net: Add a xfrm validate function to validate_xmit_skb

When we do IPsec offloading, we need a fallback for
packets that were targeted to be IPsec offloaded but
rerouted to a device that does not support IPsec offload.
For that we add a function that checks the offloading
features of the sending device and and flags the
requirement of a fallback before it calls the IPsec
output function. The IPsec output function adds the IPsec
trailer and does encryption if needed.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 17603bf190c18212b61d73634a6cfccf84ee870f..6793a30c66b1f054516a27229c29037fcdfa2f6f 100644 (file)
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -1862,6 +1862,7 @@ static inline struct xfrm_offload *xfrm_offload(struct sk_buff *skb)
 
 #ifdef CONFIG_XFRM_OFFLOAD
 void __net_init xfrm_dev_init(void);
+int validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t features);
 int xfrm_dev_state_add(struct net *net, struct xfrm_state *x,
                       struct xfrm_user_offload *xuo);
 bool xfrm_dev_offload_ok(struct sk_buff *skb, struct xfrm_state *x);
@@ -1890,6 +1891,11 @@ static inline void __net_init xfrm_dev_init(void)
 {
 }
 
+static inline int validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t features)
+{
+       return 0;
+}
+
 static inline int xfrm_dev_state_add(struct net *net, struct xfrm_state *x, struct xfrm_user_offload *xuo)
 {
        return 0;

diff --git a/net/core/dev.c b/net/core/dev.c
index ef9fe60ee294b0e2503456f68136440646c86344..5f0a864623e8cf25e8d76b2334b459361a966062 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2972,6 +2972,9 @@ static struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device
                    __skb_linearize(skb))
                        goto out_kfree_skb;
 
+               if (validate_xmit_xfrm(skb, features))
+                       goto out_kfree_skb;
+
                /* If packet is not checksummed and device does not
                 * support checksumming for this protocol, complete
                 * checksumming here.

diff --git a/net/xfrm/xfrm_device.c b/net/xfrm/xfrm_device.c
index 9bac2ba9052c564ba43cbf617ee25ba13e7981cb..8ec8a3fcf8d4740670b16c2c1af099ef0beaa5c5 100644 (file)
--- a/net/xfrm/xfrm_device.c
+++ b/net/xfrm/xfrm_device.c
@@ -22,6 +22,35 @@
 #include <net/xfrm.h>
 #include <linux/notifier.h>
 
+int validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t features)
+{
+       int err;
+       struct xfrm_state *x;
+       struct xfrm_offload *xo = xfrm_offload(skb);
+
+       if (skb_is_gso(skb))
+               return 0;
+
+       if (xo) {
+               x = skb->sp->xvec[skb->sp->len - 1];
+               if (xo->flags & XFRM_GRO || x->xso.flags & XFRM_OFFLOAD_INBOUND)
+                       return 0;
+
+               x->outer_mode->xmit(x, skb);
+
+               err = x->type_offload->xmit(x, skb, features);
+               if (err) {
+                       XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
+                       return err;
+               }
+
+               skb_push(skb, skb->data - skb_mac_header(skb));
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(validate_xmit_xfrm);
+
 int xfrm_dev_state_add(struct net *net, struct xfrm_state *x,
                       struct xfrm_user_offload *xuo)
 {