[PATCH] ipv6: Silence privacy extensions initialization

[PATCH] ipv6: Silence privacy extensions initialization

[Romain Francoise]

When a network namespace is created (via CLONE_NEWNET), the loopback
interface is automatically added to the new namespace, triggering a
printk in ipv6_add_dev() if CONFIG_IPV6_PRIVACY is set.

This is problematic for applications which use CLONE_NEWNET as
part of a sandbox, like Chromium's suid sandbox or recent versions of
vsftpd. On a busy machine, it can lead to thousands of useless
"lo: Disabled Privacy Extensions" messages appearing in dmesg.

It's easy enough to check the status of privacy extensions via the
use_tempaddr sysctl, so just removing the printk seems like the most
sensible solution.

Signed-off-by: Romain Francoise <romain@orebokech.com>
---
 net/ipv6/addrconf.c |    3 ---
 1 files changed, 0 insertions(+), 3 deletions(-)

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 5b189c9..24a1cf1 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -420,9 +420,6 @@ static struct inet6_dev * ipv6_add_dev(struct net_device *dev)
 	    dev->type == ARPHRD_TUNNEL6 ||
 	    dev->type == ARPHRD_SIT ||
 	    dev->type == ARPHRD_NONE) {
-		printk(KERN_INFO
-		       "%s: Disabled Privacy Extensions\n",
-		       dev->name);
 		ndev->cnf.use_tempaddr = -1;
 	} else {
 		in6_dev_hold(ndev);
-- 
1.7.2.3

Re: [PATCH] ipv6: Silence privacy extensions initialization

[David Miller]

From: Romain Francoise <romain@orebokech.com>
Date: Mon, 17 Jan 2011 18:59:18 +0100

> When a network namespace is created (via CLONE_NEWNET), the loopback
> interface is automatically added to the new namespace, triggering a
> printk in ipv6_add_dev() if CONFIG_IPV6_PRIVACY is set.
> 
> This is problematic for applications which use CLONE_NEWNET as
> part of a sandbox, like Chromium's suid sandbox or recent versions of
> vsftpd. On a busy machine, it can lead to thousands of useless
> "lo: Disabled Privacy Extensions" messages appearing in dmesg.
> 
> It's easy enough to check the status of privacy extensions via the
> use_tempaddr sysctl, so just removing the printk seems like the most
> sensible solution.
> 
> Signed-off-by: Romain Francoise <romain@orebokech.com>

Yes, this message always bugged me too, applied thanks!