bpf, devmap: Compute proper xdp_frame len redirecting frames

Even if it is currently forbidden to XDP_REDIRECT a multi-frag xdp_frame into
a devmap, compute proper xdp_frame length in __xdp_enqueue and is_valid_dst
routines running xdp_get_frame_len().

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/894d99c01139e921bdb6868158ff8e67f661c072.1658596075.git.lorenzo@kernel.org

diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index 1400561efb15d98b18bdc5fda6784d590610b270..a0e02b0094876b40686215fbcfcd7049876246cd 100644 (file)
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -477,7 +477,7 @@ static inline int __xdp_enqueue(struct net_device *dev, struct xdp_frame *xdpf,
        if (!dev->netdev_ops->ndo_xdp_xmit)
                return -EOPNOTSUPP;
 
-       err = xdp_ok_fwd_dev(dev, xdpf->len);
+       err = xdp_ok_fwd_dev(dev, xdp_get_frame_len(xdpf));
        if (unlikely(err))
                return err;
 
@@ -536,7 +536,7 @@ static bool is_valid_dst(struct bpf_dtab_netdev *obj, struct xdp_frame *xdpf)
            !obj->dev->netdev_ops->ndo_xdp_xmit)
                return false;
 
-       if (xdp_ok_fwd_dev(obj->dev, xdpf->len))
+       if (xdp_ok_fwd_dev(obj->dev, xdp_get_frame_len(xdpf)))
                return false;
 
        return true;