[PATCH net v4 1/3] ipv6: add a wrapper for ip6_dst_store() with flowi6 checks

[Alexey Kodanev <alexey.kodanev@oracle.com>]

Move commonly used pattern of ip6_dst_store() usage to a separate
function - ip6_dst_store_flow(), which will check the addresses
for equality using the flow information, before saving them.

There is no functional changes in this patch. In addition, it will
be used in the next patch, in ip6_sk_dst_lookup_flow().

Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
---
 include/net/ipv6.h    |  3 ++-
 net/ipv6/datagram.c   |  9 +--------
 net/ipv6/ip6_output.c | 17 +++++++++++++++++
 3 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index 8606c91..1dd31ca 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -971,7 +971,8 @@ static inline struct sk_buff *ip6_finish_skb(struct sock *sk)
 }
 
 unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst);
-
+void ip6_dst_store_flow(struct sock *sk, struct dst_entry *dst,
+			const struct flowi6 *fl6);
 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst,
 		   struct flowi6 *fl6);
 struct dst_entry *ip6_dst_lookup_flow(const struct sock *sk, struct flowi6 *fl6,
diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c
index a9f7eca..8b4fa0c 100644
--- a/net/ipv6/datagram.c
+++ b/net/ipv6/datagram.c
@@ -106,14 +106,7 @@ int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr)
 		}
 	}
 
-	ip6_dst_store(sk, dst,
-		      ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ?
-		      &sk->sk_v6_daddr : NULL,
-#ifdef CONFIG_IPV6_SUBTREES
-		      ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
-		      &np->saddr :
-#endif
-		      NULL);
+	ip6_dst_store_flow(sk, dst, &fl6);
 
 out:
 	fl6_sock_release(flowlabel);
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index a8a9195..ed87ce5 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -943,6 +943,23 @@ static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
 	return dst;
 }
 
+void ip6_dst_store_flow(struct sock *sk, struct dst_entry *dst,
+			const struct flowi6 *fl6)
+{
+#ifdef CONFIG_IPV6_SUBTREES
+	struct ipv6_pinfo *np = inet6_sk(sk);
+#endif
+
+	ip6_dst_store(sk, dst,
+		      ipv6_addr_equal(&fl6->daddr, &sk->sk_v6_daddr) ?
+		      &sk->sk_v6_daddr : NULL,
+#ifdef CONFIG_IPV6_SUBTREES
+		      ipv6_addr_equal(&fl6->saddr, &np->saddr) ?
+		      &np->saddr :
+#endif
+		      NULL);
+}
+
 static int ip6_dst_lookup_tail(struct net *net, const struct sock *sk,
 			       struct dst_entry **dst, struct flowi6 *fl6)
 {
-- 
1.8.3.1