From 5b5249a5d63428e20c8e9f35eee3fa4cd2a965c7 Mon Sep 17 00:00:00 2001
From: hidnplayr <hidnplayr@kolibrios.org>
Date: Tue, 30 May 2017 20:33:16 +0000
Subject: [PATCH] TCP: Don't increase sequence number when resending a FIN.

git-svn-id: svn://kolibrios.org@6914 a494cfbc-eb01-0410-851d-a64ba20cac60
---
 kernel/trunk/network/tcp_output.inc | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/kernel/trunk/network/tcp_output.inc b/kernel/trunk/network/tcp_output.inc
index 390f57d1f9..7a5332aa96 100644
--- a/kernel/trunk/network/tcp_output.inc
+++ b/kernel/trunk/network/tcp_output.inc
@@ -312,8 +312,7 @@ endl
         call    mutex_unlock
         popa
 
-; Fixme: returnvalue?
-
+        xor     eax, eax
         ret
 
 
@@ -465,6 +464,23 @@ endl
 
   .eos:
 
+;---------------------------------------------------
+; Dont increase sequence number when resending a FIN
+
+        test    dl, TH_FIN
+        jz      .no_fin_retransmit
+
+        test    [eax + TCP_SOCKET.t_flags], TF_SENTFIN
+        jz      .no_fin_retransmit
+
+        mov     ebx, [eax + TCP_SOCKET.SND_NXT]
+        cmp     ebx, [eax + TCP_SOCKET.SND_MAX]
+        jne     .no_fin_retransmit
+
+        dec     [eax + TCP_SOCKET.SND_NXT]
+
+  .no_fin_retransmit:
+
 ;----------------------------------------------------
 ; Calculate the receive window.
 ; Dont shrink window, but avoid silly window syndrome