freebsd-dev/sys/sys/msg.h
Ed Schouten d9c4cd2fbc Change the return type of msgrcv() to ssize_t as required by POSIX.
It looks like the msgrcv() system call is already written in such a way
that the size is internally computed as a size_t and written into all of
td_retval[0]. This means that it is effectively already returning
ssize_t. It's just that the userspace prototype doesn't match up.
2016-07-28 12:22:01 +00:00

182 lines
5.3 KiB
C

/* $FreeBSD$ */
/* $NetBSD: msg.h,v 1.4 1994/06/29 06:44:43 cgd Exp $ */
/*-
* 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 <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
#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
struct msqid_ds_old {
struct ipc_perm_old 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];
};
#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() */
time_t msg_rtime; /* time of last msgrcv() */
time_t msg_ctime; /* time of last msgctl() */
};
#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 */
struct ucred *cred; /* creator's credentials */
};
#endif /* _KERNEL */
#if !defined(_KERNEL) || defined(_WANT_MSG_PROTOTYPES)
__BEGIN_DECLS
int msgctl(int, int, struct msqid_ds *);
int msgget(key_t, int);
ssize_t msgrcv(int, void *, size_t, long, int);
int msgsnd(int, const void *, size_t, int);
#if __BSD_VISIBLE
int msgsys(int, ...);
#endif
__END_DECLS
#endif /* !_KERNEL || _WANT_MSG_PROTOTYPES */
#endif /* !_SYS_MSG_H_ */