NetBSD/usr.sbin/dhcp/common/sysconf.c

135 lines
4.2 KiB
C

/* sysconf.c
System status watcher...
!!!Boy, howdy, is this ever not guaranteed not to change!!! */
/*
* Copyright (c) 1997 The Internet Software Consortium.
* 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.
* 3. Neither the name of The Internet Software Consortium 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 INTERNET SOFTWARE CONSORTIUM 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 INTERNET SOFTWARE CONSORTIUM 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.
*
* This software has been written for the Internet Software Consortium
* by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
* Enterprises. To learn more about the Internet Software Consortium,
* see ``http://www.vix.com/isc''. To learn more about Vixie
* Enterprises, see ``http://www.vix.com''.
*/
#ifndef lint
static char copyright[] =
"$Id: sysconf.c,v 1.1.1.1 1997/10/20 23:28:53 mellon Exp $ Copyright (c) 1995, 1996 The Internet Software Consortium. All rights reserved.\n";
#endif /* not lint */
#include "dhcpd.h"
int sysconf_initialized;
int sysconf_fd;
void sysconf_startup (handler)
void (*handler) PROTO ((struct sysconf_header *, void *));
{
struct sockaddr_un name;
static int once;
/* Only initialize sysconf once. */
if (sysconf_initialized)
error ("attempted to reinitialize sysconf protocol");
sysconf_initialized = 1;
sysconf_fd = socket (AF_UNIX, SOCK_STREAM, 0);
if (sysconf_fd < 0)
error ("unable to create sysconf socket: %m");
/* XXX for now... */
name.sun_family = PF_UNIX;
strcpy (name.sun_path, "/var/run/sysconf");
name.sun_len = ((sizeof name) - (sizeof name.sun_path) +
strlen (name.sun_path));
if (connect (sysconf_fd, (struct sockaddr *)&name, name.sun_len) < 0) {
if (!once)
warn ("can't connect to sysconf socket: %m");
once = 1;
close (sysconf_fd);
sysconf_initialized = 0;
add_timeout (cur_time + 60, sysconf_restart, handler);
} else
add_protocol ("sysconf", sysconf_fd, sysconf_message, handler);
}
void sysconf_restart (v)
void *v;
{
void (*handler) PROTO ((struct sysconf_header *, void *)) = v;
sysconf_startup (handler);
}
void sysconf_message (proto)
struct protocol *proto;
{
struct sysconf_header hdr;
int status;
char *buf;
void (*handler) PROTO ((struct sysconf_header *, void *));
status = read (sysconf_fd, &hdr, sizeof hdr);
if (status < 0) {
warn ("sysconf_message: %m");
lose:
add_timeout (cur_time + 60, sysconf_restart, proto -> local);
remove_protocol (proto);
return;
}
if (status < sizeof (hdr)) {
warn ("sysconf_message: short message");
goto lose;
}
if (hdr.length) {
buf = malloc (hdr.length);
if (!buf)
error ("sysconf_message: can't buffer payload");
status = read (sysconf_fd, buf, hdr.length);
if (status < 0)
error ("sysconf_message payload read: %m");
if (status != hdr.length)
error ("sysconf_message payload: short read");
} else
buf = (char *)0;
/* Call the handler... */
if ((handler = proto -> local))
(*handler) (&hdr, buf);
if (buf)
free (buf);
}