/* gcc -Wall -pedantic af.c -lpcap -o af */

#include "waf.h"

u_int16_t handle_ethernet(u_char *args,const struct pcap_pkthdr* pkthdr,const u_char* packet);
u_char* handle_IP(u_char *args,const struct pcap_pkthdr* pkthdr,const u_char* packet);

void errsys(char msg[50])
{

/*syslog(LOG_ERR,msg);*/
printf("msg");
}

void my_callback(u_char *args,const struct pcap_pkthdr* pkthdr,const u_char* packet)
{
    u_int16_t type = handle_ethernet(args,pkthdr,packet);

    if(type == ETHERTYPE_IP)
    {/* handle IP packet */
        handle_IP(args,pkthdr,packet);
    }else if(type == ETHERTYPE_ARP)
    {/* handle arp packet */
    }
    else if(type == ETHERTYPE_REVARP)
    {/* handle reverse arp packet */
    }
}

u_char* handle_IP (u_char *args,const struct pcap_pkthdr* pkthdr,const u_char* packet)
{
    const struct my_ip* ip;
    u_int length = pkthdr->len;
    u_int hlen,off,version;
    unsigned long int ipb,ipx;
    int len;
    int is,id,i,gasit;
    /* jump pass the ethernet header */
    ip = (struct my_ip*)(packet + sizeof(struct ether_header));
    length -= sizeof(struct ether_header); 

    /* check to see we have a packet of valid length */
    if (length < sizeof(struct my_ip))
    {
        printf("truncated ip %d",length);
        return NULL;
    }

    len     = ntohs(ip->ip_len);
    hlen    = IP_HL(ip); /* header length */
    version = IP_V(ip);/* ip version */

/*     if(((ip->ip_src.s_addr)!=locip) && ((ip->ip_dst.s_addr)!=locip))*/
/*  Aici se pune numaratoarea */
}

/* handle ethernet packets, much of this code gleaned from
 * print-ether.c from tcpdump source
 */
u_int16_t handle_ethernet(u_char *args,const struct pcap_pkthdr* pkthdr,const u_char* packet)
{
    u_int caplen = pkthdr->caplen;
/*    u_int length = pkthdr->len;*/
    struct ether_header *eptr;  /* net/ethernet.h */
    u_short ether_type;

    if (caplen < ETHER_HDRLEN)
    {
        fprintf(stdout,"Packet length less than ethernet header length\n");
        return -1;
    }

    /* lets start with the ether header... */
    eptr = (struct ether_header *) packet;
    ether_type = ntohs(eptr->ether_type);

    /* Lets print SOURCE DEST TYPE LENGTH */
  /*fprintf(stdout,"ETH: ");
    fprintf(stdout,"%s ",ether_ntoa((struct ether_addr*)eptr->ether_shost));
    fprintf(stdout,"%s ",ether_ntoa((struct ether_addr*)eptr->ether_dhost));
 */
    /* check to see if we have an ip packet */
    if (ether_type == ETHERTYPE_IP)
    {
/*        fprintf(stdout,"(IP)");*/
    }else  if (ether_type == ETHERTYPE_ARP)
    {
/*        fprintf(stdout,"(ARP)");*/
    }else  if (eptr->ether_type == ETHERTYPE_REVARP)
    {
  /*      fprintf(stdout,"(RARP)");*/
    }else {
      /*  fprintf(stdout,"(?)");*/
    }
/*    fprintf(stdout," %d\n",length);*/

    return ether_type;
}

int main(int argc,char *argv[])
{ 
    char *dev; 
    char errbuf[PCAP_ERRBUF_SIZE];
    pcap_t* descr;
    struct bpf_program fp;      /* hold compiled program     */
    bpf_u_int32 maskp;          /* subnet mask               */
    bpf_u_int32 netp;           /* ip                        */
    u_char* args = NULL;
    int k,j;
    struct in_addr adrc;
    struct itimerval del;
    pid_t pid, sid;
    char *pcap_filter;
    struct bpf_program filter;

    
    dev = pcap_lookupdev(errbuf); 
    strcpy(dev,DEVICE);
    if((pcap_filter = (char *) malloc(200)) == NULL)
                printf("malloc error");
    memset(pcap_filter, 0, 200);
    strcat(pcap_filter, argv[1]);
    printf("%s",pcap_filter);    
    if(dev == NULL)
    { printf("zero%s\n",errbuf); exit(1); }

    /* ask pcap for the network address and mask of the device */
    pcap_lookupnet(dev,&netp,&maskp,errbuf);

    /* open device for reading. NOTE: defaulting to
     * promiscuous mode*/
    descr = pcap_open_live(dev,BUFSIZ,0,0,errbuf);
    if(descr == NULL)
    { printf("pcap_open_live(): qqqqqqqqqq%s\n",errbuf); exit(1); }

    if (pcap_compile(descr, &filter, pcap_filter, 0, netp) < 0)
        error("unu%s", pcap_geterr(descr));
                    
    if (pcap_setfilter(descr, &filter) < 0)
       error("doi%s", pcap_geterr(descr));
                                                    
                                                    

/*    fprintf(stdout,"IP src,  Ip dst,  len, proto\n" );*/
    /* ... and loop */ 
/*
    pcap_loop(descr,-1,my_callback,args);
*/
                                                         
    return 0;
}