text: /*	$NetBSD: throttle.c,v 1.4 2006/09/09 16:22:10 manu Exp $	*/
  
  /* Id: throttle.c,v 1.5 2006/04/05 20:54:50 manubsd Exp */
  
  /*
   * Copyright (C) 2004 Emmanuel Dreyfus
   * 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 project 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 PROJECT 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 PROJECT 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 "config.h"
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #if TIME_WITH_SYS_TIME
  # include <sys/time.h>
  # include <time.h> 
  #else 
  # if HAVE_SYS_TIME_H
  #  include <sys/time.h>
  # else
  #  include <time.h>
  # endif 
  #endif
  #include <sys/param.h>
  #include <sys/queue.h>
  #include <sys/socket.h>
  
  #include <netinet/in.h>
  #include <resolv.h>
  
  #include "vmbuf.h"
  #include "misc.h"
  #include "plog.h"
  #include "throttle.h"
  #include "sockmisc.h"
  #include "libpfkey.h"
  #include "isakmp_var.h"
  #include "isakmp.h"
  #include "isakmp_xauth.h"
  #include "isakmp_cfg.h"
  #include "gcmalloc.h"
  
  struct throttle_list throttle_list = TAILQ_HEAD_INITIALIZER(throttle_list);
  
  
  struct throttle_entry *
  throttle_add(addr)
  	struct sockaddr *addr;
  {
  	struct throttle_entry *te;
  	size_t len;
  
  	len = sizeof(*te) 
  	    - sizeof(struct sockaddr_storage) 
  	    + sysdep_sa_len(addr);
  
  	if ((te = racoon_malloc(len)) == NULL)
  		return NULL;
  
  	te->penalty = time(NULL) + isakmp_cfg_config.auth_throttle;
  	memcpy(&te->host, addr, sysdep_sa_len(addr));
  	TAILQ_INSERT_HEAD(&throttle_list, te, next);
  
  	return te;
  }
  
  int
  throttle_host(addr, authfail) 
  	struct sockaddr *addr;
  	int authfail;
  {
  	struct throttle_entry *te;
  	int found = 0;
  	time_t now;
  
  	if (isakmp_cfg_config.auth_throttle == 0)
  		return 0;
  
  	now = time(NULL);
  
  restart:
  	RACOON_TAILQ_FOREACH_REVERSE(te, &throttle_list, throttle_list, next) {
  	  /*
  	   * Remove outdated entries 
  	   */
  		if (te->penalty < now) {
  			TAILQ_REMOVE(&throttle_list, te, next);
  			racoon_free(te);
  			goto restart;
  		}
  			
  		if (cmpsaddrwop(addr, (struct sockaddr *)&te->host) == 0) {
  			found = 1;
  			break;
  		}
  	}
  
  	/* 
  	 * No match, if auth failed, allocate a new throttle entry
  	 * give no penalty even on error: this is the first time
  	 * and we are indulgent.
  	 */
  	if (!found) {
  		if (authfail) {
  			if ((te = throttle_add(addr)) == NULL) {
  				plog(LLV_ERROR, LOCATION, NULL, 
  				    "Throttle insertion failed\n");
  				return (time(NULL) 
  				    + isakmp_cfg_config.auth_throttle);
  			}
  		}
  		return 0;
  	} else {
  		/*
  		 * We had a match and auth failed, increase penalty.
  		 */
  		if (authfail) {
  			time_t remaining;
  			time_t new;
  
  			remaining = te->penalty - now;
  			new = remaining + isakmp_cfg_config.auth_throttle;
  
  			if (new > THROTTLE_PENALTY_MAX)
  				new = THROTTLE_PENALTY_MAX;
  
  			te->penalty = now + new;
  		}
  	}
  	
  	return te->penalty;
  }
  
  