From de9498f1ab1fb8ca92eae74b459d4dec38203161 Mon Sep 17 00:00:00 2001
From: Charles Kerr <charles@transmissionbt.com>
Date: Tue, 15 Dec 2009 16:48:26 +0000
Subject: [PATCH] (trunk libT) #2669 "Apply IPV6_V6ONLY to the IPv6 DHT socket"
 -- committed jch's patch for 1.80

---
 libtransmission/tr-dht.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/libtransmission/tr-dht.c b/libtransmission/tr-dht.c
index 106eae41b..c84056674 100644
--- a/libtransmission/tr-dht.c
+++ b/libtransmission/tr-dht.c
@@ -319,10 +319,18 @@ tr_dhtInit(tr_session *ss, const tr_address * tr_addr)
         goto fail;
 
     if(tr_globalIPv6()) {
+        int one = 1;
         dht6_socket = socket(PF_INET6, SOCK_DGRAM, 0);
         if(dht6_socket < 0)
             goto fail;
 
+#ifdef IPV6_V6ONLY
+        /* Since we always open an IPv4 socket on the same port, this
+           shouldn't matter.  But I'm superstitious. */
+        setsockopt(dht6_socket, IPPROTO_IPV6, IPV6_V6ONLY,
+                   &one, sizeof(one));
+#endif
+
         rebind_ipv6(1);
 
     }