

#define MSGSSZ  16                /* message segment size */

#define __MSGSEG ((MSGPOOL * 1024) / MSGSSZ) /* max no. of segments */

#define MSGSEG (__MSGSEG <= 0xffff ? __MSGSEG : 0xffff)

#ifdef __KERNEL__

#include <linux/list.h>

/* one msg_msg structure for each message */

struct msg_msg {

	struct list_head m_list; 

	long  m_type;          

	int m_ts;           /* message text size */

	struct msg_msgseg* next;

	void *security;

	/* the actual message follows immediately */

};

/* one msq_queue structure for each present queue on the system */

struct msg_queue {

	struct kern_ipc_perm q_perm;

	time_t q_stime;			/* last msgsnd time */

	time_t q_rtime;			/* last msgrcv time */

	time_t q_ctime;			/* last change time */

	unsigned long q_cbytes;		/* current number of bytes on queue */

	unsigned long q_qnum;		/* number of messages in queue */

	unsigned long q_qbytes;		/* max number of bytes on queue */

	pid_t q_lspid;			/* pid of last msgsnd */

	pid_t q_lrpid;			/* last receive pid */

	struct list_head q_messages;

	struct list_head q_receivers;

	struct list_head q_senders;

};

/* Helper routines for sys_msgsnd and sys_msgrcv */

extern long do_msgsnd(int msqid, long mtype, void __user *mtext,

			size_t msgsz, int msgflg);

extern long do_msgrcv(int msqid, long *pmtype, void __user *mtext,

			size_t msgsz, long msgtyp, int msgflg);

#endif /* __KERNEL__ */

#endif /* _LINUX_MSG_H */