From 08b44656c08c8c2f73cdac2a058be2880e3361f2 Mon Sep 17 00:00:00 2001 From: Nicolas Dichtel Date: Mon, 17 Feb 2014 14:22:21 +0100 Subject: [PATCH] gre: add link local route when local addr is any This bug was reported by Steinar H. Gunderson and was introduced by commit f7cb8886335d ("sit/gre6: don't try to add the same route two times"). root@morgental:~# ip tunnel add foo mode gre remote 1.2.3.4 ttl 64 root@morgental:~# ip link set foo up mtu 1468 root@morgental:~# ip -6 route show dev foo fe80::/64 proto kernel metric 256 but after the above commit, no such route shows up. There is no link local route because dev->dev_addr is 0 (because local ipv4 address is 0), hence no link local address is configured. In this scenario, the link local address is added manually: 'ip -6 addr add fe80::1 dev foo' and because prefix is /128, no link local route is added by the kernel. Even if the right things to do is to add the link local address with a /64 prefix, we need to restore the previous behavior to avoid breaking userpace. Reported-by: Steinar H. Gunderson Signed-off-by: Nicolas Dichtel Signed-off-by: David S. Miller --- net/ipv6/addrconf.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index ad235690684..fdbfeca36d6 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -2783,6 +2783,8 @@ static void addrconf_gre_config(struct net_device *dev) ipv6_addr_set(&addr, htonl(0xFE800000), 0, 0, 0); if (!ipv6_generate_eui64(addr.s6_addr + 8, dev)) addrconf_add_linklocal(idev, &addr); + else + addrconf_prefix_route(&addr, 64, dev, 0, 0); } #endif -- 2.43.2