From 72ee19dccad91a448ebf6899e56a2bc448e51c4a Mon Sep 17 00:00:00 2001
From: Erick Turnquist <jhujhiti@adjectivism.org>
Date: Thu, 18 Dec 2008 05:55:22 +0000
Subject: [PATCH] (trunk libT) Refactor ipv6 bind socket check

This will let the RPC server use the same test mechanism eventually. Networking code belongs in net.c anyway.
---
 libtransmission/net.c             | 29 +++++++++++++++++++++++++++++
 libtransmission/net.h             |  8 ++++++++
 libtransmission/port-forwarding.c | 19 ++++---------------
 3 files changed, 41 insertions(+), 15 deletions(-)

diff --git a/libtransmission/net.c b/libtransmission/net.c
index 9df3b47a6..2a61ae76a 100644
--- a/libtransmission/net.c
+++ b/libtransmission/net.c
@@ -155,6 +155,35 @@ tr_compareAddresses( const tr_address * a, const tr_address * b)
     return memcmp( &a->addr, &b->addr, addrlen );
 } 
 
+tr_net_af_support
+tr_net_getAFSupport( tr_port port )
+{
+    /* Do we care if an address is in use? Probably not, since it will be
+     * caught later. This will only set up the list of sockets to bind. */
+    static tr_bool alreadyDone       = FALSE;
+    static tr_net_af_support support = { FALSE, FALSE };
+    int s4, s6;
+    if( alreadyDone )
+        return support;
+    s6 = tr_netBindTCP( &tr_in6addr_any, port, TRUE );
+    if( s6 >= 0 || -s6 != EAFNOSUPPORT ) /* we support ipv6 */
+    {
+        listen( s6, 1 );
+        support.has_inet6 = TRUE;
+    }
+    s4 = tr_netBindTCP( &tr_inaddr_any, port, TRUE );
+    if( s4 >= 0 ) /* we bound *with* the ipv6 socket bound (need both)
+                   * or only have ipv4 */
+    {
+        tr_netClose( s4 );
+        support.needs_inet4 = TRUE;
+    }
+    if( s6 >= 0 )
+        tr_netClose( s6 );
+    alreadyDone = TRUE;
+    return support;
+}
+
 /***********************************************************************
  * Socket list housekeeping
  **********************************************************************/
diff --git a/libtransmission/net.h b/libtransmission/net.h
index f49f80c97..bf556c15b 100644
--- a/libtransmission/net.h
+++ b/libtransmission/net.h
@@ -87,6 +87,14 @@ void tr_normalizeV4Mapped( tr_address * const addr );
 
 tr_bool tr_isAddress( const tr_address * a );
 
+typedef struct tr_net_af_support
+{
+    tr_bool has_inet6;
+    tr_bool needs_inet4;
+} tr_net_af_support;
+
+tr_net_af_support tr_net_getAFSupport( tr_port );
+
 /***********************************************************************
  * Socket list housekeeping
  **********************************************************************/
diff --git a/libtransmission/port-forwarding.c b/libtransmission/port-forwarding.c
index cc5e3cc96..ba5924f48 100644
--- a/libtransmission/port-forwarding.c
+++ b/libtransmission/port-forwarding.c
@@ -234,29 +234,18 @@ sharedPulse( void * vshared )
 static tr_socketList *
 setupBindSockets( tr_port port )
 {
-    /* Do we care if an address is in use? Probably not, since it will be
-     * caught later. This will only set up the list of sockets to bind. */
-    int s4, s6;
+    tr_net_af_support support = tr_net_getAFSupport( port );
     tr_socketList * socks = NULL;
-    s6 = tr_netBindTCP( &tr_in6addr_any, port, TRUE );
-    if( s6 >= 0 || -s6 != EAFNOSUPPORT ) /* we support ipv6 */
-    {
+    if( support.has_inet6 )
         socks = tr_socketListNew( &tr_in6addr_any );
-        listen( s6, 1 );
-    }
-    s4 = tr_netBindTCP( &tr_inaddr_any, port, TRUE );
-    if( s4 >= 0 ) /* we bound *with* the ipv6 socket bound (need both)
-                   * or only have ipv4 */
+    if( support.needs_inet4 )
     {
         if( socks )
             tr_socketListAppend( socks, &tr_inaddr_any );
         else
             socks = tr_socketListNew( &tr_inaddr_any );
-        tr_netClose( s4 );
     }
-    if( s6 >= 0 )
-        tr_netClose( s6 );
-    return socks;
+    return socks; /* Because the dryer gremlins won't */
 }
 
 tr_shared *