[NET]: Make the device list and device lookups per namespace.

This patch makes most of the generic device layer network
namespace safe.  This patch makes dev_base_head a
network namespace variable, and then it picks up
a few associated variables.  The functions:
dev_getbyhwaddr
dev_getfirsthwbytype
dev_get_by_flags
dev_get_by_name
__dev_get_by_name
dev_get_by_index
__dev_get_by_index
dev_ioctl
dev_ethtool
dev_load
wireless_process_ioctl

were modified to take a network namespace argument, and
deal with it.

vlan_ioctl_set and brioctl_set were modified so their
hooks will receive a network namespace argument.

So basically anthing in the core of the network stack that was
affected to by the change of dev_base was modified to handle
multiple network namespaces.  The rest of the network stack was
simply modified to explicitly use &init_net the initial network
namespace.  This can be fixed when those components of the network
stack are modified to handle multiple network namespaces.

For now the ifindex generator is left global.

Fundametally ifindex numbers are per namespace, or else
we will have corner case problems with migration when
we get that far.

At the same time there are assumptions in the network stack
that the ifindex of a network device won't change.  Making
the ifindex number global seems a good compromise until
the network stack can cope with ifindex changes when
you change namespaces, and the like.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 37 insertions, 4 deletions

diff --git a/net/core/dev_mcast.c b/net/core/dev_mcast.c
index 8e069fc207cb..1c4f6198459b 100644
--- a/net/core/dev_mcast.c
+++ b/net/core/dev_mcast.c
@@ -187,11 +187,12 @@ EXPORT_SYMBOL(dev_mc_unsync);
 #ifdef CONFIG_PROC_FS
 static void *dev_mc_seq_start(struct seq_file *seq, loff_t *pos)
 {
+	struct net *net = seq->private;
 	struct net_device *dev;
 	loff_t off = 0;
 
 	read_lock(&dev_base_lock);
-	for_each_netdev(dev) {
+	for_each_netdev(net, dev) {
 		if (off++ == *pos)
 			return dev;
 	}
@@ -240,7 +241,22 @@ static const struct seq_operations dev_mc_seq_ops = {
 
 static int dev_mc_seq_open(struct inode *inode, struct file *file)
 {
-	return seq_open(file, &dev_mc_seq_ops);
+	struct seq_file *seq;
+	int res;
+	res = seq_open(file, &dev_mc_seq_ops);
+	if (!res) {
+		seq = file->private_data;
+		seq->private = get_net(PROC_NET(inode));
+	}
+	return res;
+}
+
+static int dev_mc_seq_release(struct inode *inode, struct file *file)
+{
+	struct seq_file *seq = file->private_data;
+	struct net *net = seq->private;
+	put_net(net);
+	return seq_release(inode, file);
 }
 
 static const struct file_operations dev_mc_seq_fops = {
@@ -248,14 +264,31 @@ static const struct file_operations dev_mc_seq_fops = {
 	.open    = dev_mc_seq_open,
 	.read    = seq_read,
 	.llseek  = seq_lseek,
-	.release = seq_release,
+	.release = dev_mc_seq_release,
 };
 
 #endif
 
+static int dev_mc_net_init(struct net *net)
+{
+	if (!proc_net_fops_create(net, "dev_mcast", 0, &dev_mc_seq_fops))
+		return -ENOMEM;
+	return 0;
+}
+
+static void dev_mc_net_exit(struct net *net)
+{
+	proc_net_remove(net, "dev_mcast");
+}
+
+static struct pernet_operations dev_mc_net_ops = {
+	.init = dev_mc_net_init,
+	.exit = dev_mc_net_exit,
+};
+
 void __init dev_mcast_init(void)
 {
-	proc_net_fops_create(&init_net, "dev_mcast", 0, &dev_mc_seq_fops);
+	register_pernet_subsys(&dev_mc_net_ops);
 }
 
 EXPORT_SYMBOL(dev_mc_add);