text: /*	$NetBSD: msg.h,v 1.24 2009/01/19 19:39:41 christos Exp $	*/
  
  /*-
   * Copyright (c) 1999, 2007 The NetBSD Foundation, Inc.
   * All rights reserved.
   *
   * This code is derived from software contributed to The NetBSD Foundation
   * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
   * NASA Ames Research Center, and by Andrew Doran.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
   * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
   * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
   * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   */
  
  /*
   * SVID compatible msg.h file
   *
   * Author:  Daniel Boulet
   *
   * 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 <special_includes/sys/featuretest.h>
  #include <special_includes/sys/ipc.h>
  #ifdef _KERNEL
  #include <special_includes/sys/condvar.h>
  #include <special_includes/sys/mutex.h>
  #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 */
  };
  #endif /* _KERNEL */
  
  #define MSG_NOERROR	010000		/* don't complain about too long msgs */
  
  typedef unsigned long	msgqnum_t;
  typedef size_t		msglen_t;
  
  struct msqid_ds {
  	struct ipc_perm	msg_perm;	/* operation permission strucure */
  	msgqnum_t	msg_qnum;	/* number of messages in the queue */
  	msglen_t	msg_qbytes;	/* max # of bytes in the queue */
  	pid_t		msg_lspid;	/* process ID of last msgsend() */
  	pid_t		msg_lrpid;	/* process ID of last msgrcv() */
  	time_t		msg_stime;	/* time of last msgsend() */
  	time_t		msg_rtime;	/* time of last msgrcv() */
  	time_t		msg_ctime;	/* time of last change */
  
  	/*
  	 * These members are private and used only in the internal
  	 * implementation of this interface.
  	 */
  	struct __msg	*_msg_first;	/* first message in the queue */
  	struct __msg	*_msg_last;	/* last message in the queue */
  	msglen_t	_msg_cbytes;	/* # of bytes currently in queue */
  };
  
  #if defined(_NETBSD_SOURCE)
  /*
   * 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 {
  	int32_t	msgmax;		/* max chars in a message */
  	int32_t	msgmni;		/* max message queue identifiers */
  	int32_t	msgmnb;		/* max chars in a queue */
  	int32_t	msgtql;		/* max messages in system */
  	int32_t	msgssz;		/* size of a message segment
  				   (see notes above) */
  	int32_t	msgseg;		/* number of message segments */
  };
  
  /* Warning: 64-bit structure padding is needed here */
  struct msgid_ds_sysctl {
  	struct		ipc_perm_sysctl msg_perm;
  	uint64_t	msg_qnum;
  	uint64_t	msg_qbytes;
  	uint64_t	_msg_cbytes;
  	pid_t		msg_lspid;
  	pid_t		msg_lrpid;
  	time_t		msg_stime;
  	time_t		msg_rtime;
  	time_t		msg_ctime;
  	int32_t		pad;
  };
  struct msg_sysctl_info {
  	struct	msginfo msginfo;
  	struct	msgid_ds_sysctl msgids[1];
  };
  #endif /* !_POSIX_C_SOURCE && !_XOPEN_SOURCE */
  
  #ifdef _KERNEL
  
  #ifndef MSGSSZ
  #define MSGSSZ	8		/* Each segment must be 2^N long */
  #endif
  #ifndef MSGSEG
  #define MSGSEG	2048		/* must be less than 32767 */
  #endif
  #undef MSGMAX			/* ALWAYS compute MGSMAX! */
  #define MSGMAX	(MSGSSZ*MSGSEG)
  #ifndef MSGMNB
  #define MSGMNB	2048		/* max # of bytes in a queue */
  #endif
  #ifndef MSGMNI
  #define MSGMNI	40
  #endif
  #ifndef MSGTQL
  #define MSGTQL	40
  #endif
  
  /*
   * macros to convert between msqid_ds's and msqid's.
   */
  #define MSQID(ix,ds)	((ix) & 0xffff | (((ds).msg_perm._seq << 16) & 0xffff0000))
  #define MSQID_IX(id)	((id) & 0xffff)
  #define MSQID_SEQ(id)	(((id) >> 16) & 0xffff)
  
  /*
   * Stuff allocated in machdep.h
   */
  struct msgmap {
  	short	next;		/* next segment in buffer */
      				/* -1 -> available */
      				/* 0..(MSGSEG-1) -> index of next segment */
  };
  
  typedef struct kmsq {
  	struct msqid_ds msq_u;
  	kcondvar_t	msq_cv;
  } kmsq_t;
  
  extern struct msginfo msginfo;
  extern kmsq_t	*msqs;		/* MSGMNI queues */
  extern kmutex_t	msgmutex;
  
  #define MSG_LOCKED	01000	/* Is this msqid_ds locked? */
  
  #define SYSCTL_FILL_MSG(src, dst) do { \
  	SYSCTL_FILL_PERM((src).msg_perm, (dst).msg_perm); \
  	(dst).msg_qnum = (src).msg_qnum; \
  	(dst).msg_qbytes = (src).msg_qbytes; \
  	(dst)._msg_cbytes = (src)._msg_cbytes; \
  	(dst).msg_lspid = (src).msg_lspid; \
  	(dst).msg_lrpid = (src).msg_lrpid; \
  	(dst).msg_stime = (src).msg_stime; \
  	(dst).msg_rtime = (src).msg_rtime; \
  	(dst).msg_ctime = (src).msg_ctime; \
  } while (/*CONSTCOND*/ 0)
  
  #endif /* _KERNEL */
  
  #ifndef _KERNEL
  #include <special_includes/sys/cdefs.h>
  
  __BEGIN_DECLS
  int	msgctl(int, int, struct msqid_ds *) __RENAME(__msgctl50);
  int	msgget(key_t, int);
  int	msgsnd(int, const void *, size_t, int);
  ssize_t	msgrcv(int, void *, size_t, long, int);
  __END_DECLS
  #else
  #include <special_includes/sys/systm.h>
  
  struct proc;
  
  void	msginit(void);
  int	msgctl1(struct lwp *, int, int, struct msqid_ds *);
  int	msgsnd1(struct lwp *, int, const char *, size_t, int, size_t,
      copyin_t);
  int	msgrcv1(struct lwp *, int, char *, size_t, long, int, size_t,
      copyout_t, register_t *);
  #endif /* !_KERNEL */
  
  #endif /* !_SYS_MSG_H_ */
  