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rebinding tunnels to interfaces

PATCH Applied [email protected] 2 participants 5 messages Dec 13, 2007

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Networking Network drivers IPv4/IPv6
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[email protected]

author
#0 lore raw

cover rebinding tunnels to interfaces

These two patches allow rebinding of GRE and SIT tunnels to interfaces using ip tun change <tunnel> dev <iface>
A similar change was already done for IPIP tunnels.

Michal

author
#1 lore raw

PATCH 1/2 ip_gre: Rebinding of GRE tunnels to other interfaces

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

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

# create a tunnel:
ip tunnel add tunneltest0 mode gre 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: gre/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 Michal Schmidt <[email protected]>
net/ipv4/ip_gre.c +60 -42
Index: linus-kernel.git/net/ipv4/ip_gre.c
===================================================================
@@ -896,6 +896,59 @@ tx_error:
 	return 0;
 }
 
+static void ipgre_tunnel_bind_dev(struct net_device *dev)
+{
+	struct net_device *tdev = NULL;
+	struct ip_tunnel *tunnel;
+	struct iphdr *iph;
+	int hlen = LL_MAX_HEADER;
+	int mtu = ETH_DATA_LEN;
+	int addend = sizeof(struct iphdr) + 4;
+
+	tunnel = netdev_priv(dev);
+	iph = &tunnel->parms.iph;
+
+	/* Guess output device to choose reasonable mtu and hard_header_len */
+
+	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_GRE };
+		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) {
+		hlen = tdev->hard_header_len;
+		mtu = tdev->mtu;
+	}
+	dev->iflink = tunnel->parms.link;
+
+	/* Precalculate GRE options length */
+	if (tunnel->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
+		if (tunnel->parms.o_flags&GRE_CSUM)
+			addend += 4;
+		if (tunnel->parms.o_flags&GRE_KEY)
+			addend += 4;
+		if (tunnel->parms.o_flags&GRE_SEQ)
+			addend += 4;
+	}
+	dev->hard_header_len = hlen + addend;
+	dev->mtu = mtu - addend;
+	tunnel->hlen = addend;
+
+}
+
 static int
 ipgre_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
 {

@@ -983,6 +1036,11 @@ ipgre_tunnel_ioctl (struct net_device *d
 				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;
+					ipgre_tunnel_bind_dev(dev);
+					netdev_state_change(dev);
+				}
 			}
 			if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
 				err = -EFAULT;

@@ -1162,12 +1220,8 @@ static void ipgre_tunnel_setup(struct ne
 
 static int ipgre_tunnel_init(struct net_device *dev)
 {
-	struct net_device *tdev = NULL;
 	struct ip_tunnel *tunnel;
 	struct iphdr *iph;
-	int hlen = LL_MAX_HEADER;
-	int mtu = ETH_DATA_LEN;
-	int addend = sizeof(struct iphdr) + 4;
 
 	tunnel = netdev_priv(dev);
 	iph = &tunnel->parms.iph;

@@ -1178,23 +1232,9 @@ static int ipgre_tunnel_init(struct net_
 	memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
 	memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
 
-	/* Guess output device to choose reasonable mtu and hard_header_len */
+	ipgre_tunnel_bind_dev(dev);
 
 	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_GRE };
-		struct rtable *rt;
-		if (!ip_route_output_key(&rt, &fl)) {
-			tdev = rt->u.dst.dev;
-			ip_rt_put(rt);
-		}
-
-		dev->flags |= IFF_POINTOPOINT;
-
 #ifdef CONFIG_NET_IPGRE_BROADCAST
 		if (MULTICAST(iph->daddr)) {
 			if (!iph->saddr)

@@ -1205,31 +1245,9 @@ static int ipgre_tunnel_init(struct net_
 			dev->stop = ipgre_close;
 		}
 #endif
-	} else {
+	} else
 		dev->header_ops = &ipgre_header_ops;
-	}
-
-	if (!tdev && tunnel->parms.link)
-		tdev = __dev_get_by_index(&init_net, tunnel->parms.link);
-
-	if (tdev) {
-		hlen = tdev->hard_header_len;
-		mtu = tdev->mtu;
-	}
-	dev->iflink = tunnel->parms.link;
 
-	/* Precalculate GRE options length */
-	if (tunnel->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
-		if (tunnel->parms.o_flags&GRE_CSUM)
-			addend += 4;
-		if (tunnel->parms.o_flags&GRE_KEY)
-			addend += 4;
-		if (tunnel->parms.o_flags&GRE_SEQ)
-			addend += 4;
-	}
-	dev->hard_header_len = hlen + addend;
-	dev->mtu = mtu - addend;
-	tunnel->hlen = addend;
 	return 0;
 }
author
#3 lore raw

PATCH 2/2 ipv6/sit: Rebinding of SIT tunnels to other interfaces

In reply to [email protected]

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 Michal Schmidt <[email protected]>
net/ipv6/sit.c +42 -28
Index: linus-kernel.git/net/ipv6/sit.c
===================================================================
@@ -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 *d
 			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 ne
 
 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_
 	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;
 }
maintainer Applied
#2 lore raw

Re: [patch 1/2] ip_gre: Rebinding of GRE tunnels to other interfaces

In reply to [email protected]

From: [email protected]
Date: Thu, 13 Dec 2007 14:37:49 +0100

Quoted 12 lines

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

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

# create a tunnel:
ip tunnel add tunneltest0 mode gre 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
Quoted 8 lines

tunneltest0: gre/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 Michal Schmidt <[email protected]>

Applied to net-2.6.25, thanks.

maintainer
#4 lore raw

Re: [patch 2/2] ipv6/sit: Rebinding of SIT tunnels to other interfaces

In reply to [email protected]

From: [email protected]
Date: Thu, 13 Dec 2007 14:37:50 +0100

Quoted 12 lines

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
Quoted 8 lines

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 Michal Schmidt <[email protected]>

Also applied, thanks.