xdp: XDP_REDIRECT should check IFF_UP and MTU

Otherwise we end up with attempting to send packets from down devices
or to send oversized packets, which may cause unexpected driver/device
behaviour. Generic XDP has already done this check, so reuse the logic
in native XDP.

Fixes: 814abfabef3c ("xdp: add bpf_redirect helper function")
Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index 642c97f6d1b8..d361fc1e3bf3 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -334,10 +334,15 @@ int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp,
 {
         struct net_device *dev = dst->dev;
         struct xdp_frame *xdpf;
+        int err;
 
         if (!dev->netdev_ops->ndo_xdp_xmit)
                 return -EOPNOTSUPP;
 
+        err = xdp_ok_fwd_dev(dev, xdp->data_end - xdp->data);
+        if (unlikely(err))
+                return err;
+
         xdpf = convert_to_xdp_frame(xdp);
         if (unlikely(!xdpf))
                 return -EOVERFLOW;
@@ -350,7 +355,7 @@ int dev_map_generic_redirect(struct bpf_dtab_netdev *dst, struct sk_buff *skb,
 {
         int err;
 
-        err = __xdp_generic_ok_fwd_dev(skb, dst->dev);
+        err = xdp_ok_fwd_dev(dst->dev, skb->len);
         if (unlikely(err))
                 return err;
         skb->dev = dst->dev;