Patchwork ipv6: make the net.ipv6.conf.all.use_tempaddr sysctl propagate to interface settings

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Submitter Mathieu Trudel-Lapierre
Date Jan. 10, 2012, 1:54 p.m.
Message ID <1326203674-15445-1-git-send-email-mathieu.trudel-lapierre@canonical.com>
Download mbox | patch
Permalink /patch/135364/
State New
Headers show

Comments

Mathieu Trudel-Lapierre - Jan. 10, 2012, 1:54 p.m.
The description for IPV6_PRIVACY mentions using .../all/use_tempaddr to enable
IPv6 Privacy Extensions, and IP sysctl documentation mentions 'all' as setting
all interface-specific settings. We make sure at least use_tempaddr actually
works as documented.

Signed-off-by: Mathieu Trudel-Lapierre <mathieu.trudel-lapierre@canonical.com>
---
 net/ipv6/addrconf.c |   80 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 79 insertions(+), 1 deletions(-)
Tim Gardner - Jan. 11, 2012, 8:59 a.m.
Mathieu - aren't there some updates in the Documentation directory for 
this patch ?
Mathieu Trudel-Lapierre - Jan. 11, 2012, 10:33 a.m.
Le mercredi 11 janvier 2012 à 09:59 +0100, Tim Gardner a écrit :
> Mathieu - aren't there some updates in the Documentation directory for 
> this patch ?
> 

My feeling was that the patch actually correctly implements what is
documented (if you look at the IPv6 section of network sysctls, IPv6
defines all and default separately as "applies to all", "sets the
default", etc.), so I'm not sure there is much to update.

If you feel like there ought to be some clarifications there, I'll be
happy to provide another patch :)

Patch

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index cf88df8..a20ab55 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4340,6 +4340,84 @@  int addrconf_sysctl_disable(ctl_table *ctl, int write,
 	return ret;
 }
 
+#ifdef CONFIG_IPV6_PRIVACY
+static void dev_tempaddr_change(struct inet6_dev *idev)
+{
+	if (!idev || !idev->dev)
+		return;
+
+	if (!idev->cnf.disable_ipv6) {
+		/* If ipv6 is enabled, try to bring down and back up the
+		 * interface to get new temporary addresses created
+		 */
+		addrconf_notify(NULL, NETDEV_DOWN, idev->dev);
+		addrconf_notify(NULL, NETDEV_UP, idev->dev);
+	}
+}
+
+static void addrconf_tempaddr_change(struct net *net, __s32 newf)
+{
+	struct net_device *dev;
+	struct inet6_dev *idev;
+
+	rcu_read_lock();
+	for_each_netdev_rcu(net, dev) {
+		idev = __in6_dev_get(dev);
+		if (idev) {
+			int changed = (!idev->cnf.use_tempaddr) ^ (!newf);
+			idev->cnf.use_tempaddr = newf;
+			if (changed)
+				dev_tempaddr_change(idev);
+		}
+	}
+	rcu_read_unlock();
+}
+
+static int addrconf_use_tempaddr(struct ctl_table *table, int *p, int old)
+{
+	struct net *net;
+
+	net = (struct net *)table->extra2;
+
+	if (p == &net->ipv6.devconf_dflt->use_tempaddr)
+		return 0;
+
+	if (!rtnl_trylock()) {
+		/* Restore the original values before restarting */
+		*p = old;
+		return restart_syscall();
+	}
+
+	if (p == &net->ipv6.devconf_all->use_tempaddr) {
+		__s32 newf = net->ipv6.devconf_all->use_tempaddr;
+		net->ipv6.devconf_dflt->use_tempaddr = newf;
+		addrconf_tempaddr_change(net, newf);
+	} else if ((!*p) ^ (!old))
+		dev_tempaddr_change((struct inet6_dev *)table->extra1);
+
+	rtnl_unlock();
+	return 0;
+}
+
+static
+int addrconf_sysctl_tempaddr(ctl_table *ctl, int write,
+			     void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+	int *valp = ctl->data;
+	int val = *valp;
+	loff_t pos = *ppos;
+	int ret;
+
+	ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
+
+	if (write)
+		ret = addrconf_use_tempaddr(ctl, valp, val);
+	if (ret)
+		*ppos = pos;
+	return ret;
+}
+#endif
+
 static struct addrconf_sysctl_table
 {
 	struct ctl_table_header *sysctl_header;
@@ -4431,7 +4509,7 @@  static struct addrconf_sysctl_table
 			.data		= &ipv6_devconf.use_tempaddr,
 			.maxlen		= sizeof(int),
 			.mode		= 0644,
-			.proc_handler	= proc_dointvec,
+			.proc_handler	= addrconf_sysctl_tempaddr,
 		},
 		{
 			.procname	= "temp_valid_lft",