C51 COMPILER V7.08   UIP_ARP                                                               12/26/2003 07:27:15 PAGE 1   


C51 COMPILER V7.08, COMPILATION OF MODULE UIP_ARP
OBJECT MODULE PLACED IN uip_arp.OBJ
COMPILER INVOKED BY: C:\Keil708\C51\BIN\C51.EXE uip_arp.c LARGE BROWSE DEBUG OBJECTEXTEND

line level    source

   1          /*
   2           * Copyright (c) 2001-2002, Adam Dunkels.
   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. All advertising materials mentioning features or use of this software
  14           *    must display the following acknowledgement:
  15           *      This product includes software developed by Adam Dunkels.
  16           * 4. The name of the author may not be used to endorse or promote
  17           *    products derived from this software without specific prior
  18           *    written permission.  
  19           *
  20           * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
  21           * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  22           * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23           * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
  24           * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25           * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
  26           * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  27           * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  28           * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  29           * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  30           * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.  
  31           *
  32           * This file is part of the uIP TCP/IP stack.
  33           *
  34           * $Id: uip_arp.c,v 1.3 2002/01/13 21:12:41 adam Exp $
  35           *
  36           */
  37          
  38          
  39          #include "uip_arp.h"
  40          
  41          struct arp_hdr {
  42            struct uip_eth_hdr ethhdr;
  43            u16_t hwtype;
  44            u16_t protocol;
  45            u8_t hwlen;
  46            u8_t protolen;
  47            u16_t opcode;
  48            struct uip_eth_addr shwaddr;
  49            u16_t sipaddr[2];
  50            struct uip_eth_addr dhwaddr;
  51            u16_t dipaddr[2]; 
  52          };
  53          
  54          struct ethip_hdr {
  55              struct uip_eth_hdr ethhdr;
C51 COMPILER V7.08   UIP_ARP                                                               12/26/2003 07:27:15 PAGE 2   

  56              /* IP header. */
  57              u8_t vhl,
  58              tos,          
  59              len[2],       
  60              ipid[2],        
  61              ipoffset[2],  
  62              ttl,          
  63              proto;     
  64              u16_t ipchksum;
  65              u16_t srcipaddr[2], 
  66              destipaddr[2];
  67          };
  68          
  69          #define ARP_REQUEST 1
  70          #define ARP_REPLY   2
  71          
  72          #define ARP_HWTYPE_ETH 1
  73          
  74          struct arp_entry {
  75            u16_t ipaddr[2];
  76            struct uip_eth_addr ethaddr;
  77            u8_t time;
  78          };
  79          
  80          struct uip_eth_addr ethaddr = {{UIP_ETHADDR0,
  81                                                       UIP_ETHADDR1,
  82                                                       UIP_ETHADDR2,
  83                                                       UIP_ETHADDR3,
  84                                                       UIP_ETHADDR4,
  85                                                       UIP_ETHADDR5}};
  86          
  87          static struct arp_entry arp_table[UIP_ARPTAB_SIZE];
  88          static u16_t ipaddr[2];
  89          static u8_t i, c;
  90          
  91          static u8_t time;
  92          static u8_t tmpage;
  93          
  94          #define BUF   ((struct arp_hdr *)&uip_buf[0])
  95          #define IPBUF ((struct ethip_hdr *)&uip_buf[0])
  96          /*-----------------------------------------------------------------------------------*/
  97          /*
  98          void
  99          uip_arp_init(void)
 100          {
 101            for(i = 0; i < UIP_ARPTAB_SIZE; ++i) {
 102              arp_table[i].ipaddr[0] =
 103                arp_table[i].ipaddr[1] = 0;
 104            }
 105          }
 106          */
 107          
 108          /*-----------------------------------------------------------------------------------*/
 109          void
 110          uip_arp_timer(void)
 111          {
 112   1         ++time;
 113   1         for(i = 0; i < UIP_ARPTAB_SIZE; ++i) 
 114   1         {
 115   2             if((arp_table[i].ipaddr[0] | arp_table[i].ipaddr[1]) != 0 &&
 116   2                  time - arp_table[i].time >= UIP_ARP_MAXAGE) 
 117   2                 {
C51 COMPILER V7.08   UIP_ARP                                                               12/26/2003 07:27:15 PAGE 3   

 118   3                arp_table[i].ipaddr[0] =
 119   3                    arp_table[i].ipaddr[1] = 0;
 120   3             }
 121   2         }
 122   1      }
 123          /*-----------------------------------------------------------------------------------*/
 124          static void
 125          uip_arp_update(u16_t *ipaddr, struct uip_eth_addr *ethaddr)
 126          {
 127   1        /* Walk through the ARP mapping table and try to find an entry to
 128   1           update. If none is found, the IP -> MAC address mapping is
 129   1           inserted in the ARP table. */
 130   1        for(i = 0; i < UIP_ARPTAB_SIZE; ++i) 
 131   1        {
 132   2          
 133   2          /* Only check those entries that are actually in use. */
 134   2          if(arp_table[i].ipaddr[0] != 0 &&
 135   2             arp_table[i].ipaddr[1] != 0) 
 136   2              {
 137   3                              /* Check if the source IP address of the incoming packet matches
 138   3                              the IP address in this ARP table entry. */
 139   3                              if(ipaddr[0] == arp_table[i].ipaddr[0] &&
 140   3                                  ipaddr[1] == arp_table[i].ipaddr[1]) 
 141   3                              {
 142   4                              
 143   4                                      /* An old entry found, update this and return. */
 144   4                                      for(c = 0; c < 6; ++c) 
 145   4                                      {
 146   5                                              arp_table[i].ethaddr.addr[c] = ethaddr->addr[c];
 147   5                                      }
 148   4                                      arp_table[i].time = time;
 149   4                                      return;
 150   4                      }
 151   3              }
 152   2           }
 153   1      
 154   1        /* If we get here, no existing ARP table entry was found, so we
 155   1           create one. */
 156   1      
 157   1        /* First, we try to find an unused entry in the ARP table. */
 158   1        for(i = 0; i < UIP_ARPTAB_SIZE; ++i) {
 159   2          if(arp_table[i].ipaddr[0] == 0 &&
 160   2             arp_table[i].ipaddr[1] == 0)
 161   2            break;    
 162   2        }
 163   1      
 164   1        /* If no unused entry is found, we try to find the oldest entry and
 165   1           throw it away. */
 166   1        if(i == UIP_ARPTAB_SIZE) {
 167   2          tmpage = 0;
 168   2          c = 0;
 169   2          for(i = 0; i < UIP_ARPTAB_SIZE; ++i) {
 170   3            if(time - arp_table[i].time > tmpage) {
 171   4              tmpage = time - arp_table[i].time;
 172   4              c = i;
 173   4            }
 174   3          }
 175   2          i = c;
 176   2        }
 177   1      
 178   1        /* Now, i is the ARP table entry which we will fill with the new
 179   1           information. */
C51 COMPILER V7.08   UIP_ARP                                                               12/26/2003 07:27:15 PAGE 4   

 180   1        arp_table[i].ipaddr[0] = ipaddr[0];
 181   1        arp_table[i].ipaddr[1] = ipaddr[1];
 182   1        for(c = 0; c < 6; ++c) {
 183   2          arp_table[i].ethaddr.addr[c] = ethaddr->addr[c];
 184   2        }
 185   1        arp_table[i].time = time;
 186   1      }
 187          /*-----------------------------------------------------------------------------------*/
 188          void
 189          uip_arp_ipin(void)
 190          {
 191   1      
 192   1        /* Only insert/update an entry if the source IP address of the
 193   1           incoming IP packet comes from a host on the local network. */