xfrm: Accept XFRM_STATE_AF_UNSPEC SAs on IPv4/IPv6 only hosts

Installing SAs using the XFRM_STATE_AF_UNSPEC fails on hosts with
support for one address family only. This patch accepts such SAs, even
if the processing of not supported packets will fail.

Signed-off-by: Martin Willi <martin@strongswan.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 15 deletions

diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 2fd57f8f77c1..e25ff62ab2a6 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -2022,8 +2022,9 @@ int xfrm_init_state(struct xfrm_state *x)
                 x->inner_mode = inner_mode;
         } else {
                 struct xfrm_mode *inner_mode_iaf;
+                int iafamily = AF_INET;
 
-                inner_mode = xfrm_get_mode(x->props.mode, AF_INET);
+                inner_mode = xfrm_get_mode(x->props.mode, x->props.family);
                 if (inner_mode == NULL)
                         goto error;
 
@@ -2031,22 +2032,17 @@ int xfrm_init_state(struct xfrm_state *x)
                         xfrm_put_mode(inner_mode);
                         goto error;
                 }
+                x->inner_mode = inner_mode;
 
-                inner_mode_iaf = xfrm_get_mode(x->props.mode, AF_INET6);
-                if (inner_mode_iaf == NULL)
-                        goto error;
+                if (x->props.family == AF_INET)
+                        iafamily = AF_INET6;
 
-                if (!(inner_mode_iaf->flags & XFRM_MODE_FLAG_TUNNEL)) {
-                        xfrm_put_mode(inner_mode_iaf);
-                        goto error;
-                }
-
-                if (x->props.family == AF_INET) {
-                        x->inner_mode = inner_mode;
-                        x->inner_mode_iaf = inner_mode_iaf;
-                } else {
-                        x->inner_mode = inner_mode_iaf;
-                        x->inner_mode_iaf = inner_mode;
+                inner_mode_iaf = xfrm_get_mode(x->props.mode, iafamily);
+                if (inner_mode_iaf) {
+                        if (inner_mode_iaf->flags & XFRM_MODE_FLAG_TUNNEL)
+                                x->inner_mode_iaf = inner_mode_iaf;
+                        else
+                                xfrm_put_mode(inner_mode_iaf);
                 }
         }