svn commit: r190982 - head/sys/dev/fxp

[Pyun YongHyeon]

Author: yongari
Date: Mon Apr 13 00:32:34 2009
New Revision: 190982
URL: http://svn.freebsd.org/changeset/base/190982

Log:
  Don't blindly set IP packet length from interface MTU in TSO case.
  Remote host can advertise smaller MSS than that of sender so upper
  stack might have adjusted the MSS which in turn generates IP
  packets that are less size than that of interface MTU.
  
  Reported by:	Bjoern Koenig ( bkoenig <> alpha-tierchen dot de )
  Tested by:	Bjoern Koenig ( bkoenig <> alpha-tierchen dot de )
  MFC after:	3 days

Modified:
  head/sys/dev/fxp/if_fxp.c

Modified: head/sys/dev/fxp/if_fxp.c
==============================================================================
--- head/sys/dev/fxp/if_fxp.c	Sun Apr 12 23:10:01 2009	(r190981)
+++ head/sys/dev/fxp/if_fxp.c	Mon Apr 13 00:32:34 2009	(r190982)
@@ -1485,7 +1485,8 @@ fxp_encap(struct fxp_softc *sc, struct m
 		 * checksum in the first frame driver should compute it.
 		 */
 		ip->ip_sum = 0;
-		ip->ip_len = htons(ifp->if_mtu);
+		ip->ip_len = htons(m->m_pkthdr.tso_segsz + (ip->ip_hl << 2) +
+		    (tcp->th_off << 2));
 		tcp->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
 		    htons(IPPROTO_TCP + (tcp->th_off << 2) +
 		    m->m_pkthdr.tso_segsz));