From aba76787a56f5c6594b548dc950beefeef2f306c Mon Sep 17 00:00:00 2001
From: xtaci <daniel820313@gmail.com>
Date: Tue, 11 Jun 2019 15:27:26 +0800
Subject: [PATCH] bug fix

---
 sess.go     | 5 +++--
 tx_linux.go | 4 ++--
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/sess.go b/sess.go
index ba049b1..8f163fb 100644
--- a/sess.go
+++ b/sess.go
@@ -104,8 +104,9 @@ type (
 		nonce Entropy
 
 		// packets waiting to be sent on wire
-		txqueue []ipv4.Message
-		xconn   batchConn // for x/net
+		txqueue         []ipv4.Message
+		xconn           batchConn // for x/net
+		xconnWriteError error
 
 		mu sync.Mutex
 	}
diff --git a/tx_linux.go b/tx_linux.go
index e609aac..b61d77c 100644
--- a/tx_linux.go
+++ b/tx_linux.go
@@ -13,7 +13,7 @@ import (
 
 func (s *UDPSession) tx(txqueue []ipv4.Message) {
 	// default version
-	if s.xconn == nil {
+	if s.xconn == nil || s.xconnWriteError != nil {
 		s.defaultTx(txqueue)
 		return
 	}
@@ -36,7 +36,7 @@ func (s *UDPSession) tx(txqueue []ipv4.Message) {
 			if operr, ok := err.(*net.OpError); ok {
 				if se, ok := operr.Err.(*os.SyscallError); ok {
 					if se.Syscall == "sendmmsg" {
-						s.xconn = nil // set s.xconn to nil permanently
+						s.xconnWriteError = se
 						s.defaultTx(txqueue)
 						return
 					}