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 <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 @@
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 @@
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 @@
(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 @@
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 @@
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 <linux/netfilter_ipv6.h>
#include <linux/slab.h>
#include <linux/hash.h>
+#include <linux/etherdevice.h>
#include <asm/uaccess.h>
#include <linux/atomic.h>
@@ -1471,6 +1472,9 @@
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);
}