* Check for ip_id zero senders and low cost update of zero ip_id.

This commit is contained in:
bg- 2007-02-01 14:35:23 +00:00
parent f96f17f629
commit 6690d7ca8f

View file

@ -28,7 +28,7 @@
*
* This file is part of the uIP TCP/IP stack.
*
* $Id: tunslip.c,v 1.8 2007/01/23 12:33:42 bg- Exp $
* $Id: tunslip.c,v 1.9 2007/02/01 14:35:23 bg- Exp $
*
*/
@ -630,10 +630,13 @@ write_to_serial(int outfd, void *inbuf, int len)
return;
}
if (iphdr->ip_id == 0) {
iphdr->ip_id = htons(ip_id++);
iphdr->ip_sum = 0;
iphdr->ip_sum = ~htons(ip4sum(0, iphdr, 20));
if (iphdr->ip_id == 0 && iphdr->ip_off & IP_DF) {
uint16_t nid = htons(ip_id++);
iphdr->ip_id = nid;
nid = ~nid; /* negate */
iphdr->ip_sum += nid; /* add */
if (iphdr->ip_sum < nid) /* 1-complement overflow? */
iphdr->ip_sum++;
ecode = check_ip(inbuf, len);
if(ecode < 0) {
fprintf(stderr, "tun_to_serial: drop packet %d\n", ecode);