[B.A.T.M.A.N.] [PATCH v10 01/16] batman-adv: Handle parent interfaces in a different netns

Sven Eckelmann
2016-07-03T11:31:33Z

From: Andrew Lunn <andrew@lunn.ch>

batman-adv tries to prevent the user from placing a batX soft
interface into another batman mesh as a hard interface. It does this
by walking up the devices list of parents and ensures they are all
none batX interfaces. iflink can point to an interface in a different
namespace, so also retrieve the parents name space when finding the
parent and use it when doing the comparison.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
[sven@narfation.org: Fix alignments, simplify parent netns retrieval]
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
---
compat.h | 7 ++++++
net/batman-adv/hard-interface.c | 50 +++++++++++++++++++++++++++++++++++------
2 files changed, 50 insertions(+), 7 deletions(-)

diff --git a/compat.h b/compat.h
index 7d5c8b6..fc78948 100644
--- a/compat.h
+++ b/compat.h
@@ -146,6 +146,13 @@ static int __batadv_interface_kill_vid(struct net_device *dev, __be16 proto,\

#endif /* < KERNEL_VERSION(3, 15, 0) */

+#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 0, 0)
+
+/* WARNING for batadv_getlink_net */
+#define get_link_net get_xstats_size || 1 || netdev->rtnl_link_ops->get_xstats_size
+
+#endif /* < KERNEL_VERSION(4, 0, 0) */
+
#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 3, 0)

#define IFF_NO_QUEUE 0; dev->tx_queue_len = 0
diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
index 714af8e..43c9a3e 100644
--- a/net/batman-adv/hard-interface.c
+++ b/net/batman-adv/hard-interface.c
@@ -35,6 +35,8 @@
#include <linux/rtnetlink.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
+#include <net/net_namespace.h>
+#include <net/rtnetlink.h>

#include "bat_v.h"
#include "bridge_loop_avoidance.h"
@@ -84,25 +86,55 @@ out:
}

/**
+ * batadv_getlink_net - return link net namespace (of use fallback)
+ * @netdev: net_device to check
+ * @fallback_net: return in case get_link_net is not available for @netdev
+ *
+ * Return: result of rtnl_link_ops->get_link_net or @fallback_net
+ */
+static const struct net *batadv_getlink_net(const struct net_device *netdev,
+ const struct net *fallback_net)
+{
+ if (!netdev->rtnl_link_ops)
+ return fallback_net;
+
+ if (!netdev->rtnl_link_ops->get_link_net)
+ return fallback_net;
+
+ return netdev->rtnl_link_ops->get_link_net(netdev);
+}
+
+/**
* batadv_mutual_parents - check if two devices are each others parent
- * @dev1: 1st net_device
- * @dev2: 2nd net_device
+ * @dev1: 1st net dev
+ * @net1: 1st devices netns
+ * @dev2: 2nd net dev
+ * @net2: 2nd devices netns
*
* veth devices come in pairs and each is the parent of the other!
*
* Return: true if the devices are each others parent, otherwise false
*/
static bool batadv_mutual_parents(const struct net_device *dev1,
- const struct net_device *dev2)
+ const struct net *net1,
+ const struct net_device *dev2,
+ const struct net *net2)
{
int dev1_parent_iflink = dev_get_iflink(dev1);
int dev2_parent_iflink = dev_get_iflink(dev2);
+ const struct net *dev1_parent_net;
+ const struct net *dev2_parent_net;
+
+ dev1_parent_net = batadv_getlink_net(dev1, net1);
+ dev2_parent_net = batadv_getlink_net(dev2, net2);

if (!dev1_parent_iflink || !dev2_parent_iflink)
return false;

return (dev1_parent_iflink == dev2->ifindex) &&
- (dev2_parent_iflink == dev1->ifindex);
+ (dev2_parent_iflink == dev1->ifindex) &&
+ net_eq(dev1_parent_net, net2) &&
+ net_eq(dev2_parent_net, net1);
}

/**
@@ -120,8 +152,9 @@ static bool batadv_mutual_parents(const struct net_device *dev1,
*/
static bool batadv_is_on_batman_iface(const struct net_device *net_dev)
{
- struct net_device *parent_dev;
struct net *net = dev_net(net_dev);
+ struct net_device *parent_dev;
+ const struct net *parent_net;
bool ret;

/* check if this is a batman-adv mesh interface */
@@ -133,13 +166,16 @@ static bool batadv_is_on_batman_iface(const struct net_device *net_dev)
dev_get_iflink(net_dev) == net_dev->ifindex)
return false;

+ parent_net = batadv_getlink_net(net_dev, net);
+
/* recurse over the parent device */
- parent_dev = __dev_get_by_index(net, dev_get_iflink(net_dev));
+ parent_dev = __dev_get_by_index((struct net *)parent_net,
+ dev_get_iflink(net_dev));
/* if we got a NULL parent_dev there is something broken.. */
if (WARN(!parent_dev, "Cannot find parent device"))
return false;

- if (batadv_mutual_parents(net_dev, parent_dev))
+ if (batadv_mutual_parents(net_dev, net, parent_dev, parent_net))
return false;

ret = batadv_is_on_batman_iface(parent_dev);
--
2.8.1