ipv4: gre: add GRO capability

Add GRO capability to IPv4 GRE tunnels, using the gro_cells
infrastructure.

Tested using IPv4 and IPv6 TCP traffic inside this tunnel, and
checking GRO is building large packets.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 2 deletions

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index ef0b861ce044..b1871d993d22 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -740,8 +740,7 @@ static int ipgre_rcv(struct sk_buff *skb)
                 tstats->rx_bytes += skb->len;
                 u64_stats_update_end(&tstats->syncp);
 
-                netif_rx(skb);
-
+                gro_cells_receive(&tunnel->gro_cells, skb);
                 return 0;
         }
         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
@@ -1319,6 +1318,9 @@ static const struct net_device_ops ipgre_netdev_ops = {
 
 static void ipgre_dev_free(struct net_device *dev)
 {
+        struct ip_tunnel *tunnel = netdev_priv(dev);
+
+        gro_cells_destroy(&tunnel->gro_cells);
         free_percpu(dev->tstats);
         free_netdev(dev);
 }
@@ -1350,6 +1352,7 @@ static int ipgre_tunnel_init(struct net_device *dev)
 {
         struct ip_tunnel *tunnel;
         struct iphdr *iph;
+        int err;
 
         tunnel = netdev_priv(dev);
         iph = &tunnel->parms.iph;
@@ -1376,6 +1379,12 @@ static int ipgre_tunnel_init(struct net_device *dev)
         if (!dev->tstats)
                 return -ENOMEM;
 
+        err = gro_cells_init(&tunnel->gro_cells, dev);
+        if (err) {
+                free_percpu(dev->tstats);
+                return err;
+        }
+
         return 0;
 }