From e837735ec406a347756e0ef3aea124a6d51ea1ba Mon Sep 17 00:00:00 2001 From: Nicolas Dichtel Date: Tue, 20 Aug 2013 12:16:06 +0200 Subject: [PATCH] ip6_tunnel: ensure to always have a link local address When an Xin6 tunnel is set up, we check other netdevices to inherit the link- local address. If none is available, the interface will not have any link-local address. RFC4862 expects that each interface has a link local address. Now than this kind of tunnels supports x-netns, it's easy to fall in this case (by creating the tunnel in a netns where ethernet interfaces stand and then moving it to a other netns where no ethernet interface is available). RFC4291, Appendix A suggests two methods: the first is the one currently implemented, the second is to generate a unique identifier, so that we can always generate the link-local address. Let's use eth_random_addr() to generate this interface indentifier. I remove completly the previous method, hence for the whole life of the interface, the link-local address remains the same (previously, it depends on which ethernet interfaces were up when the tunnel interface was set up). Signed-off-by: Nicolas Dichtel Signed-off-by: David S. Miller --- net/ipv6/addrconf.c | 56 +++++++++++++-------------------------------------- net/ipv6/ip6_tunnel.c | 4 ++++ 2 files changed, 18 insertions(+), 42 deletions(-) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 3ca23e8..8549a5d 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -1814,6 +1814,16 @@ static int addrconf_ifid_gre(u8 *eui, struct net_device *dev) return __ipv6_isatap_ifid(eui, *(__be32 *)dev->dev_addr); } +static int addrconf_ifid_ip6tnl(u8 *eui, struct net_device *dev) +{ + memcpy(eui, dev->perm_addr, 3); + memcpy(eui + 5, dev->perm_addr + 3, 3); + eui[3] = 0xFF; + eui[4] = 0xFE; + eui[0] ^= 2; + return 0; +} + static int ipv6_generate_eui64(u8 *eui, struct net_device *dev) { switch (dev->type) { @@ -1832,6 +1842,8 @@ static int ipv6_generate_eui64(u8 *eui, struct net_device *dev) return addrconf_ifid_eui64(eui, dev); case ARPHRD_IEEE1394: return addrconf_ifid_ieee1394(eui, dev); + case ARPHRD_TUNNEL6: + return addrconf_ifid_ip6tnl(eui, dev); } return -1; } @@ -2709,7 +2721,8 @@ static void addrconf_dev_config(struct net_device *dev) (dev->type != ARPHRD_ARCNET) && (dev->type != ARPHRD_INFINIBAND) && (dev->type != ARPHRD_IEEE802154) && - (dev->type != ARPHRD_IEEE1394)) { + (dev->type != ARPHRD_IEEE1394) && + (dev->type != ARPHRD_TUNNEL6)) { /* Alas, we support only Ethernet autoconfiguration. */ return; } @@ -2795,44 +2808,6 @@ ipv6_inherit_linklocal(struct inet6_dev *idev, struct net_device *link_dev) return -1; } -static void ip6_tnl_add_linklocal(struct inet6_dev *idev) -{ - struct net_device *link_dev; - struct net *net = dev_net(idev->dev); - - /* first try to inherit the link-local address from the link device */ - if (idev->dev->iflink && - (link_dev = __dev_get_by_index(net, idev->dev->iflink))) { - if (!ipv6_inherit_linklocal(idev, link_dev)) - return; - } - /* then try to inherit it from any device */ - for_each_netdev(net, link_dev) { - if (!ipv6_inherit_linklocal(idev, link_dev)) - return; - } - pr_debug("init ip6-ip6: add_linklocal failed\n"); -} - -/* - * Autoconfigure tunnel with a link-local address so routing protocols, - * DHCPv6, MLD etc. can be run over the virtual link - */ - -static void addrconf_ip6_tnl_config(struct net_device *dev) -{ - struct inet6_dev *idev; - - ASSERT_RTNL(); - - idev = addrconf_add_dev(dev); - if (IS_ERR(idev)) { - pr_debug("init ip6-ip6: add_dev failed\n"); - return; - } - ip6_tnl_add_linklocal(idev); -} - static int addrconf_notify(struct notifier_block *this, unsigned long event, void *ptr) { @@ -2900,9 +2875,6 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event, addrconf_gre_config(dev); break; #endif - case ARPHRD_TUNNEL6: - addrconf_ip6_tnl_config(dev); - break; case ARPHRD_LOOPBACK: init_loopback(dev); break; diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c index cc3bb20..d6e00a3 100644 --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -41,6 +41,7 @@ #include #include #include +#include #include #include @@ -1471,6 +1472,9 @@ static void ip6_tnl_dev_setup(struct net_device *dev) dev->flags |= IFF_NOARP; dev->addr_len = sizeof(struct in6_addr); dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; + /* This perm addr will be used as interface identifier by IPv6 */ + dev->addr_assign_type = NET_ADDR_RANDOM; + eth_random_addr(dev->perm_addr); } -- 2.7.4