net: ip_tunnel: remove 'csum_help' argument to iptunnel_handle_offloads

All users now pass false, so we can remove it, and remove the code that
 was conditional upon it.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/vxlan.c

@@ -1721,7 +1721,7 @@ static int vxlan_build_skb(struct sk_buff *skb, struct dst_entry *dst,
 	if (WARN_ON(!skb))
 		return -ENOMEM;
 
-	skb = iptunnel_handle_offloads(skb, false, type);
+	skb = iptunnel_handle_offloads(skb, type);
 	if (IS_ERR(skb))
 		return PTR_ERR(skb);
 

include/net/ip_tunnels.h

@@ -279,8 +279,7 @@ void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
 struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
 					     gfp_t flags);
 
-struct sk_buff *iptunnel_handle_offloads(struct sk_buff *skb, bool gre_csum,
-					 int gso_type_mask);
+struct sk_buff *iptunnel_handle_offloads(struct sk_buff *skb, int gso_type_mask);
 
 static inline void iptunnel_xmit_stats(struct net_device *dev, int pkt_len)
 {

include/net/udp_tunnel.h

@@ -103,8 +103,7 @@ static inline struct sk_buff *udp_tunnel_handle_offloads(struct sk_buff *skb,
 {
 	int type = udp_csum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
 
-	/* As we're a UDP tunnel, we support LCO, so don't need csum_help */
-	return iptunnel_handle_offloads(skb, false, type);
+	return iptunnel_handle_offloads(skb, type);
 }
 
 static inline void udp_tunnel_gro_complete(struct sk_buff *skb, int nhoff)

net/ipv4/fou.c

@@ -787,7 +787,7 @@ int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
 						       SKB_GSO_UDP_TUNNEL;
 	__be16 sport;
 
-	skb = iptunnel_handle_offloads(skb, false, type);
+	skb = iptunnel_handle_offloads(skb, type);
 
 	if (IS_ERR(skb))
 		return PTR_ERR(skb);
@@ -820,7 +820,7 @@ int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
 
 	optlen += need_priv ? GUE_LEN_PRIV : 0;
 
-	skb = iptunnel_handle_offloads(skb, false, type);
+	skb = iptunnel_handle_offloads(skb, type);
 
 	if (IS_ERR(skb))
 		return PTR_ERR(skb);

net/ipv4/ip_gre.c

@@ -503,8 +503,7 @@ static void __gre_xmit(struct sk_buff *skb, struct net_device *dev,
 static struct sk_buff *gre_handle_offloads(struct sk_buff *skb,
 					   bool csum)
 {
-	return iptunnel_handle_offloads(skb, false,
-					csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
+	return iptunnel_handle_offloads(skb, csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
 }
 
 static struct rtable *gre_get_rt(struct sk_buff *skb,

net/ipv4/ip_tunnel_core.c

@@ -148,7 +148,6 @@ struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
 EXPORT_SYMBOL_GPL(iptunnel_metadata_reply);
 
 struct sk_buff *iptunnel_handle_offloads(struct sk_buff *skb,
-					 bool csum_help,
 					 int gso_type_mask)
 {
 	int err;
@@ -166,18 +165,13 @@ struct sk_buff *iptunnel_handle_offloads(struct sk_buff *skb,
 		return skb;
 	}
 
-	/* If packet is not gso and we are not offloading inner checksum,
-	 * clear encapsulation flag. This allows setting CHECKSUM_PARTIAL
-	 * on the outer header without confusing devices that implement
-	 * NETIF_F_IP_CSUM with encapsulation.
-	 */
-	if (skb->ip_summed == CHECKSUM_PARTIAL && csum_help) {
-		skb->encapsulation = 0;
-		err = skb_checksum_help(skb);
-		if (unlikely(err))
-			goto error;
-	} else if (skb->ip_summed != CHECKSUM_PARTIAL) {
+	if (skb->ip_summed != CHECKSUM_PARTIAL) {
 		skb->ip_summed = CHECKSUM_NONE;
+		/* We clear encapsulation here to prevent badly-written
+		 * drivers potentially deciding to offload an inner checksum
+		 * if we set CHECKSUM_PARTIAL on the outer header.
+		 * This should go away when the drivers are all fixed.
+		 */
 		skb->encapsulation = 0;
 	}
 

net/ipv4/ipip.c

@@ -219,7 +219,7 @@ static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
 	if (unlikely(skb->protocol != htons(ETH_P_IP)))
 		goto tx_error;
 
-	skb = iptunnel_handle_offloads(skb, false, SKB_GSO_IPIP);
+	skb = iptunnel_handle_offloads(skb, SKB_GSO_IPIP);
 	if (IS_ERR(skb))
 		goto out;
 

net/ipv6/sit.c

@@ -911,7 +911,7 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
 		goto tx_error;
 	}
 
-	skb = iptunnel_handle_offloads(skb, false, SKB_GSO_SIT);
+	skb = iptunnel_handle_offloads(skb, SKB_GSO_SIT);
 	if (IS_ERR(skb)) {
 		ip_rt_put(rt);
 		goto out;
@@ -1000,7 +1000,7 @@ static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
 	struct ip_tunnel *tunnel = netdev_priv(dev);
 	const struct iphdr  *tiph = &tunnel->parms.iph;
 
-	skb = iptunnel_handle_offloads(skb, false, SKB_GSO_IPIP);
+	skb = iptunnel_handle_offloads(skb, SKB_GSO_IPIP);
 	if (IS_ERR(skb))
 		goto out;
 

net/netfilter/ipvs/ip_vs_xmit.c

@@ -1019,8 +1019,7 @@ ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
 	if (IS_ERR(skb))
 		goto tx_error;
 
-	skb = iptunnel_handle_offloads(
-		skb, false, __tun_gso_type_mask(AF_INET, cp->af));
+	skb = iptunnel_handle_offloads(skb, __tun_gso_type_mask(AF_INET, cp->af));
 	if (IS_ERR(skb))
 		goto tx_error;
 
@@ -1112,8 +1111,7 @@ ip_vs_tunnel_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
 	if (IS_ERR(skb))
 		goto tx_error;
 
-	skb = iptunnel_handle_offloads(
-		skb, false, __tun_gso_type_mask(AF_INET6, cp->af));
+	skb = iptunnel_handle_offloads(skb, __tun_gso_type_mask(AF_INET6, cp->af));
 	if (IS_ERR(skb))
 		goto tx_error;