xdp: disable XDP_REDIRECT for xdp frags

XDP_REDIRECT is not fully supported yet for xdp frags since not
all XDP capable drivers can map non-linear xdp_frame in ndo_xdp_xmit
so disable it for the moment.

Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/0da25e117d0e2673f5d0ce6503393c55c6fb1be9.1642758637.git.lorenzo@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/net/core/filter.c b/net/core/filter.c
index 945ccaa..a06931c 100644 (file)
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4266,6 +4266,14 @@ int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp,
        struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
        enum bpf_map_type map_type = ri->map_type;
 
+       /* XDP_REDIRECT is not fully supported yet for xdp frags since
+        * not all XDP capable drivers can map non-linear xdp_frame in
+        * ndo_xdp_xmit.
+        */
+       if (unlikely(xdp_buff_has_frags(xdp) &&
+                    map_type != BPF_MAP_TYPE_CPUMAP))
+               return -EOPNOTSUPP;
+
        if (map_type == BPF_MAP_TYPE_XSKMAP)
                return __xdp_do_redirect_xsk(ri, dev, xdp, xdp_prog);