/*
 *  T.c
 *
 *  compile: gcc -Wall T.c -o T -lipq
 */
 
#include <netinet/in.h>
#include <libipq.h>
#include <linux/netfilter.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <netinet/ip.h>
#include <netinet/udp.h>
#include <netinet/tcp.h>
 
#define BUFSIZE 65536
 
 
 
 
static void die(struct ipq_handle *h) {
     
    ipq_perror("passer");
    ipq_destroy_handle(h);
     
}
 
 
void start_packet_engine() {
    
        int status;
    unsigned char buf[BUFSIZE];
    struct ipq_handle *h;
 
     
    printf("\nWaiting for packets\n");
     
 
    h = ipq_create_handle(0, PF_INET);
     
    if (!h)
        die(h);
     
     
    status = ipq_set_mode(h, IPQ_COPY_PACKET, BUFSIZE);
     
    if (status < 0)
        die(h);
     
     
    do {
        status = ipq_read(h, buf, BUFSIZE, 0);
        if (status < 0)
            die(h);
         
         
        switch (ipq_message_type(buf)) {
             
            case NLMSG_ERROR: {
                fprintf(stderr, "Received error message %d\n",
                ipq_get_msgerr(buf));
                break;
            }
          case IPQM_PACKET:
 {
  ipq_packet_msg_t *m = ipq_get_packet(buf);
   
  
  status = ipq_set_verdict(h, m->packet_id,NF_ACCEPT, 0, NULL);
     
  break;
     }
    }
 
               
        
    }
    while (1);
     
    printf("Engine Stopped...\n");
     
    ipq_destroy_handle(h);
     
}
 
int main() {
    start_packet_engine();
    return 0;
}