/* $FreeBSD: src/sys/sys/msg.h,v 1.20 2005/01/07 02:29:23 imp Exp $ */

/*	$NetBSD: msg.h,v 1.4 1994/06/29 06:44:43 cgd Exp $	*/

/*-

 * SVID compatible msg.h file

 *

 * Author:  Daniel Boulet

 *

 *© Portions copyright (c) 2006 Nokia Corporation.  All rights reserved.

 * Copyright 1993 Daniel Boulet and RTMX Inc.

 *

 * This system call was implemented by Daniel Boulet under contract from RTMX.

 *

 * Redistribution and use in source forms, with and without modification,

 * are permitted provided that this entire comment appears intact.

 *

 * Redistribution in binary form may occur without any restrictions.

 * Obviously, it would be nice if you gave credit where credit is due

 * but requiring it would be too onerous.

 *

 * This software is provided ``AS IS'' without any warranties of any kind.

 */

#ifndef _SYS_MSG_H_

#define _SYS_MSG_H_

#include <sys/cdefs.h>

#include <sys/_types.h>

#include <sys/ipc.h>

/*

 * The MSG_NOERROR identifier value, the msqid_ds struct and the msg struct

 * are as defined by the SV API Intel 386 Processor Supplement.

 */

#define MSG_NOERROR	010000		/* don't complain about too long msgs */

typedef	unsigned long	msglen_t;

typedef	unsigned long	msgqnum_t;

#ifndef _PID_T_DECLARED

typedef	__pid_t		pid_t;

#define	_PID_T_DECLARED

#endif

#ifndef _SIZE_T_DECLARED

typedef	__size_t	size_t;

#define	_SIZE_T_DECLARED

#endif

#ifndef _SSIZE_T_DECLARED

typedef	__ssize_t	ssize_t;

#define	_SSIZE_T_DECLARED

#endif

#ifndef _TIME_T_DECLARED

typedef	__time_t	time_t;

#define	_TIME_T_DECLARED

#endif

/*

 * XXX there seems to be no prefix reserved for this header, so the name

 * "msg" in "struct msg" and the names of all of the nonstandard members

 * (mainly "msg_pad*) are namespace pollution.

 */

struct msqid_ds {

	struct	ipc_perm msg_perm;	/* msg queue permission bits */

	struct	msg *msg_first;	/* first message in the queue */

	struct	msg *msg_last;	/* last message in the queue */

	msglen_t msg_cbytes;	/* number of bytes in use on the queue */

	msgqnum_t msg_qnum;	/* number of msgs in the queue */

	msglen_t msg_qbytes;	/* max # of bytes on the queue */

	pid_t	msg_lspid;	/* pid of last msgsnd() */

	pid_t	msg_lrpid;	/* pid of last msgrcv() */

	time_t	msg_stime;	/* time of last msgsnd() */

	long	msg_pad1;

	time_t	msg_rtime;	/* time of last msgrcv() */

	long	msg_pad2;

	time_t	msg_ctime;	/* time of last msgctl() */

	long	msg_pad3;

	long	msg_pad4[4];

};

#if __BSD_VISIBLE

/*

 * Structure describing a message.  The SVID doesn't suggest any

 * particular name for this structure.  There is a reference in the

 * msgop man page that reads "The structure mymsg is an example of what

 * this user defined buffer might look like, and includes the following

 * members:".  This sentence is followed by two lines equivalent

 * to the mtype and mtext field declarations below.  It isn't clear

 * if "mymsg" refers to the name of the structure type or the name of an

 * instance of the structure...

 */

struct mymsg {

	long	mtype;		/* message type (+ve integer) */

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

};

#endif

#ifdef _KERNEL

struct msg {

	struct	msg *msg_next;  /* next msg in the chain */

	long	msg_type; 	/* type of this message */

				/* >0 -> type of this message */

				/* 0 -> free header */

	u_short	msg_ts;		/* size of this message */

	short	msg_spot;	/* location of start of msg in buffer */

	struct	label *label;	/* MAC Framework label */

};

/*

 * Based on the configuration parameters described in an SVR2 (yes, two)

 * config(1m) man page.

 *

 * Each message is broken up and stored in segments that are msgssz bytes

 * long.  For efficiency reasons, this should be a power of two.  Also,

 * it doesn't make sense if it is less than 8 or greater than about 256.

 * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of

 * two between 8 and 1024 inclusive (and panic's if it isn't).

 */

struct msginfo {

	int	msgmax,		/* max chars in a message */

		msgmni,		/* max message queue identifiers */

		msgmnb,		/* max chars in a queue */

		msgtql,		/* max messages in system */

		msgssz,		/* size of a message segment (see notes above) */

		msgseg;		/* number of message segments */

};

extern struct msginfo	msginfo;

/*

 * Kernel wrapper for the user-level structure.

 */

struct msqid_kernel {

	/*

	 * Data structure exposed to user space.

	 */

	struct	msqid_ds u;

	/*

	 * Kernel-private components of the message queue.

	 */

	struct	label *label;	/* MAC label */

};

#else /* !_KERNEL */

/* Template for struct to be used as argument for `msgsnd' and `msgrcv'.  */

struct msgbuf

  {

    long int mtype;     /* type of received/sent message */

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

  };

// FUNCTION PROTOTYPES

// FORWARD DECLARATIONS

// CLASS/STRUCT/FUNCTION DECLARATION

__BEGIN_DECLS

/*

* Get the message queue identifier using the IPC key generated by ftok.

*/

IMPORT_C int msgget(key_t key, int msgflg);

/*

* Used to send a message to the queue associated with the message identifier specified by msqid.

*/

IMPORT_C int msgsnd(int msqid, const void *msgp, size_t msgsz, int msgflg);

/*

* Reads a message from the queue associated with the message queue identifier.

*/

IMPORT_C ssize_t msgrcv(int msqid, void* msgp, size_t msgsz, long msgtyp, int msgflg);

/*

* Provides an interface to control message queue and control operations as specified by cmd.

*/

IMPORT_C int msgctl(int msqid, int cmd, struct msqid_ds* buf);

__END_DECLS

#endif /* !_KERNEL */

#endif // _SYS_MSG_H_

//  End of File