Commit 8a4a50f9 authored by Michal Schmidt's avatar Michal Schmidt Committed by David S. Miller
Browse files

[IPV6] sit: Rebinding of SIT tunnels to other interfaces 



This is similar to the change already done for IPIP tunnels.

Once created, a SIT tunnel can't be bound to another device.
To reproduce:

# create a tunnel:
ip tunnel add tunneltest0 mode sit remote 10.0.0.1 dev eth0
# try to change the bounding device from eth0 to eth1:
ip tunnel change tunneltest0 dev eth1
# show the result:
ip tunnel show tunneltest0

tunneltest0: ipv6/ip  remote 10.0.0.1  local any  dev eth0  ttl inherit

Notice the bound device has not changed from eth0 to eth1.

This patch fixes it. When changing the binding, it also recalculates the
MTU according to the new bound device's MTU.

Signed-off-by: default avatarMichal Schmidt <mschmidt@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ee34c1eb

net/ipv6/sit.c

+42 −28
Original line number Diff line number Diff line
@@ -669,6 +669,42 @@ tx_error: 
	return 0;

}



static void ipip6_tunnel_bind_dev(struct net_device *dev)

{

	struct net_device *tdev = NULL;

	struct ip_tunnel *tunnel;

	struct iphdr *iph;



	tunnel = netdev_priv(dev);

	iph = &tunnel->parms.iph;



	if (iph->daddr) {

		struct flowi fl = { .nl_u = { .ip4_u =

					      { .daddr = iph->daddr,

						.saddr = iph->saddr,

						.tos = RT_TOS(iph->tos) } },

				    .oif = tunnel->parms.link,

				    .proto = IPPROTO_IPV6 };

		struct rtable *rt;

		if (!ip_route_output_key(&rt, &fl)) {

			tdev = rt->u.dst.dev;

			ip_rt_put(rt);

		}

		dev->flags |= IFF_POINTOPOINT;

	}



	if (!tdev && tunnel->parms.link)

		tdev = __dev_get_by_index(&init_net, tunnel->parms.link);



	if (tdev) {

		dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);

		dev->mtu = tdev->mtu - sizeof(struct iphdr);

		if (dev->mtu < IPV6_MIN_MTU)

			dev->mtu = IPV6_MIN_MTU;

	}

	dev->iflink = tunnel->parms.link;

}



static int

ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)

{
@@ -740,6 +776,11 @@ ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) 
			if (cmd == SIOCCHGTUNNEL) {

				t->parms.iph.ttl = p.iph.ttl;

				t->parms.iph.tos = p.iph.tos;

				if (t->parms.link != p.link) {

					t->parms.link = p.link;

					ipip6_tunnel_bind_dev(dev);

					netdev_state_change(dev);

				}

			}

			if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))

				err = -EFAULT;
@@ -808,12 +849,9 @@ static void ipip6_tunnel_setup(struct net_device *dev) 


static int ipip6_tunnel_init(struct net_device *dev)

{

	struct net_device *tdev = NULL;

	struct ip_tunnel *tunnel;

	struct iphdr *iph;



	tunnel = netdev_priv(dev);

	iph = &tunnel->parms.iph;



	tunnel->dev = dev;

	strcpy(tunnel->parms.name, dev->name);
@@ -821,31 +859,7 @@ static int ipip6_tunnel_init(struct net_device *dev) 
	memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);

	memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);



	if (iph->daddr) {

		struct flowi fl = { .nl_u = { .ip4_u =

					      { .daddr = iph->daddr,

						.saddr = iph->saddr,

						.tos = RT_TOS(iph->tos) } },

				    .oif = tunnel->parms.link,

				    .proto = IPPROTO_IPV6 };

		struct rtable *rt;

		if (!ip_route_output_key(&rt, &fl)) {

			tdev = rt->u.dst.dev;

			ip_rt_put(rt);

		}

		dev->flags |= IFF_POINTOPOINT;

	}



	if (!tdev && tunnel->parms.link)

		tdev = __dev_get_by_index(&init_net, tunnel->parms.link);



	if (tdev) {

		dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);

		dev->mtu = tdev->mtu - sizeof(struct iphdr);

		if (dev->mtu < IPV6_MIN_MTU)

			dev->mtu = IPV6_MIN_MTU;

	}

	dev->iflink = tunnel->parms.link;

	ipip6_tunnel_bind_dev(dev);



	return 0;

}

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