*** ip.c	Mon May 23 01:17:48 1994
--- /usr/src/linux/net/inet/ip.c	Wed May 25 21:19:46 1994
***************
*** 177,182 ****
--- 177,183 ----
  	return mac;
  }
  
+ int ip_id_count = 0;
  
  /*
   * This routine builds the appropriate hardware/IP headers for
***************
*** 192,198 ****
    	struct rtable *rt;
    	unsigned char *buff;
    	unsigned long raddr;
-   	static int count = 0;
    	int tmp;
    	unsigned long src;
  
--- 193,198 ----
***************
*** 295,302 ****
  	iph->saddr    = saddr;
  	iph->protocol = type;
  	iph->ihl      = 5;
! 	iph->id       = htons(count++);
! 
  	/* Setup the IP options. */
  #ifdef Not_Yet_Avail
  	build_options(iph, opt);
--- 295,301 ----
  	iph->saddr    = saddr;
  	iph->protocol = type;
  	iph->ihl      = 5;
!   
  	/* Setup the IP options. */
  #ifdef Not_Yet_Avail
  	build_options(iph, opt);
***************
*** 1683,1688 ****
--- 1682,1688 ----
  	iph = (struct iphdr *)ptr;
  	skb->ip_hdr = iph;
  	iph->tot_len = ntohs(skb->len-dev->hard_header_len);
+ 	iph->id      = htons(ip_id_count++);
  
  	/*
  	 *	Do we need to fragment. Again this is inefficient. 
***************
*** 1834,1839 ****
--- 1834,1866 ----
  		}
  #endif
  		skb->when = jiffies;
+ 
+ 		/* 
+ 		 * In general it's OK just to use the old packet.  However we
+ 		 * need to use the current ack and window fields.  Urg and 
+ 		 * urg_ptr could possibly stand to be updated as well, but we 
+ 		 * don't keep the necessary data.  That shouldn't be a problem,
+ 		 * if the other end is doing the right thing.  Since we're 
+ 		 * changing the packet, we have to issue a new IP identifier.
+ 		 */
+ 
+ 		/* this check may be unnecessary - retransmit only for TCP */
+ 		if (sk->protocol == IPPROTO_TCP) {
+ 		  struct tcphdr *th;
+ 		  struct iphdr *iph;
+ 		  int size;
+ 
+ 		  iph = (struct iphdr *)(skb->data + dev->hard_header_len);
+ 		  th = (struct tcphdr *)(((char *)iph) + (iph->ihl << 2));
+ 		  size = skb->len - (((unsigned char *) th) - skb->data);
+ 
+ 		  iph->id = htons(ip_id_count++);
+ 		  ip_send_check(iph);
+ 
+ 		  th->ack_seq = ntohl(sk->acked_seq);
+ 		  th->window = ntohs(tcp_select_window(sk));
+ 		  tcp_send_check(th, sk->saddr, sk->daddr, size, sk);
+ 		}
  
  		/* 
  		 *	If the interface is (still) up and running, kick it.