From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Lamparter Subject: [PATCH v2] ipv6: addrconf: fix mcast route for GRE devices Date: Wed, 30 Jul 2014 17:39:57 +0200 Message-ID: <1406734797-122248-1-git-send-email-equinox@diac24.net> References: <20140730153503.GJ801478@jupiter.n2.diac24.net> Cc: David Lamparter , Hannes Frederic Sowa , Stephen Hemminger To: netdev@vger.kernel.org Return-path: Received: from spaceboyz.net ([87.106.131.203]:59101 "EHLO spaceboyz.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753182AbaG3PkN (ORCPT ); Wed, 30 Jul 2014 11:40:13 -0400 In-Reply-To: <20140730153503.GJ801478@jupiter.n2.diac24.net> Sender: netdev-owner@vger.kernel.org List-ID: GRE devices, for some reason, were coming up with an autoconfigured address, but no ff00::/8 route in the local table. This breaks any kind of multicast, in particular OSPFv3, mDNS, - and ND. In fact, IPv6 only works at all because there is little need for ND on PtP devices. Adding any other IPv6 address on the device from userspace would rectify this issue through inet6_addr_add()/addrconf_add_dev() - and would leave the route around even if the address was later removed. (This is probably why this issue was not discovered earlier. AFAICS it has been there from the beginning, e.g. aee80b5 "generate link local address for GRE tunnel") (Note: multicast is supported on GRE devices of all kinds, including PtP GRE, P-t-Mcast GRE and NBMA-GRE.) Fixes: aee80b54b235 (ipv6: generate link local address for GRE tunnel) Signed-off-by: David Lamparter Cc: Hannes Frederic Sowa Cc: Stephen Hemminger --- net/ipv6/addrconf.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 0b239fc..7540a25 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -2818,10 +2818,9 @@ static void addrconf_gre_config(struct net_device *dev) ASSERT_RTNL(); - if ((idev = ipv6_find_idev(dev)) == NULL) { - pr_debug("%s: add_dev failed\n", __func__); + idev = addrconf_add_dev(dev); + if (IS_ERR(idev)) return; - } addrconf_addr_gen(idev, true); } -- 1.8.5.5