1 files changed, 9 insertions, 1 deletions

diff --git a/include/net/flow.h b/include/net/flow.h
index 64fd24836650..8109a159d1b3 100644
--- a/include/net/flow.h
+++ b/include/net/flow.h
@@ -11,6 +11,14 @@
 #include <linux/in6.h>
 #include <linux/atomic.h>
 
+/*
+ * ifindex generation is per-net namespace, and loopback is
+ * always the 1st device in ns (see net_dev_init), thus any
+ * loopback device should get ifindex 1
+ */
+
+#define LOOPBACK_IFINDEX        1
+
 struct flowi_common {
         int     flowic_oif;
         int     flowic_iif;
@@ -80,7 +88,7 @@ static inline void flowi4_init_output(struct flowi4 *fl4, int oif,
                                       __be16 dport, __be16 sport)
 {
         fl4->flowi4_oif = oif;
-        fl4->flowi4_iif = 0;
+        fl4->flowi4_iif = LOOPBACK_IFINDEX;
         fl4->flowi4_mark = mark;
         fl4->flowi4_tos = tos;
         fl4->flowi4_scope = scope;