سورس pocket Sniffer

سورس یک برنامه Pocket Sniffer

#include <stdio.h>
#include <string.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
int main(int argc, char *argv[])

    {
    int s, bytes,a=0,sy=0,f=0,r=0,u=0,p=0;
     int ac=0,syc=0,fc=0,rc=0;
    struct tcphdr *tcp;
    struct iphdr*ip;
    struct in_addr addr;
    charbuffer[4000];
    s = socket(AF_INET, SOCK_RAW, IPPROTO_TCP);
    if (s == -1)

        {
        perror("socket() failed");
        return 1;
    }

    ip = (struct iphdr*) buffer;
    tcp = (struct tcphdr*) (buffer + sizeof(struct iphdr));
    while( (bytes = recv(s, buffer, sizeof(buffer), 0)) > 0)

        {
        addr.s_addr = ip->saddr;
         a=ntohs(tcp->ack);
         sy=ntohs(tcp->syn);
         r=ntohs(tcp->rst);
         f=ntohs(tcp->fin);
         p=ntohs(tcp->psh);
         u=ntohs(tcp->urg);
         if (ip->saddr!=inet_addr("192.168.0.113"))
         {
         printf("Packet from source:%s\nwith flags ->",inet_ntoa(addr));
         if(a==256)

             {
             printf("Ack ");
             }
             if ( sy==256)
             {printf("Syn ");
             ;}
             if (f==256)

                 {
                 printf("Fin ");
                 }
                 if (r==256)

                     {
                     printf("Rst ");
                     }
                     if (p==256)

                         {
                         printf("Psh ");
                         }
                         if (u==256)

                             {
                             printf("Urg");
                             }
                             printf("\n");
                             printf("With the sequence number of ->%i\n",ntohl(tcp->seq));
                             printf("From port->%i\n\n",ntohs(tcp->source));
                             }
                        }

                        if (bytes == -1)

                            {
                            perror("recv() failed");
                            return 2;
                        }

                        return 0;
                         
                    }