ipv4: Namespaceify ip_default_ttl sysctl knob

Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index 848fe80..bc8f7f9 100644
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -80,6 +80,7 @@
 	int sysctl_tcp_ecn;
 	int sysctl_tcp_ecn_fallback;
 
+	int sysctl_ip_default_ttl;
 	int sysctl_ip_no_pmtu_disc;
 	int sysctl_ip_fwd_use_pmtu;
 	int sysctl_ip_nonlocal_bind;
diff --git a/include/net/route.h b/include/net/route.h
index a3b9ef7..9b0a523 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -329,14 +329,13 @@
 	return skb->skb_iif;
 }
 
-extern int sysctl_ip_default_ttl;
-
 static inline int ip4_dst_hoplimit(const struct dst_entry *dst)
 {
 	int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
+	struct net *net = dev_net(dst->dev);
 
 	if (hoplimit == 0)
-		hoplimit = sysctl_ip_default_ttl;
+		hoplimit = net->ipv4.sysctl_ip_default_ttl;
 	return hoplimit;
 }