[NET]: Make /proc/net per network namespace

This patch makes /proc/net per network namespace.  It modifies the global
variables proc_net and proc_net_stat to be per network namespace.
The proc_net file helpers are modified to take a network namespace argument,
and all of their callers are fixed to pass &init_net for that argument.
This ensures that all of the /proc/net files are only visible and
usable in the initial network namespace until the code behind them
has been updated to be handle multiple network namespaces.

Making /proc/net per namespace is necessary as at least some files
in /proc/net depend upon the set of network devices which is per
network namespace, and even more files in /proc/net have contents
that are relevant to a single network namespace.

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

1 files changed, 2 insertions, 1 deletions

diff --git a/net/core/dev_mcast.c b/net/core/dev_mcast.c
index 20330c572610..8e069fc207cb 100644
--- a/net/core/dev_mcast.c
+++ b/net/core/dev_mcast.c
@@ -41,6 +41,7 @@
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 #include <linux/init.h>
+#include <net/net_namespace.h>
 #include <net/ip.h>
 #include <net/route.h>
 #include <linux/skbuff.h>
@@ -254,7 +255,7 @@ static const struct file_operations dev_mc_seq_fops = {
 
 void __init dev_mcast_init(void)
 {
-        proc_net_fops_create("dev_mcast", 0, &dev_mc_seq_fops);
+        proc_net_fops_create(&init_net, "dev_mcast", 0, &dev_mc_seq_fops);
 }
 
 EXPORT_SYMBOL(dev_mc_add);