From 5198dabcce9da535c4531b53990cfa11bd9f7896 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Wed, 3 Oct 2012 14:18:55 -0400
Subject: [PATCH] man: document behaviour of ListenStream= with only a port
 number in regards to IPv4/IPv6

---
 man/systemd.socket.xml   | 21 +++++++++++++++++----
 src/core/load-fragment.c |  6 ++++--
 src/shared/socket-util.c |  3 ++-
 3 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/man/systemd.socket.xml b/man/systemd.socket.xml
index 6cf6c79e1..7885b0748 100644
--- a/man/systemd.socket.xml
+++ b/man/systemd.socket.xml
@@ -170,8 +170,13 @@
 
                                 <para>If the address string is a
                                 single number it is read as port
-                                number to listen on for both IPv4 and
-                                IPv6.</para>
+                                number to listen on via
+                                IPv6. Depending on the value of
+                                <varname>BindIPv6Only=</varname> (see below) this
+                                might result in the service being
+                                available via both IPv6 and IPv4 (default) or
+                                just via IPv6.
+                                </para>
 
                                 <para>If the address string is a
                                 string in the format v.w.x.y:z it is
@@ -181,7 +186,12 @@
 
                                 <para>If the address string is a
                                 string in the format [x]:y it is read
-                                as IPv6 address x on a port y.</para>
+                                as IPv6 address x on a port y. Note
+                                that this might make the service
+                                available via IPv4, too, depending on
+                                the <varname>BindIPv6Only=</varname>
+                                setting (see below).
+                                </para>
 
                                 <para>Note that SOCK_SEQPACKET
                                 (i.e. <varname>ListenSequentialPacket=</varname>)
@@ -286,7 +296,10 @@
                                 default, surprise!) the system wide
                                 default setting is used, as controlled
                                 by
-                                <filename>/proc/sys/net/ipv6/bindv6only</filename>.</para>
+                                <filename>/proc/sys/net/ipv6/bindv6only</filename>,
+                                which in turn defaults to the
+                                equivalent of
+                                <option>both</option>.</para>
                                 </listitem>
                         </varlistentry>
 
diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c
index 93f051af4..2504d730d 100644
--- a/src/core/load-fragment.c
+++ b/src/core/load-fragment.c
@@ -326,10 +326,12 @@ int config_parse_socket_bind(
 
         s = SOCKET(data);
 
-        if ((b = socket_address_bind_ipv6_only_from_string(rvalue)) < 0) {
+        b = socket_address_bind_ipv6_only_from_string(rvalue);
+        if (b < 0) {
                 int r;
 
-                if ((r = parse_boolean(rvalue)) < 0) {
+                r = parse_boolean(rvalue);
+                if (r < 0) {
                         log_error("[%s:%u] Failed to parse bind IPv6 only value, ignoring: %s", filename, line, rvalue);
                         return 0;
                 }
diff --git a/src/shared/socket-util.c b/src/shared/socket-util.c
index 7e65f8a69..4908403d9 100644
--- a/src/shared/socket-util.c
+++ b/src/shared/socket-util.c
@@ -167,7 +167,8 @@ int socket_address_parse(SocketAddress *a, const char *s) {
                 } else {
 
                         /* Just a port */
-                        if ((r = safe_atou(s, &u)) < 0)
+                        r = safe_atou(s, &u);
+                        if (r < 0)
                                 return r;
 
                         if (u <= 0 || u > 0xFFFF)
-- 
2.30.2