[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/tcp_probe.c b/net/ipv4/tcp_probe.c
index b76398d..87dd5bf 100644
--- a/net/ipv4/tcp_probe.c
+++ b/net/ipv4/tcp_probe.c
@@ -26,6 +26,7 @@
 #include <linux/module.h>
 #include <linux/ktime.h>
 #include <linux/time.h>
+#include <net/net_namespace.h>
 
 #include <net/tcp.h>
 
@@ -228,7 +229,7 @@ static __init int tcpprobe_init(void)
 	if (!tcp_probe.log)
 		goto err0;
 
-	if (!proc_net_fops_create(procname, S_IRUSR, &tcpprobe_fops))
+	if (!proc_net_fops_create(&init_net, procname, S_IRUSR, &tcpprobe_fops))
 		goto err0;
 
 	ret = register_jprobe(&tcp_jprobe);
@@ -238,7 +239,7 @@ static __init int tcpprobe_init(void)
 	pr_info("TCP probe registered (port=%d)\n", port);
 	return 0;
  err1:
-	proc_net_remove(procname);
+	proc_net_remove(&init_net, procname);
  err0:
 	kfree(tcp_probe.log);
 	return ret;
@@ -247,7 +248,7 @@ module_init(tcpprobe_init);
 
 static __exit void tcpprobe_exit(void)
 {
-	proc_net_remove(procname);
+	proc_net_remove(&init_net, procname);
 	unregister_jprobe(&tcp_jprobe);
 	kfree(tcp_probe.log);
 }