icmp.lst

单片机控制RTL8019AS的程序,C语言编写,仿真通过.

C51 COMPILER V7.06   ICMP                                                                  10/09/2006 21:51:55 PAGE 1   


C51 COMPILER V7.06, COMPILATION OF MODULE ICMP
OBJECT MODULE PLACED IN icmp.OBJ
COMPILER INVOKED BY: D:\Program Files\Keil\C51\BIN\C51.EXE icmp.c BROWSE DEBUG OBJECTEXTEND

stmt level    source

   1          //-----------------------------------------------------------------------------
   2          // Net ICMP.C
   3          //
   4          // This module handles ICMP messages
   5          // Refer to RFC 792, 896, 950, 1122, and 1191
   6          //-----------------------------------------------------------------------------
   7          #include <general.h>
   8          
   9          
  10          //------------------------------------------------------------------------
  11          // This builds a ping response message.  It allocates memory for the
  12          // entire outgoing message, including Eth and IP headers.  See "TCP/IP
  13          // Illustrated, Volume 1" Sect 7.2 for info on Ping messages
  14          //------------------------------------------------------------------------
  15          void ping_send(UCHAR xdata * inbuf, ULONG ipaddr, UINT len)
  16          {
  17   1         PING_HEADER xdata * ping_in;
  18   1         PING_HEADER xdata * ping_out;
  19   1         UCHAR xdata * outbuf;
  20   1                  
  21   1         ping_in = (PING_HEADER xdata *)(inbuf + 34);
  22   1            
  23   1         // Allocate memory for entire outgoing message
  24   1         outbuf = (UCHAR xdata *)malloc(len + 34);
  25   1         if (outbuf == NULL)
  26   1         {
  27   2            return;
  28   2         }      
  29   1            
  30   1         // Ping response message payload starts at offset 34
  31   1         ping_out = (PING_HEADER xdata *)(outbuf + 34);
  32   1      
  33   1         ping_out->msg_type = 0;
  34   1         ping_out->msg_code = 0;
  35   1         ping_out->checksum = 0;
  36   1         ping_out->identifier = ping_in->identifier;
  37   1         ping_out->sequence = ping_in->sequence;
  38   1         
  39   1         memcpy(&ping_out->echo_data, &ping_in->echo_data, len - 8);
  40   1                  
  41   1         // Compute checksum over the ICMP header plus
  42   1              // optional data and insert complement
  43   1         ping_out->checksum = ~cksum(outbuf + 34, len);
  44   1                              
  45   1      
  46   1         ip_send(outbuf, ipaddr, ICMP_TYPE, len);
  47   1      }
  48          
  49          
  50          
  51          //------------------------------------------------------------------------
  52          // This builds an outgoing ICMP destination port unreachable response
  53          // message.  See See "TCP/IP Illustrated, Volume 1" Sect 6.5.  This
  54          // message is typically sent in response to a UDP message directed
  55          // to a port that has no corresponding application running. 
C51 COMPILER V7.06   ICMP                                                                  10/09/2006 21:51:55 PAGE 2   

  56          // Todo: The spec says we should return all options that were in
  57          // the original incoming IP header.  Right now we cut off everything
  58          // after the first 20 bytes. 
  59          //------------------------------------------------------------------------
  60          void dest_unreach_send(UCHAR xdata * inbuf, ULONG ipaddr)
  61          {
  62   1         UCHAR xdata * outbuf;
  63   1         ICMP_ERR_HEADER xdata * icmp;
  64   1                  
  65   1         // Allocate memory for entire outgoing message
  66   1         // including eth and IP haders.  Always 70 bytes
  67   1         outbuf = (UCHAR xdata *)malloc(70);
  68   1         if (outbuf == NULL)
  69   1         {
  70   2            return;
  71   2         }      
  72   1            
  73   1         icmp = (ICMP_ERR_HEADER xdata *)(outbuf + 34);
  74   1         
  75   1         // Fill in ICMP error message header
  76   1         icmp->msg_type = 3;   // destination unreachable
  77   1         icmp->msg_code = 3;   // port unreachable
  78   1         icmp->checksum = 0;
  79   1            
  80   1         // Fill in ICMP error message data
  81   1         icmp->msg_data = 0;
  82   1                 
  83   1         // Copy in 20 byte original incoming IP header
  84   1         // plus 8 bytes of data
  85   1         memcpy(&icmp->echo_data, inbuf + 14, 28);
  86   1                                     
  87   1         // Compute checksum over the 36 byte long ICMP
  88   1         // header plus data and insert complement
  89   1         icmp->checksum = ~cksum(outbuf + 34, 36);
  90   1            
  91   1         // Forward message to the IP layer
  92   1         ip_send(outbuf, ipaddr, ICMP_TYPE, 36);
  93   1      }
  94          
  95          
  96          
  97          
  98          //------------------------------------------------------------------------
  99          // This handles incoming ICMP messages.  See "TCP/IP Illustrated,
 100          // Volume 1" Sect 6.2 for discussion of the various ICMP messages
 101          //------------------------------------------------------------------------
 102          void icmp_rcve(UCHAR xdata * inbuf, UINT len)
 103          {
 104   1         IP_HEADER * ip;
 105   1         UCHAR idata msg_type;
 106   1         UINT idata temp;
 107   1         
 108   1         // Allow for 14 bytes eth header
 109   1         ip = (IP_HEADER *)(inbuf + 14);
 110   1              
 111   1         // IP header has been adjusted if necessary to always be 
 112   1              // 20 bytes so message starts at an offset of 34
 113   1         // Validate checksum of entire ICMP message incl data 
 114   1              temp = cksum(inbuf + 34, len);
 115   1              
 116   1              if (temp != 0xFFFF)
 117   1              {
C51 COMPILER V7.06   ICMP                                                                  10/09/2006 21:51:55 PAGE 3   

 118   2            return; 
 119   2         }
 120   1            
 121   1         // Switch on the message type
 122   1         msg_type = *(inbuf + 34);
 123   1         switch(msg_type)
 124   1         {
 125   2            case 3:
 126   2            break;
 127   2      
 128   2                 case 8:
 129   2      
 130   2            ping_send(inbuf, ip->source_ipaddr, len); 
 131   2            break;
 132   2      
 133   2            default:
 134   2            break;
 135   2         }
 136   1      }
 137          


MODULE INFORMATION:   STATIC OVERLAYABLE
   CODE SIZE        =    500    ----
   CONSTANT SIZE    =   ----    ----
   XDATA SIZE       =   ----    ----
   PDATA SIZE       =   ----    ----
   DATA SIZE        =   ----      31
   IDATA SIZE       =   ----       3
   BIT SIZE         =   ----    ----
END OF MODULE INFORMATION.


C51 COMPILATION COMPLETE.  0 WARNING(S),  0 ERROR(S)