ipv4: hash net ptr into fragmentation bucket selection

As namespaces are sometimes used with overlapping ip address ranges,
we should also use the namespace as input to the hash to select the ip
fragmentation counter bucket.

Cc: Eric Dumazet <edumazet@google.com>
Cc: Flavio Leitner <fbl@redhat.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ip.h b/include/net/ip.h
index 025c61c..d0808a3 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -318,9 +318,10 @@
 }
 
 u32 ip_idents_reserve(u32 hash, int segs);
-void __ip_select_ident(struct iphdr *iph, int segs);
+void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);
 
-static inline void ip_select_ident_segs(struct sk_buff *skb, struct sock *sk, int segs)
+static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb,
+					struct sock *sk, int segs)
 {
 	struct iphdr *iph = ip_hdr(skb);
 
@@ -337,13 +338,14 @@
 			iph->id = 0;
 		}
 	} else {
-		__ip_select_ident(iph, segs);
+		__ip_select_ident(net, iph, segs);
 	}
 }
 
-static inline void ip_select_ident(struct sk_buff *skb, struct sock *sk)
+static inline void ip_select_ident(struct net *net, struct sk_buff *skb,
+				   struct sock *sk)
 {
-	ip_select_ident_segs(skb, sk, 1);
+	ip_select_ident_segs(net, skb, sk, 1);
 }
 
 static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)