7320fd3a30
of supported operations by example read() and write() operations. Inspired by: http://www.daemonnews.org/200010/blueprints.html PR: 16173 Submitted by: sobomax
178 lines
6.1 KiB
C
178 lines
6.1 KiB
C
/* 08 Nov 1998*/
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/*
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* cdev.c
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*
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* 08 Nov 1998 Rajesh Vaidheeswarran
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*
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* Copyright (c) 1998 Rajesh Vaidheeswarran
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by Rajesh Vaidheeswarran.
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* 4. The name Rajesh Vaidheeswarran may not be used to endorse or promote
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* products derived from this software without specific prior written
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* permission.
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*
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* THIS SOFTWARE IS PROVIDED BY RAJESH VAIDHEESWARRAN ``AS IS'' AND ANY
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* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE RAJESH VAIDHEESWARRAN BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* Copyright (c) 1993 Terrence R. Lambert.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by Terrence R. Lambert.
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* 4. The name Terrence R. Lambert may not be used to endorse or promote
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* products derived from this software without specific prior written
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* permission.
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*
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* THIS SOFTWARE IS PROVIDED BY TERRENCE R. LAMBERT ``AS IS'' AND ANY
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* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE TERRENCE R. LAMBERT BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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*
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* $FreeBSD$
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*/
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#include <sys/types.h>
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#include <sys/uio.h>
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/ioccom.h>
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#include <sys/systm.h>
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#include <sys/conf.h>
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#include "cdev.h"
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/*
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* This is the actual code for the system call... it can't be static because
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* it is exported to another part of the module... the only place it needs
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* to be referenced is the sysent we are interested in.
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*
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* To write your own system call using this as a template, you could strip
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* out this code and use the rest as a prototype module, changing only the
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* function names and the number of arguments to the call in the module
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* specific "sysent".
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*
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* You would have to use the "-R" option of "ld" to ensure a linkable file
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* if you were to do this, since you would need to combine multiple ".o"
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* files into a single ".o" file for use by "modload".
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*/
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#define CDEV_IOCTL1 _IOR('C', 1, u_int)
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/* Stores string recv'd by _write() */
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static char buf[512+1];
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static int len;
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int
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mydev_open(dev_t dev, int flag, int otyp, struct proc *procp)
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{
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printf("mydev_open: dev_t=%d, flag=%x, otyp=%x, procp=%p\n",
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dev2udev(dev), flag, otyp, procp);
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memset(&buf, '\0', 513);
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len = 0;
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return (0);
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}
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int
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mydev_close(dev_t dev, int flag, int otyp, struct proc *procp)
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{
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printf("mydev_close: dev_t=%d, flag=%x, otyp=%x, procp=%p\n",
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dev2udev(dev), flag, otyp, procp);
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return (0);
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}
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int
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mydev_ioctl(dev_t dev, u_long cmd, caddr_t arg, int mode, struct proc *procp)
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{
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int error = 0;
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printf("mydev_ioctl: dev_t=%d, cmd=%lx, arg=%p, mode=%x procp=%p\n",
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dev2udev(dev), cmd, arg, mode, procp);
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switch(cmd) {
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case CDEV_IOCTL1:
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printf("you called mydev_ioctl CDEV_IOCTL1\n");
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break;
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default:
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printf("No such ioctl for me!\n");
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error = EINVAL;
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break;
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}
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return error;
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}
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/*
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* mydev_write takes in a character string and saves it
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* to buf for later accessing.
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*/
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int
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mydev_write(dev_t dev, struct uio *uio, int ioflag)
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{
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int err = 0;
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printf("mydev_write: dev_t=%d, uio=%p, ioflag=%d\n",
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dev2udev(dev), uio, ioflag);
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err = copyinstr(uio->uio_iov->iov_base, &buf, 512, &len);
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if (err != 0) {
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printf("Write to \"cdev\" failed.\n");
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}
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return(err);
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}
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/*
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* The mydev_read function just takes the buf that was saved
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* via mydev_write() and returns it to userland for
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* accessing.
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*/
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int
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mydev_read(dev_t dev, struct uio *uio, int ioflag)
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{
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int err = 0;
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printf("mydev_read: dev_t=%d, uio=%p, ioflag=%d\n",
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dev2udev(dev), uio, ioflag);
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if (len <= 0) {
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err = -1;
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} else { /* copy buf to userland */
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copystr(&buf, uio->uio_iov->iov_base, 513, &len);
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}
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return(err);
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}
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