qede: Prevent GSO on long Geneve headers

Due to hardware limitation, when transmitting a geneve-encapsulated
packet with more than 32 bytes worth of geneve options the hardware
would not be able to crack the packet and consider it a regular UDP
packet.

This implements the ndo_features_check() in qede in order to prevent
GSO on said transmitted packets.

Signed-off-by: Manish Chopra <manish.chopra@caviumnetworks.com>
Signed-off-by: Yuval Mintz <Yuval.Mintz@caviumnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/qlogic/qede/qede_main.c b/drivers/net/ethernet/qlogic/qede/qede_main.c
index 7d5dc1e15fc44e29f2f4a21d46170ebd6d28f5c2..6c2b09c255d5f75c02ed23fedebf5e7d221dc0db 100644 (file)
--- a/drivers/net/ethernet/qlogic/qede/qede_main.c
+++ b/drivers/net/ethernet/qlogic/qede/qede_main.c
@@ -2240,6 +2240,40 @@ static void qede_udp_tunnel_del(struct net_device *dev,
        schedule_delayed_work(&edev->sp_task, 0);
 }
 
+/* 8B udp header + 8B base tunnel header + 32B option length */
+#define QEDE_MAX_TUN_HDR_LEN 48
+
+static netdev_features_t qede_features_check(struct sk_buff *skb,
+                                            struct net_device *dev,
+                                            netdev_features_t features)
+{
+       if (skb->encapsulation) {
+               u8 l4_proto = 0;
+
+               switch (vlan_get_protocol(skb)) {
+               case htons(ETH_P_IP):
+                       l4_proto = ip_hdr(skb)->protocol;
+                       break;
+               case htons(ETH_P_IPV6):
+                       l4_proto = ipv6_hdr(skb)->nexthdr;
+                       break;
+               default:
+                       return features;
+               }
+
+               /* Disable offloads for geneve tunnels, as HW can't parse
+                * the geneve header which has option length greater than 32B.
+                */
+               if ((l4_proto == IPPROTO_UDP) &&
+                   ((skb_inner_mac_header(skb) -
+                     skb_transport_header(skb)) > QEDE_MAX_TUN_HDR_LEN))
+                       return features & ~(NETIF_F_CSUM_MASK |
+                                           NETIF_F_GSO_MASK);
+       }
+
+       return features;
+}
+
 static const struct net_device_ops qede_netdev_ops = {
        .ndo_open = qede_open,
        .ndo_stop = qede_close,
@@ -2264,6 +2298,7 @@ static const struct net_device_ops qede_netdev_ops = {
 #endif
        .ndo_udp_tunnel_add = qede_udp_tunnel_add,
        .ndo_udp_tunnel_del = qede_udp_tunnel_del,
+       .ndo_features_check = qede_features_check,
 };
 
 /* -------------------------------------------------------------------------