File xinetd-2.3.14-ipv6-ipv4-fallback.patch of Package xinetd

--- xinetd/confparse.c
+++ xinetd/confparse.c
@@ -544,10 +544,9 @@
    }
 
    if( SC_IPV4( scp ) && SC_IPV6( scp ) ) {
-      msg( LOG_ERR, func, 
-         "Service %s specified as both IPv4 and IPv6 - DISABLING", 
+      msg( LOG_INFO, func,
+         "Service %s will use IPv6 or fallback to IPv4",
 	 SC_NAME(scp));
-      return FAILED ;
    }
    
    /*
--- xinetd/service.c
+++ xinetd/service.c
@@ -322,12 +322,29 @@
       return( OK );
    }
 
-   if( SC_IPV4( scp ) ) {
+   if( SC_IPV4( scp ) && !SC_IPV6(scp) ) {
       SVC_FD(sp) = socket( AF_INET, 
                            SC_SOCKET_TYPE( scp ), SC_PROTOVAL( scp ) ) ;
    } else if( SC_IPV6( scp ) ) {
       SVC_FD(sp) = socket( AF_INET6, 
                            SC_SOCKET_TYPE( scp ), SC_PROTOVAL( scp ) ) ;
+      /* service with IPv6-IPv4 fallback
+       *  - if IPv6 succeeds, use IPv6 and clear the IPv4 flag
+       *  - if IPv6 fails, use IPv4 socket and clear the IPv6 flag
+       */
+      if( SVC_FD(sp) == -1 ) {
+         if( SC_IPV4(scp) ) {
+            msg( LOG_INFO, func,
+                 "IPv6 socket creation failed (%m), service = %s", SC_ID( scp ) );
+            msg( LOG_INFO, func,
+                 "falling back to IPv4, service = %s", SC_ID( scp ) );
+            M_CLEAR(SC_XFLAGS(scp), SF_IPV6);
+            SVC_FD(sp) = socket( AF_INET,
+                                 SC_SOCKET_TYPE( scp ), SC_PROTOVAL( scp ) ) ;
+         }
+      } else {
+         M_CLEAR(SC_XFLAGS(scp), SF_IPV4);
+      }
    }
 
    if ( SVC_FD(sp) == -1 )
--- etc/xinetd.d/chargen
+++ etc/xinetd.d/chargen
@@ -10,4 +10,5 @@
 	user		= root
 	wait		= no
 	disable		= yes
+	FLAGS		= IPv6 IPv4
 }                                                                               
--- etc/xinetd.d/chargen-udp
+++ etc/xinetd.d/chargen-udp
@@ -11,4 +11,5 @@
 	wait		= yes
 	disable		= yes
 	port		= 19
+	FLAGS		= IPv6 IPv4
 }                                                                               
--- etc/xinetd.d/daytime
+++ etc/xinetd.d/daytime
@@ -10,4 +10,5 @@
 	user		= root
 	wait		= no
 	disable		= yes
+	FLAGS		= IPv6 IPv4
 }                                                                               
--- etc/xinetd.d/daytime-udp
+++ etc/xinetd.d/daytime-udp
@@ -11,4 +11,5 @@
 	wait		= yes
 	disable		= yes
 	port		= 13
+	FLAGS		= IPv6 IPv4
 }                                                                               
--- etc/xinetd.d/discard
+++ etc/xinetd.d/discard
@@ -10,4 +10,5 @@
 	user		= root
 	wait		= no
 	disable		= yes
+	FLAGS		= IPv6 IPv4
 }                                                                               
--- etc/xinetd.d/discard-udp
+++ etc/xinetd.d/discard-udp
@@ -11,4 +11,5 @@
 	wait		= yes
 	disable		= yes
 	port		= 9
+	FLAGS		= IPv6 IPv4
 }                                                                               
--- etc/xinetd.d/echo
+++ etc/xinetd.d/echo
@@ -10,4 +10,5 @@
 	user		= root
 	wait		= no
 	disable		= yes
+	FLAGS		= IPv6 IPv4
 }                                                                               
--- etc/xinetd.d/echo-udp
+++ etc/xinetd.d/echo-udp
@@ -11,4 +11,5 @@
 	wait		= yes
 	disable		= yes
 	port		= 7
+	FLAGS		= IPv6 IPv4
 }                                                                               
--- etc/xinetd.d/servers
+++ etc/xinetd.d/servers
@@ -10,4 +10,5 @@
 	wait		= no
 	disable		= yes
 	only_from	= 127.0.0.1
+	FLAGS		= IPv6 IPv4
 }                                                                               
--- etc/xinetd.d/services
+++ etc/xinetd.d/services
@@ -10,4 +10,5 @@
 	wait		= no
 	disable		= yes
 	only_from	= 127.0.0.1
+	FLAGS		= IPv6 IPv4
 }                                                                               
--- etc/xinetd.d/time
+++ etc/xinetd.d/time
@@ -11,4 +11,5 @@
 	user		= root
 	wait		= no
 	disable		= yes
+	FLAGS		= IPv6 IPv4
 }                                                                               
--- etc/xinetd.d/time-udp
+++ etc/xinetd.d/time-udp
@@ -11,4 +11,5 @@
 	wait		= yes
 	disable		= yes
 	port		= 37
+	FLAGS		= IPv6 IPv4
 }                                                                               
--- xinetd/xinetd.conf.man
+++ xinetd/xinetd.conf.man
@@ -142,6 +142,10 @@
 .TP
 .B IPv6
 Sets the service to be an IPv6 service (AF_INET6), if IPv6 is available on the system.
+If you give both the IPv4 and IPv6 flag, then xinetd will first try to create
+an IPv6 service (wich can accept IPv4 connections by default), and if that
+fails (ie. the operating system doesn't have IPv6 support), it will create an
+IPv4 service.
 .TP
 .B REUSE
 The REUSE flag is deprecated.  All services now implicitly use the REUSE flag.