Projects/Webserver/Lib/uip/uip-neighbor.c

   1 /*
   2  * Copyright (c) 2006, Swedish Institute of Computer Science.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the Institute nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * This file is part of the uIP TCP/IP stack
  30  *
  31  * $Id: uip-neighbor.c,v 1.2 2006/06/12 08:00:30 adam Exp $
  32  */
  33
  34 /**
  35  * \file
  36  *         Database of link-local neighbors, used by IPv6 code and
  37  *         to be used by a future ARP code rewrite.
  38  * \author
  39  *         Adam Dunkels <adam@sics.se>
  40  */
  41
  42 #include "uip-neighbor.h"
  43
  44 #include <string.h>
  45
  46 #define MAX_TIME 128
  47
  48 #ifdef UIP_NEIGHBOR_CONF_ENTRIES
  49 #define ENTRIES UIP_NEIGHBOR_CONF_ENTRIES
  50 #else /* UIP_NEIGHBOR_CONF_ENTRIES */
  51 #define ENTRIES 8
  52 #endif /* UIP_NEIGHBOR_CONF_ENTRIES */
  53
  54 struct neighbor_entry {
  55   uip_ipaddr_t ipaddr;
  56   struct uip_neighbor_addr addr;
  57   u8_t time;
  58 };
  59 static struct neighbor_entry entries[ENTRIES];
  60
  61 /*---------------------------------------------------------------------------*/
  62 void
  63 uip_neighbor_init(void)
  64 {
  65   int i;
  66
  67   for(i = 0; i < ENTRIES; ++i) {
  68     entries[i].time = MAX_TIME;
  69   }
  70 }
  71 /*---------------------------------------------------------------------------*/
  72 void
  73 uip_neighbor_periodic(void)
  74 {
  75   int i;
  76
  77   for(i = 0; i < ENTRIES; ++i) {
  78     if(entries[i].time < MAX_TIME) {
  79       entries[i].time++;
  80     }
  81   }
  82 }
  83 /*---------------------------------------------------------------------------*/
  84 void
  85 uip_neighbor_add(uip_ipaddr_t ipaddr, struct uip_neighbor_addr *addr)
  86 {
  87   int i, oldest;
  88   u8_t oldest_time;
  89
  90   printf("Adding neighbor with link address %02x:%02x:%02x:%02x:%02x:%02x\n",
  91          addr->addr.addr[0], addr->addr.addr[1], addr->addr.addr[2], addr->addr.addr[3],
  92          addr->addr.addr[4], addr->addr.addr[5]);
  93
  94   /* Find the first unused entry or the oldest used entry. */
  95   oldest_time = 0;
  96   oldest = 0;
  97   for(i = 0; i < ENTRIES; ++i) {
  98     if(entries[i].time == MAX_TIME) {
  99       oldest = i;
 100       break;
 101     }
 102     if(uip_ipaddr_cmp(entries[i].ipaddr, addr)) {
 103       oldest = i;
 104       break;
 105     }
 106     if(entries[i].time > oldest_time) {
 107       oldest = i;
 108       oldest_time = entries[i].time;
 109     }
 110   }
 111
 112   /* Use the oldest or first free entry (either pointed to by the
 113      "oldest" variable). */
 114   entries[oldest].time = 0;
 115   uip_ipaddr_copy(entries[oldest].ipaddr, ipaddr);
 116   memcpy(&entries[oldest].addr, addr, sizeof(struct uip_neighbor_addr));
 117 }
 118 /*---------------------------------------------------------------------------*/
 119 static struct neighbor_entry *
 120 find_entry(uip_ipaddr_t ipaddr)
 121 {
 122   int i;
 123
 124   for(i = 0; i < ENTRIES; ++i) {
 125     if(uip_ipaddr_cmp(entries[i].ipaddr, ipaddr)) {
 126       return &entries[i];
 127     }
 128   }
 129   return NULL;
 130 }
 131 /*---------------------------------------------------------------------------*/
 132 void
 133 uip_neighbor_update(uip_ipaddr_t ipaddr)
 134 {
 135   struct neighbor_entry *e;
 136
 137   e = find_entry(ipaddr);
 138   if(e != NULL) {
 139     e->time = 0;
 140   }
 141 }
 142 /*---------------------------------------------------------------------------*/
 143 struct uip_neighbor_addr *
 144 uip_neighbor_lookup(uip_ipaddr_t ipaddr)
 145 {
 146   struct neighbor_entry *e;
 147
 148   e = find_entry(ipaddr);
 149   if(e != NULL) {
 150     /*    printf("Lookup neighbor with link address %02x:%02x:%02x:%02x:%02x:%02x\n",
 151            e->addr.addr.addr[0], e->addr.addr.addr[1], e->addr.addr.addr[2], e->addr.addr.addr[3],
 152            e->addr.addr.addr[4], e->addr.addr.addr[5]);*/
 153
 154     return &e->addr;
 155   }
 156   return NULL;
 157 }
 158 /*---------------------------------------------------------------------------*/