From a423831f25396c54f92cdfc6f92a104ed77c2ee6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Lyson=C4=9Bk?= <olysonek@redhat.com>
Date: Fri, 24 Nov 2017 11:26:37 +0100
Subject: [PATCH] Improve documentation of ascii_* options

Resolves: rhbz#1517227
---
 vsftpd.conf   |  3 ++-
 vsftpd.conf.5 | 20 ++++++++++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/vsftpd.conf b/vsftpd.conf
index 39d1955..acbc1e9 100644
--- a/vsftpd.conf
+++ b/vsftpd.conf
@@ -73,7 +73,8 @@ xferlog_std_format=YES
 #
 # By default the server will pretend to allow ASCII mode but in fact ignore
 # the request. Turn on the below options to have the server actually do ASCII
-# mangling on files when in ASCII mode.
+# mangling on files when in ASCII mode. The vsftpd.conf(5) man page explains
+# the behaviour when these options are disabled.
 # Beware that on some FTP servers, ASCII support allows a denial of service
 # attack (DoS) via the command "SIZE /big/file" in ASCII mode. vsftpd
 # predicted this attack and has always been safe, reporting the size of the
diff --git a/vsftpd.conf.5 b/vsftpd.conf.5
index d1f0db5..b6ddf05 100644
--- a/vsftpd.conf.5
+++ b/vsftpd.conf.5
@@ -113,11 +113,31 @@ Default: YES
 .TP
 .B ascii_download_enable
 When enabled, ASCII mode data transfers will be honoured on downloads.
+When disabled, the server will pretend to allow ASCII mode but in fact
+ignore requests to activate it. So the client will think the ASCII mode
+is active and therefore may still translate any
+.BR <CRLF>
+character sequences in the received file. See the following article for
+a detailed explanation of the behaviour:
+https://access.redhat.com/articles/3250241.
+
+Turn this option on to have the server actually do
+ASCII mangling on files when in ASCII mode.
 
 Default: NO
 .TP
 .B ascii_upload_enable
 When enabled, ASCII mode data transfers will be honoured on uploads.
+When disabled, the server will pretend to allow ASCII mode but in fact
+ignore requests to activate it. So the client will think the ASCII mode
+is active and will translate native line terminators to the standard
+.BR <CRLF>
+line terminators for transmission, but the server will not do
+any translation. See the following article for a detailed explanation
+of the behaviour: https://access.redhat.com/articles/3250241.
+
+Turn this option on to have the server actually do
+ASCII mangling on files when in ASCII mode.
 
 Default: NO
 .TP
-- 
2.14.3