1999-03-16 03:40:46 +03:00
|
|
|
.\" $NetBSD: ioctl.9,v 1.2 1999/03/16 00:40:47 garbled Exp $
|
1999-03-07 18:21:04 +03:00
|
|
|
.\"
|
|
|
|
|
.\" Copyright (c) 1999 The NetBSD Foundation, Inc.
|
|
|
|
|
.\" All rights reserved.
|
|
|
|
|
.\"
|
|
|
|
|
.\" This code is derived from software contributed to The NetBSD Foundation
|
|
|
|
|
.\" by Heiko W.Rupp <hwr@pilhuhn.de>
|
|
|
|
|
.\"
|
|
|
|
|
.\" 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.
|
|
|
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
|
|
|
.\" must display the following acknowledgement:
|
|
|
|
|
.\" This product includes software developed by the NetBSD
|
|
|
|
|
.\" Foundation, Inc. and its contributors.
|
|
|
|
|
.\" 4. Neither the name of the The NetBSD Foundation nor the names of its
|
|
|
|
|
.\" contributors may be used to endorse or promote products derived
|
|
|
|
|
.\" from this software without specific prior written permission.
|
|
|
|
|
.\"
|
|
|
|
|
.\" 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.
|
|
|
|
|
.\"
|
|
|
|
|
.Dd March 7, 1999
|
|
|
|
|
.Dt IOCTL 9
|
1999-03-16 03:40:46 +03:00
|
|
|
.Os
|
1999-03-07 18:21:04 +03:00
|
|
|
.Sh NAME
|
|
|
|
|
.Nm ioctl
|
|
|
|
|
.Nd how to implement a new ioctl call to access device drivers
|
|
|
|
|
.Sh SYNOPSIS
|
|
|
|
|
.Fd #include <sys/ioctl.h>
|
|
|
|
|
.Fd #include <sys/ioccom.h>
|
|
|
|
|
.Ft int
|
|
|
|
|
.Fn ioctl int, unsigned long, ...
|
|
|
|
|
.Sh DESCRIPTION
|
|
|
|
|
.Nm Ioctl
|
|
|
|
|
are internally defined as
|
|
|
|
|
.Bl -tag -witdh define
|
|
|
|
|
.It #define FOOIOCTL fun(t,n,pt)
|
|
|
|
|
.El
|
|
|
|
|
|
|
|
|
|
where the different wariables and funcions are:
|
|
|
|
|
.Bl -tag -width FOOIOCTL
|
|
|
|
|
.It Fn FOOIOCTL
|
|
|
|
|
the name as the ioctl is later known in a as second argument to a
|
|
|
|
|
.Xr ioctl
|
|
|
|
|
system call. E.g. ioctl(s,FOOIOCTL,...)
|
|
|
|
|
.It Fn fun
|
|
|
|
|
a macro which can be one of
|
|
|
|
|
.Bl -tag -withh _IOWR
|
|
|
|
|
.It _IOR
|
|
|
|
|
the call only reads parameters from the kernel and does not
|
|
|
|
|
pass any to it
|
|
|
|
|
.It _IOW
|
|
|
|
|
the call only writes parameters to the kernel, but does not want anything
|
|
|
|
|
back
|
|
|
|
|
.It _IOWR
|
|
|
|
|
the call writes data to the kernel and wants information back.
|
|
|
|
|
.El
|
|
|
|
|
.It t
|
|
|
|
|
This integer describes to which subsystem the ioctl applies.
|
|
|
|
|
T
|
|
|
|
|
can be one of
|
|
|
|
|
.Bl -tag -with 'a'
|
|
|
|
|
.It 'd' the disk subsystem
|
|
|
|
|
.It 'f' files
|
|
|
|
|
.It 'i' a (pseudo) interface
|
|
|
|
|
.It 'r' the routing subsystem
|
|
|
|
|
.It 's' the socket layer
|
|
|
|
|
.It 't' the tty layer
|
|
|
|
|
.It 'u' user defined ???
|
|
|
|
|
.El
|
|
|
|
|
.It n
|
|
|
|
|
This numbers the ioctl within the group. There may be only one
|
|
|
|
|
.Fn n
|
|
|
|
|
for a given
|
|
|
|
|
.Fn t .
|
|
|
|
|
This is a unsigned 8 bit number.
|
|
|
|
|
.It pt
|
|
|
|
|
This specifyies the type of the passed parameter. This one gets internally
|
|
|
|
|
transformed to the size of the parameter, so if you e.g. want to pass
|
|
|
|
|
a structure, then you have to spezify that structure and not a pointer
|
|
|
|
|
to it or sizeof(struct foo)
|
|
|
|
|
.El
|
|
|
|
|
|
|
|
|
|
In order for the new ioctl to be known to the system it is installed
|
|
|
|
|
in either <sys/ioctl.h> or one of the files that are reached from
|
|
|
|
|
<sys/ioctl.h>.
|
|
|
|
|
.Sh EXAMPLE
|
|
|
|
|
|
|
|
|
|
#define FOOIOCTL _IOWR('i',23,int)
|
|
|
|
|
|
|
|
|
|
int a=3;
|
|
|
|
|
error = ioctl(s,FOOICTL, &a);
|
|
|
|
|
|
|
|
|
|
Within the ioctl()-routine of the driver, it can be then accessd like
|
|
|
|
|
|
|
|
|
|
driver_ioctl(..,cmd,data)
|
|
|
|
|
u_long cmd;
|
|
|
|
|
caddr_t data;
|
|
|
|
|
|
|
|
|
|
...
|
|
|
|
|
switch(cmd) {
|
|
|
|
|
case FOOIOCTL:
|
|
|
|
|
int *a = (int *)data;
|
|
|
|
|
printf(" Value passed: %d\n",a);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
.Sh NOTES
|
|
|
|
|
Note that if you e.g. try to read information from e.g. a ethernet
|
|
|
|
|
driver where the name of the card is included in the third argument
|
|
|
|
|
(e.g. ioctl(s,READFROMETH,struct ifreq *)), then you have to use
|
|
|
|
|
the _IOWR() form not the _IOR(), as passing the name of the card to the
|
|
|
|
|
kernel already consists of writing data.
|
|
|
|
|
.Sh SEE ALSO
|
|
|
|
|
.Xr ioctl 2
|
