usrappinit.c

此代码主要完成在vxworks 环境下的网络编程

/* usrAppInit.c - stub application initialization routine */

/* Copyright 1984-1998 Wind River Systems, Inc. */

/*
modification history
--------------------
01a,02jun98,ms   written
*/

/*
DESCRIPTION
Initialize user application code.
*/ 
  
/******************************************************************************
*
* usrAppInit - initialize the users application
*/ 

#include <stdio.h>
#include "vxWorks.h"
#include "sockLib.h"
#include "inetLib.h"



#include "udpip.h"
 
 void udp_send(UCHAR *outbuf,  UINT len,UINT my_udpport, UINT send_udpport);
  void udp_rcve(UCHAR  * inbuf, UINT len);
  void ip_send(UCHAR * outbuf,  UINT len,ULONG my_ipaddr,ULONG send_ipaddr);
  void ip_rcve(UCHAR  * inbuf);

  

  
  UINT cksum(UCHAR *check,UINT length);
   UINT source_udpport;
   ULONG source_ipaddr;
   UINT aim_udpport;
   ULONG aim_ipaddr;


   UINT output_len;
   UINT  input_len;
   UCHAR *input_buf;
   UCHAR  *output_buf;


   char testme;


void usrAppInit (void)
    {
#ifdef	USER_APPL_INIT
	USER_APPL_INIT;		/* for backwards compatibility */
#endif

    /* add application specific code here */
    printf("Hello world.\n");
    }
/*

//---------------------------------------------------------------------------




//------------------------------------------------------------------------
//	This handles outgoing UDP messages
// See "TCP/IP Illustrated, Volume 1" Sect 11.1 - 11.3
//------------------------------------------------------------------------
*/
void udp_send(UCHAR *outbuf,  UINT len,UINT my_udpport, UINT send_udpport)
{
	ULONG  sum;
  	UINT  result;
    UDP_HEADER  udp;
    UDP_HEADER *udper;
          udper = &udp;

	udper->source_port = my_udpport;
        udper->dest_port = send_udpport;
        	udper->length = 8 + len;

	udper->checksum =1;


    /*	sum = (ULONG)cksum(outbuf + 26, 8 + udper->length);

	// Add in the rest of pseudoheader which is
	// zero, protocol id, and UDP length
	sum += (ULONG)0x0011;
	sum += (ULONG)udper->length;

	// In case there was a carry, add it back around
	result = (UINT)(sum + (sum >> 16));
	udper->checksum = ~result;
        */

     output_buf=outbuf+8;


       memcpy(output_buf,(const void* )udper,  8);

       output_len=len+8;

 

	ip_send(output_buf, output_len, source_ipaddr, aim_ipaddr );
       
}


/*
//------------------------------------------------------------------------
// This handles incoming UDP messages
// See "TCP/IP Illustrated, Volume 1" Sect 11.1 - 11.3
//------------------------------------------------------------------------

*/
void udp_rcve(UCHAR  * inbuf, UINT len)
{
   UINT  result;
 
   UDP_HEADER * udp;

   ULONG  sum;
   
     memcpy((void *)udp, (void *)inbuf, 8)  ;

        if (len <udp->length) return;
		   

	if (udp->checksum == 0)
	{
          return ;
	}
	else
	{
	
		sum = (ULONG)cksum(inbuf + 26, 8 + udp->length);
		
	
		sum += (ULONG)0x0011;     
		sum += (ULONG)udp->length;

		result = (UINT)(sum + (sum >> 16));
		
		if (result != 0xFFFF)
		{

			return;
		}
       input_buf=input_buf-8;
       input_len=udp->length-8;

	}   

}




void ip_send(UCHAR * outbuf,  UINT len ,ULONG my_ipaddr,ULONG send_ipaddr)
{
    IP_HEADER  IPHEAD;
    IP_HEADER  * ip;
     ip=&IPHEAD;

  /**** UCHAR xdata * hwaddr;*/


   ip->ver_len = 0x45;         
   ip->type_of_service = 0;
   ip->total_length = 20 + len;
   ip->identifier =1 ;   
   ip->fragment_info = 0;          
   ip->time_to_live = 32;           
   ip->protocol_id = UDP_TYPE;     
   ip->header_cksum = 0;
   ip->source_ipaddr = source_ipaddr;
   ip->dest_ipaddr = aim_ipaddr;

 
   ip->header_cksum = ~cksum(outbuf + 14, 20);
   
 

   output_buf=outbuf+20;
   output_len=len+20;

      memcpy((void *)output_buf, (void *)ip , 20)  ;


/* 	if (send_ipaddr == NULL)
	{
	
   wait.buf = outbuf;
		wait.ipaddr = ip->dest_ipaddr;
		wait.proto_id = proto_id;
		wait.len = len;
		wait.timer = ARP_TIMEOUT;
               
      return;
	}
    */
    return;

  }

/*
//------------------------------------------------------------------------
// This handles incoming IP datagrams from the Ethernet layer
// See "TCP/IP Illustrated, Volume 1" Sect 3.2
//------------------------------------------------------------------------
*/
void ip_rcve(UCHAR  * inbuf)
{
     	IP_HEADER  iphead;
        IP_HEADER  * ip;
     

    	UINT header_len, payload_len;

        ip=&iphead;
        memcpy ((void *)ip,(void *)inbuf,20);

            
  
   if (ip->dest_ipaddr != source_ipaddr) return;

  
	header_len = 4 * (0x0F & ip->ver_len);
	payload_len = ip->total_length - header_len;

   if (cksum(inbuf + 14, header_len) != 0xFFFF)
	{
	   return;
   }

	if ((ip->ver_len >> 4) != 0x04)   	{

   	return;
	}

   if ((ip->fragment_info & 0x3FFF) != 0)
   {

	   return;
   }
       

   /*	if (header_len > 20)
	{

   			
      // Use memmove because of overlap
      memmove(inbuf + 34, inbuf + 14 + header_len, payload_len);

		// Adjust info to reflect the move
		header_len = 20;
		ip->ver_len = 0x45;
		ip->total_length = 20 + payload_len;
	}
	    */  
   if(ip->protocol_id!=UDP_TYPE)
	{ return;
        }


 input_buf=inbuf-20;

     udp_rcve(input_buf, payload_len);     
	

 }  


UINT cksum(UCHAR *check,UINT length)
{
	LONG sum=0;
	UINT i;
	UINT  *ptr;
        
    ptr=(UINT  *)check;
	for (i=0;i<(length)/2;i++)
	{
		sum+=*ptr++;
	}
	if (length&0x01)
	{
		sum=sum+((*ptr)&0xff00);
	}
	sum=(sum&0xffff)+((sum>>16)&0xffff);
	if(sum&0xffff0000)
	{
		sum++;
	}
	return ( (UINT)((sum)&0xffff));

}



 void  send_udp()
{

	

   UCHAR    Buffer[188*7]; 
   UCHAR   *mybuff;      
     UINT    code;
     UINT   test;

    mybuff=Buffer;
   for(  code=0;code<188*7;code++)

{ Buffer[code]='a';
}

        output_len=strlen(Buffer);
       output_buf=mybuff+output_len ;

    aim_udpport=21;
    source_udpport=22;
    aim_ipaddr=2000  ;
    source_ipaddr=1000 ;

      for( test =0; test < 1; test++)
  
   {  udp_send(output_buf,  output_len,source_udpport,aim_udpport) ;

}

return;

}