xfrm: Add a XFRM_STATE_AF_UNSPEC flag to xfrm_usersa_info

Add a XFRM_STATE_AF_UNSPEC flag to handle the AF_UNSPEC behavior for
the selector family. Userspace applications can set this flag to leave
the selector family of the xfrm_state unspecified.  This can be used
to to handle inter family tunnels if the selector is not set from
userspace.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 2 insertions, 2 deletions

diff --git a/include/linux/xfrm.h b/include/linux/xfrm.h
index 2ca6bae88721..fb0c215a3051 100644
--- a/include/linux/xfrm.h
+++ b/include/linux/xfrm.h
@@ -339,6 +339,7 @@ struct xfrm_usersa_info {
 #define XFRM_STATE_NOPMTUDISC   4
 #define XFRM_STATE_WILDRECV     8
 #define XFRM_STATE_ICMP         16
+#define XFRM_STATE_AF_UNSPEC    32
 };
 
 struct xfrm_usersa_id {
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index b976d9ed10e4..04c41504f84c 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -277,9 +277,8 @@ static void copy_from_user_state(struct xfrm_state *x, struct xfrm_usersa_info *
         memcpy(&x->props.saddr, &p->saddr, sizeof(x->props.saddr));
         x->props.flags = p->flags;
 
-        if (!x->sel.family)
+        if (!x->sel.family && !(p->flags & XFRM_STATE_AF_UNSPEC))
                 x->sel.family = p->family;
-
 }
 
 /*