Commit 2774c7ab authored by Eric W. Biederman's avatar Eric W. Biederman Committed by David S. Miller
Browse files

[NET]: Make the loopback device per network namespace. 



This patch makes loopback_dev per network namespace.  Adding
code to create a different loopback device for each network
namespace and adding the code to free a loopback device
when a network namespace exits.

This patch modifies all users the loopback_dev so they
access it as init_net.loopback_dev, keeping all of the
code compiling and working.  A later pass will be needed to
update the users to use something other than the initial network
namespace.

Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0cc217e1

drivers/net/loopback.c

+21 −5
Original line number Diff line number Diff line
@@ -57,6 +57,7 @@ 
#include <linux/ip.h>

#include <linux/tcp.h>

#include <linux/percpu.h>

#include <net/net_namespace.h>



struct pcpu_lstats {

	unsigned long packets;
@@ -252,7 +253,7 @@ static void loopback_setup(struct net_device *dev) 
}



/* Setup and register the loopback device. */

static int __init loopback_init(void)

static int loopback_net_init(struct net *net)

{

	struct net_device *dev;

	int err;
@@ -262,12 +263,13 @@ static int __init loopback_init(void) 
	if (!dev)

		goto out;



	dev->nd_net = net;

	err = register_netdev(dev);

	if (err)

		goto out_free_netdev;



	err = 0;

	loopback_dev = dev;

	net->loopback_dev = dev;



out:

	if (err)
@@ -279,7 +281,21 @@ out_free_netdev: 
	goto out;

}



fs_initcall(loopback_init);

static void loopback_net_exit(struct net *net)

{

	struct net_device *dev = net->loopback_dev;



	unregister_netdev(dev);

}



static struct pernet_operations loopback_net_ops = {

       .init = loopback_net_init,

       .exit = loopback_net_exit,

};



static int __init loopback_init(void)

{

	return register_pernet_device(&loopback_net_ops);

}



struct net_device *loopback_dev;

EXPORT_SYMBOL(loopback_dev);
 
fs_initcall(loopback_init);

include/linux/netdevice.h

+0 −1
Original line number Diff line number Diff line
@@ -742,7 +742,6 @@ struct packet_type { 
#include <linux/interrupt.h>

#include <linux/notifier.h>



extern struct net_device		*loopback_dev;		/* The loopback */

extern rwlock_t				dev_base_lock;		/* Device list lock */

include/net/net_namespace.h

+3 −0
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
#include <linux/list.h>



struct proc_dir_entry;

struct net_device;

struct net {

	atomic_t		count;		/* To decided when the network

						 *  namespace should be freed.
@@ -23,6 +24,8 @@ struct net { 
	struct proc_dir_entry 	*proc_net_stat;

	struct proc_dir_entry 	*proc_net_root;



	struct net_device       *loopback_dev;          /* The loopback */



	struct list_head 	dev_base_head;

	struct hlist_head 	*dev_name_head;

	struct hlist_head	*dev_index_head;

net/core/dst.c

+3 −2
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#include <linux/types.h>

#include <net/net_namespace.h>



#include <net/net_namespace.h>

#include <net/dst.h>



/*
@@ -278,11 +279,11 @@ static inline void dst_ifdown(struct dst_entry *dst, struct net_device *dev, 
	if (!unregister) {

		dst->input = dst->output = dst_discard;

	} else {

		dst->dev = loopback_dev;

		dst->dev = init_net.loopback_dev;

		dev_hold(dst->dev);

		dev_put(dev);

		if (dst->neighbour && dst->neighbour->dev == dev) {

			dst->neighbour->dev = loopback_dev;

			dst->neighbour->dev = init_net.loopback_dev;

			dev_put(dev);

			dev_hold(dst->neighbour->dev);

		}

net/decnet/dn_dev.c

+2 −2
Original line number Diff line number Diff line
@@ -869,10 +869,10 @@ last_chance: 
		rv = dn_dev_get_first(dev, addr);

		read_unlock(&dev_base_lock);

		dev_put(dev);

		if (rv == 0 || dev == loopback_dev)

		if (rv == 0 || dev == init_net.loopback_dev)

			return rv;

	}

	dev = loopback_dev;

	dev = init_net.loopback_dev;

	dev_hold(dev);

	goto last_chance;

}

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