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

197 lines
5.4 KiB
C

/* dispatch.c
Network input dispatcher... */
/*
* Copyright (c) 1995-2000 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 in cooperation with Vixie Enterprises and Nominum, Inc.
* To learn more about the Internet Software Consortium, see
* ``http://www.isc.org/''. To learn more about Vixie Enterprises,
* see ``http://www.vix.com''. To learn more about Nominum, Inc., see
* ``http://www.nominum.com''.
*/
#ifndef lint
static char copyright[] =
"$Id: dispatch.c,v 1.4 2000/06/10 18:17:20 mellon Exp $ Copyright (c) 1995-2000 The Internet Software Consortium. All rights reserved.\n";
#endif /* not lint */
#include "dhcpd.h"
struct timeout *timeouts;
static struct timeout *free_timeouts;
int interfaces_invalidated;
/* Wait for packets to come in using select(). When one does, call
receive_packet to receive the packet and possibly strip hardware
addressing information from it, and then call through the
bootp_packet_handler hook to try to do something with it. */
void dispatch ()
{
fd_set r, w, x;
struct protocol *l;
int max = 0;
int count;
struct timeval tv, *tvp;
isc_result_t status;
do {
/* Call any expired timeouts, and then if there's
still a timeout registered, time out the select
call then. */
another:
if (timeouts) {
struct timeout *t;
if (timeouts -> when <= cur_time) {
t = timeouts;
timeouts = timeouts -> next;
(*(t -> func)) (t -> what);
if (t -> unref)
(*t -> unref) (&t -> what, MDL);
t -> next = free_timeouts;
free_timeouts = t;
goto another;
}
tv.tv_sec = timeouts -> when;
tv.tv_usec = 0;
tvp = &tv;
} else
tvp = (struct timeval *)0;
/* Wait for a packet or a timeout... XXX */
status = omapi_one_dispatch (0, tvp);
} while (status == ISC_R_TIMEDOUT || status == ISC_R_SUCCESS);
log_fatal ("omapi_one_dispatch failed: %s -- exiting.",
isc_result_totext (status));
}
void add_timeout (when, where, what, ref, unref)
TIME when;
void (*where) PROTO ((void *));
void *what;
tvref_t ref;
tvunref_t unref;
{
struct timeout *t, *q;
/* See if this timeout supersedes an existing timeout. */
t = (struct timeout *)0;
for (q = timeouts; q; q = q -> next) {
if ((where == NULL || q -> func == where) &&
q -> what == what) {
if (t)
t -> next = q -> next;
else
timeouts = q -> next;
break;
}
t = q;
}
/* If we didn't supersede a timeout, allocate a timeout
structure now. */
if (!q) {
if (free_timeouts) {
q = free_timeouts;
free_timeouts = q -> next;
} else {
q = ((struct timeout *)
dmalloc (sizeof (struct timeout), MDL));
if (!q)
log_fatal ("add_timeout: no memory!");
}
memset (q, 0, sizeof *q);
q -> func = where;
q -> ref = ref;
q -> unref = unref;
if (q -> ref)
(*q -> ref)(&q -> what, what, MDL);
else
q -> what = what;
}
q -> when = when;
/* Now sort this timeout into the timeout list. */
/* Beginning of list? */
if (!timeouts || timeouts -> when > q -> when) {
q -> next = timeouts;
timeouts = q;
return;
}
/* Middle of list? */
for (t = timeouts; t -> next; t = t -> next) {
if (t -> next -> when > q -> when) {
q -> next = t -> next;
t -> next = q;
return;
}
}
/* End of list. */
t -> next = q;
q -> next = (struct timeout *)0;
}
void cancel_timeout (where, what)
void (*where) PROTO ((void *));
void *what;
{
struct timeout *t, *q;
/* Look for this timeout on the list, and unlink it if we find it. */
t = (struct timeout *)0;
for (q = timeouts; q; q = q -> next) {
if (q -> func == where && q -> what == what) {
if (t)
t -> next = q -> next;
else
timeouts = q -> next;
break;
}
t = q;
}
/* If we found the timeout, put it on the free list. */
if (q) {
if (q -> unref)
(*q -> unref) (&q -> what, MDL);
q -> next = free_timeouts;
free_timeouts = q;
}
}