From cb0ce956b9c3b6e274aa6154ad55010f2b098b09 Mon Sep 17 00:00:00 2001
From: Russ Magee <rmagee@gmail.com>
Date: Sun, 25 Mar 2018 23:00:37 -0700
Subject: [PATCH] Server-side client hangup working; TODO - client-side
 handling of post-exit EOF (broken pipe)

---
 hkexnet.go | 30 +++++++++++++++++++++---------
 1 file changed, 21 insertions(+), 9 deletions(-)

diff --git a/hkexnet.go b/hkexnet.go
index 61943db..b74407e 100644
--- a/hkexnet.go
+++ b/hkexnet.go
@@ -300,6 +300,7 @@ func (hl HKExListener) Accept() (hc Conn, err error) {
 func (c Conn) Read(b []byte) (n int, err error) {
 	//log.Printf("[Decrypting...]\r\n")
 	log.Printf("Read() requests %d bytes\n", len(b))
+
 	for {
 		//log.Printf("c.dBuf.Len(): %d\n", c.dBuf.Len())
 		if c.dBuf.Len() > 0 /* len(b) */ {
@@ -311,21 +312,32 @@ func (c Conn) Read(b []byte) (n int, err error) {
 
 		// Read the hmac LSB and payload len first
 		err = binary.Read(c.c, binary.BigEndian, &hmacIn)
-		if err != nil {
-			if err.Error() != "EOF" {
-				log.Println("Error was:", err.Error())
+		// Normal client 'exit' from interactive session will cause
+		// (on server side) err.Error() == "<iface/addr info ...>: use of closed network connection"
+		if err != nil && err.Error() != "EOF" {
+			if !strings.HasSuffix(err.Error(), "use of closed network connection") {
+				log.Println("unexpected Read() err:", err)
 			} else {
-				return 0, err
+				log.Println("[Client hung up]")
+				return 0, io.EOF
 			}
 		}
 
+		//if err != nil {
+		//	if err.Error() != "EOF" {
+		//		log.Println("Error was:", err.Error())
+		//	} else {
+		//		return 0, err
+		//	}
+		//}
+
 		err = binary.Read(c.c, binary.BigEndian, &payloadLen)
 		if err != nil {
-			//			if err.Error() != "EOF" {
-			panic(err)
-			//			} else {
-			//				return 0, err
-			//			}
+			if err.Error() != "EOF" {
+				panic(err)
+			} // else {
+			//	return 0, err
+			//}
 		}
 		if payloadLen > 16384 {
 			panic("Insane payloadLen")