[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, 4 insertions, 3 deletions

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index c7ca94bd152c..efd2a9202d68 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -91,6 +91,7 @@
 #include <linux/jhash.h>
 #include <linux/rcupdate.h>
 #include <linux/times.h>
+#include <net/net_namespace.h>
 #include <net/protocol.h>
 #include <net/ip.h>
 #include <net/route.h>
@@ -3011,15 +3012,15 @@ int __init ip_rt_init(void)
 #ifdef CONFIG_PROC_FS
         {
         struct proc_dir_entry *rtstat_pde = NULL; /* keep gcc happy */
-        if (!proc_net_fops_create("rt_cache", S_IRUGO, &rt_cache_seq_fops) ||
+        if (!proc_net_fops_create(&init_net, "rt_cache", S_IRUGO, &rt_cache_seq_fops) ||
             !(rtstat_pde = create_proc_entry("rt_cache", S_IRUGO,
-                                             proc_net_stat))) {
+                                             init_net.proc_net_stat))) {
                 return -ENOMEM;
         }
         rtstat_pde->proc_fops = &rt_cpu_seq_fops;
         }
 #ifdef CONFIG_NET_CLS_ROUTE
-        create_proc_read_entry("rt_acct", 0, proc_net, ip_rt_acct_read, NULL);
+        create_proc_read_entry("rt_acct", 0, init_net.proc_net, ip_rt_acct_read, NULL);
 #endif
 #endif
 #ifdef CONFIG_XFRM