raw socket[linux]

Ponizszy kod ma za zadanie budowac pakiet eth+ip+tcp lecz niestety naglowek eth nie jest dodawany.
Czekam na wasze propozycje co do poprawy tego zrodla.

#define __USE_BSD	/* use bsd'ish ip header */
#include <sys/socket.h>	/* these headers are for a Linux system, but */
#include <netinet/in.h>	/* the names on other systems are easy to guess.. */
#include <netinet/ip.h>
#include <net/ethernet.h>
#define __FAVOR_BSD	/* use bsd'ish tcp header */
#include <netinet/tcp.h>
#include <unistd.h>
 
#define P 25		/* lets flood the sendmail port */
 
unsigned short		/* this function generates header checksums */
csum (unsigned short *buf, int nwords)
{
  unsigned long sum;
  for (sum = 0; nwords > 0; nwords--)
    sum += *buf++;
  sum = (sum >> 16) + (sum & 0xffff);
  sum += (sum >> 16);
  return ~sum;
}
 
int main (void)
{
  int s = socket (PF_INET, SOCK_RAW, htons(ETH_P_ALL));	
  int packetsize = sizeof(struct ether_header) + sizeof(struct iphdr) + sizeof(struct tcphdr);
  char datagram[packetsize];
  struct ether_header *eth = (struct ether_header *) datagram;
  struct ip *iph = (struct ip*) (datagram + sizeof(struct ether_header));
  struct tcphdr *tcph = (struct tcphdr*) 
  (datagram + sizeof(struct ether_header) +sizeof(struct ip));
 
  struct sockaddr_in sin;			
  sin.sin_family = AF_INET;
  sin.sin_port = htons (P);
  sin.sin_addr.s_addr = inet_addr ("2.2.2.2");
 
  memset (datagram, 0, packetsize);	
  char smac[]="11:11:11:11:11:11";
  char dmac[]="22:22:22:22:22:22";
 
  memcpy(eth->ether_dhost,(u_char *)ether_aton(dmac),ETH_ALEN); // Destination MAC
  memcpy(eth->ether_shost,(u_char *)ether_aton(smac),ETH_ALEN); // Source MAC
  eth->ether_type = htons(ETHERTYPE_IP); // IP Protokoll
 
  iph->ip_hl = 5;
  iph->ip_v = 4;
  iph->ip_tos = 0;
  iph->ip_len = sizeof(struct ether_header)+sizeof (struct ip) + sizeof (struct tcphdr);	
  iph->ip_id = htonl (54321);	
  iph->ip_off = 0;
  iph->ip_ttl = 255;
  iph->ip_p = 6;
  iph->ip_sum = 0;		
  iph->ip_src.s_addr = inet_addr ("1.1.1.1"); 
  iph->ip_dst.s_addr = sin.sin_addr.s_addr;
 
  tcph->th_sport = htons (1234);	
  tcph->th_dport = htons (P);
  tcph->th_seq = random ();
  tcph->th_ack = 0;
  tcph->th_x2 = 0;
  tcph->th_off = 0;		
  tcph->th_flags = TH_SYN;	
  tcph->th_win = htonl (65535);	
  tcph->th_sum = 0;
 
  tcph->th_urp = 0;
 
  iph->ip_sum = csum ((unsigned short *) datagram, iph->ip_len >> 1);
 
 
  {				
    int one = 1;
    const int *val = &one;
    if (setsockopt (s, IPPROTO_IP, IP_HDRINCL, val, sizeof (one)) < 0)
      printf ("Warning: Cannot set HDRINCL!\n");
  }
 
 
      if (sendto (s,		
		  datagram,	
		  iph->ip_len,	
		  0,		
		  (struct sockaddr *) &sin,	
		  sizeof (sin)) < 0)		
	printf ("error\n");
      else
	printf ("WYSLALEM \n");
 
 
  return 0;
}