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/* $NetBSD: ping.c,v 1.5 2020/04/30 10:55:32 christos Exp $ */
/*-
* Copyright (c) 2015 The NetBSD Foundation, Inc.
* All rights reserved.
*
* 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.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ping.c,v 1.5 2020/04/30 10:55:32 christos Exp $");
#include <sys/param.h>
#include <sys/conf.h>
#include <sys/device.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include "ping.h"
/*
* Create a device /dev/ping in order to test this module.
*
* To use this device you need to do:
* mknod /dev/ping c 351 0
*
*/
dev_type_open(ping_open);
dev_type_close(ping_close);
dev_type_ioctl(ping_ioctl);
static struct cdevsw ping_cdevsw = {
.d_open = ping_open,
.d_close = ping_close,
.d_read = noread,
.d_write = nowrite,
.d_ioctl = ping_ioctl,
.d_stop = nostop,
.d_tty = notty,
.d_poll = nopoll,
.d_mmap = nommap,
.d_kqfilter = nokqfilter,
.d_discard = nodiscard,
.d_flag = D_OTHER
};
struct ping_softc {
int refcnt;
};
static struct ping_softc sc;
int
ping_open(dev_t self __unused, int flag __unused, int mode __unused,
struct lwp *l __unused)
{
if (sc.refcnt > 0)
return EBUSY;
++sc.refcnt;
return 0;
}
int
ping_close(dev_t self __unused, int flag __unused, int mode __unused,
struct lwp *l __unused)
{
--sc.refcnt;
return 0;
}
int
ping_ioctl(dev_t self __unused, u_long cmd, void *data, int flag,
struct lwp *l __unused)
{
switch(cmd) {
case CMD_PING:
printf("ping: pong!\n");
return 0;
default:
return ENOTTY;
}
}
MODULE(MODULE_CLASS_MISC, ping, NULL);
static int
ping_modcmd(modcmd_t cmd, void *arg __unused)
{
/* The major should be verified and changed if needed to avoid
* conflicts with other devices. */
int cmajor = 351, bmajor = -1;
switch (cmd) {
case MODULE_CMD_INIT:
if (devsw_attach("ping", NULL, &bmajor, &ping_cdevsw, &cmajor))
return ENXIO;
return 0;
case MODULE_CMD_FINI:
if (sc.refcnt > 0)
return EBUSY;
devsw_detach(NULL, &ping_cdevsw);
return 0;
default:
return ENOTTY;
}
}
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