uIP 1.0: uip/uip-neighbor.c Source File

00001 /*
+00002  * Copyright (c) 2006, Swedish Institute of Computer Science.
+00003  * All rights reserved.
+00004  *
+00005  * Redistribution and use in source and binary forms, with or without
+00006  * modification, are permitted provided that the following conditions
+00007  * are met:
+00008  * 1. Redistributions of source code must retain the above copyright
+00009  *    notice, this list of conditions and the following disclaimer.
+00010  * 2. Redistributions in binary form must reproduce the above copyright
+00011  *    notice, this list of conditions and the following disclaimer in the
+00012  *    documentation and/or other materials provided with the distribution.
+00013  * 3. Neither the name of the Institute nor the names of its contributors
+00014  *    may be used to endorse or promote products derived from this software
+00015  *    without specific prior written permission.
+00016  *
+00017  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+00018  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+00019  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+00020  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+00021  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+00022  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+00023  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+00024  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+00025  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+00026  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+00027  * SUCH DAMAGE.
+00028  *
+00029  * This file is part of the uIP TCP/IP stack
+00030  *
+00031  * $Id: uip-neighbor.c,v 1.2 2006/06/12 08:00:30 adam Exp $
+00032  */
+00033 
+00034 /**
+00035  * \file
+00036  *         Database of link-local neighbors, used by IPv6 code and
+00037  *         to be used by a future ARP code rewrite.
+00038  * \author
+00039  *         Adam Dunkels <adam@sics.se>
+00040  */
+00041 
+00042 #include "uip-neighbor.h"
+00043 
+00044 #include <string.h>
+00045 
+00046 #define MAX_TIME 128
+00047 
+00048 #ifdef UIP_NEIGHBOR_CONF_ENTRIES
+00049 #define ENTRIES UIP_NEIGHBOR_CONF_ENTRIES
+00050 #else /* UIP_NEIGHBOR_CONF_ENTRIES */
+00051 #define ENTRIES 8
+00052 #endif /* UIP_NEIGHBOR_CONF_ENTRIES */
+00053 
+00054 struct neighbor_entry {
+00055   uip_ipaddr_t ipaddr;
+00056   struct uip_neighbor_addr addr;
+00057   u8_t time;
+00058 };
+00059 static struct neighbor_entry entries[ENTRIES];
+00060 
+00061 /*---------------------------------------------------------------------------*/
+00062 void
+00063 uip_neighbor_init(void)
+00064 {
+00065   int i;
+00066 
+00067   for(i = 0; i < ENTRIES; ++i) {
+00068     entries[i].time = MAX_TIME;
+00069   }
+00070 }
+00071 /*---------------------------------------------------------------------------*/
+00072 void
+00073 uip_neighbor_periodic(void)
+00074 {
+00075   int i;
+00076 
+00077   for(i = 0; i < ENTRIES; ++i) {
+00078     if(entries[i].time < MAX_TIME) {
+00079       entries[i].time++;
+00080     }
+00081   }
+00082 }
+00083 /*---------------------------------------------------------------------------*/
+00084 void
+00085 uip_neighbor_add(uip_ipaddr_t ipaddr, struct uip_neighbor_addr *addr)
+00086 {
+00087   int i, oldest;
+00088   u8_t oldest_time;
+00089 
+00090   printf("Adding neighbor with link address %02x:%02x:%02x:%02x:%02x:%02x\n",
+00091          addr->addr.addr[0], addr->addr.addr[1], addr->addr.addr[2], addr->addr.addr[3],
+00092          addr->addr.addr[4], addr->addr.addr[5]);
+00093   
+00094   /* Find the first unused entry or the oldest used entry. */
+00095   oldest_time = 0;
+00096   oldest = 0;
+00097   for(i = 0; i < ENTRIES; ++i) {
+00098     if(entries[i].time == MAX_TIME) {
+00099       oldest = i;
+00100       break;
+00101     }
+00102     if(uip_ipaddr_cmp(entries[i].ipaddr, addr)) {
+00103       oldest = i;
+00104       break;
+00105     }
+00106     if(entries[i].time > oldest_time) {
+00107       oldest = i;
+00108       oldest_time = entries[i].time;
+00109     }
+00110   }
+00111 
+00112   /* Use the oldest or first free entry (either pointed to by the
+00113      "oldest" variable). */
+00114   entries[oldest].time = 0;
+00115   uip_ipaddr_copy(entries[oldest].ipaddr, ipaddr);
+00116   memcpy(&entries[oldest].addr, addr, sizeof(struct uip_neighbor_addr));
+00117 }
+00118 /*---------------------------------------------------------------------------*/
+00119 static struct neighbor_entry *
+00120 find_entry(uip_ipaddr_t ipaddr)
+00121 {
+00122   int i;
+00123   
+00124   for(i = 0; i < ENTRIES; ++i) {
+00125     if(uip_ipaddr_cmp(entries[i].ipaddr, ipaddr)) {
+00126       return &entries[i];
+00127     }
+00128   }
+00129   return NULL;
+00130 }
+00131 /*---------------------------------------------------------------------------*/
+00132 void
+00133 uip_neighbor_update(uip_ipaddr_t ipaddr)
+00134 {
+00135   struct neighbor_entry *e;
+00136 
+00137   e = find_entry(ipaddr);
+00138   if(e != NULL) {
+00139     e->time = 0;
+00140   }
+00141 }
+00142 /*---------------------------------------------------------------------------*/
+00143 struct uip_neighbor_addr *
+00144 uip_neighbor_lookup(uip_ipaddr_t ipaddr)
+00145 {
+00146   struct neighbor_entry *e;
+00147 
+00148   e = find_entry(ipaddr);
+00149   if(e != NULL) {
+00150     /*    printf("Lookup neighbor with link address %02x:%02x:%02x:%02x:%02x:%02x\n",
+00151            e->addr.addr.addr[0], e->addr.addr.addr[1], e->addr.addr.addr[2], e->addr.addr.addr[3],
+00152            e->addr.addr.addr[4], e->addr.addr.addr[5]);*/
+00153 
+00154     return &e->addr;
+00155   }
+00156   return NULL;
+00157 }
+00158 /*---------------------------------------------------------------------------*/
+