[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, 3 insertions, 2 deletions

diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index a646409c2d06..d78599a9dbd5 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -91,6 +91,7 @@
 #include <linux/rtnetlink.h>
 #include <linux/times.h>
 
+#include <net/net_namespace.h>
 #include <net/arp.h>
 #include <net/ip.h>
 #include <net/protocol.h>
@@ -2613,8 +2614,8 @@ static const struct file_operations igmp_mcf_seq_fops = {
 
 int __init igmp_mc_proc_init(void)
 {
-        proc_net_fops_create("igmp", S_IRUGO, &igmp_mc_seq_fops);
-        proc_net_fops_create("mcfilter", S_IRUGO, &igmp_mcf_seq_fops);
+        proc_net_fops_create(&init_net, "igmp", S_IRUGO, &igmp_mc_seq_fops);
+        proc_net_fops_create(&init_net, "mcfilter", S_IRUGO, &igmp_mcf_seq_fops);
         return 0;
 }
 #endif