[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>

net/decnet/af_decnet.c

@@ -128,6 +128,7 @@ Version 0.0.6    2.1.110   07-aug-98   Eduardo Marcelo Serrat
 #include <linux/stat.h>
 #include <linux/init.h>
 #include <linux/poll.h>
+#include <net/net_namespace.h>
 #include <net/neighbour.h>
 #include <net/dst.h>
 #include <net/fib_rules.h>
@@ -2399,7 +2400,7 @@ static int __init decnet_init(void)
 	dev_add_pack(&dn_dix_packet_type);
 	register_netdevice_notifier(&dn_dev_notifier);
 
-	proc_net_fops_create("decnet", S_IRUGO, &dn_socket_seq_fops);
+	proc_net_fops_create(&init_net, "decnet", S_IRUGO, &dn_socket_seq_fops);
 	dn_register_sysctl();
 out:
 	return rc;
@@ -2428,7 +2429,7 @@ static void __exit decnet_exit(void)
 	dn_neigh_cleanup();
 	dn_fib_cleanup();
 
-	proc_net_remove("decnet");
+	proc_net_remove(&init_net, "decnet");
 
 	proto_unregister(&dn_proto);
 }

net/decnet/dn_dev.c

@@ -42,6 +42,7 @@
 #include <linux/notifier.h>
 #include <asm/uaccess.h>
 #include <asm/system.h>
+#include <net/net_namespace.h>
 #include <net/neighbour.h>
 #include <net/dst.h>
 #include <net/flow.h>
@@ -1462,7 +1463,7 @@ void __init dn_dev_init(void)
 	rtnl_register(PF_DECnet, RTM_DELADDR, dn_nl_deladdr, NULL);
 	rtnl_register(PF_DECnet, RTM_GETADDR, NULL, dn_nl_dump_ifaddr);
 
-	proc_net_fops_create("decnet_dev", S_IRUGO, &dn_dev_seq_fops);
+	proc_net_fops_create(&init_net, "decnet_dev", S_IRUGO, &dn_dev_seq_fops);
 
 #ifdef CONFIG_SYSCTL
 	{
@@ -1483,7 +1484,7 @@ void __exit dn_dev_cleanup(void)
 	}
 #endif /* CONFIG_SYSCTL */
 
-	proc_net_remove("decnet_dev");
+	proc_net_remove(&init_net, "decnet_dev");
 
 	dn_dev_devices_off();
 }

net/decnet/dn_neigh.c

@@ -38,6 +38,7 @@
 #include <linux/rcupdate.h>
 #include <linux/jhash.h>
 #include <asm/atomic.h>
+#include <net/net_namespace.h>
 #include <net/neighbour.h>
 #include <net/dst.h>
 #include <net/flow.h>
@@ -611,11 +612,11 @@ static const struct file_operations dn_neigh_seq_fops = {
 void __init dn_neigh_init(void)
 {
 	neigh_table_init(&dn_neigh_table);
-	proc_net_fops_create("decnet_neigh", S_IRUGO, &dn_neigh_seq_fops);
+	proc_net_fops_create(&init_net, "decnet_neigh", S_IRUGO, &dn_neigh_seq_fops);
 }
 
 void __exit dn_neigh_cleanup(void)
 {
-	proc_net_remove("decnet_neigh");
+	proc_net_remove(&init_net, "decnet_neigh");
 	neigh_table_clear(&dn_neigh_table);
 }

net/decnet/dn_route.c

@@ -77,6 +77,7 @@
 #include <linux/rcupdate.h>
 #include <linux/times.h>
 #include <asm/errno.h>
+#include <net/net_namespace.h>
 #include <net/netlink.h>
 #include <net/neighbour.h>
 #include <net/dst.h>
@@ -1814,7 +1815,7 @@ void __init dn_route_init(void)
 
 	dn_dst_ops.gc_thresh = (dn_rt_hash_mask + 1);
 
-	proc_net_fops_create("decnet_cache", S_IRUGO, &dn_rt_cache_seq_fops);
+	proc_net_fops_create(&init_net, "decnet_cache", S_IRUGO, &dn_rt_cache_seq_fops);
 
 #ifdef CONFIG_DECNET_ROUTER
 	rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute, dn_fib_dump);
@@ -1829,6 +1830,6 @@ void __exit dn_route_cleanup(void)
 	del_timer(&dn_route_timer);
 	dn_run_flush(0);
 
-	proc_net_remove("decnet_cache");
+	proc_net_remove(&init_net, "decnet_cache");
 }