[PATCH NET-PREV 31/51] ip6_vti: Use __register_netdevice() in .newlink and .changelink

[Kirill Tkhai <tkhai@ya.ru>]

The objective is to conform .newlink and .changelink with their
callers, which already assign nd_lock (and matches master nd_lock
if there is one).

Signed-off-by: Kirill Tkhai <tkhai@ya.ru>
---
 net/ipv6/ip6_vti.c |   36 ++++++++++++++++++++++++++----------
 1 file changed, 26 insertions(+), 10 deletions(-)

diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c
index 590737c27537..b20a18c403e9 100644
--- a/net/ipv6/ip6_vti.c
+++ b/net/ipv6/ip6_vti.c
@@ -182,7 +182,7 @@ static int vti6_tnl_create2(struct net_device *dev)
 	int err;
 
 	dev->rtnl_link_ops = &vti6_link_ops;
-	err = register_netdevice(dev);
+	err = __register_netdevice(dev);
 	if (err < 0)
 		goto out;
 
@@ -196,7 +196,8 @@ static int vti6_tnl_create2(struct net_device *dev)
 	return err;
 }
 
-static struct ip6_tnl *vti6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
+static struct ip6_tnl *vti6_tnl_create(struct net *net, struct nd_lock *nd_lock,
+				       struct __ip6_tnl_parm *p)
 {
 	struct net_device *dev;
 	struct ip6_tnl *t;
@@ -221,6 +222,7 @@ static struct ip6_tnl *vti6_tnl_create(struct net *net, struct __ip6_tnl_parm *p
 	t->parms = *p;
 	t->net = dev_net(dev);
 
+	attach_nd_lock(dev, nd_lock);
 	err = vti6_tnl_create2(dev);
 	if (err < 0)
 		goto failed_free;
@@ -228,6 +230,7 @@ static struct ip6_tnl *vti6_tnl_create(struct net *net, struct __ip6_tnl_parm *p
 	return t;
 
 failed_free:
+	detach_nd_lock(dev);
 	free_netdev(dev);
 failed:
 	return NULL;
@@ -247,8 +250,8 @@ static struct ip6_tnl *vti6_tnl_create(struct net *net, struct __ip6_tnl_parm *p
  * Return:
  *   matching tunnel or NULL
  **/
-static struct ip6_tnl *vti6_locate(struct net *net, struct __ip6_tnl_parm *p,
-				   int create)
+static struct ip6_tnl *vti6_locate(struct net *net, struct nd_lock *nd_lock,
+				   struct __ip6_tnl_parm *p, int create)
 {
 	const struct in6_addr *remote = &p->raddr;
 	const struct in6_addr *local = &p->laddr;
@@ -269,7 +272,7 @@ static struct ip6_tnl *vti6_locate(struct net *net, struct __ip6_tnl_parm *p,
 	}
 	if (!create)
 		return NULL;
-	return vti6_tnl_create(net, p);
+	return vti6_tnl_create(net, nd_lock, p);
 }
 
 /**
@@ -791,6 +794,10 @@ vti6_parm_to_user(struct ip6_tnl_parm2 *u, const struct __ip6_tnl_parm *p)
  *   %-EINVAL if passed tunnel parameters are invalid,
  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
  *   %-ENODEV if attempting to change or delete a nonexisting device
+ *
+ * XXX: Currently ->ndo_siocdevprivate is called with @dev unlocked
+ * (the only place where @dev may be locked is phonet_device_autoconf(),
+ *  but it can't be caller of this).
  **/
 static int
 vti6_siocdevprivate(struct net_device *dev, struct ifreq *ifr, void __user *data, int cmd)
@@ -801,6 +808,7 @@ vti6_siocdevprivate(struct net_device *dev, struct ifreq *ifr, void __user *data
 	struct ip6_tnl *t = NULL;
 	struct net *net = dev_net(dev);
 	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
+	struct nd_lock *nd_lock;
 
 	memset(&p1, 0, sizeof(p1));
 
@@ -812,7 +820,9 @@ vti6_siocdevprivate(struct net_device *dev, struct ifreq *ifr, void __user *data
 				break;
 			}
 			vti6_parm_from_user(&p1, &p);
-			t = vti6_locate(net, &p1, 0);
+			lock_netdev(dev, &nd_lock);
+			t = vti6_locate(net, nd_lock, &p1, 0);
+			unlock_netdev(nd_lock);
 		} else {
 			memset(&p, 0, sizeof(p));
 		}
@@ -834,7 +844,9 @@ vti6_siocdevprivate(struct net_device *dev, struct ifreq *ifr, void __user *data
 		if (p.proto != IPPROTO_IPV6  && p.proto != 0)
 			break;
 		vti6_parm_from_user(&p1, &p);
-		t = vti6_locate(net, &p1, cmd == SIOCADDTUNNEL);
+		lock_netdev(dev, &nd_lock);
+		t = vti6_locate(net, nd_lock, &p1, cmd == SIOCADDTUNNEL);
+		unlock_netdev(nd_lock);
 		if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) {
 			if (t) {
 				if (t->dev != dev) {
@@ -866,7 +878,9 @@ vti6_siocdevprivate(struct net_device *dev, struct ifreq *ifr, void __user *data
 				break;
 			err = -ENOENT;
 			vti6_parm_from_user(&p1, &p);
-			t = vti6_locate(net, &p1, 0);
+			lock_netdev(dev, &nd_lock);
+			t = vti6_locate(net, nd_lock, &p1, 0);
+			unlock_netdev(nd_lock);
 			if (!t)
 				break;
 			err = -EPERM;
@@ -1001,6 +1015,7 @@ static int vti6_newlink(struct net *src_net, struct net_device *dev,
 			struct nlattr *tb[], struct nlattr *data[],
 			struct netlink_ext_ack *extack)
 {
+	struct nd_lock *nd_lock = rcu_dereference_protected(dev->nd_lock, true);
 	struct net *net = dev_net(dev);
 	struct ip6_tnl *nt;
 
@@ -1009,7 +1024,7 @@ static int vti6_newlink(struct net *src_net, struct net_device *dev,
 
 	nt->parms.proto = IPPROTO_IPV6;
 
-	if (vti6_locate(net, &nt->parms, 0))
+	if (vti6_locate(net, nd_lock, &nt->parms, 0))
 		return -EEXIST;
 
 	return vti6_tnl_create2(dev);
@@ -1028,6 +1043,7 @@ static int vti6_changelink(struct net_device *dev, struct nlattr *tb[],
 			   struct nlattr *data[],
 			   struct netlink_ext_ack *extack)
 {
+	struct nd_lock *nd_lock = rcu_dereference_protected(dev->nd_lock, true);
 	struct ip6_tnl *t;
 	struct __ip6_tnl_parm p;
 	struct net *net = dev_net(dev);
@@ -1038,7 +1054,7 @@ static int vti6_changelink(struct net_device *dev, struct nlattr *tb[],
 
 	vti6_netlink_parms(data, &p);
 
-	t = vti6_locate(net, &p, 0);
+	t = vti6_locate(net, nd_lock, &p, 0);
 
 	if (t) {
 		if (t->dev != dev)