[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, 6 insertions, 5 deletions

diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 986d1c83a000..95a8f8f2de71 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -34,6 +34,7 @@
  *		2 of the License, or (at your option) any later version.
  */
 #include <linux/types.h>
+#include <net/net_namespace.h>
 #include <net/icmp.h>
 #include <net/protocol.h>
 #include <net/tcp.h>
@@ -383,20 +384,20 @@ int __init ip_misc_proc_init(void)
 {
 	int rc = 0;
 
-	if (!proc_net_fops_create("netstat", S_IRUGO, &netstat_seq_fops))
+	if (!proc_net_fops_create(&init_net, "netstat", S_IRUGO, &netstat_seq_fops))
 		goto out_netstat;
 
-	if (!proc_net_fops_create("snmp", S_IRUGO, &snmp_seq_fops))
+	if (!proc_net_fops_create(&init_net, "snmp", S_IRUGO, &snmp_seq_fops))
 		goto out_snmp;
 
-	if (!proc_net_fops_create("sockstat", S_IRUGO, &sockstat_seq_fops))
+	if (!proc_net_fops_create(&init_net, "sockstat", S_IRUGO, &sockstat_seq_fops))
 		goto out_sockstat;
 out:
 	return rc;
 out_sockstat:
-	proc_net_remove("snmp");
+	proc_net_remove(&init_net, "snmp");
 out_snmp:
-	proc_net_remove("netstat");
+	proc_net_remove(&init_net, "netstat");
 out_netstat:
 	rc = -ENOMEM;
 	goto out;