datapath: backport: ip_tunnel_core: iptunnel_handle_offloads returns int and doesn't free skb

There is return type change in upstream handle-offload functions.
Following patch brings these changes in.
This is backport of aed069df ("ip_tunnel_core:
iptunnel_handle_offloads returns int and doesn't free skb")
I have also removed duplicate definitions of tunnel_handle_offloads()
from ip-tunnel header.

Signed-off-by: Pravin B Shelar <pshelar@ovn.org>
Acked-by: Jesse Gross <jesse@kernel.org>

7 files changed, 106 insertions, 95 deletions

diff --git a/datapath/linux/compat/geneve.c b/datapath/linux/compat/geneve.c
index 8d25f7a2e..45597002f 100644
--- a/datapath/linux/compat/geneve.c
+++ b/datapath/linux/compat/geneve.c
@@ -547,10 +547,8 @@ static int geneve_build_skb(struct rtable *rt, struct sk_buff *skb,
 			+ GENEVE_BASE_HLEN + opt_len + sizeof(struct iphdr)
 			+ (skb_vlan_tag_present(skb) ? VLAN_HLEN : 0);
 	err = skb_cow_head(skb, min_headroom);
-	if (unlikely(err)) {
-		kfree_skb(skb);
+	if (unlikely(err))
 		goto free_rt;
-	}
 
 	skb = vlan_hwaccel_push_inside(skb);
 	if (!skb) {
@@ -558,11 +556,9 @@ static int geneve_build_skb(struct rtable *rt, struct sk_buff *skb,
 		goto free_rt;
 	}
 
-	skb = udp_tunnel_handle_offloads(skb, csum, 0, false);
-	if (IS_ERR(skb)) {
-		err = PTR_ERR(skb);
+	err = udp_tunnel_handle_offloads(skb, csum, false);
+	if (err)
 		goto free_rt;
-	}
 	gnvh = (struct genevehdr *)__skb_push(skb, sizeof(*gnvh) + opt_len);
 	gnvh->ver = GENEVE_VER;
 	gnvh->opt_len = opt_len / 4;
@@ -688,7 +684,7 @@ netdev_tx_t rpl_geneve_xmit(struct sk_buff *skb)
 		err = geneve_build_skb(rt, skb, key->tun_flags, vni,
 				       info->options_len, opts, udp_csum);
 		if (unlikely(err))
-			goto err;
+			goto tx_error;
 
 		tos = ip_tunnel_ecn_encap(key->tos, iip, skb);
 		ttl = key->ttl;
@@ -698,7 +694,7 @@ netdev_tx_t rpl_geneve_xmit(struct sk_buff *skb)
 		err = geneve_build_skb(rt, skb, 0, geneve->vni,
 				       0, NULL, udp_csum);
 		if (unlikely(err))
-			goto err;
+			goto tx_error;
 
 		tos = ip_tunnel_ecn_encap(fl4.flowi4_tos, iip, skb);
 		ttl = geneve->ttl;
@@ -717,7 +713,7 @@ netdev_tx_t rpl_geneve_xmit(struct sk_buff *skb)
 
 tx_error:
 	dev_kfree_skb(skb);
-err:
+
 	if (err == -ELOOP)
 		dev->stats.collisions++;
 	else if (err == -ENETUNREACH)
diff --git a/datapath/linux/compat/include/net/ip_tunnels.h b/datapath/linux/compat/include/net/ip_tunnels.h
index 26c9041f0..cea75a11c 100644
--- a/datapath/linux/compat/include/net/ip_tunnels.h
+++ b/datapath/linux/compat/include/net/ip_tunnels.h
@@ -31,11 +31,27 @@ static inline int rpl_iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
 }
 #endif
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(3,18,0)
-struct sk_buff *ovs_iptunnel_handle_offloads(struct sk_buff *skb,
-					     bool csum_help, int gso_type_mask,
-					     void (*fix_segment)(struct sk_buff *));
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,7,0)
+int ovs_iptunnel_handle_offloads(struct sk_buff *skb,
+				 bool csum_help, int gso_type_mask,
+				 void (*fix_segment)(struct sk_buff *));
+
+/* This is is required to compile upstream gre.h. gre_handle_offloads()
+ * is defined in gre.h and needs iptunnel_handle_offloads(). This provides
+ * default signature for this function.
+ * rpl prefix is to make OVS build happy.
+ */
+#define iptunnel_handle_offloads rpl_iptunnel_handle_offloads
+struct sk_buff *rpl_iptunnel_handle_offloads(struct sk_buff *skb,
+					 bool csum_help,
+					 int gso_type_mask);
+#else
+
+#define ovs_iptunnel_handle_offloads(skb, csum_help, gso_type_mask, fix_segment) \
+	iptunnel_handle_offloads(skb, gso_type_mask)
+#endif
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3,18,0)
 #define iptunnel_xmit rpl_iptunnel_xmit
 int rpl_iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
 		      __be32 src, __be32 dst, __u8 proto, __u8 tos, __u8 ttl,
@@ -43,9 +59,6 @@ int rpl_iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
 
 #else
 
-#define ovs_iptunnel_handle_offloads(skb, csum_help, gso_type_mask, fix_segment) \
-	iptunnel_handle_offloads(skb, csum_help, gso_type_mask)
-
 #define rpl_iptunnel_xmit iptunnel_xmit
 int rpl_iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
 		      __be32 src, __be32 dst, __u8 proto, __u8 tos, __u8 ttl,
@@ -53,14 +66,6 @@ int rpl_iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
 
 #endif /* 3.18 */
 
-/* This is not required for OVS on kernel older than 3.18, but gre.h
- * header file needs this declaration for function gre_handle_offloads().
- * So it is defined for all kernel version.
- */
-#define rpl_iptunnel_handle_offloads iptunnel_handle_offloads
-struct sk_buff *rpl_iptunnel_handle_offloads(struct sk_buff *skb, bool gre_csum,
-					 int gso_type_mask);
-
 #ifndef TUNNEL_CSUM
 #define TUNNEL_CSUM	__cpu_to_be16(0x01)
 #define TUNNEL_ROUTING	__cpu_to_be16(0x02)
diff --git a/datapath/linux/compat/include/net/udp_tunnel.h b/datapath/linux/compat/include/net/udp_tunnel.h
index 85aed9809..23e66f148 100644
--- a/datapath/linux/compat/include/net/udp_tunnel.h
+++ b/datapath/linux/compat/include/net/udp_tunnel.h
@@ -6,21 +6,10 @@
 
 #include <net/dst_metadata.h>
 #include <linux/netdev_features.h>
+
 #ifdef HAVE_UDP_TUNNEL_IPV6
 #include_next <net/udp_tunnel.h>
 
-static inline struct sk_buff *
-rpl_udp_tunnel_handle_offloads(struct sk_buff *skb, bool udp_csum,
-		int type, bool is_vxlan)
-{
-	if (skb_is_gso(skb) && skb_is_encapsulated(skb)) {
-		kfree_skb(skb);
-		return ERR_PTR(-ENOSYS);
-	}
-	return udp_tunnel_handle_offloads(skb, udp_csum);
-}
-#define udp_tunnel_handle_offloads rpl_udp_tunnel_handle_offloads
-
 #else
 
 #include <net/ip_tunnels.h>
@@ -84,20 +73,56 @@ int rpl_udp_tunnel_xmit_skb(struct rtable *rt,
 #define udp_tunnel_sock_release rpl_udp_tunnel_sock_release
 void rpl_udp_tunnel_sock_release(struct socket *sock);
 
+#define udp_tunnel_encap_enable(sock) udp_encap_enable()
+
+#if IS_ENABLED(CONFIG_IPV6)
+#define udp_tunnel6_xmit_skb rpl_udp_tunnel6_xmit_skb
+int rpl_udp_tunnel6_xmit_skb(struct dst_entry *dst, struct sock *sk,
+			 struct sk_buff *skb,
+			 struct net_device *dev, struct in6_addr *saddr,
+			 struct in6_addr *daddr,
+			 __u8 prio, __u8 ttl, __be16 src_port,
+			 __be16 dst_port, bool nocheck);
+#endif
+
+static inline void udp_tunnel_gro_complete(struct sk_buff *skb, int nhoff)
+{
+	struct udphdr *uh;
+
+	uh = (struct udphdr *)(skb->data + nhoff - sizeof(struct udphdr));
+	skb_shinfo(skb)->gso_type |= uh->check ?
+		SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
+}
+#endif
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,7,0)
+/* 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
 void ovs_udp_gso(struct sk_buff *skb);
 void ovs_udp_csum_gso(struct sk_buff *skb);
 
-#define udp_tunnel_encap_enable(sock) udp_encap_enable()
-static inline struct sk_buff *udp_tunnel_handle_offloads(struct sk_buff *skb,
-                                                         bool udp_csum,
-							 int type,
-							 bool is_vxlan)
+static inline int rpl_udp_tunnel_handle_offloads(struct sk_buff *skb,
+						 bool udp_csum,
+						 bool is_vxlan)
 {
+	int type = 0;
+
 	void (*fix_segment)(struct sk_buff *);
 
 	if (skb_is_gso(skb) && skb_is_encapsulated(skb)) {
-		kfree_skb(skb);
-		return ERR_PTR(-ENOSYS);
+		return -ENOSYS;
 	}
 
 	type |= udp_csum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
@@ -113,27 +138,9 @@ static inline struct sk_buff *udp_tunnel_handle_offloads(struct sk_buff *skb,
 
 	return ovs_iptunnel_handle_offloads(skb, udp_csum, type, fix_segment);
 }
-
-#if IS_ENABLED(CONFIG_IPV6)
-#define udp_tunnel6_xmit_skb rpl_udp_tunnel6_xmit_skb
-int rpl_udp_tunnel6_xmit_skb(struct dst_entry *dst, struct sock *sk,
-			 struct sk_buff *skb,
-			 struct net_device *dev, struct in6_addr *saddr,
-			 struct in6_addr *daddr,
-			 __u8 prio, __u8 ttl, __be16 src_port,
-			 __be16 dst_port, bool nocheck);
-#endif
-
-static inline void udp_tunnel_gro_complete(struct sk_buff *skb, int nhoff)
-{
-	struct udphdr *uh;
-
-	uh = (struct udphdr *)(skb->data + nhoff - sizeof(struct udphdr));
-	skb_shinfo(skb)->gso_type |= uh->check ?
-		SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
-}
 #endif
 
+#define udp_tunnel_handle_offloads rpl_udp_tunnel_handle_offloads
 static inline void ovs_udp_tun_rx_dst(struct ip_tunnel_info *info,
 				  struct sk_buff *skb,
 				  unsigned short family,
diff --git a/datapath/linux/compat/ip_gre.c b/datapath/linux/compat/ip_gre.c
index 67db9af73..995f5daad 100644
--- a/datapath/linux/compat/ip_gre.c
+++ b/datapath/linux/compat/ip_gre.c
@@ -171,7 +171,8 @@ static int gre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
 	return 0;
 }
 
-#ifndef HAVE_GRE_HANDLE_OFFLOADS
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,7,0)
+/* gre_handle_offloads() has different return type on older kernsl. */
 static void gre_nop_fix(struct sk_buff *skb) { }
 
 static void gre_csum_fix(struct sk_buff *skb)
@@ -193,7 +194,7 @@ static bool is_gre_gso(struct sk_buff *skb)
 	return skb_is_gso(skb);
 }
 
-static struct sk_buff *rpl_gre_handle_offloads(struct sk_buff *skb, bool gre_csum)
+static int rpl_gre_handle_offloads(struct sk_buff *skb, bool gre_csum)
 {
 	int type = gre_csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE;
 	gso_fix_segment_t fix_segment;
@@ -213,12 +214,11 @@ static bool is_gre_gso(struct sk_buff *skb)
 		(SKB_GSO_GRE | SKB_GSO_GRE_CSUM);
 }
 
-static struct sk_buff *rpl_gre_handle_offloads(struct sk_buff *skb, bool gre_csum)
+static int rpl_gre_handle_offloads(struct sk_buff *skb, bool gre_csum)
 {
-	if (skb_is_gso(skb) && skb_is_encapsulated(skb)) {
-		kfree_skb(skb);
-		return ERR_PTR(-ENOSYS);
-	}
+	if (skb_is_gso(skb) && skb_is_encapsulated(skb))
+		return -ENOSYS;
+
 #undef gre_handle_offloads
 	return gre_handle_offloads(skb, gre_csum);
 }
@@ -318,11 +318,9 @@ netdev_tx_t rpl_gre_fb_xmit(struct sk_buff *skb)
 	}
 
 	/* Push Tunnel header. */
-	skb = rpl_gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM));
-	if (IS_ERR(skb)) {
-		skb = NULL;
+	err = rpl_gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM));
+	if (err)
 		goto err_free_rt;
-	}
 
 	flags = tun_info->key.tun_flags & (TUNNEL_CSUM | TUNNEL_KEY);
 	build_header(skb, tunnel_hlen, flags, htons(ETH_P_TEB),
diff --git a/datapath/linux/compat/ip_tunnels_core.c b/datapath/linux/compat/ip_tunnels_core.c
index ee4fadcb5..cb0223ee2 100644
--- a/datapath/linux/compat/ip_tunnels_core.c
+++ b/datapath/linux/compat/ip_tunnels_core.c
@@ -86,10 +86,12 @@ int rpl_iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
 	return pkt_len;
 }
 EXPORT_SYMBOL_GPL(rpl_iptunnel_xmit);
+#endif
 
-struct sk_buff *ovs_iptunnel_handle_offloads(struct sk_buff *skb,
-					     bool csum_help, int gso_type_mask,
-					     void (*fix_segment)(struct sk_buff *))
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,7,0)
+int ovs_iptunnel_handle_offloads(struct sk_buff *skb,
+				 bool csum_help, int gso_type_mask,
+				 void (*fix_segment)(struct sk_buff *))
 {
 	int err;
 
@@ -103,17 +105,19 @@ struct sk_buff *ovs_iptunnel_handle_offloads(struct sk_buff *skb,
 		goto error;
 	}
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3,18,0)
 	if (gso_type_mask)
 		fix_segment = NULL;
 
 	OVS_GSO_CB(skb)->fix_segment = fix_segment;
+#endif
 
 	if (skb_is_gso(skb)) {
 		err = skb_unclone(skb, GFP_ATOMIC);
 		if (unlikely(err))
 			goto error;
 		skb_shinfo(skb)->gso_type |= gso_type_mask;
-		return skb;
+		return 0;
 	}
 
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(3,8,0)
@@ -133,15 +137,12 @@ struct sk_buff *ovs_iptunnel_handle_offloads(struct sk_buff *skb,
 	} else if (skb->ip_summed != CHECKSUM_PARTIAL)
 		skb->ip_summed = CHECKSUM_NONE;
 
-	return skb;
+	return 0;
 error:
-	kfree_skb(skb);
-	return ERR_PTR(err);
+	return err;
 }
 EXPORT_SYMBOL_GPL(ovs_iptunnel_handle_offloads);
-#endif
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4,7,0)
 int rpl___iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
 			       __be16 inner_proto, bool raw_proto, bool xnet)
 {
diff --git a/datapath/linux/compat/lisp.c b/datapath/linux/compat/lisp.c
index c7260126d..7c1aa3151 100644
--- a/datapath/linux/compat/lisp.c
+++ b/datapath/linux/compat/lisp.c
@@ -344,12 +344,9 @@ netdev_tx_t rpl_lisp_xmit(struct sk_buff *skb)
 	skb_reset_mac_header(skb);
 	skb->vlan_tci = 0;
 
-	skb = udp_tunnel_handle_offloads(skb, false, 0, false);
-	if (IS_ERR(skb)) {
-		err = PTR_ERR(skb);
-		skb = NULL;
+	err = udp_tunnel_handle_offloads(skb, false, false);
+	if (err)
 		goto err_free_rt;
-	}
 
 	src_port = htons(get_src_port(net, skb));
 	dst_port = lisp_dev->dst_port;
diff --git a/datapath/linux/compat/vxlan.c b/datapath/linux/compat/vxlan.c
index 4374a3a6b..4e65b4341 100644
--- a/datapath/linux/compat/vxlan.c
+++ b/datapath/linux/compat/vxlan.c
@@ -1030,6 +1030,7 @@ static int vxlan6_xmit_skb(struct dst_entry *dst, struct sock *sk,
 			   __be16 src_port, __be16 dst_port, __be32 vni,
 			   struct vxlan_metadata *md, bool xnet, u32 vxflags)
 {
+	void (*fix_segment)(struct sk_buff *);
 	struct vxlanhdr *vxh;
 	int min_headroom;
 	int err;
@@ -1074,9 +1075,11 @@ static int vxlan6_xmit_skb(struct dst_entry *dst, struct sock *sk,
 		goto err;
 	}
 
-	skb = udp_tunnel_handle_offloads(skb, udp_sum, type, true);
-	if (IS_ERR(skb)) {
-		err = -EINVAL;
+	type |= udp_sum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
+	fix_segment = udp_sum ? ovs_udp_gso : ovs_udp_csum_gso;
+	err = ovs_iptunnel_handle_offloads(skb, udp_sum, type, fix_segment);
+	if (err) {
+		kfree_skb(skb);
 		goto err;
 	}
 
@@ -1123,6 +1126,7 @@ static int vxlan_xmit_skb(struct rtable *rt, struct sock *sk, struct sk_buff *sk
 			  __be16 src_port, __be16 dst_port, __be32 vni,
 			  struct vxlan_metadata *md, bool xnet, u32 vxflags)
 {
+	void (*fix_segment)(struct sk_buff *);
 	struct vxlanhdr *vxh;
 	int min_headroom;
 	int err;
@@ -1162,10 +1166,13 @@ static int vxlan_xmit_skb(struct rtable *rt, struct sock *sk, struct sk_buff *sk
 	if (WARN_ON(!skb))
 		return -ENOMEM;
 
-	skb = udp_tunnel_handle_offloads(skb, udp_sum, type, true);
-	if (IS_ERR(skb))
-		return PTR_ERR(skb);
-
+	type |= udp_sum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
+	fix_segment = udp_sum ? ovs_udp_gso : ovs_udp_csum_gso;
+	err = ovs_iptunnel_handle_offloads(skb, udp_sum, type, fix_segment);
+	if (err) {
+		kfree_skb(skb);
+		return err;
+	}
 	vxh = (struct vxlanhdr *) __skb_push(skb, sizeof(*vxh));
 	vxh->vx_flags = htonl(VXLAN_HF_VNI);
 	vxh->vx_vni = vni;