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Message-Id: <1341940299-896-1-git-send-email-christian.franke@adytonsystems.com>
Date: Tue, 10 Jul 2012 19:11:39 +0200
From: Christian Franke <christian.franke@...tonsystems.com>
To: netdev@...r.kernel.org
Cc: Christian Franke <christian.franke@...tonsystems.com>
Subject: [PATCH] net/ipv4/ipip: support move across network namespaces
Allow moving ipip devices from one netns to another. This makes it
possible to isolate the tunneled network from the transport network.
Signed-off-by: Christian Franke <christian.franke@...tonsystems.com>
---
include/net/ipip.h | 1 +
net/ipv4/ipip.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++------
2 files changed, 74 insertions(+), 8 deletions(-)
diff --git a/include/net/ipip.h b/include/net/ipip.h
index a93cf6d..60f5152 100644
--- a/include/net/ipip.h
+++ b/include/net/ipip.h
@@ -18,6 +18,7 @@ struct ip_tunnel_6rd_parm {
struct ip_tunnel {
struct ip_tunnel __rcu *next;
struct net_device *dev;
+ struct net *transport_net;
int err_count; /* Number of arrived ICMP errors */
unsigned long err_time; /* Time when the last ICMP error arrived */
diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c
index 715338a..d996f35 100644
--- a/net/ipv4/ipip.c
+++ b/net/ipv4/ipip.c
@@ -99,6 +99,7 @@
#include <asm/uaccess.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
+#include <linux/notifier.h>
#include <linux/in.h>
#include <linux/tcp.h>
#include <linux/udp.h>
@@ -151,6 +152,13 @@ struct pcpu_tstats {
struct u64_stats_sync syncp;
};
+static inline struct net *transport_net(struct net_device *dev)
+{
+ struct ip_tunnel *t = netdev_priv(dev);
+
+ return t->transport_net ? t->transport_net : dev_net(dev);
+}
+
static struct rtnl_link_stats64 *ipip_get_stats64(struct net_device *dev,
struct rtnl_link_stats64 *tot)
{
@@ -314,7 +322,7 @@ failed_free:
/* called with RTNL */
static void ipip_tunnel_uninit(struct net_device *dev)
{
- struct net *net = dev_net(dev);
+ struct net *net = transport_net(dev);
struct ipip_net *ipn = net_generic(net, ipip_net_id);
if (dev == ipn->fb_tunnel_dev)
@@ -481,7 +489,7 @@ static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
dst = rt->rt_gateway;
}
- rt = ip_route_output_ports(dev_net(dev), &fl4, NULL,
+ rt = ip_route_output_ports(transport_net(dev), &fl4, NULL,
dst, tiph->saddr,
0, 0,
IPPROTO_IPIP, RT_TOS(tos),
@@ -631,7 +639,7 @@ ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
int err = 0;
struct ip_tunnel_parm p;
struct ip_tunnel *t;
- struct net *net = dev_net(dev);
+ struct net *net = transport_net(dev);
struct ipip_net *ipn = net_generic(net, ipip_net_id);
switch (cmd) {
@@ -652,6 +660,9 @@ ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
break;
case SIOCADDTUNNEL:
+ /* New tunnels will be created in the current namespace */
+ net = dev_net(dev);
+ ipn = net_generic(net, ipip_net_id);
case SIOCCHGTUNNEL:
err = -EPERM;
if (!capable(CAP_NET_ADMIN))
@@ -701,6 +712,13 @@ ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
t->parms.iph.tos = p.iph.tos;
t->parms.iph.frag_off = p.iph.frag_off;
if (t->parms.link != p.link) {
+ if (!net_eq(dev_net(dev),
+ transport_net(dev))) {
+ pr_info_once("%s: rebinding a device moved across namespaces is not supported\n",
+ __func__);
+ err = -ENOTTY;
+ goto done;
+ }
t->parms.link = p.link;
ipip_tunnel_bind_dev(dev);
netdev_state_change(dev);
@@ -759,6 +777,10 @@ static const struct net_device_ops ipip_netdev_ops = {
static void ipip_dev_free(struct net_device *dev)
{
+ struct ip_tunnel *t = netdev_priv(dev);
+
+ if (t->transport_net)
+ put_net(t->transport_net);
free_percpu(dev->tstats);
free_netdev(dev);
}
@@ -774,7 +796,6 @@ static void ipip_tunnel_setup(struct net_device *dev)
dev->flags = IFF_NOARP;
dev->iflink = 0;
dev->addr_len = 4;
- dev->features |= NETIF_F_NETNS_LOCAL;
dev->features |= NETIF_F_LLTX;
dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
}
@@ -904,6 +925,40 @@ static struct pernet_operations ipip_net_ops = {
.size = sizeof(struct ipip_net),
};
+static int ipip_device_event(struct notifier_block *unused,
+ unsigned long event, void *ptr)
+{
+ struct net_device *dev = ptr;
+ struct ip_tunnel *t;
+
+ if (dev->type != ARPHRD_TUNNEL)
+ return NOTIFY_DONE;
+
+ t = netdev_priv(dev);
+ switch (event) {
+ case NETDEV_UNREGISTER:
+ /* When the tunnel is moved from its natural
+ * network namespace, it will keep a reference
+ * to it. */
+ if (dev->reg_state != NETREG_UNREGISTERING) {
+ if (!t->transport_net)
+ t->transport_net = get_net(dev_net(dev));
+ }
+ break;
+ case NETDEV_REGISTER:
+ if (net_eq(dev_net(dev), t->transport_net)) {
+ put_net(t->transport_net);
+ t->transport_net = NULL;
+ }
+ break;
+ }
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block ipip_notifier_block = {
+ .notifier_call = ipip_device_event,
+};
+
static int __init ipip_init(void)
{
int err;
@@ -913,11 +968,20 @@ static int __init ipip_init(void)
err = register_pernet_device(&ipip_net_ops);
if (err < 0)
return err;
+
+ err = register_netdevice_notifier(&ipip_notifier_block);
+ if (err < 0)
+ goto out_notifier;
+
err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
- if (err < 0) {
- unregister_pernet_device(&ipip_net_ops);
- pr_info("%s: can't register tunnel\n", __func__);
- }
+ if (err < 0)
+ goto out_xfrm;
+ return err;
+out_xfrm:
+ unregister_netdevice_notifier(&ipip_notifier_block);
+out_notifier:
+ unregister_pernet_device(&ipip_net_ops);
+ pr_info("%s: can't register tunnel\n", __func__);
return err;
}
@@ -926,6 +990,7 @@ static void __exit ipip_fini(void)
if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET))
pr_info("%s: can't deregister tunnel\n", __func__);
+ unregister_netdevice_notifier(&ipip_notifier_block);
unregister_pernet_device(&ipip_net_ops);
}
--
1.7.11.1
--
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