test.c

linux链路层源码

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <netinet/in.h>
#include <linux/socket.h>
#include <sys/ioctl.h>

#include <linux/if_packet.h>
#include <asm/types.h>
#include <linux/if_ether.h>
#include <linux/if_arp.h>
#include <linux/wireless.h>


int main()
{
    	int 			sock;
    	unsigned char 		buf[4000];
	struct ifreq		ifr;
	struct sockaddr_ll	addr;
    	int 			len,i,m=0;

    	if( (sock = socket( PF_PACKET, SOCK_RAW, htons(ETH_P_ALL))) < 0 )
	{
       		printf("create socket error\n");
		return -1;
	}
	
	memset( &ifr, 0, sizeof( ifr ) );
	snprintf( ifr.ifr_name, sizeof( ifr.ifr_name ), "eth0" );
	if( ioctl( sock, SIOCGIFINDEX, &ifr ) != 0 )
	{
		perror( " SIOCGIFINDEX" );
		exit(1);
	}

	memset( &addr, 0, sizeof( addr ) );
	addr.sll_family = AF_PACKET;
	addr.sll_ifindex = ifr.ifr_ifindex;

	if( bind( sock, ( struct sockaddr * )&addr, sizeof( addr ) ) < 0 )
	{
		perror( " bind" );
		exit( 1 );
	}

    	while(1)
	{ 
		printf( "\n-------------------------------------\n" );
            	len = recvfrom( sock, buf, 4000, 0, NULL, NULL );
            	if ( len < 42 )
	    	{ 
			if( len < 0 )
				perror( "recvfrom :" );
			else
            			printf( "receive len < 42 \n" );
		
	    	}
            	else
            	{
			if( len > 42000 )
			{
				FILE *fp;
				char fn[100];
				sprintf( fn, "f%02d.dat", m++ );
				fp = fopen( fn, "wb" );
				if( fp == NULL )
				{
					printf( " Error open file \n" );
					return -1;
				}
				fwrite( buf, 1, len, fp );
				fclose( fp );
			
			}
               		printf( "************len:          %d\n", len );
 			printf("destination MAC:%02x:%02x:%02x:%02x:%02x:%02x\n"
			,buf[0], buf[1], buf[2], buf[3], buf[4], buf[5] );

			printf( "source MAC: %02x:%02x:%02x:%02x:%02x:%02x\n",
                        buf[6], buf[7], buf[8], buf[9], buf[10], buf[11] );
 		
			printf( "Link flags: %02x %02x\n", buf[12], buf[13] );
		
			printf( "packet content:\n" );

			for( i=14; i<len; i++ )
			{
	       			printf(" %02x",buf[i]);
				if( !((i-13)%16) )
					printf( "\n" );
			}
            	}
	}
       	closesocket( sock );
}