ipv6: move ip6_dst_hoplimit() into core kernel

It will be used by vxlan, and may not be inlined.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NCong Wang <amwang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/net/ip6_route.h

@@ -112,8 +112,6 @@ extern struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev,
 					   const struct in6_addr *addr,
 					   bool anycast);
 
-extern int			ip6_dst_hoplimit(struct dst_entry *dst);
-
 /*
  *	support functions for ND
  *

include/net/ipv6.h

@@ -658,6 +658,8 @@ static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_add
 
 extern void ipv6_select_ident(struct frag_hdr *fhdr, struct rt6_info *rt);
 
+extern int ip6_dst_hoplimit(struct dst_entry *dst);
+
 /*
  *	Header manipulation
  */

net/ipv6/output_core.c

@@ -5,6 +5,7 @@
 #include <linux/export.h>
 #include <net/ipv6.h>
 #include <net/ip6_fib.h>
+#include <net/addrconf.h>
 
 void ipv6_select_ident(struct frag_hdr *fhdr, struct rt6_info *rt)
 {
@@ -75,3 +76,24 @@ int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
 	return offset;
 }
 EXPORT_SYMBOL(ip6_find_1stfragopt);
+
+#if IS_ENABLED(CONFIG_IPV6)
+int ip6_dst_hoplimit(struct dst_entry *dst)
+{
+	int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
+	if (hoplimit == 0) {
+		struct net_device *dev = dst->dev;
+		struct inet6_dev *idev;
+
+		rcu_read_lock();
+		idev = __in6_dev_get(dev);
+		if (idev)
+			hoplimit = idev->cnf.hop_limit;
+		else
+			hoplimit = dev_net(dev)->ipv6.devconf_all->hop_limit;
+		rcu_read_unlock();
+	}
+	return hoplimit;
+}
+EXPORT_SYMBOL(ip6_dst_hoplimit);
+#endif

net/ipv6/route.c

@@ -1354,25 +1354,6 @@ static int ip6_dst_gc(struct dst_ops *ops)
 	return entries > rt_max_size;
 }
 
-int ip6_dst_hoplimit(struct dst_entry *dst)
-{
-	int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
-	if (hoplimit == 0) {
-		struct net_device *dev = dst->dev;
-		struct inet6_dev *idev;
-
-		rcu_read_lock();
-		idev = __in6_dev_get(dev);
-		if (idev)
-			hoplimit = idev->cnf.hop_limit;
-		else
-			hoplimit = dev_net(dev)->ipv6.devconf_all->hop_limit;
-		rcu_read_unlock();
-	}
-	return hoplimit;
-}
-EXPORT_SYMBOL(ip6_dst_hoplimit);
-
 /*
  *
  */