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/* $OpenBSD: handle_cookie_request.c,v 1.3 2001/01/28 22:45:08 niklas Exp $ */
/*
* Copyright 1997-2000 Niels Provos <provos@citi.umich.edu>
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Niels Provos.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
/*
* handle_cookie_request:
* receive a COOKIE_REQUEST packet; return -1 on failure, 0 on success
*
*/
#ifndef lint
static char rcsid[] = "$OpenBSD: handle_cookie_request.c,v 1.3 2001/01/28 22:45:08 niklas Exp $";
#endif
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <sys/time.h>
#include "config.h"
#include "photuris.h"
#include "packets.h"
#include "state.h"
#include "cookie.h"
#include "buffer.h"
#include "packet.h"
int
handle_cookie_request(u_char *packet, int size,
u_int8_t *address, u_int16_t port,
u_int8_t *schemes, u_int16_t ssize)
{
struct cookie_request *header;
struct stateob *prev_st, *st = NULL;
time_t tm = 0;
u_int8_t icookie[COOKIE_SIZE];
/* XXX - check resource limit */
if (size != COOKIE_REQUEST_PACKET_SIZE)
return -1; /* packet too small/big */
header = (struct cookie_request *) packet;
if ((prev_st=state_find(address)) != NULL) {
int exceeded = 1, match = 0;
st = prev_st;
/*
* Find exchanges which are not timed out and the rcookie doesnt
* match any exchange -> resource limit.
*/
tm = time(NULL);
while(prev_st != NULL) {
if (prev_st->lifetime > tm)
exceeded = 0;
if (prev_st->lifetime > st->lifetime)
st = prev_st;
if ((!prev_st->initiator &&
!bcmp(prev_st->rcookie, header->rcookie, COOKIE_SIZE))||
(prev_st->initiator &&
!bcmp(prev_st->icookie, header->rcookie, COOKIE_SIZE)))
match = 1;
prev_st = state_find_next(prev_st, address);
}
if (!match && !exceeded) {
packet_size = PACKET_BUFFER_SIZE;
photuris_error_message(st, packet_buffer, &packet_size,
header->icookie, header->rcookie,
header->counter, RESOURCE_LIMIT);
send_packet();
return 0;
}
}
bcopy(header->icookie, icookie, COOKIE_SIZE);
packet_size = PACKET_BUFFER_SIZE;
if (photuris_cookie_response(st != NULL &&
st->lifetime > tm ? st : NULL,
packet_buffer, &packet_size,
icookie, header->counter,
address, port,
schemes, ssize) == -1 )
return -1; /* Some error happened */
send_packet();
return 0;
}
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