Merge branch 'csum_fixes'

Tom Herbert says:

====================
Fixes related to some recent checksum modifications.

- Fix GSO constants to match NETIF flags
- Fix logic in saving checksum complete in __skb_checksum_complete
- Call __skb_checksum_complete from UDP if we are checksumming over
  whole packet in order to save checksum.
- Fixes to VXLAN to work correctly with checksum complete
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

7 files changed, 60 insertions, 25 deletions

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index e0995ffd046d..ade33ef82823 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -1156,15 +1156,7 @@ static int vxlan_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
         if (!vs)
                 goto drop;
 
-        /* If the NIC driver gave us an encapsulated packet
-         * with the encapsulation mark, the device checksummed it
-         * for us. Otherwise force the upper layers to verify it.
-         */
-        if ((skb->ip_summed != CHECKSUM_UNNECESSARY && skb->ip_summed != CHECKSUM_PARTIAL) ||
-            !skb->encapsulation)
-                skb->ip_summed = CHECKSUM_NONE;
-
-        skb->encapsulation = 0;
+        skb_pop_rcv_encapsulation(skb);
 
         vs->rcv(vs, skb, vxh->vx_vni);
         return 0;
@@ -1201,6 +1193,7 @@ static void vxlan_rcv(struct vxlan_sock *vs,
         skb_reset_mac_header(skb);
         skb_scrub_packet(skb, !net_eq(vxlan->net, dev_net(vxlan->dev)));
         skb->protocol = eth_type_trans(skb, vxlan->dev);
+        skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
 
         /* Ignore packet loops (and multicast echo) */
         if (ether_addr_equal(eth_hdr(skb)->h_source, vxlan->dev->dev_addr))
diff --git a/include/linux/netdev_features.h b/include/linux/netdev_features.h
index e5a589435e2b..d99800cbdcf3 100644
--- a/include/linux/netdev_features.h
+++ b/include/linux/netdev_features.h
@@ -117,6 +117,7 @@ enum {
 #define NETIF_F_GSO_IPIP        __NETIF_F(GSO_IPIP)
 #define NETIF_F_GSO_SIT         __NETIF_F(GSO_SIT)
 #define NETIF_F_GSO_UDP_TUNNEL  __NETIF_F(GSO_UDP_TUNNEL)
+#define NETIF_F_GSO_UDP_TUNNEL_CSUM __NETIF_F(GSO_UDP_TUNNEL_CSUM)
 #define NETIF_F_GSO_MPLS        __NETIF_F(GSO_MPLS)
 #define NETIF_F_HW_VLAN_STAG_FILTER __NETIF_F(HW_VLAN_STAG_FILTER)
 #define NETIF_F_HW_VLAN_STAG_RX __NETIF_F(HW_VLAN_STAG_RX)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index abe3de1db932..66f9a04ec270 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -3305,6 +3305,13 @@ static inline bool net_gso_ok(netdev_features_t features, int gso_type)
         BUILD_BUG_ON(SKB_GSO_TCP_ECN != (NETIF_F_TSO_ECN >> NETIF_F_GSO_SHIFT));
         BUILD_BUG_ON(SKB_GSO_TCPV6   != (NETIF_F_TSO6 >> NETIF_F_GSO_SHIFT));
         BUILD_BUG_ON(SKB_GSO_FCOE    != (NETIF_F_FSO >> NETIF_F_GSO_SHIFT));
+        BUILD_BUG_ON(SKB_GSO_GRE     != (NETIF_F_GSO_GRE >> NETIF_F_GSO_SHIFT));
+        BUILD_BUG_ON(SKB_GSO_GRE_CSUM != (NETIF_F_GSO_GRE_CSUM >> NETIF_F_GSO_SHIFT));
+        BUILD_BUG_ON(SKB_GSO_IPIP    != (NETIF_F_GSO_IPIP >> NETIF_F_GSO_SHIFT));
+        BUILD_BUG_ON(SKB_GSO_SIT     != (NETIF_F_GSO_SIT >> NETIF_F_GSO_SHIFT));
+        BUILD_BUG_ON(SKB_GSO_UDP_TUNNEL != (NETIF_F_GSO_UDP_TUNNEL >> NETIF_F_GSO_SHIFT));
+        BUILD_BUG_ON(SKB_GSO_UDP_TUNNEL_CSUM != (NETIF_F_GSO_UDP_TUNNEL_CSUM >> NETIF_F_GSO_SHIFT));
+        BUILD_BUG_ON(SKB_GSO_MPLS    != (NETIF_F_GSO_MPLS >> NETIF_F_GSO_SHIFT));
 
         return (features & feature) == feature;
 }
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 5b5cd3189c98..ec89301ada41 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -338,17 +338,18 @@ enum {
 
         SKB_GSO_GRE = 1 << 6,
 
-        SKB_GSO_IPIP = 1 << 7,
+        SKB_GSO_GRE_CSUM = 1 << 7,
 
-        SKB_GSO_SIT = 1 << 8,
+        SKB_GSO_IPIP = 1 << 8,
 
-        SKB_GSO_UDP_TUNNEL = 1 << 9,
+        SKB_GSO_SIT = 1 << 9,
 
-        SKB_GSO_MPLS = 1 << 10,
+        SKB_GSO_UDP_TUNNEL = 1 << 10,
 
         SKB_GSO_UDP_TUNNEL_CSUM = 1 << 11,
 
-        SKB_GSO_GRE_CSUM = 1 << 12,
+        SKB_GSO_MPLS = 1 << 12,
+
 };
 
 #if BITS_PER_LONG > 32
@@ -1853,6 +1854,18 @@ static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len)
         return pskb_may_pull(skb, skb_network_offset(skb) + len);
 }
 
+static inline void skb_pop_rcv_encapsulation(struct sk_buff *skb)
+{
+        /* Only continue with checksum unnecessary if device indicated
+         * it is valid across encapsulation (skb->encapsulation was set).
+         */
+        if (skb->ip_summed == CHECKSUM_UNNECESSARY && !skb->encapsulation)
+                skb->ip_summed = CHECKSUM_NONE;
+
+        skb->encapsulation = 0;
+        skb->csum_valid = 0;
+}
+
 /*
  * CPUs often take a performance hit when accessing unaligned memory
  * locations. The actual performance hit varies, it can be small if the
diff --git a/include/net/udp.h b/include/net/udp.h
index 2ecfc6e15609..68a1fefe3dfe 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -111,7 +111,9 @@ struct sk_buff;
  */
 static inline __sum16 __udp_lib_checksum_complete(struct sk_buff *skb)
 {
-        return __skb_checksum_complete_head(skb, UDP_SKB_CB(skb)->cscov);
+        return (UDP_SKB_CB(skb)->cscov == skb->len ?
+                __skb_checksum_complete(skb) :
+                __skb_checksum_complete_head(skb, UDP_SKB_CB(skb)->cscov));
 }
 
 static inline int udp_lib_checksum_complete(struct sk_buff *skb)
diff --git a/net/core/datagram.c b/net/core/datagram.c
index 6b1c04ca1d50..488dd1a825c0 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -739,22 +739,38 @@ __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len)
         __sum16 sum;
 
         sum = csum_fold(skb_checksum(skb, 0, len, skb->csum));
-        if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) && !sum &&
-            !skb->csum_complete_sw)
-                netdev_rx_csum_fault(skb->dev);
-
-        /* Save checksum complete for later use */
-        skb->csum = sum;
-        skb->ip_summed = CHECKSUM_COMPLETE;
-        skb->csum_complete_sw = 1;
-
+        if (likely(!sum)) {
+                if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) &&
+                    !skb->csum_complete_sw)
+                        netdev_rx_csum_fault(skb->dev);
+        }
+        skb->csum_valid = !sum;
         return sum;
 }
 EXPORT_SYMBOL(__skb_checksum_complete_head);
 
 __sum16 __skb_checksum_complete(struct sk_buff *skb)
 {
-        return __skb_checksum_complete_head(skb, skb->len);
+        __wsum csum;
+        __sum16 sum;
+
+        csum = skb_checksum(skb, 0, skb->len, 0);
+
+        /* skb->csum holds pseudo checksum */
+        sum = csum_fold(csum_add(skb->csum, csum));
+        if (likely(!sum)) {
+                if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) &&
+                    !skb->csum_complete_sw)
+                        netdev_rx_csum_fault(skb->dev);
+        }
+
+        /* Save full packet checksum */
+        skb->csum = csum;
+        skb->ip_summed = CHECKSUM_COMPLETE;
+        skb->csum_complete_sw = 1;
+        skb->csum_valid = !sum;
+
+        return sum;
 }
 EXPORT_SYMBOL(__skb_checksum_complete);
 
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index bf92824af3f7..9cd5344fad73 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -689,6 +689,9 @@ static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
         new->ooo_okay           = old->ooo_okay;
         new->no_fcs             = old->no_fcs;
         new->encapsulation      = old->encapsulation;
+        new->encap_hdr_csum     = old->encap_hdr_csum;
+        new->csum_valid         = old->csum_valid;
+        new->csum_complete_sw   = old->csum_complete_sw;
 #ifdef CONFIG_XFRM
         new->sp                 = secpath_get(old->sp);
 #endif