commit 03328ec8bb86b93fa70bb6b2a9b37c40e686a1f7
author Steven Luong <sluong@cisco.com> Mon Jan 27 10:37:56 2020 -0800
committer Damjan Marion <dmarion@me.com> Mon Jan 27 20:42:43 2020 +0000
tree b7ab5d60102a8127fad4bbf44027332791a45fd8
parent 14053c9dbd75182f5302f7388d17508f3930f7ce

interface: Add missing ip4 udp->checksum = 0 prior to computing checksum

For ip4 tcp, ip6 tcp, and ip6 udp packet, we set checksum = 0 prior to
computing the checksum. We missed ip4 udp case. This oversight requires all
clients to set udp->checksum = 0 if ip4 udp checksum offload is needed.

Type: fix

Signed-off-by: Steven Luong <sluong@cisco.com>
Change-Id: Ic608811e82099f3bec469e123671e9b281f38d76

src/vnet/interface_output.c

diff --git a/src/vnet/interface_output.c b/src/vnet/interface_output.c
index 73c7a31..eadee69 100644
--- a/src/vnet/interface_output.c
+++ b/src/vnet/interface_output.c
@@ -189,7 +189,10 @@
 	  th->checksum = ip4_tcp_udp_compute_checksum (vm, b, ip4);
 	}
       else if (b->flags & VNET_BUFFER_F_OFFLOAD_UDP_CKSUM)
-	uh->checksum = ip4_tcp_udp_compute_checksum (vm, b, ip4);
+	{
+	  uh->checksum = 0;
+	  uh->checksum = ip4_tcp_udp_compute_checksum (vm, b, ip4);
+	}
     }
   else if (is_ip6)
     {