原始套接字的简单tcp包嗅探

原始套接字

sock_raw = socket(AF_INET , SOCK_RAW , IPPROTO_TCP);
while(1)
{
data_size = recvfrom(sock_raw , buffer , 65536 , 0 , &saddr , &saddr_size);
}

/*
* main.cpp
*
*  Created on: Mar 11, 2016
*/

#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>

#include <netinet/ip_icmp.h>
#include <netinet/udp.h>
#include <netinet/tcp.h>
#include <netinet/ip.h>

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>

FILE* logfile;
int sockfd;
int tcp=0,udp=0,icmp=0,others=0,igmp=0,total=0,i,j;
struct sockaddr_in source,dest;

void process_packet(unsigned char* buffer , int size);
void print_ip_header(unsigned char* , int);
void print_tcp_packet(unsigned char* , int);
void print_udp_packet(unsigned char * , int);
void print_icmp_packet(unsigned char* , int);
void PrintData (unsigned char* , int);

int main()
{
struct sockaddr addr;
int datasize;
socklen_t saddr_size =  sizeof(addr);
unsigned  char* buffer = (unsigned char*)malloc(65536);

logfile = fopen("log.txt","w");
if(logfile == NULL)  printf("unable to create file\n");
printf("Starting.....\n");

sockfd =  socket(AF_INET, SOCK_RAW,IPPROTO_TCP);
if(sockfd < 0)
{
fprintf(stderr,"open socket error: ",strerror(errno));
}

while(1)
{
datasize = recvfrom(sockfd, buffer, 65536,0 ,&addr,&saddr_size );
if(datasize < 0)
{
printf("Recvfrom error, failed to get packets\n");
return -1;
}
process_packet(buffer,datasize);
//not work??????????????
//fprintf(logfile,"%s\n",buffer);
}

close(sockfd);
fclose(logfile);
printf("Finished");
return 0;
}

void process_packet(unsigned char* buffer , int size)
{
struct iphdr *iph = (struct iphdr*)buffer;
total++;
switch(iph->protocol)
{
case 1:
++icmp;
//print_icmp_packet(buffer,size);
break;

case 2:
++igmp;
break;
case 6:
++tcp;
print_tcp_packet(buffer , size);
break;
case 17:
++udp;
print_udp_packet(buffer , size);
break;

default:
++others;
break;
}
printf("TCP : %d   UDP : %d   ICMP : %d   IGMP : %d   Others : %d   Total : %d\r",
tcp,udp,icmp,igmp,others,total);

}

void print_ip_header(unsigned char* Buffer, int  size)
{
unsigned short iphdrlen;
struct iphdr *iph = (struct iphdr *)Buffer;
iphdrlen = iph->ihl*4;
memset(&source, 0, sizeof(source));
source.sin_addr.s_addr = iph->saddr;

memset(&dest, 0, sizeof(dest));
dest.sin_addr.s_addr = iph->daddr;

fprintf(logfile, "\n");
fprintf(logfile, "IP Header\n");
fprintf(logfile, "   |-IP Version        : %d\n",
(unsigned int) iph->version);
fprintf(logfile, "   |-IP Header Length  : %d DWORDS or %d Bytes\n",
(unsigned int) iph->ihl, ((unsigned int) (iph->ihl)) * 4);
fprintf(logfile, "   |-Type Of Service   : %d\n", (unsigned int) iph->tos);
fprintf(logfile, "   |-IP Total Length   : %d  Bytes(Size of Packet)\n",
ntohs(iph->tot_len));
fprintf(logfile, "   |-Identification    : %d\n", ntohs(iph->id));
//fprintf(logfile,"   |-Reserved ZERO Field   : %d\n",(unsigned int)iphdr->ip_reserved_zero);
//fprintf(logfile,"   |-Dont Fragment Field   : %d\n",(unsigned int)iphdr->ip_dont_fragment);
//fprintf(logfile,"   |-More Fragment Field   : %d\n",(unsigned int)iphdr->ip_more_fragment);
fprintf(logfile, "   |-TTL      : %d\n", (unsigned int) iph->ttl);
fprintf(logfile, "   |-Protocol : %d\n", (unsigned int) iph->protocol);
fprintf(logfile, "   |-Checksum : %d\n", ntohs(iph->check));
fprintf(logfile, "   |-Source IP        : %s\n",
inet_ntoa(source.sin_addr));
fprintf(logfile, "   |-Destination IP   : %s\n", inet_ntoa(dest.sin_addr));
}

void print_tcp_packet(unsigned char* Buffer, int Size)
{
unsigned short iphdrlen;

struct iphdr *iph = (struct iphdr *)Buffer;
iphdrlen = iph->ihl*4;

struct tcphdr *tcph=(struct tcphdr*)(Buffer + iphdrlen);

fprintf(logfile,"\n\n***********************TCP Packet*************************\n");

print_ip_header(Buffer,Size);

fprintf(logfile,"\n");
fprintf(logfile,"TCP Header\n");
fprintf(logfile,"   |-Source Port      : %u\n",ntohs(tcph->source));
fprintf(logfile,"   |-Destination Port : %u\n",ntohs(tcph->dest));
fprintf(logfile,"   |-Sequence Number    : %u\n",ntohl(tcph->seq));
fprintf(logfile,"   |-Acknowledge Number : %u\n",ntohl(tcph->ack_seq));
fprintf(logfile,"   |-Header Length      : %d DWORDS or %d BYTES\n" ,(unsigned int)tcph->doff,(unsigned int)tcph->doff*4);
//fprintf(logfile,"   |-CWR Flag : %d\n",(unsigned int)tcph->cwr);
//fprintf(logfile,"   |-ECN Flag : %d\n",(unsigned int)tcph->ece);
fprintf(logfile,"   |-Urgent Flag          : %d\n",(unsigned int)tcph->urg);
fprintf(logfile,"   |-Acknowledgement Flag : %d\n",(unsigned int)tcph->ack);
fprintf(logfile,"   |-Push Flag            : %d\n",(unsigned int)tcph->psh);
fprintf(logfile,"   |-Reset Flag           : %d\n",(unsigned int)tcph->rst);
fprintf(logfile,"   |-Synchronise Flag     : %d\n",(unsigned int)tcph->syn);
fprintf(logfile,"   |-Finish Flag          : %d\n",(unsigned int)tcph->fin);
fprintf(logfile,"   |-Window         : %d\n",ntohs(tcph->window));
fprintf(logfile,"   |-Checksum       : %d\n",ntohs(tcph->check));
fprintf(logfile,"   |-Urgent Pointer : %d\n",tcph->urg_ptr);
fprintf(logfile,"\n");
fprintf(logfile,"                        DATA Dump                         ");
fprintf(logfile,"\n");

fprintf(logfile,"IP Header\n");
PrintData(Buffer,iphdrlen);

fprintf(logfile,"TCP Header\n");
PrintData(Buffer+iphdrlen,tcph->doff*4);

fprintf(logfile,"Data Payload\n");
PrintData(Buffer + iphdrlen + tcph->doff*4 , (Size - tcph->doff*4-iph->ihl*4) );

fprintf(logfile,"\n###########################################################");
}

void print_udp_packet(unsigned char *Buffer , int Size)
{

unsigned short iphdrlen;

struct iphdr *iph = (struct iphdr *)Buffer;
iphdrlen = iph->ihl*4;

struct udphdr *udph = (struct udphdr*)(Buffer + iphdrlen);

fprintf(logfile,"\n\n***********************UDP Packet*************************\n");

print_ip_header(Buffer,Size);

fprintf(logfile,"\nUDP Header\n");
fprintf(logfile,"   |-Source Port      : %d\n" , ntohs(udph->source));
fprintf(logfile,"   |-Destination Port : %d\n" , ntohs(udph->dest));
fprintf(logfile,"   |-UDP Length       : %d\n" , ntohs(udph->len));
fprintf(logfile,"   |-UDP Checksum     : %d\n" , ntohs(udph->check));

fprintf(logfile,"\n");
fprintf(logfile,"IP Header\n");
PrintData(Buffer , iphdrlen);

fprintf(logfile,"UDP Header\n");
PrintData(Buffer+iphdrlen , sizeof udph);

fprintf(logfile,"Data Payload\n");
PrintData(Buffer + iphdrlen + sizeof udph ,( Size - sizeof udph - iph->ihl * 4 ));

fprintf(logfile,"\n###########################################################");
}

void print_icmp_packet(unsigned char* Buffer , int Size)
{
unsigned short iphdrlen;

struct iphdr *iph = (struct iphdr *)Buffer;
iphdrlen = iph->ihl*4;

struct icmphdr *icmph = (struct icmphdr *)(Buffer + iphdrlen);

fprintf(logfile,"\n\n***********************ICMP Packet*************************\n");

print_ip_header(Buffer , Size);

fprintf(logfile,"\n");

fprintf(logfile,"ICMP Header\n");
fprintf(logfile,"   |-Type : %d",(unsigned int)(icmph->type));

if((unsigned int)(icmph->type) == 11)
fprintf(logfile,"  (TTL Expired)\n");
else if((unsigned int)(icmph->type) == ICMP_ECHOREPLY)
fprintf(logfile,"  (ICMP Echo Reply)\n");
fprintf(logfile,"   |-Code : %d\n",(unsigned int)(icmph->code));
fprintf(logfile,"   |-Checksum : %d\n",ntohs(icmph->checksum));
//fprintf(logfile,"   |-ID       : %d\n",ntohs(icmph->id));
//fprintf(logfile,"   |-Sequence : %d\n",ntohs(icmph->sequence));
fprintf(logfile,"\n");

fprintf(logfile,"IP Header\n");
PrintData(Buffer,iphdrlen);

fprintf(logfile,"UDP Header\n");
PrintData(Buffer + iphdrlen , sizeof icmph);

fprintf(logfile,"Data Payload\n");
PrintData(Buffer + iphdrlen + sizeof icmph , (Size - sizeof icmph - iph->ihl * 4));

fprintf(logfile,"\n###########################################################");
}

void PrintData (unsigned char* data , int Size)
{

for(i=0 ; i < Size ; i++)
{
if( i!=0 && i%16==0)   //if one line of hex printing is complete...
{
fprintf(logfile,"         ");
for(j=i-16 ; j<i ; j++)
{
if(data[j]>=32 && data[j]<=128)
fprintf(logfile,"%c",(unsigned char)data[j]); //if its a number or alphabet

else fprintf(logfile,"."); //otherwise print a dot
}
fprintf(logfile,"\n");
}

if(i%16==0) fprintf(logfile,"   ");
fprintf(logfile," %02X",(unsigned int)data[i]);

if( i==Size-1)  //print the last spaces
{
for(j=0;j<15-i%16;j++) fprintf(logfile,"   "); //extra spaces

fprintf(logfile,"         ");

for(j=i-i%16 ; j<=i ; j++)
{
if(data[j]>=32 && data[j]<=128) fprintf(logfile,"%c",(unsigned char)data[j]);
else fprintf(logfile,".");
}
fprintf(logfile,"\n");
}
}
}

***********************TCP Packet*************************

IP Header
|-IP Version        : 4
|-IP Header Length  : 5 DWORDS or 20 Bytes
|-Type Of Service   : 0
|-IP Total Length   : 129  Bytes(Size of Packet)
|-Identification    : 7322
|-TTL      : 51
|-Protocol : 6
|-Checksum : 11872
|-Source IP        : 107.224.156.181
|-Destination IP   : 10.85.23.12

TCP Header
|-Source Port      : 44
|-Destination Port : 51139
|-Sequence Number    : 2867594165
|-Acknowledge Number : 3874566180
|-Header Length      : 8 DWORDS or 32 BYTES
|-Urgent Flag          : 0
|-Acknowledgement Flag : 1
|-Push Flag            : 1
|-Reset Flag           : 0
|-Synchronise Flag     : 0
|-Finish Flag          : 0
|-Window         : 151
|-Checksum       : 38077
|-Urgent Pointer : 0

DATA Dump
IP Header
45 00 00 81 1C 9A 40 00 33 06 2E 60 68 E0 9C B5         E.....@.3..`h...
0A 55 EC 92                                             .U..
TCP Header
01 BB C7 C3 AA EC 03 B5 E6 F1 30 24 80 18 00 97         ..........0$€...
94 BD 00 00 01 01 08 0A 93 2C E2 18 00 A8 A8 AB         .........,......
Data Payload
47 CA D2 84 49 64 01 1F 2C 26 5D 3E 58 44 00 82         G...Id..,&]>XD..
19 BD DA 27 FB 54 C1 2A 7C 3A 6B 19 87 D2 06 36         ...'.T.*|:k....6
86 B3 0D 70 A0 63 C2 F4 D7 6F E1 CE 2B F2 AC D6         ...p.c...o..+...
F0 FE DB 6C CD DE 17 B9 AD A7 52 8A D0 A9 AB 64         ...l......R....d
7C 4B 42 92 BC 9B A7 E7 B4 5D 30 82 0A                  |KB......]0..

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