net: ipv6: Move ip6_route_get_saddr to inline

VRF driver needs access to ip6_route_get_saddr code. Since it does
little beyond ipv6_dev_get_saddr and ipv6_dev_get_saddr is already
exported for modules move ip6_route_get_saddr to the header as an
inline.

Code move only; no functional change.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
index f55bf3d..d97305d 100644
--- a/include/net/ip6_route.h
+++ b/include/net/ip6_route.h
@@ -18,6 +18,7 @@
 	__u8			prefix[0];	/* 0,8 or 16 */
 };
 
+#include <net/addrconf.h>
 #include <net/flow.h>
 #include <net/ip6_fib.h>
 #include <net/sock.h>
@@ -88,9 +89,23 @@
 int ip6_ins_rt(struct rt6_info *);
 int ip6_del_rt(struct rt6_info *);
 
-int ip6_route_get_saddr(struct net *net, struct rt6_info *rt,
-			const struct in6_addr *daddr, unsigned int prefs,
-			struct in6_addr *saddr);
+static inline int ip6_route_get_saddr(struct net *net, struct rt6_info *rt,
+				      const struct in6_addr *daddr,
+				      unsigned int prefs,
+				      struct in6_addr *saddr)
+{
+	struct inet6_dev *idev =
+			rt ? ip6_dst_idev((struct dst_entry *)rt) : NULL;
+	int err = 0;
+
+	if (rt && rt->rt6i_prefsrc.plen)
+		*saddr = rt->rt6i_prefsrc.addr;
+	else
+		err = ipv6_dev_get_saddr(net, idev ? idev->dev : NULL,
+					 daddr, prefs, saddr);
+
+	return err;
+}
 
 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
 			    const struct in6_addr *saddr, int oif, int flags);