[PATCH net 6/6] ipv6: fix missing notification for ignore_routes_with_linkdown

[Fernando Fernandez Mancera <fmancera@suse.de>]

When changing the ignore_routes_with_linkdown sysctl for a specific
interface, the RTM_NEWNETCONF netlink notification was not being emitted
to userspace. Fix this by emitting the notification when needed.

In addition, fix bogus return value for successful "all" and specific
interface write operation leading to a wrong reset of the position
pointer.

Fixes: 35103d11173b ("net: ipv6 sysctl option to ignore routes when nexthop link is down")
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
---
 net/ipv6/addrconf.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 1cfb223476bd..2d81569b692b 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -955,11 +955,7 @@ static int addrconf_fixup_linkdown(const struct ctl_table *table, int *p, int ne
 						     NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN,
 						     NETCONFA_IFINDEX_DEFAULT,
 						     net->ipv6.devconf_dflt);
-		rtnl_net_unlock(net);
-		return 0;
-	}
-
-	if (p == &net->ipv6.devconf_all->ignore_routes_with_linkdown) {
+	} else if (p == &net->ipv6.devconf_all->ignore_routes_with_linkdown) {
 		WRITE_ONCE(net->ipv6.devconf_dflt->ignore_routes_with_linkdown, newf);
 		addrconf_linkdown_change(net, newf);
 		if ((!newf) ^ (!old))
@@ -968,11 +964,21 @@ static int addrconf_fixup_linkdown(const struct ctl_table *table, int *p, int ne
 						     NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN,
 						     NETCONFA_IFINDEX_ALL,
 						     net->ipv6.devconf_all);
+	} else {
+		if (!newf ^ !old) {
+			struct inet6_dev *idev = table->extra1;
+
+			inet6_netconf_notify_devconf(net,
+						     RTM_NEWNETCONF,
+						     NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN,
+						     idev->dev->ifindex,
+						     &idev->cnf);
+		}
 	}
 
 	rtnl_net_unlock(net);
 
-	return 1;
+	return 0;
 }
 
 #endif
-- 
2.54.0