From 3ffbdffd7e96e406fd3136818e0402cf0c2f0d4d Mon Sep 17 00:00:00 2001
From: gVisor bot <gvisor-bot@google.com>
Date: Mon, 19 Aug 2019 12:41:48 -0700
Subject: [PATCH] Internal change.

PiperOrigin-RevId: 264218306
---
 pkg/tcpip/link/sniffer/sniffer.go | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/pkg/tcpip/link/sniffer/sniffer.go b/pkg/tcpip/link/sniffer/sniffer.go
index fc584c6a4..36c8c46fc 100644
--- a/pkg/tcpip/link/sniffer/sniffer.go
+++ b/pkg/tcpip/link/sniffer/sniffer.go
@@ -360,10 +360,9 @@ func logPacket(prefix string, protocol tcpip.NetworkProtocolNumber, b buffer.Vie
 		if fragmentOffset == 0 && len(udp) >= header.UDPMinimumSize {
 			srcPort = udp.SourcePort()
 			dstPort = udp.DestinationPort()
+			details = fmt.Sprintf("xsum: 0x%x", udp.Checksum())
+			size -= header.UDPMinimumSize
 		}
-		size -= header.UDPMinimumSize
-
-		details = fmt.Sprintf("xsum: 0x%x", udp.Checksum())
 
 	case header.TCPProtocolNumber:
 		transName = "tcp"