fou: Split out {fou,gue}_build_header

Create __fou_build_header and __gue_build_header. These implement the
protocol generic parts of building the fou and gue header.
fou_build_header and gue_build_header implement the IPv4 specific
functions and call the __*_build_header functions.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 41 insertions, 14 deletions

diff --git a/include/net/fou.h b/include/net/fou.h
index 19b8a0c62a98..7d2fda2a3a9c 100644
--- a/include/net/fou.h
+++ b/include/net/fou.h
@@ -11,9 +11,9 @@
 size_t fou_encap_hlen(struct ip_tunnel_encap *e);
 static size_t gue_encap_hlen(struct ip_tunnel_encap *e);
 
-int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
-                     u8 *protocol, struct flowi4 *fl4);
-int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
-                     u8 *protocol, struct flowi4 *fl4);
+int __fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
+                       u8 *protocol, __be16 *sport, int type);
+int __gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
+                       u8 *protocol, __be16 *sport, int type);
 
 #endif
diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c
index 6cbc72535426..f4f2ddd8f216 100644
--- a/net/ipv4/fou.c
+++ b/net/ipv4/fou.c
@@ -780,6 +780,22 @@ static void fou_build_udp(struct sk_buff *skb, struct ip_tunnel_encap *e,
         *protocol = IPPROTO_UDP;
 }
 
+int __fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
+                       u8 *protocol, __be16 *sport, int type)
+{
+        int err;
+
+        err = iptunnel_handle_offloads(skb, type);
+        if (err)
+                return err;
+
+        *sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev),
+                                                skb, 0, 0, false);
+
+        return 0;
+}
+EXPORT_SYMBOL(__fou_build_header);
+
 int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
                      u8 *protocol, struct flowi4 *fl4)
 {
@@ -788,26 +804,21 @@ int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
         __be16 sport;
         int err;
 
-        err = iptunnel_handle_offloads(skb, type);
+        err = __fou_build_header(skb, e, protocol, &sport, type);
         if (err)
                 return err;
 
-        sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev),
-                                               skb, 0, 0, false);
         fou_build_udp(skb, e, fl4, protocol, sport);
 
         return 0;
 }
 EXPORT_SYMBOL(fou_build_header);
 
-int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
-                     u8 *protocol, struct flowi4 *fl4)
+int __gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
+                       u8 *protocol, __be16 *sport, int type)
 {
-        int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM ? SKB_GSO_UDP_TUNNEL_CSUM :
-                                                       SKB_GSO_UDP_TUNNEL;
         struct guehdr *guehdr;
         size_t hdrlen, optlen = 0;
-        __be16 sport;
         void *data;
         bool need_priv = false;
         int err;
@@ -826,8 +837,8 @@ int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
                 return err;
 
         /* Get source port (based on flow hash) before skb_push */
-        sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev),
-                                               skb, 0, 0, false);
+        *sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev),
+                                                skb, 0, 0, false);
 
         hdrlen = sizeof(struct guehdr) + optlen;
 
@@ -872,6 +883,22 @@ int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
 
         }
 
+        return 0;
+}
+EXPORT_SYMBOL(__gue_build_header);
+
+int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
+                     u8 *protocol, struct flowi4 *fl4)
+{
+        int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM ? SKB_GSO_UDP_TUNNEL_CSUM :
+                                                       SKB_GSO_UDP_TUNNEL;
+        __be16 sport;
+        int err;
+
+        err = __gue_build_header(skb, e, protocol, &sport, type);
+        if (err)
+                return err;
+
         fou_build_udp(skb, e, fl4, protocol, sport);
 
         return 0;