From 3aaac55a7ac3bcafb229c171936f6d1e5c252158 Mon Sep 17 00:00:00 2001
From: Avi Kivity <avi@cloudius-systems.com>
Date: Sun, 1 Mar 2015 18:45:35 +0200
Subject: [PATCH] tcp: fix bad checksum on RST packets

We neglected to set offload_info::needs_csum on reset packets, resuling in
them being ignored by the recipient.  Symptoms include connection attempts
to closed ports (seastar = passive end) hanging instead the active end
understanding the port is closed.
---
 net/tcp.hh | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/tcp.hh b/net/tcp.hh
index 188acb6d5b..1cd31395b1 100644
--- a/net/tcp.hh
+++ b/net/tcp.hh
@@ -806,15 +806,17 @@ void tcp<InetTraits>::respond_with_reset(tcp_hdr* rth, ipaddr local_ip, ipaddr f
     *th = hton(*th);
 
     checksummer csum;
+    offload_info oi;
     InetTraits::tcp_pseudo_header_checksum(csum, local_ip, foreign_ip, sizeof(*th));
     if (hw_features().tx_csum_l4_offload) {
         th->checksum = ~csum.get();
+        oi.needs_csum = true;
     } else {
         csum.sum(p);
         th->checksum = csum.get();
+        oi.needs_csum = false;
     }
 
-    offload_info oi;
     oi.protocol = ip_protocol_num::tcp;
     oi.tcp_hdr_len = sizeof(tcp_hdr);
     p.set_offload_info(oi);