ipv6: rename and move ip6_dst_lookup_tunnel()

At the moment ip6_dst_lookup_tunnel() is used only by bareudp.
Ideally, other UDP tunnel implementations should use it, but to do so
the function needs to accept new parameters that are specific for UDP
tunnels, such as the ports.

Prepare for these changes by renaming the function to
udp_tunnel6_dst_lookup() and move it to file
net/ipv6/ip6_udp_tunnel.c.

This is similar to what already done for IPv4 in commit bf3fcbf7
("ipv4: rename and move ip_route_output_tunnel()").
Suggested-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/bareudp.c

@@ -371,8 +371,8 @@ static int bareudp6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
 	if (!sock)
 		return -ESHUTDOWN;
 
-	dst = ip6_dst_lookup_tunnel(skb, dev, bareudp->net, sock, &saddr, info,
-				    IPPROTO_UDP, use_cache);
+	dst = udp_tunnel6_dst_lookup(skb, dev, bareudp->net, sock, &saddr, info,
+				     IPPROTO_UDP, use_cache);
 	if (IS_ERR(dst))
 		return PTR_ERR(dst);
 
@@ -498,9 +498,9 @@ static int bareudp_fill_metadata_dst(struct net_device *dev,
 		struct in6_addr saddr;
 		struct socket *sock = rcu_dereference(bareudp->sock);
 
-		dst = ip6_dst_lookup_tunnel(skb, dev, bareudp->net, sock,
-					    &saddr, info, IPPROTO_UDP,
-					    use_cache);
+		dst = udp_tunnel6_dst_lookup(skb, dev, bareudp->net, sock,
+					     &saddr, info, IPPROTO_UDP,
+					     use_cache);
 		if (IS_ERR(dst))
 			return PTR_ERR(dst);
 

include/net/ipv6.h

@@ -1133,12 +1133,6 @@ struct dst_entry *ip6_dst_lookup_flow(struct net *net, const struct sock *sk, st
 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
 					 const struct in6_addr *final_dst,
 					 bool connected);
-struct dst_entry *ip6_dst_lookup_tunnel(struct sk_buff *skb,
-					struct net_device *dev,
-					struct net *net, struct socket *sock,
-					struct in6_addr *saddr,
-					const struct ip_tunnel_info *info,
-					u8 protocol, bool use_cache);
 struct dst_entry *ip6_blackhole_route(struct net *net,
 				      struct dst_entry *orig_dst);
 

include/net/udp_tunnel.h

@@ -169,6 +169,13 @@ struct rtable *udp_tunnel_dst_lookup(struct sk_buff *skb,
 				     const struct ip_tunnel_key *key,
 				     __be16 sport, __be16 dport, u8 tos,
 				     struct dst_cache *dst_cache);
+struct dst_entry *udp_tunnel6_dst_lookup(struct sk_buff *skb,
+					 struct net_device *dev,
+					 struct net *net,
+					 struct socket *sock,
+					 struct in6_addr *saddr,
+					 const struct ip_tunnel_info *info,
+					 u8 protocol, bool use_cache);
 
 struct metadata_dst *udp_tun_rx_dst(struct sk_buff *skb, unsigned short family,
 				    __be16 flags, __be64 tunnel_id,

net/ipv6/ip6_output.c

@@ -1283,74 +1283,6 @@ struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
 }
 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow);
 
-/**
- *      ip6_dst_lookup_tunnel - perform route lookup on tunnel
- *      @skb: Packet for which lookup is done
- *      @dev: Tunnel device
- *      @net: Network namespace of tunnel device
- *      @sock: Socket which provides route info
- *      @saddr: Memory to store the src ip address
- *      @info: Tunnel information
- *      @protocol: IP protocol
- *      @use_cache: Flag to enable cache usage
- *      This function performs a route lookup on a tunnel
- *
- *      It returns a valid dst pointer and stores src address to be used in
- *      tunnel in param saddr on success, else a pointer encoded error code.
- */
-
-struct dst_entry *ip6_dst_lookup_tunnel(struct sk_buff *skb,
-					struct net_device *dev,
-					struct net *net,
-					struct socket *sock,
-					struct in6_addr *saddr,
-					const struct ip_tunnel_info *info,
-					u8 protocol,
-					bool use_cache)
-{
-	struct dst_entry *dst = NULL;
-#ifdef CONFIG_DST_CACHE
-	struct dst_cache *dst_cache;
-#endif
-	struct flowi6 fl6;
-	__u8 prio;
-
-#ifdef CONFIG_DST_CACHE
-	dst_cache = (struct dst_cache *)&info->dst_cache;
-	if (use_cache) {
-		dst = dst_cache_get_ip6(dst_cache, saddr);
-		if (dst)
-			return dst;
-	}
-#endif
-	memset(&fl6, 0, sizeof(fl6));
-	fl6.flowi6_mark = skb->mark;
-	fl6.flowi6_proto = protocol;
-	fl6.daddr = info->key.u.ipv6.dst;
-	fl6.saddr = info->key.u.ipv6.src;
-	prio = info->key.tos;
-	fl6.flowlabel = ip6_make_flowinfo(prio, info->key.label);
-
-	dst = ipv6_stub->ipv6_dst_lookup_flow(net, sock->sk, &fl6,
-					      NULL);
-	if (IS_ERR(dst)) {
-		netdev_dbg(dev, "no route to %pI6\n", &fl6.daddr);
-		return ERR_PTR(-ENETUNREACH);
-	}
-	if (dst->dev == dev) { /* is this necessary? */
-		netdev_dbg(dev, "circular route to %pI6\n", &fl6.daddr);
-		dst_release(dst);
-		return ERR_PTR(-ELOOP);
-	}
-#ifdef CONFIG_DST_CACHE
-	if (use_cache)
-		dst_cache_set_ip6(dst_cache, dst, &fl6.saddr);
-#endif
-	*saddr = fl6.saddr;
-	return dst;
-}
-EXPORT_SYMBOL_GPL(ip6_dst_lookup_tunnel);
-
 static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src,
 					       gfp_t gfp)
 {

net/ipv6/ip6_udp_tunnel.c

+
 // SPDX-License-Identifier: GPL-2.0-only
 #include <linux/module.h>
 #include <linux/errno.h>
@@ -112,4 +113,72 @@ int udp_tunnel6_xmit_skb(struct dst_entry *dst, struct sock *sk,
 }
 EXPORT_SYMBOL_GPL(udp_tunnel6_xmit_skb);
 
+/**
+ *      udp_tunnel6_dst_lookup - perform route lookup on UDP tunnel
+ *      @skb: Packet for which lookup is done
+ *      @dev: Tunnel device
+ *      @net: Network namespace of tunnel device
+ *      @sock: Socket which provides route info
+ *      @saddr: Memory to store the src ip address
+ *      @info: Tunnel information
+ *      @protocol: IP protocol
+ *      @use_cache: Flag to enable cache usage
+ *      This function performs a route lookup on a UDP tunnel
+ *
+ *      It returns a valid dst pointer and stores src address to be used in
+ *      tunnel in param saddr on success, else a pointer encoded error code.
+ */
+
+struct dst_entry *udp_tunnel6_dst_lookup(struct sk_buff *skb,
+					 struct net_device *dev,
+					 struct net *net,
+					 struct socket *sock,
+					 struct in6_addr *saddr,
+					 const struct ip_tunnel_info *info,
+					 u8 protocol,
+					 bool use_cache)
+{
+	struct dst_entry *dst = NULL;
+#ifdef CONFIG_DST_CACHE
+	struct dst_cache *dst_cache;
+#endif
+	struct flowi6 fl6;
+	__u8 prio;
+
+#ifdef CONFIG_DST_CACHE
+	dst_cache = (struct dst_cache *)&info->dst_cache;
+	if (use_cache) {
+		dst = dst_cache_get_ip6(dst_cache, saddr);
+		if (dst)
+			return dst;
+	}
+#endif
+	memset(&fl6, 0, sizeof(fl6));
+	fl6.flowi6_mark = skb->mark;
+	fl6.flowi6_proto = protocol;
+	fl6.daddr = info->key.u.ipv6.dst;
+	fl6.saddr = info->key.u.ipv6.src;
+	prio = info->key.tos;
+	fl6.flowlabel = ip6_make_flowinfo(prio, info->key.label);
+
+	dst = ipv6_stub->ipv6_dst_lookup_flow(net, sock->sk, &fl6,
+					      NULL);
+	if (IS_ERR(dst)) {
+		netdev_dbg(dev, "no route to %pI6\n", &fl6.daddr);
+		return ERR_PTR(-ENETUNREACH);
+	}
+	if (dst->dev == dev) { /* is this necessary? */
+		netdev_dbg(dev, "circular route to %pI6\n", &fl6.daddr);
+		dst_release(dst);
+		return ERR_PTR(-ELOOP);
+	}
+#ifdef CONFIG_DST_CACHE
+	if (use_cache)
+		dst_cache_set_ip6(dst_cache, dst, &fl6.saddr);
+#endif
+	*saddr = fl6.saddr;
+	return dst;
+}
+EXPORT_SYMBOL_GPL(udp_tunnel6_dst_lookup);
+
 MODULE_LICENSE("GPL");