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Commit 275019d2 authored by Andrew Lunn's avatar Andrew Lunn Committed by Simon Wunderlich
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batman-adv: Handle parent interfaces in a different netns 



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: default avatarAndrew Lunn <andrew@lunn.ch>
[sven@narfation.org: Fix alignments, simplify parent netns retrieval]
Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
Signed-off-by: default avatarSimon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: default avatarMarek Lindner <mareklindner@neomailbox.ch>
parent b5dcbad2

net/batman-adv/hard-interface.c

+43 −7
Original line number Diff line number Diff line
@@ -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"
@@ -83,26 +85,56 @@ batadv_hardif_get_by_netdev(const struct net_device *net_dev) 
	return hard_iface;

}



/**

 * 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);