vti: use right inner_mode for inbound inter address family policy checks

In case of inter address family tunneling (IPv6 over vti4 or IPv4 over
vti6), the inbound policy checks in vti_rcv_cb() and vti6_rcv_cb() are
using the wrong address family. As a result, all inbound inter address
family traffic is dropped.

Use the xfrm_ip2inner_mode() helper, as done in xfrm_input() (i.e., also
increment LINUX_MIB_XFRMINSTATEMODEERROR in case of error), to select the
inner_mode that contains the right address family for the inbound policy
checks.

Signed-off-by: Thomas Zeitlhofer <thomas.zeitlhofer+lkml@ze-it.at>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

diff --git a/net/ipv4/ip_vti.c b/net/ipv4/ip_vti.c
index cc701fa..5d7944f 100644 (file)
--- a/net/ipv4/ip_vti.c
+++ b/net/ipv4/ip_vti.c
@@ -88,6 +88,7 @@ static int vti_rcv_cb(struct sk_buff *skb, int err)
        struct net_device *dev;
        struct pcpu_sw_netstats *tstats;
        struct xfrm_state *x;
+       struct xfrm_mode *inner_mode;
        struct ip_tunnel *tunnel = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4;
        u32 orig_mark = skb->mark;
        int ret;
@@ -105,7 +106,19 @@ static int vti_rcv_cb(struct sk_buff *skb, int err)
        }
 
        x = xfrm_input_state(skb);
-       family = x->inner_mode->afinfo->family;
+
+       inner_mode = x->inner_mode;
+
+       if (x->sel.family == AF_UNSPEC) {
+               inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
+               if (inner_mode == NULL) {
+                       XFRM_INC_STATS(dev_net(skb->dev),
+                                      LINUX_MIB_XFRMINSTATEMODEERROR);
+                       return -EINVAL;
+               }
+       }
+
+       family = inner_mode->afinfo->family;
 
        skb->mark = be32_to_cpu(tunnel->parms.i_key);
        ret = xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family);

diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c
index d90a11f..52a2f73 100644 (file)
--- a/net/ipv6/ip6_vti.c
+++ b/net/ipv6/ip6_vti.c
@@ -340,6 +340,7 @@ static int vti6_rcv_cb(struct sk_buff *skb, int err)
        struct net_device *dev;
        struct pcpu_sw_netstats *tstats;
        struct xfrm_state *x;
+       struct xfrm_mode *inner_mode;
        struct ip6_tnl *t = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6;
        u32 orig_mark = skb->mark;
        int ret;
@@ -357,7 +358,19 @@ static int vti6_rcv_cb(struct sk_buff *skb, int err)
        }
 
        x = xfrm_input_state(skb);
-       family = x->inner_mode->afinfo->family;
+
+       inner_mode = x->inner_mode;
+
+       if (x->sel.family == AF_UNSPEC) {
+               inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
+               if (inner_mode == NULL) {
+                       XFRM_INC_STATS(dev_net(skb->dev),
+                                      LINUX_MIB_XFRMINSTATEMODEERROR);
+                       return -EINVAL;
+               }
+       }
+
+       family = inner_mode->afinfo->family;
 
        skb->mark = be32_to_cpu(t->parms.i_key);
        ret = xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family);