datapath: Add support for kernel 4.6

Most of patch iron out USE_UPSTREAM_TUNNEL case where datapath
directly use upstream tunneling modules.

Signed-off-by: Pravin B Shelar <pshelar@ovn.org>
Acked-by: Jesse Gross <jesse@kernel.org>
Acked-by: Amitabha Biswas <abiswas@us.ibm.com>

8 files changed, 49 insertions, 33 deletions

diff --git a/acinclude.m4 b/acinclude.m4
index 3f31e5f0e..faf79eb9d 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -134,10 +134,10 @@ AC_DEFUN([OVS_CHECK_LINUX], [
     AC_MSG_RESULT([$kversion])
 
     if test "$version" -ge 4; then
-       if test "$version" = 4 && test "$patchlevel" -le 5; then
+       if test "$version" = 4 && test "$patchlevel" -le 6; then
           : # Linux 4.x
        else
-          AC_ERROR([Linux kernel in $KBUILD is version $kversion, but version newer than 4.5.x is not supported (please refer to the FAQ for advice)])
+          AC_ERROR([Linux kernel in $KBUILD is version $kversion, but version newer than 4.6.x is not supported (please refer to the FAQ for advice)])
        fi
     elif test "$version" = 3 && test "$patchlevel" -ge 10; then
        : # Linux 3.x
@@ -393,7 +393,6 @@ AC_DEFUN([OVS_CHECK_LINUX_COMPAT], [
 
   OVS_GREP_IFELSE([$KSRC/include/linux/etherdevice.h], [eth_hw_addr_random])
   OVS_GREP_IFELSE([$KSRC/include/linux/etherdevice.h], [ether_addr_copy])
-  OVS_GREP_IFELSE([$KSRC/nclude/linux/if_ether.h], [inner_eth_hdr])
 
   OVS_GREP_IFELSE([$KSRC/include/uapi/linux/if_link.h], [IFLA_GENEVE_TOS])
   OVS_GREP_IFELSE([$KSRC/include/uapi/linux/if_link.h], [rtnl_link_stats64])
@@ -640,6 +639,8 @@ AC_DEFUN([OVS_CHECK_LINUX_COMPAT], [
                                    [OVS_DEFINE([HAVE_UDP_FLOW_SRC_PORT])])])
   OVS_GREP_IFELSE([$KSRC/include/net/udp.h], [udp_v4_check])
   OVS_GREP_IFELSE([$KSRC/include/net/udp_tunnel.h], [udp_tunnel_gro_complete])
+  OVS_GREP_IFELSE([$KSRC/include/net/udp_tunnel.h], [sk_buff.*udp_tunnel_handle_offloads],
+                  [OVS_DEFINE([HAVE_UDP_TUNNEL_HANDLE_OFFLOAD_RET_SKB])])
   OVS_FIND_FIELD_IFELSE([$KSRC/include/net/udp_tunnel.h], [udp_tunnel_sock_cfg],
                         [gro_receive])
 
diff --git a/datapath/linux/compat/geneve.c b/datapath/linux/compat/geneve.c
index f78260634..834b34c68 100644
--- a/datapath/linux/compat/geneve.c
+++ b/datapath/linux/compat/geneve.c
@@ -757,7 +757,7 @@ static int geneve_build_skb(struct rtable *rt, struct sk_buff *skb,
 	if (unlikely(err))
 		goto free_rt;
 
-	err = udp_tunnel_handle_offloads(skb, udp_sum, false);
+	err = udp_tunnel_handle_offloads(skb, udp_sum);
 	if (err)
 		goto free_rt;
 
@@ -790,7 +790,7 @@ static int geneve6_build_skb(struct dst_entry *dst, struct sk_buff *skb,
 	if (unlikely(err))
 		goto free_dst;
 
-	err = udp_tunnel_handle_offloads(skb, udp_sum, false);
+	err = udp_tunnel_handle_offloads(skb, udp_sum);
 	if (err)
 		goto free_dst;
 
diff --git a/datapath/linux/compat/include/linux/if_ether.h b/datapath/linux/compat/include/linux/if_ether.h
index b2cb56d4b..ac0f1edb3 100644
--- a/datapath/linux/compat/include/linux/if_ether.h
+++ b/datapath/linux/compat/include/linux/if_ether.h
@@ -11,10 +11,9 @@
 #define ETH_P_8021AD    0x88A8          /* 802.1ad Service VLAN         */
 #endif
 
-#ifndef HAVE_INNER_ETH_HDR
+#define inner_eth_hdr rpl_inner_eth_hdr
 static inline struct ethhdr *inner_eth_hdr(const struct sk_buff *skb)
 {
 	return (struct ethhdr *)skb_inner_mac_header(skb);
 }
 #endif
-#endif
diff --git a/datapath/linux/compat/include/net/dst_cache.h b/datapath/linux/compat/include/net/dst_cache.h
index 53ca42abd..ff4d83b83 100644
--- a/datapath/linux/compat/include/net/dst_cache.h
+++ b/datapath/linux/compat/include/net/dst_cache.h
@@ -7,7 +7,10 @@
 #include <net/ip6_fib.h>
 #endif
 
-#ifndef USE_UPSTREAM_TUNNEL
+#ifdef USE_UPSTREAM_TUNNEL
+#include_next <net/dst_cache.h>
+
+#else
 struct dst_cache {
 	struct dst_cache_pcpu __percpu *cache;
 	unsigned long reset_ts;
diff --git a/datapath/linux/compat/include/net/dst_metadata.h b/datapath/linux/compat/include/net/dst_metadata.h
index 6660dfc72..279b7144b 100644
--- a/datapath/linux/compat/include/net/dst_metadata.h
+++ b/datapath/linux/compat/include/net/dst_metadata.h
@@ -48,7 +48,6 @@ static inline struct metadata_dst *metadata_dst_alloc(u8 optslen, gfp_t flags)
 }
 
 #define skb_tunnel_info ovs_skb_tunnel_info
-#endif
 
 static inline void ovs_tun_rx_dst(struct metadata_dst *md_dst, int optslen)
 {
@@ -100,6 +99,8 @@ static inline void ovs_ipv6_tun_rx_dst(struct metadata_dst *md_dst,
 	info->key.label = ip6_flowlabel(ip6h);
 }
 
+#endif /* USE_UPSTREAM_TUNNEL */
+
 void ovs_ip_tunnel_rcv(struct net_device *dev, struct sk_buff *skb,
 		      struct metadata_dst *tun_dst);
 #endif /* __NET_DST_METADATA_WRAPPER_H */
diff --git a/datapath/linux/compat/include/net/ip_tunnels.h b/datapath/linux/compat/include/net/ip_tunnels.h
index 6775c9aaf..3df770d9b 100644
--- a/datapath/linux/compat/include/net/ip_tunnels.h
+++ b/datapath/linux/compat/include/net/ip_tunnels.h
@@ -91,9 +91,6 @@ struct tnl_ptk_info {
 #undef TUNNEL_OPTIONS_PRESENT
 #define TUNNEL_OPTIONS_PRESENT (TUNNEL_GENEVE_OPT | TUNNEL_VXLAN_OPT)
 
-#define skb_is_encapsulated ovs_skb_is_encapsulated
-bool ovs_skb_is_encapsulated(struct sk_buff *skb);
-
 /* Used to memset ip_tunnel padding. */
 #define IP_TUNNEL_KEY_SIZE	offsetofend(struct ip_tunnel_key, tp_dst)
 
@@ -345,4 +342,8 @@ static inline int iptunnel_pull_offloads(struct sk_buff *skb)
 	return 0;
 }
 #endif /* USE_UPSTREAM_TUNNEL */
+
+#define skb_is_encapsulated ovs_skb_is_encapsulated
+bool ovs_skb_is_encapsulated(struct sk_buff *skb);
+
 #endif /* __NET_IP_TUNNELS_H */
diff --git a/datapath/linux/compat/include/net/udp_tunnel.h b/datapath/linux/compat/include/net/udp_tunnel.h
index ded7f305c..8afacb865 100644
--- a/datapath/linux/compat/include/net/udp_tunnel.h
+++ b/datapath/linux/compat/include/net/udp_tunnel.h
@@ -11,19 +11,6 @@
 #ifdef USE_UPSTREAM_TUNNEL
 #include_next <net/udp_tunnel.h>
 
-/* this is to handle the return type change in handle-offload
- * functions.
- */
-static inline int
-rpl_udp_tunnel_handle_offloads(struct sk_buff *skb, bool udp_csum,
-			       bool is_vxlan)
-{
-	if (skb_is_gso(skb) && skb_is_encapsulated(skb)) {
-		return -ENOSYS;
-	}
-	return udp_tunnel_handle_offloads(skb, udp_csum);
-}
-
 #else
 
 #include <net/addrconf.h>
@@ -161,8 +148,7 @@ void ovs_udp_gso(struct sk_buff *skb);
 void ovs_udp_csum_gso(struct sk_buff *skb);
 
 static inline int rpl_udp_tunnel_handle_offloads(struct sk_buff *skb,
-						 bool udp_csum,
-						 bool is_vxlan)
+						 bool udp_csum)
 {
 	int type = 0;
 
@@ -177,15 +163,16 @@ static inline int rpl_udp_tunnel_handle_offloads(struct sk_buff *skb,
 		fix_segment = ovs_udp_gso;
 	else
 		fix_segment = ovs_udp_csum_gso;
-
 #if LINUX_VERSION_CODE < KERNEL_VERSION(3,18,0)
-	if (!is_vxlan)
-		type = 0;
+	/* This functuin is not used by vxlan lan tunnel. On older
+	 * udp offload only supports vxlan, therefore fallback to software
+	 * segmentation.
+	 */
+	type = 0;
 #endif
 
 	return ovs_iptunnel_handle_offloads(skb, udp_csum, type, fix_segment);
 }
-#endif /* USE_UPSTREAM_TUNNEL */
 
 #define udp_tunnel_handle_offloads rpl_udp_tunnel_handle_offloads
 static inline void ovs_udp_tun_rx_dst(struct metadata_dst *md_dst,
@@ -205,5 +192,6 @@ static inline void ovs_udp_tun_rx_dst(struct metadata_dst *md_dst,
 	if (udp_hdr(skb)->check)
 		info->key.tun_flags |= TUNNEL_CSUM;
 }
+#endif /* USE_UPSTREAM_TUNNEL */
 
 #endif
diff --git a/datapath/linux/compat/lisp.c b/datapath/linux/compat/lisp.c
index dd2305947..feef48602 100644
--- a/datapath/linux/compat/lisp.c
+++ b/datapath/linux/compat/lisp.c
@@ -290,6 +290,26 @@ static struct rtable *lisp_get_rt(struct sk_buff *skb,
 	return ip_route_output_key(net, fl);
 }
 
+/* this is to handle the return type change in handle-offload
+ * functions.
+ */
+#if !defined(HAVE_UDP_TUNNEL_HANDLE_OFFLOAD_RET_SKB) || !defined(USE_UPSTREAM_TUNNEL)
+static struct sk_buff *
+__udp_tunnel_handle_offloads(struct sk_buff *skb, bool udp_csum)
+{
+	int err;
+
+	err = udp_tunnel_handle_offloads(skb, udp_csum);
+	if (err) {
+		kfree_skb(skb);
+		return NULL;
+	}
+	return skb;
+}
+#else
+#define __udp_tunnel_handle_offloads udp_tunnel_handle_offloads
+#endif
+
 netdev_tx_t rpl_lisp_xmit(struct sk_buff *skb)
 {
 	struct net_device *dev = skb->dev;
@@ -344,10 +364,13 @@ netdev_tx_t rpl_lisp_xmit(struct sk_buff *skb)
 	skb_reset_mac_header(skb);
 	skb->vlan_tci = 0;
 
-	err = udp_tunnel_handle_offloads(skb, false, false);
-	if (err)
+	if (skb_is_gso(skb) && skb_is_encapsulated(skb))
 		goto err_free_rt;
 
+	skb = __udp_tunnel_handle_offloads(skb, false);
+	if (!skb)
+		return NETDEV_TX_OK;
+
 	src_port = htons(get_src_port(net, skb));
 	dst_port = lisp_dev->dst_port;