net: ip6_gre: Split up ip6gre_newlink()

BugLink: http://bugs.launchpad.net/bugs/1783418
[ Upstream commit 7fa38a7c852ec99e3a7fc375eb2c21c50c2e46b8 ]

Extract from ip6gre_newlink() a reusable function
ip6gre_newlink_common(). The ip6gre_tnl_link_config() call needs to be
made customizable for ERSPAN, thus reorder it with calls to
ip6_tnl_change_mtu() and dev_hold(), and extract the whole tail to the
caller, ip6gre_newlink(). Thus enable an ERSPAN-specific _newlink()
function without a lot of duplicity.

Fixes: 5a963eb61b7c ("ip6_gre: Add ERSPAN native tunnel support")
Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: William Tu <u9012063@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index d1dba10519b00c3f53dbb1f0c12dab00f618abb1..0973c358f0eeae47f59a6505c34a6d16bfb7f7db 100644 (file)
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -1400,13 +1400,12 @@ static bool ip6gre_netlink_encap_parms(struct nlattr *data[],
        return ret;
 }
 
-static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
-                         struct nlattr *tb[], struct nlattr *data[],
-                         struct netlink_ext_ack *extack)
+static int ip6gre_newlink_common(struct net *src_net, struct net_device *dev,
+                                struct nlattr *tb[], struct nlattr *data[],
+                                struct netlink_ext_ack *extack)
 {
        struct ip6_tnl *nt;
        struct net *net = dev_net(dev);
-       struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
        struct ip_tunnel_encap ipencap;
        int err;
 
@@ -1434,18 +1433,30 @@ static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
        if (err)
                goto out;
 
-       ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
-
        if (tb[IFLA_MTU])
                ip6_tnl_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
 
        dev_hold(dev);
-       ip6gre_tunnel_link(ign, nt);
 
 out:
        return err;
 }
 
+static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
+                         struct nlattr *tb[], struct nlattr *data[],
+                         struct netlink_ext_ack *extack)
+{
+       int err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
+       struct ip6_tnl *nt = netdev_priv(dev);
+       struct net *net = dev_net(dev);
+
+       if (!err) {
+               ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
+               ip6gre_tunnel_link(net_generic(net, ip6gre_net_id), nt);
+       }
+       return err;
+}
+
 static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
                             struct nlattr *data[],
                             struct netlink_ext_ack *extack)