receive.c~

抓取数据包

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/types.h>
//#include <linux/in.h>
#include <linux/if_ether.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
#define SERVER_IP "192.168.0.106"

#define PWORD(addr) \
        ((unsigned char *)&addr)[0],\
        ((unsigned char *)&addr)[1]


int main(int argc,char **argv)
{
int sock,n;
char buffer[2048];
unsigned char *iphead,*ethhead,*tcphead,*datahead;
struct ip *ip;
struct tcphdr * tcp;
char *ptr1,*ptr2;

struct sockaddr_in serv_addr;
int addr_len =sizeof(struct sockaddr_in);

serv_addr.sin_addr.s_addr = inet_addr(SERVER_IP);
//serv_addr.sin_addr.s_addr = htonl(SERVER_IP);

	if((sock=socket(PF_PACKET,SOCK_RAW,htons(ETH_P_IP)))<0)
	//if((sock=socket(PF_INET,SOCK_STREAM,0))<0)
  	{
		perror("socket");
		exit(1);
   	}
	printf("\n Now analysis the packets !\n");

	while(1)
	{	
	  printf("============================================\n");
	  //n=recvfrom(sock,buffer,2048,0,NULL,NULL);
	  //n=recvfrom(sock,buffer,2048,0,(struct sockaddr *)&serv_addr,(socklen_t *)&addr_len);
	n=recvfrom(sock,buffer,2048,0,NULL,NULL);
	  printf("%d bytes read : \n",n);

	  if(n<42)
	    {
		perror("recvfrom():");
		printf("Incomplete packet(errorno is %d)\n",errno);
		close(sock);
		exit(0);
	    }

	  ethhead=(unsigned char *)buffer;
	  printf("DST MAC address:%02x:%02x:%02x:%02x:%02x:%02x\n",ethhead[0],ethhead[1],ethhead[2],ethhead[3],ethhead[4],ethhead[5]);
	  printf("SOURCE   MAC address:%02x:%02x:%02x:%02x:%02x:%02x\n",ethhead[6],ethhead[7],ethhead[8],ethhead[9],ethhead[10],ethhead[11]);


/*-----------------IP Head-------------------------*/
iphead=(unsigned char *)(buffer+14);
//	  ip=(struct ip *)(buffer+14);
	  if(*iphead==0x45)
	   {
		ip=(struct ip *)iphead;
		

		//printf("Source host %d.%d.%d.%d\n",iphead[12],iphead[13],iphead[14],iphead[15]);
		//printf("Dest host %d.%d.%d.%d\n",iphead[16],iphead[17],iphead[18],iphead[19]);
		printf("IP Header IP->ip_v        : %d\n",ip->ip_v);
		printf("IP Header IP->ip_hl       : %d\n",ip->ip_hl);
		printf("IP Header IP->ip_tos      : %d\n",ip->ip_tos);
		printf("IP Header IP->ip_total_len: %d\n",ntohs(ip->ip_len));
		printf("IP Header IP->ip_ident    : %d\n",ntohs(ip->ip_id));
		printf("IP Header IP->ip_offset   : %d\n",PWORD(ip->ip_off));
		printf("IP Header IP->ip_ttl      : %d\n",ip->ip_ttl);
		printf("IP Header IP->ip_proto    : %d\n",ip->ip_p);
		printf("IP Header IP->ip_checksum : %d\n",PWORD(ip->ip_sum));
		printf("IP Header IP->ip_SRC_IP   : %s\n",inet_ntoa(ip->ip_src));
		printf("IP Header IP->ip_DST_IP   : %s\n",inet_ntoa(ip->ip_dst));


	    }

printf("-------------------------------------------\n");
/*-----------------TCP Head------------------------*/
tcphead=(iphead+20);

	tcp=(struct tcphdr *)tcphead;
	printf("TCP Header TCP->sport      : %d\n",ntohs(tcp->source));
	printf("TCP Header TCP->dport      : %d\n",ntohs(tcp->dest));
	printf("TCP Header TCP->tcp-seq    : %u\n",ntohl(tcp->seq));
	printf("TCP Header TCP->tcp-ack    : %u\n",ntohl(tcp->ack_seq));
	printf("TCP Header TCP->date-offset: %d\n",tcp->doff);
	printf("TCP Header TCP->tcp-res1   : %d\n",tcp->res1);
	printf("TCP Header TCP->URG        : %d\n",tcp->urg);
	printf("TCP Header TCP->ACK        : %d\n",tcp->ack);
	printf("TCP Header TCP->PSH        : %d\n",tcp->psh);
	printf("TCP Header TCP->RST        : %d\n",tcp->rst);
	printf("TCP Header TCP->SYN        : %d\n",tcp->syn);
	printf("TCP Header TCP->FIN        : %d\n",tcp->fin);
	printf("TCP Header TCP->tcp-res2   : %d\n",tcp->res2);
	printf("TCP Header TCP->Window     : %d\n",ntohs(tcp->window));
	printf("TCP Header TCP->Checksum   : %d\n",PWORD(tcp->check));
	printf("TCP Header TCP->urp        : %d\n",ntohs(tcp->urg_ptr));

//	printf("Source,Dest ports %d,%d\n",(iphead[20]<<8)+iphead[21],iphead[22]<<8+iphead[23]);
//	 printf("Layer-4 protocol %d\n",iphead[9]);

printf("-------------------------------------------\n");
/*-----------------Data Parse----------------------*/
datahead=(unsigned char *)((int)tcp+(int)(tcp->doff*4));

printf("The Packet data buf : %s\n",datahead);




	}


}