Merge remote-tracking branch 'spi/topic/dma' into spi-next

[cascardo/linux.git] / net / ipv4 / ip_tunnel.c

diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index c7bd72e..89e8861 100644 (file)
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -943,17 +943,31 @@ done:
 }
 EXPORT_SYMBOL_GPL(ip_tunnel_ioctl);
 
-int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu)
+int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict)
 {
        struct ip_tunnel *tunnel = netdev_priv(dev);
        int t_hlen = tunnel->hlen + sizeof(struct iphdr);
+       int max_mtu = 0xFFF8 - dev->hard_header_len - t_hlen;
 
-       if (new_mtu < 68 ||
-           new_mtu > 0xFFF8 - dev->hard_header_len - t_hlen)
+       if (new_mtu < 68)
                return -EINVAL;
+
+       if (new_mtu > max_mtu) {
+               if (strict)
+                       return -EINVAL;
+
+               new_mtu = max_mtu;
+       }
+
        dev->mtu = new_mtu;
        return 0;
 }
+EXPORT_SYMBOL_GPL(__ip_tunnel_change_mtu);
+
+int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu)
+{
+       return __ip_tunnel_change_mtu(dev, new_mtu, true);
+}
 EXPORT_SYMBOL_GPL(ip_tunnel_change_mtu);
 
 static void ip_tunnel_dev_free(struct net_device *dev)