From: Alex Williamson <alex.williamson@redhat.com>
Date: Fri, 5 Nov 2010 20:52:08 +0000 (-0600)
Subject: e1000: Fix TCP checksum overflow with TSO
X-Git-Tag: TizenStudio_2.0_p2.3~3861^2~28
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=449648944ec063c008f90dcfeb529f3932469161;p=sdk%2Femulator%2Fqemu.git

e1000: Fix TCP checksum overflow with TSO

When adding the length to the pseudo header, we're not properly
accounting for overflow.

From: Mark Wu <dwu@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---

diff --git a/hw/e1000.c b/hw/e1000.c
index 532efdc..677165f 100644
--- a/hw/e1000.c
+++ b/hw/e1000.c
@@ -384,9 +384,12 @@ xmit_seg(E1000State *s)
         } else	// UDP
             cpu_to_be16wu((uint16_t *)(tp->data+css+4), len);
         if (tp->sum_needed & E1000_TXD_POPTS_TXSM) {
+            unsigned int phsum;
             // add pseudo-header length before checksum calculation
             sp = (uint16_t *)(tp->data + tp->tucso);
-            cpu_to_be16wu(sp, be16_to_cpup(sp) + len);
+            phsum = be16_to_cpup(sp) + len;
+            phsum = (phsum >> 16) + (phsum & 0xffff);
+            cpu_to_be16wu(sp, phsum);
         }
         tp->tso_frames++;
     }