From 7ad21ca66f5a46be231fffe884ac2c3b5d97c7ae Mon Sep 17 00:00:00 2001
From: Hans Nilsson <hans@erlang.org>
Date: Tue, 4 Apr 2017 19:53:05 +0200
Subject: ssh: document what happens when ssh:daemon sets both HostAddr and ip
 option

The idea is that the HostAddress argument takes precedence over an
ip-option. However, an ip-option overrides the 'any' HostAddr.

This fixes the case of dameon(Port, [{ip,IP}..] in a non-surprising
way.
---
 lib/ssh/doc/src/ssh.xml | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

(limited to 'lib/ssh/doc')

diff --git a/lib/ssh/doc/src/ssh.xml b/lib/ssh/doc/src/ssh.xml
index 88d402cf38..48c9aa18e9 100644
--- a/lib/ssh/doc/src/ssh.xml
+++ b/lib/ssh/doc/src/ssh.xml
@@ -379,7 +379,7 @@
       on the given port.</fsummary>
       <type>
         <v>Port = integer()</v>
-	<v>HostAddress = ip_address() | any</v>
+	<v>HostAddress = ip_address() | any | loopback</v>
 	<v>Options = [{Option, Value}]</v>
         <v>Option = atom()</v>
 	<v>Value = term()</v>
@@ -390,6 +390,26 @@
         <p>Starts a server listening for SSH connections on the given
         port. If the <c>Port</c> is 0, a random free port is selected. See
 	<seealso marker="#daemon_info/1">daemon_info/1</seealso> about how to find the selected port number.</p>
+
+	<p>Please note that by historical reasons both the <c>HostAddress</c> argument and the inet socket option
+	<c>ip</c> set the listening address. This is a source of possible inconsistent settings.</p>
+
+	<p>The rules for handling the two address passing options are:</p>
+	<list>
+	  <item>if <c>HostAddress</c> is an ip-address, that ip-address is the listening address.
+	  An ip-option will be discarded if present.</item>
+
+	  <item>if <c>HostAddress</c> is <c>loopback</c>, the listening address
+	  is <c>loopback</c> and an loopback address will be choosen by the underlying layers.
+	  An ip-option will be discarded if present.</item>
+
+	  <item>if <c>HostAddress</c> is <c>any</c> and no ip-option is present, the listening address is
+	  <c>any</c> and the socket will listen to all addresses</item>
+
+	  <item>if <c>HostAddress</c> is <c>any</c> and an ip-option is present, the listening address is
+	  set to the value of the ip-option</item>
+	</list>
+
 	<p>Options:</p>
         <taglist>
 	  <tag><c><![CDATA[{inet, inet | inet6}]]></c></tag>
-- 
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