[src/netbsd-3]: src/sys/netinet Pull up revision 1.150 (requested by yamt in ...

[tron <tron%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/4688e20fa0b7
branches:  netbsd-3
changeset: 575362:4688e20fa0b7
user:      tron <tron%NetBSD.org@localhost>
date:      Wed Apr 13 21:34:51 2005 +0000

description:
Pull up revision 1.150 (requested by yamt in ticket #145):
when doing TSO, avoid to use duplicated ip_id heavily.
XXX ip_randomid

diffstat:

 sys/netinet/ip_output.c |  25 ++++++++++++++++++++++---
 1 files changed, 22 insertions(+), 3 deletions(-)

diffs (46 lines):

diff -r 7325acec4a14 -r 4688e20fa0b7 sys/netinet/ip_output.c
--- a/sys/netinet/ip_output.c   Wed Apr 13 21:33:35 2005 +0000
+++ b/sys/netinet/ip_output.c   Wed Apr 13 21:34:51 2005 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ip_output.c,v 1.149 2005/03/11 17:07:51 matt Exp $     */
+/*     $NetBSD: ip_output.c,v 1.149.2.1 2005/04/13 21:34:51 tron Exp $ */
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -98,7 +98,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ip_output.c,v 1.149 2005/03/11 17:07:51 matt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ip_output.c,v 1.149.2.1 2005/04/13 21:34:51 tron Exp $");
 
 #include "opt_pfil_hooks.h"
 #include "opt_inet.h"
@@ -235,7 +235,26 @@
        if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) {
                ip->ip_v = IPVERSION;
                ip->ip_off = htons(0);
-               ip->ip_id = ip_newid();
+               if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) {
+                       ip->ip_id = ip_newid();
+               } else {
+
+                       /*
+                        * TSO capable interfaces (typically?) increment
+                        * ip_id for each segment.
+                        * "allocate" enough ids here to increase the chance
+                        * for them to be unique.
+                        *
+                        * note that the following calculation is not
+                        * needed to be precise.  wasting some ip_id is fine.
+                        */
+
+                       unsigned int segsz = m->m_pkthdr.segsz;
+                       unsigned int datasz = ntohs(ip->ip_len) - hlen;
+                       unsigned int num = howmany(datasz, segsz);
+
+                       ip->ip_id = ip_newid_range(num);
+               }
                ip->ip_hl = hlen >> 2;
                ipstat.ips_localout++;
        } else {