netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH] IPIP: Allow rebinding the tunnel to another interface
@ 2007-12-12 15:34 Michal Schmidt
  2007-12-12 16:00 ` Patrick McHardy
  0 siblings, 1 reply; 5+ messages in thread
From: Michal Schmidt @ 2007-12-12 15:34 UTC (permalink / raw)
  To: netdev; +Cc: David S. Miller, Marcela Maslanova

Hello,

Once created, an IP tunnel can't be bound to another device.
(reported as https://bugzilla.redhat.com/show_bug.cgi?id=419671)

To reproduce:

# create a tunnel:
ip tunnel add tunneltest0 mode ipip 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: ip/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.

If the change is acceptable, I'll do the same for GRE and SIT tunnels.

Signed-off-by: Michal Schmidt <mschmidt@redhat.com>

diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c
index 8c2b2b0..05b267b 100644
--- a/net/ipv4/ipip.c
+++ b/net/ipv4/ipip.c
@@ -651,6 +651,40 @@ tx_error:
 	return 0;
 }
 
+static void ipip_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 = { .oif = tunnel->parms.link,
+				    .nl_u = { .ip4_u =
+					      { .daddr = iph->daddr,
+						.saddr = iph->saddr,
+						.tos = RT_TOS(iph->tos) } },
+				    .proto = IPPROTO_IPIP };
+		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);
+	}
+	dev->iflink = tunnel->parms.link;
+}
+
 static int
 ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
 {
@@ -723,6 +757,10 @@ ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
 				t->parms.iph.ttl = p.iph.ttl;
 				t->parms.iph.tos = p.iph.tos;
 				t->parms.iph.frag_off = p.iph.frag_off;
+				if (t->parms.link != p.link) {
+					t->parms.link = p.link;
+					ipip_tunnel_bind_dev(dev);
+				}
 			}
 			if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
 				err = -EFAULT;
@@ -791,12 +829,9 @@ static void ipip_tunnel_setup(struct net_device *dev)
 
 static int ipip_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);
@@ -804,29 +839,7 @@ static int ipip_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 = { .oif = tunnel->parms.link,
-				    .nl_u = { .ip4_u =
-					      { .daddr = iph->daddr,
-						.saddr = iph->saddr,
-						.tos = RT_TOS(iph->tos) } },
-				    .proto = IPPROTO_IPIP };
-		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);
-	}
-	dev->iflink = tunnel->parms.link;
+	ipip_tunnel_bind_dev(dev);
 
 	return 0;
 }
-- 
1.5.3.3


^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2007-12-12 19:02 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2007-12-12 15:34 [PATCH] IPIP: Allow rebinding the tunnel to another interface Michal Schmidt
2007-12-12 16:00 ` Patrick McHardy
2007-12-12 16:29   ` Michal Schmidt
2007-12-12 16:33     ` Patrick McHardy
2007-12-12 19:02     ` David Miller

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).